8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C.  20549

___________________________

FORM 8-K

___________________________

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported):  April 29, 2021

 ___________________________

ACCELERON PHARMA INC.

(Exact name of Registrant as specified in its charter)

Delaware		001-36065	27-0072226
(State or other jurisdiction of incorporation)		(Commission File Number)	(I.R.S. Employer Identification Number)
128 Sidney Street
Cambridge,	MA		02139
(Address of principal executive offices)			(Zip Code)

Registrant’s telephone number, including area code:  (617) 649-9200

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐            Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐            Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐            Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐            Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Exchange Act:

Title of each class	Ticker Symbol(s)	Name of each exchange on which registered
Common Stock, $0.001 per share	XLRN	The Nasdaq Global Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company            ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.            ☐

Item 2.02    Results of Operations and Financial Condition.

On April 29, 2021, Bristol Myers Squibb ("BMS") announced that net sales of REBLOZYL® (luspatercept-aamt) were approximately $112 million for the quarter ended March 31, 2021. As previously disclosed, under the collaboration agreement between Acceleron Pharma Inc. (the "Company") and BMS for REBLOZYL, the Company is eligible to receive tiered royalty payments from BMS on net sales of REBLOZYL in the low-to-mid 20% range. The Company expects to report royalty revenue of approximately $22.4 million from net sales of REBLOZYL in the quarter ended March 31, 2021.

This preliminary unaudited revenue estimate is the responsibility of management and is subject to the completion of the Company’s customary quarter-end financial closing procedures, including management’s review and finalization, as well as review procedures by the Company’s independent registered public accounting firm, which have not yet been completed. During the course of the Company’s review process, items may be identified that would require it to make adjustments, which could result in material changes to the Company’s preliminary unaudited estimated financial results. Consequently, this revenue estimate should not be viewed as a substitute for the Company’s earnings release and the Quarterly Report on Form 10-Q for the quarter ended March 31, 2021.

The information contained in this Item is being furnished and shall not be deemed "filed" for any purpose, and shall not be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, regardless of any general incorporation language in any such filing.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	ACCELERON PHARMA INC.
	By:	/s/ Adam M. Veness, Esq.
		Adam M. Veness, Esq.
		Senior Vice President, General Counsel and Secretary
Date: April 29, 2021

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Cover Page	Apr. 29, 2021
Cover [Abstract]
Document Type	8-K
Document Period End Date	Apr. 29, 2021
Entity Registrant Name	ACCELERON PHARMA INC.
Entity Incorporation, State or Country Code	DE
Entity File Number	001-36065
Entity Tax Identification Number	27-0072226
Entity Address, Address Line One	128 Sidney Street
Entity Address, City or Town	Cambridge,
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02139
City Area Code	617
Local Phone Number	649-9200
Written Communications	false
Soliciting Material	false
Pre-commencement Tender Offer	false
Pre-commencement Issuer Tender Offer	false
Title of 12(b) Security	Common Stock, $0.001 per share
Trading Symbol	XLRN
Security Exchange Name	NASDAQ
Entity Emerging Growth Company	false
Entity Central Index Key	0001280600
Amendment Flag	false