Washington, D.C. 20549

(Name of Issuer)

(Title of Class of Securities)

(CUSIP Number)

(Name, Address and Telephone Number of Person Authorized to
Receive Notices and Communications)

(Date of Event Which Requires Filing of this Statement)

 

 

CUSIP No.		20010A103

(1) This Schedule 13D amendment (the “13D/A”) is filed by MPM BioVentures III-QP, L.P. (“BV III QP”), MPM BioVentures III, L.P. (“BV III”), MPM BioVentures III Parallel Fund, L.P. (“BV III PF”), MPM BioVentures III GmbH & Co. Beteiligungs KG (“BV III KG”), MPM Asset Management Investors 2003 BVIII LLC (“AM LLC”), MPM Bio IV NVS Strategic Fund, L.P. (“MPM NVS”), MPM BioVentures III GP, L.P. (“BV III GP”), MPM BioVentures III LLC (“BV III LLC), MPM BioVentures IV GP LLC (“BV IV GP”) and MPM BioVentures IV LLC (“BV IV LLC” and collectively with BV III QP, BV III, BV III PF, BV III KG, AM LLC, MPM NVS, BV III GP, BV III LLC and BV IV GP, the “MPM Entities”) and Luke Evnin, Ansbert Gadicke, Nicholas Galakatos, Michael Steinmetz, Kurt Wheeler, Nicholas Simon III, Dennis Henner, Todd Foley, Vaughn M. Kailian, James Paul Scopa, Steven St. Peter and John Vander Vort (collectively, the “Listed Persons”). BV III GP and BV III LLC are the direct and indirect general partners of BV III QP, BV III, BV III PF and BV III KG. Luke Evnin, Ansbert Gadicke, Nicholas Galakatos, Michael Steinmetz, Kurt Wheeler, Nicholas Simon III and Dennis Henner are Series A members of BV III LLC and managers of AM LLC. BV IV GP and BV IV LLC are the direct and indirect general partners of MPM NVS. Luke Evnin, Ansbert Gadicke, Todd Foley, Vaughn M. Kailian, James Paul Scopa, Steven St. Peter and John Vander Vort are members of BV IV LLC.

(2) Consists of common stock, par value $0.0001 per share (“Common Stock”) of Radius Health, Inc. (the “Issuer”), issuable upon conversion of 224,528 shares of Series A-1 Convertible Preferred Stock, 181,364 shares of Series A-2 Convertible Preferred Stock and 44,395 shares of Series A-3 Convertible Preferred Stock (collectively with the Issuer’s Series A-4 Convertible Preferred Stock, Series A-5 Convertible Preferred Stock and Series A-6 Convertible Preferred Stock, the “Preferred Stock”). The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. The Reporting Person is a party to certain agreements with the Separately Filing Group Members (as defined below), which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the Securities and Exchange Commission (the “SEC”) on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 4,502,870 shares of Common Stock issuable upon conversion of the Preferred Stock held by BV III QP), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 88.3%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of 15,096 shares of Series A-1 Convertible Preferred Stock, 12,194 shares of Series A-2 Convertible Preferred Stock and 2,985 shares of Series A-3 Convertible Preferred Stock. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. The Reporting Person is a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 302,750 shares of Common Stock issuable upon conversion of the Preferred Stock held by BV III), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 33.6%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of 4,346 shares of Series A-1 Convertible Preferred Stock, 3,511 shares of Series A-2 Convertible Preferred Stock and 859 shares of Series A-3 Convertible Preferred Stock. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. The Reporting Person is a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 87,160 shares of Common Stock issuable upon conversion of the Preferred Stock held by AM LLC), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 12.7%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of 6,779 shares of Series A-1 Convertible Preferred Stock, 5,477 shares of Series A-2 Convertible Preferred Stock and 1,340 shares of Series A-3 Convertible Preferred Stock. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. The Reporting Person is a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, as amended (the “Exchange Act”), which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 135,960 shares of Common Stock issuable upon conversion of the Preferred Stock held by BV III PF), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 18.5%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of 18,975 shares of Series A-1 Convertible Preferred Stock, 15,327 shares of Series A-2 Convertible Preferred Stock and 3,752 shares of Series A-3 Convertible Preferred Stock. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. The Reporting Person is a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 380,540 shares of Common Stock issuable upon conversion of the Preferred Stock held by BV III KG), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 38.8%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of 114,537 shares of Series A-1 Convertible Preferred Stock and 184,242 shares of Series A-2 Convertible Preferred Stock. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. The Reporting Person is a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 2,987,790 shares of Common Stock issuable upon conversion of the Preferred Stock held by MPM NVS), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 83.3%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of an aggregate of 265,378 shares of Series A-1 Convertible Preferred Stock, 214,362 shares of Series A-2 Convertible Preferred Stock and 52,472 shares of Series A-3 Convertible Preferred Stock held by BV III QP, BV III, BVIII PF and BV III KG. BV III GP and BV III LLC are the direct and indirect general partners of BV III QP, BV III, BV III PF and BV III KG. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. Affiliates of the Reporting Person are a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 5,322,120 shares of Common Stock issuable upon conversion of the Preferred Stock held by BV III QP, BV III, BVIII PF and BV III KG), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 89.9%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of an aggregate of 265,378 shares of Series A-1 Convertible Preferred Stock, 214,362 shares of Series A-2 Convertible Preferred Stock and 52,472 shares of Series A-3 Convertible Preferred Stock held by BV III QP, BV III, BVIII PF and BV III KG. BV III GP and BV III LLC are the direct and indirect general partners of BV III QP, BV III, BV III PF and BV III KG. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. Affiliates of the Reporting Person are a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 5,322,120 shares of Common Stock issuable upon conversion of the Preferred Stock held by BV III QP, BV III, BVIII PF and BV III KG), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 89.9%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of 114,537 shares of Series A-1 Convertible Preferred Stock and 184,242 shares of Series A-2 Convertible Preferred Stock held by MPM NVS. BV IV GP and BV IV LLC are the direct and indirect general partners of MPM NVS. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. Affiliates of the Reporting Person are a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 2,987,790 shares of Common Stock issuable upon conversion of the Preferred Stock held by MPM NVS), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 83.3%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of 114,537 shares of Series A-1 Convertible Preferred Stock and 184,242 shares of Series A-2 Convertible Preferred Stock held by MPM NVS. BV IV GP and BV IV LLC are the direct and indirect general partners of MPM NVS. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. Affiliates of the Reporting Person are a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 2,987,790 shares of Common Stock issuable upon conversion of the Preferred Stock held by MPM NVS), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 83.3%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of an aggregate of 384,261 shares of Series A-1 Convertible Preferred Stock, 402,115 shares of Series A-2 Convertible Preferred Stock and 53,331 shares of Series A-3 Convertible Preferred Stock held by BV III QP, BV III, BVIII PF, BV III KG, AM LLC and MPM NVS. BV III GP and BV III LLC are the direct and indirect general partners of BV III QP, BV III, BV III PF and BV III KG. BV IV GP and BV IV LLC are the direct and indirect general partners of MPM NVS. The Reporting Person is a Series A member of BV III LLC, a manager of AM LLC and a member of BV IV LLC. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. Affiliates of the Reporting Person are a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 8,397,070 shares of Common Stock issuable upon conversion of preferred stock held by the MPM Entities), it would result in an applicable percentage of 93.3%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of an aggregate of 384,261 shares of Series A-1 Convertible Preferred Stock, 402,115 shares of Series A-2 Convertible Preferred Stock and 53,331 shares of Series A-3 Convertible Preferred Stock held by BV III QP, BV III, BVIII PF, BV III KG, AM LLC and MPM NVS. BV III GP and BV III LLC are the direct and indirect general partners of BV III QP, BV III, BV III PF and BV III KG. BV IV GP and BV IV LLC are the direct and indirect general partners of MPM NVS. The Reporting Person is a Series A member of BV III LLC, a manager of AM LLC and a member of BV IV LLC. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. Affiliates of the Reporting Person are a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 8,397,070 shares of Common Stock issuable upon conversion of preferred stock held by the MPM Entities), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 93.3%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of an aggregate of 269,724 shares of Series A-1 Convertible Preferred Stock, 217,873 shares of Series A-2 Convertible Preferred Stock and 53,331 shares of Series A-3 Convertible Preferred Stock held by BV III QP, BV III, BVIII PF, BV III KG and AM LLC. BV III GP and BV III LLC are the direct and indirect general partners of BV III QP, BV III, BV III PF and BV III KG. The Reporting Person is a Series A member of BV III LLC and a manager of AM LLC. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. Affiliates of the Reporting Person are a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 5,409,280 shares of Common Stock issuable upon conversion of the Preferred Stock held by BV III QP, BV III, BVIII PF, BV III KG and AM LLC), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 90.0%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of an aggregate of 269,724 shares of Series A-1 Convertible Preferred Stock, 217,873 shares of Series A-2 Convertible Preferred Stock and 53,331 shares of Series A-3 Convertible Preferred Stock held by BV III QP, BV III, BVIII PF, BV III KG and AM LLC. BV III GP and BV III LLC are the direct and indirect general partners of BV III QP, BV III, BV III PF and BV III KG. The Reporting Person is a Series A member of BV III LLC and a manager of AM LLC. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. Affiliates of the Reporting Person are a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 5,409,280 shares of Common Stock issuable upon conversion of the Preferred Stock held by BV III QP, BV III, BVIII PF, BV III KG and AM LLC), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 90.0%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of an aggregate of 269,724 shares of Series A-1 Convertible Preferred Stock, 217,873 shares of Series A-2 Convertible Preferred Stock and 53,331 shares of Series A-3 Convertible Preferred Stock held by BV III QP, BV III, BVIII PF, BV III KG and AM LLC. BV III GP and BV III LLC are the direct and indirect general partners of BV III QP, BV III, BV III PF and BV III KG. The Reportin g Person is a Series A member of BV III LLC and a manager of AM LLC. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. Affiliates of the Reporting Person are a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a resu lt, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 5,409,280 shares of Common Stock issuable upon conversion of the Preferred Stock held by BV III QP, BV III, BVIII PF, BV III KG and AM LLC), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 90.0%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of an aggregate of 269,724 shares of Series A-1 Convertible Preferred Stock, 217,873 shares of Series A-2 Convertible Preferred Stock and 53,331 shares of Series A-3 Convertible Preferred Stock held by BV III QP, BV III, BVIII PF, BV III KG and AM LLC. BV III GP and BV III LLC are the direct and indirect general partners of BV III QP, BV III, BV III PF and BV III KG. The Reportin g Person is a Series A member of BV III LLC and a manager of AM LLC. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. Affiliates of the Reporting Person are a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a resu lt, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 5,409,280 shares of Common Stock issuable upon conversion of the Preferred Stock held by BV III QP, BV III, BVIII PF, BV III KG and AM LLC), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 90.0%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of an aggregate of 269,724 shares of Series A-1 Convertible Preferred Stock, 217,873 shares of Series A-2 Convertible Preferred Stock and 53,331 shares of Series A-3 Convertible Preferred Stock held by BV III QP, BV III, BVIII PF, BV III KG and AM LLC. BV III GP and BV III LLC are the direct and indirect general partners of BV III QP, BV III, BV III PF and BV III KG. The Reportin g Person is a Series A member of BV III LLC and a manager of AM LLC. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion ratio of 10 shares of Common Stock for every one share of Preferred Stock. Affiliates of the Reporting Person are a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a resu lt, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 5,409,280 shares of Common Stock issuable upon conversion of the Preferred Stock held by BV III QP, BV III, BVIII PF, BV III KG and AM LLC), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 90.0%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of 114,537 shares of Series A-1 Convertible Preferred Stock and 184,242 shares of Series A-2 Convertible Preferred Stock held by MPM NVS). BV IV GP and BV IV LLC are the direct and indirect general partners of MPM NVS. The Reporting Person is a member of BV IV LLC. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion r atio of 10 shares of Common Stock for every one share of Preferred Stock. Affiliates of the Reporting Person are a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separ ately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 2,987,790 shares of Common Stock issuable upon conversion of the Preferred Stock held by MPM NVS), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 83.3%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of 114,537 shares of Series A-1 Convertible Preferred Stock and 184,242 shares of Series A-2 Convertible Preferred Stock held by MPM NVS). BV IV GP and BV IV LLC are the direct and indirect general partners of MPM NVS. The Reporting Person is a member of BV IV LLC. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion r atio of 10 shares of Common Stock for every one share of Preferred Stock. Affiliates of the Reporting Person are a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separ ately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 2,987,790 shares of Common Stock issuable upon conversion of the Preferred Stock held by MPM NVS), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 83.3%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of 114,537 shares of Series A-1 Convertible Preferred Stock and 184,242 shares of Series A-2 Convertible Preferred Stock held by MPM NVS). BV IV GP and BV IV LLC are the direct and indirect general partners of MPM NVS. The Reporting Person is a member of BV IV LLC. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion r atio of 10 shares of Common Stock for every one share of Preferred Stock. Affiliates of the Reporting Person are a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separ ately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 2,987,790 shares of Common Stock issuable upon conversion of the Preferred Stock held by MPM NVS), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 83.3%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of 114,537 shares of Series A-1 Convertible Preferred Stock and 184,242 shares of Series A-2 Convertible Preferred Stock held by MPM NVS). BV IV GP and BV IV LLC are the direct and indirect general partners of MPM NVS. The Reporting Person is a member of BV IV LLC. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion r atio of 10 shares of Common Stock for every one share of Preferred Stock. Affiliates of the Reporting Person are a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separ ately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 2,987,790 shares of Common Stock issuable upon conversion of the Preferred Stock held by MPM NVS), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 83.3%.

CUSIP No.		None

(1) This 13D/A is filed by the MPM Entities and the Listed Persons.

(2) Consists of Common Stock of the Issuer issuable upon conversion of 114,537 shares of Series A-1 Convertible Preferred Stock and 184,242 shares of Series A-2 Convertible Preferred Stock held by MPM NVS). BV IV GP and BV IV LLC are the direct and indirect general partners of MPM NVS. The Reporting Person is a member of BV IV LLC. The Preferred Stock is convertible at any time, in whole or in part, at the election of the holder at a conversion r atio of 10 shares of Common Stock for every one share of Preferred Stock. Affiliates of the Reporting Person are a party to certain agreements with the Separately Filing Group Members, which agreements contain, among other things, certain voting agreements and limitations on the sale of their shares of Common Stock. As a result, the Reporting Person may be deemed to be a member of a “group,” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Person and the Separ ately Filing Group Members. Shares listed as beneficially owned by the Reporting Persons exclude shares held by any other Reporting Person or by any of the Separately Filing Group Members, in each case as to which the Reporting Persons disclaims beneficial ownership.

(3) This percentage is calculated based upon 21,354,127 shares of outstanding Common Stock, which consists of: (i) 599,247 shares of Common Stock and (ii) an aggregate of 20,754,880 shares of Common Stock issuable upon conversion of outstanding Preferred Stock, outstanding as of December 15, 2011 following completion of the Offering (as defined below) as disclosed in the Issuer’s Preliminary Information Statement on Schedule 14C, filed with the SEC on December 16, 2011. Because shares of Preferred Stock vote together with Common Stock on an as-converted basis, such percentage reflects the Reporting Person’s voting percentage of the Issuer’s outstanding capital stock. If the percentage calculation was calculated in accordance with Rule 13d-3(d)(1) promulgated under the Exchange Act, which requires that only the outstanding shares of Common Stock and shares issuable upon conversion of derivative securities held by the Reporting Person (i.e., 2,987,790 shares of Common Stock issuable upon conversion of the Preferred Stock held by MPM NVS), excluding shares held by any of the Separately Filing Group Members, as to which the Reporting Person disclaims beneficial ownership, it would result in an applicable percentage of 83.3%.

Explanatory Note:

This Amendment No. 1 to Schedule 13D (“Amendment No. 1”) is being filed as an amendment to the initial statement on Schedule 13D relating to the Common Stock, par value $0.0001 per share (the “Common Stock”) of Radius Health, Inc., a Delaware corporation (the “Issuer”), as filed with the Securities and Exchange Commission (the “SEC”) on May 27, 2011 (the “Original Schedule 13D”).

All capitalized terms not otherwise defined herein shall have the meaning ascribed to the terms in the Original Schedule 13D. The Original Schedule 13D is hereby amended and supplemented as follows and, except as expressly amended below, the Original Schedule 13D remains in full force and effect.

Item 2. Identity and Background

“Item 2. Identity and Background” of the Original Schedule 13D is hereby amended and restated in its entirety as follows:

(a) The persons and entities filing this statement are MPM BioVentures III-QP, L.P. (“BV III QP”), MPM BioVentures III, L.P. (“BV III”), MPM BioVentures III Parallel Fund, L.P. (“BV III PF”), MPM BioVentures III GmbH & Co. Beteiligungs KG (“BV III KG”), MPM Asset Management Investors 2003 BVIII LLC (“AM LLC”), MPM Bio IV NVS Strategic Fund, L.P. (“MPM NVS”), MPM BioVentures III GP, L.P. (“BV III GP”), MPM BioVentures III LLC (“BV III LLC), MPM BioVentures IV GP LLC (“MPM IV GP”) and MPM BioVentures IV LLC (“MPM IV LLC” and, collectively with BV III QP, BV III, BV III PF, BV III KG, AM LLC, MPM NVS, BV III GP and MPM IV GP, the “MPM Entities”) and Luke Evnin, Ansbert Gadicke, Nicholas Galakatos, Michael Steinmetz, Kurt Wheeler, Nicholas Simon III, Dennis Henner, Todd Foley, Vaughn M. Kailian, James Paul Scopa, Steven St. Peter and John Vander Vort (collectively, the “Listed Persons” and together with the MPM Entities, the “Filing Persons”).

(b) The address of the principal place of business for each of the MPM Entities and Ansbert Gadicke, Luke Evnin, Nicholas Galakatos, Michael Steinmetz, Kurt Wheeler, Nicholas Simon III, Dennis Henner, Steven St. Peter, Vaughn Kailian, Todd Foley and John Vander Vort is The John Hancock Tower, 200 Clarendon Street, 54^th Floor, Boston, MA 02116 and the address of the principal place of business for James Paul Scopa is 601 Gateway Blvd., Suite 350, S. San Francisco, CA 94080.

(c) The principal business of each of the MPM Entities is the venture capital investment business. Each of the Listed Persons is a general partner of various venture capital investment funds.

(d) During the last five years, none of the Filing Persons, to the knowledge of the MPM Entities, has been convicted in any criminal proceeding (excluding traffic violations or similar misdemeanors).

(e) During the last five years, none of the Filing Persons, to the knowledge of the MPM Entities, has been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

(f) Each of the Listed Persons is a United States citizen and each of the MPM Entities is a Delaware limited partnership or limited liability company, except BV III KG, which was organized in Germany and MPM NVS, which was organized in Bermuda.

In accordance with the provisions of General Instruction C to Schedule 13D, information concerning the managers and each other person controlling the general partners of the MPM Entities required by Item 2 of Schedule 13D is listed on Schedule 1 hereto and is incorporated by reference herein.

The Reporting Persons may be deemed to be members of a “group” within the meaning of Section 13(d)(3) of the Exchange Act, comprised of the Reporting Persons and the other stockholders party to the Stockholders’ Agreement, dated as of May 17, 2011, as amended (the “Separately Filing Group Members”). It is the understanding of the Reporting Persons that the Separately Filing Group Members are filing separate Schedule 13Ds pursuant to Rule 13d-1(k)(2) under the Exchange Act.

Item 3. Source and Amount of Funds or Other Consideration

“Item 3. Source and Amount of Funds or Other Consideration” of the Original Schedule 13D is hereby amended by adding the following at the end thereof:

On November 18, 2011, pursuant to the terms of that certain Series A-1 Convertible Preferred Stock Purchase Agreement (the “Purchase Agreement”), dated as of April 25, 2011, among the Issuer and the investors referenced therein (the “Investors”), the Issuer issued an aggregate of 263,178 shares of Series A-1 Convertible Preferred Stock (the “Series A-1 Shares”) to the Investors. Such shares, were issued in connection with the consummation of the Stage II Closing contemplated by the Purchase Agreement at a purchase price of $81.42 per share resulting in aggregate proceeds to the Issuer of $21.4 million. Each Series A-1 Share is convertible at the option of the holder at any time into ten shares of Common Stock. The MPM Entities participated in the offering and acquired an aggregate of 91,676 shares of Series A-1 Convertible Preferred Stock of the Issuer (the “Series A-1 Shares”), for a total purchase price of $7,464,259.92. BV III purchased 3,437 shares, BV III QP purchased 51,119 shares, BV III KG purchased 4,320 shares, BV III PF purchased 1,543 shares, AM LLC purchased 989 shares and MPM NVS purchased 30,268 shares.

On December 14, 2011, pursuant to the terms of the Purchase Agreement, the Issuer issued an aggregate of 263,180 Series A-1 Shares to the Investors. The Series A-1 Shares were issued in connection with the consummation of the Stage III Closing contemplated by the Purchase Agreement at a purchase price of $81.42 per share resulting in aggregate proceeds to the Issuer of $21.4 million (the “Offering”). The MPM Entities participated in the Offering and acquired an aggregate of 91,676 shares of Series A-1 Shares, for a total purchase price of $7,464,259.92. BV III purchased 3,437 shares, BV III QP purchased 51,119 shares, BV III KG purchased 4,320 shares, BV III PF purchased 1,543 shares, AM LLC purchased 989 shares and MPM NVS purchased 30,268 shares.

Item 5. Interest in Securities of the Issuer

“Item 5. Interest in Securities of the Issuer” is hereby amended and restated in its entirety as follows:

The following information with respect to the beneficial ownership of the Common Stock by the persons filing this 13D/A is provided as of the date of this filing:

		Shares of
		Common Stock
		on an As-												Sole				Shared
		Converted Basis				Sole Voting				Shared Voting				Dispositive				Dispositive Power				Beneficial				Percentage of
Filing Person		(1)				Power (1)				Power (1)				Power (1)				(1)				Ownership(2)				Class (2)(3)
BV III QP(4)			4,502,870				4,502,870				0				4,502,870				0				4,502,870				21.1	%
BV III(5)			302,750				302,750				0				302,750				0				302,750				1.4	%
BV III PF(6)			135,960				135,960				0				135,960				0				135,960				0.6	%
BV III KG(7)			380,540				380,540				0				380,540				0				380,540				1.8	%
AM LLC(8)			87,160				87,160				0				87,160				0				87,160				0.4	%
MPM NVS(9)			2,987,790				2,987,790				0				2,987,790				0				2,987,790				14.0	%
BV III GP(10)			5,322,120				0				5,322,120				0				5,322,120				5,322,120				24.9	%
BV III LLC(10)			5,322,120				0				5,322,120				0				5,322,120				5,322,120				24.9	%
BV IV GP(11)			2,987,790				0				2,987,790				0				2,987,790				2,987,790				14.0	%
BV IV LLC(11)			2,987,790				0				2,987,790				0				2,987,790				2,987,790				14.0	%
Luke Evnin(12)(13)			8,397,070				0				8,397,070				0				8,397,070				8,397,070				39.3	%
Ansbert Gadicke(12)(13)			8,397,070				0				8,397,070				0				8,397,070				8,397,070				39.3	%
Nicholas Galakatos(12)			5,409,280				0				5,409,280				0				5,409,280				5,409,280				25.3	%
Michael Steinmetz(12)			5,409,280				0				5,409,280				0				5,409,280				5,409,280				25.3	%
Kurt Wheeler(12)			5,409,280				0				5,409,280				0				5,409,280				5,409,280				25.3	%
Nicholas Simon III(12)			5,409,280				0				5,409,280				0				5,409,280				5,409,280				25.3	%
Dennis Henner(12)			5,409,280				0				5,409,280				0				5,409,280				5,409,280				25.3	%
Todd Foley(13)			2,987,790				0				2,987,790				0				2,987,790				2,987,790				14.0	%
Vaughn Kailian(13)			2,987,790				0				2,987,790				0				2,987,790				2,987,790				14.0	%
James Paul Scopa(13)			2,987,790				0				2,987,790				0				2,987,790				2,987,790				14.0	%
Steven St. Peter(13)			2,987,790				0				2,987,790				0				2,987,790				2,987,790				14.0	%
John Vander Vort(13)			2,987,790				0				2,987,790				0				2,987,790				2,987,790				14.0	%

The information provided and incorporated by reference in Item 3 is hereby incorporated by reference in this Item 5.

Item 7. Material to Be Filed as Exhibits

A.

Amended and Restated Stockholders’ Agreement, dated as of May 17, 2011, as amended by Amendment No. 1, dated as of November 7, 2011, Amendment No. 2, dated as of November 7, 2011, and Amendment No. 3, dated as of December 15, 2011, by and among the Company and the stockholders party thereto (incorporated by reference to Exhibit 10.1 of the Issuer’s Current Report on Form 8-K (SEC File No. 000-53173), filed with the SEC on December 15, 2011).

B.

Agreement regarding filing of joint Schedule 13D.

SIGNATURES

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated: December 23, 2011

MPM BIOVENTURES III, L.P.				MPM BIOVENTURES III-QP, L.P.
By:		MPM BioVentures III GP, L.P., its General Partner		By:		MPM BioVentures III GP, L.P., its General Partner
By:		MPM BioVentures III LLC, its General Partner		By:		MPM BioVentures III LLC, its General Partner
By:		/s/ Luke Evnin   Name: Luke Evnin		By:		/s/ Luke Evnin   Name: Luke Evnin
		Title: Series A Member				Title: Series A Member
MPM BIOVENTURES III PARALLEL FUND, L.P.				MPM BIOVENTURES III GMBH & CO. BETEILIGUNGS KG
By:		MPM BioVentures III GP, L.P., its General Partner		By:		MPM BioVentures III GP, L.P., in its capacity as the Managing Limited Partner
By:		MPM BioVentures III LLC, its General Partner		By:		MPM BioVentures III LLC, its General Partner
By:		/s/ Luke Evnin		By:		/s/ Luke Evnin
		Name: Luke Evnin				Name: Luke Evnin
		Title: Series A Member				Title: Series A Member
MPM ASSET MANAGEMENT INVESTORS 2003 BVIII LLC				MPM BIOVENTURES III GP, L.P.
				By:		MPM BioVentures III LLC,
By:		/s/ Luke Evnin   Name: Luke Evnin				its General Partner
		Title: Manager		By:		/s/ Luke Evnin   Name: Luke Evnin
						Title: Series A Member
MPM BIOVENTURES III LLC
By:		/s/ Luke Evnin
		Name: Luke Evnin
		Title: Series A Member
MPM Bio IV NVS Strategic Fund, L.P.				MPM BIOVENTURES IV GP LLC
By:		MPM BIOVENTURES IV GP LLC, its General Partner		By:		MPM BIOVENTURES IV LLC, its Managing Member
By:		MPM BIOVENTURES IV LLC, its Managing Member
By:		/s/ Luke Evnin		By:		/s/ Luke Evnin
		Name: Luke Evnin				Name: Luke Evnin
		Title: Member				Title: Member

MPM BIOVENTURES IV LLC
By:		/s/ Luke Evnin
		Name: Luke Evnin
		Title: Member
		/s/ Luke Evnin				/s/ Ansbert Gadicke
		Luke Evnin				Ansbert Gadicke
		/s/ Nicholas Galakatos				/s/ Michael Steinmetz
		Nicholas Galakatos				Michael Steinmetz
		/s/ Kurt Wheeler   Kurt Wheeler				/s/ Nicholas Simon III   Nicholas Simon III
		/s/ Dennis Henner				/s/ Todd Foley
		Dennis Henner				Todd Foley
		/s/ Vaughn Kailian				/s/ James Paul Scopa
		Vaughn Kailian				James Paul Scopa
		/s/ Steven St. Peter				/s/ John Vander Vort
		Steven St. Peter				John Vander Vort