SC 13D/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC  20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 3)*

HALOZYME THERAPEUTICS, INC.

(Name of Issuer)

Common Stock, $0.001 par value per share

(Title of Class of Securities)

406 37H 109

(CUSIP Number)

Third Security, LLC

The Governor Tyler

1881 Grove Ave.

Radford, Virginia 24141

Attention:  Marcus E. Smith, Esq.

Telephone No.:  540-633-7971

Copy to:

David I. Meyers, Esq.

John Owen Gwathmey, Esq.

Troutman Sanders LLP

1001 Haxall Point

Richmond, Virginia 23219

(804) 697-1200

(Name, Address and Telephone Number of Person

Authorized to Receive Notices and Communications)

June 23, 2008

(Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition which is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), (f) or (g), check the following box ¨.

NOTE:  Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

* The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

1	NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS RANDAL J. KIRK
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF GROUP			(a) o (b) x
3	SEC USE ONLY
4	SOURCE OF FUNDS PF
5	CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)			o
6	CITIZENSHIP OR PLACE OF ORGANIZATION United States
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 380,000
		8	SHARED VOTING POWER 14,801,569
		9	SOLE DISPOSITIVE POWER 380,000
		10	SHARED DISPOSITIVE POWER 14,801,569
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 15,181,569
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 19.1%
14	TYPE OF REPORTING PERSON IN

1	NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS NEW RIVER MANAGEMENT V, LP          I.R.S. Identification No.:  56-2652938
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF GROUP			(a) o (b) x
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)			o
6	CITIZENSHIP OR PLACE OF ORGANIZATION United States
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 6,328,853
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 6,328,853
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 6,328,853
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 8.0%
14	TYPE OF REPORTING PERSON PN

This Amendment No. 3 (the “Amendment”) amends and supplements the Statement on Schedule 13D, dated May 15, 2007 and filed on May 24, 2007, as amended by Amendment No. 1 dated May 30, 2007 and filed on June 5, 2007, and Amendment No. 2 dated March 19, 2008 and filed on March 24, 2008 (the “Original Schedule 13D”), relating to the Common Stock, par value $0.001 per share (the “Common Stock”), of Halozyme Therapeutics, Inc., a Delaware corporation (the “Company”).  Mr. Randal J. Kirk (“Mr. Kirk”) is filing this Amendment to disclose the acquisition by Kirkfield, L.L.C., a Virginia limited liability company (“Kirkfield”), of an aggregate of 1,299,886 shares of Common Stock in open market purchases and private transactions, as described in Item 5(c) below.  As described in this Amendment, some of the Common Stock that is beneficially owned by Mr. Kirk is directly beneficially owned by one of the following entities, each of which is controlled by Mr. Kirk: Radford Investments Limited Partnership, a Delaware limited partnership (“Radford”), Randal J. Kirk (2000) Limited Partnership, a Delaware limited partnership (“2000LP”), RJK, L.L.C., a Virginia limited liability company (“RJK”), Third Security Staff 2001 LLC, a Virginia limited liability company (“Staff 2001”), New River Management IV, LP, a Virginia limited partnership (“NRM IV”), New River Management V, LP, a Delaware limited partnership (“NRM V”) and Kirkfield.

Except as set forth below, there are no changes to the information set forth in the Original Schedule 13D.

Item 2. Identity and Background.

Item 2 of the Original Schedule 13D is hereby amended and restated to read in its entirety as follows:

“This Statement is being filed on behalf of Mr. Kirk, Radford, 2000LP, RJK, Staff 2001, NRM IV, NRM V and Kirkfield (collectively, the “Reporting Persons”).

(a)-(c)The address of the principal business office of each of the Reporting Persons is The Governor Tyler, 1881 Grove Avenue, Radford, Virginia 24141. The present principal occupation/employment of Mr. Kirk is Senior Managing Director and Chief Executive Officer of Third Security, LLC, an investment management firm founded by Mr. Kirk. The principal business of each of Radford, 2000LP, RJK, Staff 2001, NRM IV, NRM V and Kirkfield is investment.

(d)-(e)      During the last five years, none of the Reporting Persons or, to the best of the Reporting Persons' knowledge, any of the managers or joint holders of the Reporting Persons, has been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors) or been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding is or was 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)Mr. Kirk is a citizen of the United States. Radford, 2000LP and NRM V are entities organized under the laws of Delaware. NRM IV, RJK, Staff 2001 and Kirkfield are entities organized under the laws of the Commonwealth of Virginia.”

Item 3.  Source and Amount of Funds or Other Consideration.

Item 3 of the Original Schedule 13D is hereby amended and supplemented as follows:

“Kirkfield acquired 1,299,886 shares of Common Stock reported herein through open market purchases and private transactions for an aggregate purchase price of approximately $7.48 million using Kirkfield’s working capital. In addition, Kirkfield acquired a warrant entitling the holder to purchase 136,300 shares at an exercise price of $1.75 per share for a purchase price of approximately $570,000 using Kirkfield's working capital.”

Item 5.  Interest in Securities of the Issuer.

Item 5(a) of the Original Schedule 13D is hereby amended and restated to read in its entirety as follows:

“(a)          The aggregate number and percentage of shares of Common Stock to which this statement relates is 15,181,569 shares of Common Stock, representing 19.1% of the 79,517,144 shares of Common Stock outstanding as of the date of this statement, based upon the number of shares disclosed by the Company as of May 1, 2008, in the Company’s Quarterly Report on Form 10-Q for the fiscal quarter ended March 31, 2008 (the most recent available filing by the Company with the Securities and Exchange Commission). Mr. Kirk directly beneficially owns 380,000 shares of Common Stock to which this statement relates (10,000 of such shares of Common Stock he has the right to acquire pursuant to immediately exercisable stock options). The remaining 14,801,569 shares of Common Stock to which this statement relates are directly beneficially owned as follows:

Owner	Shares
Radford	3,000,000
2000LP	2,189,050
RJK	522,460
Staff 2001	135,000
NRM IV	1,326,320
NRM V	6,328,853
Kirkfield	1,299,886

Mr. Kirk could be deemed to have indirect beneficial ownership of the shares of Common Stock directly beneficially owned by Radford, 2000LP, RJK, Staff 2001, NRM IV, NRM V and Kirkfield.”

Item 5(b) of the Original Schedule 13D is hereby amended and restated to read in its entirety as follows:

“(b)         Number of shares of Common Stock as to which such persons have:

(i) sole power to vote or to direct the vote – 380,000

(ii) shared power to vote or to direct the vote – 14,801,569 (1)

(iii) sole power to dispose of or to direct the disposition of – 380,000

(iv) shared power to dispose of or to direct the disposition of – 14,801,569 (1)

(1)  Includes shares of Common Stock held by the following entities over which Mr. Kirk (or an entity over which he exercises exclusive control) exercises exclusive control: 3,000,000 shares of Common Stock held by Radford; 2,189,050 shares of Common Stock held by 2000LP; 522,460 shares of Common Stock held by RJK; 135,000 shares of Common Stock held by Staff 2001; 1,326,320 shares of Common Stock held by NRM IV, 6,328,853 shares held by NRM V and 1,299,886 shares held by Kirkfield.”

Item 5(c) of the Original Schedule 13D is hereby amended and supplemented as follows:

“(c)         Kirkfield made the following purchases on the open market during the past 60 days:

Date of Purchase	Purchase Price		Number of Shares
6/11/2008	$	5.35		5,000
6/11/2008	$	5.30		14,600
6/11/2008	$	5.29		15,400
6/11/2008	$	5.28		13,412
6/11/2008	$	5.27		1,588
6/11/2008	$	5.26		24,200
6/11/2008	$	5.25		37,100
6/11/2008	$	5.24		4,139
6/12/2008	$	5.45		5,000
6/12/2008	$	5.44		2,759
6/12/2008	$	5.43		14,983
6/12/2008	$	5.42		11,728
6/12/2008	$	5.41		20,593
6/12/2008	$	5.40		1,937
6/13/2007	$	5.62		1,874
6/13/2007	$	5.60		4,951
6/13/2007	$	5.59		5,921
6/13/2007	$	5.58		4,741
6/13/2007	$	5.57		1,300
6/13/2007	$	5.56		2,938
6/13/2007	$	5.50		3,100
6/13/2007	$	5.49		6,501
6/13/2007	$	5.48		2,499
6/13/2007	$	5.47		8,700

Date of Purchase	Purchase Price		Number of Shares
6/13/2007	$	5.46		3,200
6/16/2008	$	5.80		2,300
6/16/2008	$	5.79		500
6/16/2008	$	5.75		11,500
6/16/2008	$	5.74		1,500
6/16/2008	$	5.70		2,600
6/16/2008	$	5.69		1,200
6/16/2008	$	5.68		3,004
6/16/2008	$	5.67		1,800
6/16/2008	$	5.66		1,396
6/17/2008	$	6.00		29,200
6/17/2008	$	5.99		3,861
6/17/2008	$	5.98		200
6/17/2008	$	5.97		939
6/17/2008	$	5.96		1,800
6/17/2008	$	5.95		2,000
6/17/2008	$	5.92		974
6/17/2008	$	5.90		1,026
6/17/2008	$	5.85		1,700
6/17/2008	$	5.83		100
6/17/2008	$	5.82		200
6/18/2008	$	5.85		4000
6/18/2008	$	5.84		500
6/18/2008	$	5.83		3,700
6/18/2008	$	5.82		4,400
6/18/2008	$	5.81		400
6/18/2008	$	5.80		1,300
6/18/2008	$	5.79		700
6/18/2008	$	5.77		5,400
6/18/2008	$	5.76		500
6/18/2008	$	5.75		100
6/18/2008	$	5.74		3,000
6/18/2008	$	5.72		3,000
6/18/2008	$	5.67		5,900
6/18/2008	$	5.66		3,927
6/19/2008	$	6.04		34,900
6/19/2008	$	6.03		100
6/19/2008	$	6.00		17,200
6/19/2008	$	5.98		800
6/19/2008	$	5.97		6,900
6/20/2008	$	5.95		13,276
6/20/2008	$	5.94		8,344
6/20/2008	$	5.93		7,900
6/20/2008	$	5.92		380
6/20/2008	$	5.91		100

Date of Purchase	Purchase Price		Number of Shares
6/20/2008	$	5.90		8,474
6/20/2008	$	5.88		12,386
6/20/2008	$	5.87		10,200
6/20/2008	$	5.86		4,200
6/20/2008	$	5.85		23,480
6/20/2008	$	5.84		15,719
6/20/2008	$	5.83		20,323
6/20/2008	$	5.82		7,618
6/20/2008	$	5.81		5,700
6/20/2008	$	5.80		6,217
6/20/2008	$	5.79		7,400
6/20/2008	$	5.78		15,383
6/20/2008	$	5.77		1,200
6/20/2008	$	5.76		100
6/20/2008	$	5.75		2,500
6/20/2008	$	5.74		4,600
6/23/2008	$	5.84		3,080
6/23/2008	$	5.83		7,000
6/23/2008	$	5.82		1,200
6/23/2008	$	5.81		1300
6/23/2008	$	5.80		6,220
6/23/2008	$	5.79		1,200
6/23/2008	$	5.78		5,000
6/23/2008	$	5.72		1,496
6/23/2008	$	5.71		23,504
6/23/2008	$	5.70		24,100
6/23/2008	$	5.69		6,400
6/23/2008	$	5.68		6,700
6/23/2008	$	5.67		10,808
6/23/2008	$	5.66		9,800
6/23/2008	$	5.65		13,092
6/23/2008	$	5.63		9100
6/23/2008	$	5.62		10,400
6/23/2008	$	5.61		4,200
6/23/2008	$	5.60		4,271
6/23/2008	$	5.59		300
6/23/2008	$	5.58		200
6/23/2008	$	5.57		819
6/23/2008	$	5.55		22,344
6/23/2008	$	5.53		3,300
6/23/2008	$	5.52		500
6/23/2008	$	5.51		1,500

In addition, on June 23, 2008, Kirkfield purchased 427,100 shares for $5.93 per share, 132,361 shares for $5.64 per share and a warrant exerisable for 136,300 shares at an exercise price of $1.75 per share for $4.18 per share in privately negotiated transactions.

Other than the purchases as reported herein and a 15,000 share restricted stock award granted to Mr. Kirk on May 12, 2008, the Reporting Persons have not engaged in any transactions in shares of Common Stock since the filing of Amendment No. 2 with the Securities and Exchange Commission on March 24, 2008.”

Item 6.  Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.

Item 6 of the Original Schedule 13D is hereby amended and supplemented as follows:

In connection with the private purchases set forth in Item 5(c) above, Kirkfield entered into a Purchase Agreement with each of two private sellers, the form of which is attached hereto as Exhibit 10.1.

The warrant purchased for $4.18 per share in one of the private transactions is attached hereto as Exhibit 4.1. The warrant entitles the holder to purchase 136,300 shares at an exercise price of $1.75 per share. The warrant terminates on January 28, 2009.

Item 7.  Material to be Filed as Exhibits.

The following documents are being filed as exhibits to this Amendment and are incorporated herein by reference:

Exhibit 4.1 Callable Stock Purchase Warrant, dated January 28, 2004

Exhibit 10.1 Form of Purchase Agreement entered into on June 23, 2008 between Kirkfield, L.L.C. and two private sellers

Exhibit 99.1 Joint Filing Agreement, dated as of July 1, 2008, by and among Randal J. Kirk and Kirkfield, L.L.C.

SIGNATURE

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.

Date: July 1, 2008

/s/Randal J. Kirk                                                                

Randal J. Kirk

EXHIBIT INDEX

Exhibit Number	Exhibit
Ehibit 4.1	Callable Stock Purchase Warrant, dated January 28, 2004
Exhibit 10.1	Form of Purchase Agreement entered into on June 23, 2008 between Kirkfield, L.L.C. and two private sellers
Exhibit 99.1	Joint Filing Agreement, dated as of July 1, 2008, by and among Randal J. Kirk and Kirkfield, L.L.C.

EX-10.1

EXHIBIT 10.1

PURCHASE AGREEMENT

This Purchase Agreement (“Agreement”) is made and entered into as of June 23, 2008, between ________________ (the “Seller”) and Kirkfield, L.L.C. (the “Buyer”).

WHEREAS, the Seller is willing to sell to the Buyer, and the Buyer is willing to purchase from the Seller, __________________ (_________) shares of Common Stock (the “Shares”) and a warrant entitling the Seller or its assigns to purchase ________________ (_________) shares (“Warrant” and together with the Shares, “Securities”) of Halozyme Therapeutics, Inc., a Delaware corporation (the “Company”), currently held by the Seller.

ACCORDINGLY, THE PARTIES AGREE AS FOLLOWS:

1.   Sale of Securities.  The Seller hereby agrees to sell to the Buyer, and the Buyer hereby agrees to purchase from the Seller, all of the Securities on the Closing Date.  For purposes of this Agreement, “Closing Date” shall mean such date as soon as practicable after the date hereof but in no event later than three (3) business days after the date hereof on which all of the conditions to transfer of the Securities have been satisfied.

2.   Purchase Price.  The purchase price for the Shares is ____________________ Dollars ($___________) and for the Warrant is ___________________ Dollars ($_______) resulting in an aggregate purchase price of __________________________ Dollars ($_______) (the “Purchase Price”) for the Securities.  The Purchase Price shall be paid from the Buyer to the Seller on the Closing Date in immediately available funds against delivery by the Seller to the Buyer of (i) a certificate or certificates representing the Shares registered in the name of the Buyer or, if not so registered, accompanied by stock powers in form sufficient to permit transfer of the Shares into the name of the Buyer on the books of the stock transfer agent of the Company and (ii) the original Warrant accompanied by a Certificate of Transfer evidencing the assignment of the Warrant to the Buyer in accordance with the terms of the Warrant.

3.   Representations and Warranties of the Seller.  The Seller represents and warrants to the Buyer as follows:

(a)   Organization of Seller.   Seller is a corporation duly formed and validly existing under the laws of ______________.

(b)   Shares.  The Seller is the lawful owner of the Shares, and the Seller has the full power and authority to sell the Shares, free and clear of any liens or encumbrances whatsoever.  All of the Shares have been validly issued and are fully paid and nonassessable; and no person has any present or future right (conditional, preemptive or otherwise) to acquire any of the Shares.  Upon delivery of such Shares and payment therefor pursuant hereto, good and valid title to all such Shares free and clear of all liens or encumbrances whatsoever, options, warrants, purchase rights, contracts, commitments, equities, claims and demands will be transferred to Buyer, and such Shares shall be validly issued, fully paid and nonassessable.

(c)   Warrants.  The Seller is the lawful owner of the Warrant, and the Seller has the full power and authority to sell the Warrant, free and clear of any liens or encumbrances whatsoever.  The Warrant has been validly issued and upon payment in full of the Warrant Price (as defined in the Warrant) all of the shares issuable upon exercise of the Warrant (the “Underlying Shares”) will be validly issued, fully paid and nonassessable; and no person has any present or future right (conditional, preemptive or otherwise) to acquire the Warrant or any of the Underlying Shares.  Upon delivery of such Warrant and payment therefor pursuant hereto, good and valid title to such Warrant free and clear of all liens or encumbrances whatsoever, options, warrants, purchase rights, contracts, commitments, equities, claims and demands will be transferred to Buyer.

(d)   No Breach or Conflict.  The sale of the Securities contemplated by this Agreement does not conflict with, or result in a breach of, or a default under, or give rise to a right of acceleration under, any agreement or instrument to which the Seller is a party.

(e)   Enforceability.  Upon the execution and delivery of this Agreement, this Agreement will be a valid and binding obligation of Seller, enforceable in accordance with its terms, except (a) as limited by applicable bankruptcy, insolvency, reorganization, moratorium or other laws of general application affecting enforcement of creditors’ rights, (b) general principles of equity that restrict the availability of equitable remedies, and (c) to the extent that the enforceability of any indemnification provisions hereof may be limited by applicable laws.

(f)   Consent.  No consent of any other person, and no notice to, filing or registration with, or consent, approval or authorization of, any court or governmental authority, regulatory or self-regulatory agency or any other third party is necessary or is required to be made or obtained by Seller, in connection with the execution and delivery of this Agreement or the consummation of the transactions contemplated hereby, except as may be required under the state securities laws of the jurisdiction in which the Buyer is resident.

(g)   Litigation.  There is no litigation, arbitration proceeding, governmental investigation, citation or action of any kind pending or, to the knowledge of Seller, proposed or threatened that seeks restraint, prohibition, damages or other relief in connection with this Agreement or the consummation of the transactions contemplated hereby or that otherwise might impair the Securities.

(h)   Fees and Expenses of Brokers and Others.  Seller is not committed to any liability for any brokers’ or finders’ fees or any similar fees in connection with the transactions contemplated hereby, and Seller has not retained any broker or other intermediary to act on its behalf in connection with the transactions contemplated by this Agreement.

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(i)   Consultation with Advisors.  Seller has consulted with such legal, accounting, tax and financial advisors as he deems necessary or appropriate concerning the terms and conditions of the sale of the Securities, including the tax consequences thereof.

(j)   Truth and Completeness of Representations and Warranties.  None of the information contained in the representations and warranties of the Seller set forth in this Agreement contains any untrue statement of a material fact or omits or will omit to state a material fact necessary to make the statements contained herein or therein not misleading.  Seller is not aware of any nonpublic information concerning the Company that would be material to Buyer’s decision to purchase the Securities.

4.   Representations and Warranties of the Buyer.  The Buyer represents and warrants to the Seller as follows:

(a)   Organization of Buyer.  Buyer is a limited liability company duly formed and validly existing under the laws of the Commonwealth of Virginia.

(b)   Investment Intent.  The Buyer is acquiring the Securities for its own account for investment, not for the interest of any other person, not for resale to any other person and not with a view to or in connection with a sale or distribution, as such term is defined in the Securities Act of 1933, as amended (the “Securities Act”).

(c)   Knowledge and Experience.  The Buyer is an “accredited investor” (as such term is defined in Regulation D under the Securities Act), is knowledgeable and experienced in businesses of the sort conducted by the Company.

(d)   Investment Risk.  The Buyer understands that the Buyer may be required to hold the Securities indefinitely due to the requirements of the Securities Act.  The Buyer is capable of evaluating the merits and risks involved in the acquisition of the Securities and is capable of bearing the economic risk of such investment.

(e)   Resale.  The Buyer is aware that any resale inconsistent with the Securities Act may create liability on its part and/or the part of the Seller, and agrees not to assign, sell, pledge, transfer or otherwise dispose of or transfer any of the Securities unless in compliance with the Securities Act and applicable state securities laws.

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5.   Closing.  The parties agree to take all such steps as soon as practicable after the date hereof necessary to close the purchase of the Securities pursuant to the terms set forth in this Agreement, including the execution of any additional documents or agreements and the provision of any necessary instructions to the Company’s transfer agent.  The parties hereby acknowledge and agree that the closing hereunder shall be conditioned upon each party’s respective representations and warranties contained herein being true and correct as of the Closing Date and undertake the obligation to provide the other party written notice of any information that may cause such representations and warranties to be untrue as of the Closing Date.

6.   Indemnification.

(a)   Seller’s Indemnification.  Seller hereby indemnifies and holds Buyer and its directors, officers, members and affiliates (collectively, the “ Buyer Indemnified Parties”) harmless from and against, and agrees to defend promptly the Buyer Indemnified Parties from and reimburse the Buyer Indemnified Parties for, any and all losses, liabilities, claims, damages (including incidental and consequential damages), costs, expenses (including costs of investigation and defense and reasonable attorneys’ fees) and obligations (hereinafter referred to collectively as “Losses”) that the Indemnified Parties may at any time suffer or incur, or become subject to, as a result of or in connection with:  (i) any material breach or inaccuracy of any of the representations and warranties made by Seller in this Agreement or any other agreement or instrument delivered by Seller pursuant to this Agreement; and (ii) any failure of Seller to carry out, perform, satisfy and discharge any of its covenants, agreements, undertakings, liabilities or obligations under this Agreement or under any of the agreements and instruments delivered by Seller pursuant to this Agreement.

(b)   Buyer’s Indemnification.  Buyer hereby indemnifies and holds Seller harmless from and against, and agrees to defend promptly the Seller from and reimburse the Seller for, any and all Losses that Seller may at any time suffer or incur, or become subject to, as a result of or in connection with: (P)(i) any material breach or inaccuracy of any of the representations and warranties made by Buyer in this Agreement or any other agreement or instrument delivered by Buyer pursuant to this Agreement; and (ii) any failure of Buyer to carry out, perform, satisfy and discharge any of its covenants, agreements, undertakings, liabilities or obligations under this Agreement or under any of the agreements and instruments delivered by Buyer pursuant to this Agreement.

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7.   Survival of Representations. Warranties and Covenants.  All agreements, representations, warranties and covenants made by the parties in this Agreement shall survive the closing of the purchase of the Securities hereunder for the full period of the applicable statute of limitations.

8.   Successors and Assigns.  This Agreement shall be binding upon and shall inure to the benefit of the undersigned parties and their respective heirs, personal representatives, successors and assigns.

9.   Entire Agreement and Amendments.  This Agreement represents the entire agreement of the parties with respect to the subject matter hereof, and no other agreement with respect thereto, including any prior written or oral representation or understanding of the parties, shall have any further force or effect.  The Buyer and the Seller each represents and warrants to the other that, in entering this Agreement, he has relied on no statements, representations, inducements or promises made by the other party except as are expressly set forth in this Agreement.  This Agreement may be modified only by a subsequent writing signed by both parties to this Agreement.

10.   Notices.  All notices, consents, offers and other communications by and between Buyer and Seller under this Agreement will be in writing and will be deemed to have been received when personally delivered, one business day after the date of transmittal if sent by reputable overnight courier service or five days after mailing by certified mail, return receipt requested, to Buyer at 1881 Grove Avenue, Radford, Virginia 24141, Attention: Tad Fisher, and to Seller at _________________________________ or to such other address as each may specify to the other in accordance with the provisions of this Section 10.

11.   Counterparts. This Agreement may be executed in counterparts, each of which shall be deemed an original, but all of which shall constitute one and the same instrument.

12.   Governing Law.  This Agreement shall be governed by, and construed in accordance with, the laws of the Commonwealth of Virginia, without reference to the choice of laws provisions thereof.

[REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]

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IN WITNESS WHEREOF, the parties have duly executed this Agreement as of the day and year first above written.

THE BUYER:
KIRKFIELD, L.L.C.
By:	THIRD SECURITY, LLC
	Its:	Manager
	By:
		Name:	Randal J. Kirk
		Title:	Manager, Third Security, LLC
THE SELLER:
By:
	Its:
	By:
		Name:
		Title:

 - 6 - -

EX-99.1

EXHIBIT 99.1

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k) promulgated under the Securities Exchange Act of 1934, as amended, the persons names below agree to the joint filing on behalf of each of them a Statement on Schedule 13D (including amendments thereto) with regard to the common stock of Halozyme Therapeutics, Inc., and further agree that this Joint Filing Agreement be included as an exhibit to such joint filings.  In evidence thereof, the undersigned, being duly authorized, hereby execute this agreement as of the 1st day of July, 2008.

Date:  July 1, 2008	/s/Randal J. Kirk
	Randal J. Kirk
Date:  July 1, 2008	NEW RIVER MANAGEMENT V, LP
	By:	Third Security Capital Partners V, LLC, its general partner
	By:	Third Security, LLC, its manager
	By:	/s/Randal J. Kirk
		Randal J. Kirk
		Manager

EX-4.1

EXHIBIT 4.1

THE SECURITIES EVIDENCED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE SOLD, TRANSFERRED, ASSIGNED OR HYPOTHECATED UNLESS (i) THERE IS AN EFFECTIVE REGISTRATION STATEMENT UNDER SUCH ACT COVERING SUCH SECURITIES, (ii) THE SALE IS MADE IN ACCORDANCE WITH RULE 144 UNDER THE ACT, OR (iii) THE COMPANY RECEIVES AN OPINION OF COUNSEL FOR THE HOLDER OF THESE SECURITIES REASONABLY SATISFACTORY TO THE COMPANY STATING THAT SUCH SALE, TRANSFER, ASSIGNMENT OR HYPOTHECATION IS EXEMPT FROM THE REGISTRATION REQUIREMENTS OF SUCH ACT.

Dated: January 28, 2004

HALOZYME THERAPEUTICS, INC.

CALLABLE STOCK PURCHASE WARRANT

136,300 Shares

1.      Number of Shares Subject to Warrant.  FOR VALUE RECEIVED, subject to the terms and conditions herein set forth, Kirkfield, L.L.C. (the “Holder”), is entitled to purchase from Halozyme Therapeutics, Inc., a Nevada corporation (the “Company”), at any time before the termination of this Warrant pursuant to Section 3 hereof, at a price per share equal to the Warrant Price (as defined below), the Warrant Stock (as defined below) upon exercise of this Warrant pursuant to Section 7 hereof.

This Warrant represents the remaining Warrant Stock exercisable from that certain Callable Stock Purchase Warrant originally issued by Deliatroph Pharmaceuticals, Inc. (the Company’s predecessor entity) to Bonanza Master Fund, LTD (“Bonanza”) on or about January 28, 2004 (the “Original Warrant”).  On June 24, 2008 the Original Warrant was transferred in whole by Bonanza to the Holder. The Company has previously exercised its call rights under the Original Warrant on November 9, 2004, and August 9, 2006, and this Warrant represents all available remaining shares issuable to the Holder.  The Original Warrant was one of a series of warrants (the “Original Warrants”) issued in connection with the January 2004 financing of Deliatroph Pharmaceuticals, Inc.  The Original Warrants, as well as all replacement warrants issued in connection with the Company’s call right or warrant exercises are collectively referred to herein as “Callable Warrants.”

2.      Definitions.  As used in this Warrant, the following terms shall have definitions ascribed to them below:

(a)           “Holder” shall mean Kirkfield, L.L.C. or its assigns.

(b)           “Warrant Price” shall be $1.75 per share.

(c)           “Warrant Stock” shall mean 136,300 shares of the Common Stock of the Company.

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3.      Termination.  This Warrant shall terminate and no longer be exercisable at 5:00 p.m., California time, on January 28, 2009.

4.      Fractional Shares.  No fractional shares shall be issuable upon exercise or conversion of the Warrant and the number of shares to be issued shall be rounded down to the nearest whole share.  If a fractional share interest arises upon any exercise or conversion of the Warrant, the Company shall eliminate such fractional share interest by paying the Holder an amount computed by multiplying the fractional interest by the fair market value of a full share.

4A.           Callable Warrant.  This warrant may be redeemed by the Company upon thirty (30) days advance written notice “Notice of Redemption” to Holder, for a price of $0.01 per share, provided that (i) a registration statement with the Securities and Exchange Commission is then in effect as to the shares of Common Stock underlying the Warrant and will be in effect as of a date thirty (30) days from the date of giving the Notice of Redemption; (ii) that for a period of twenty (20) trading days prior to the giving of the Notice of Redemption the Common Stock has closed at a price of $2.00 per share or higher; and (iii) that Callable Warrants, covering no more than an aggregate of 1,913,100 shares of Common Stock underlying the Callable Warrants, have been or will be called for redemption in the ninety (90) day period proceeding or following the giving of the Notice of Redemption.

5.      No Shareholder Rights.  This Warrant, by itself, as distinguished from any shares purchased hereunder, shall not entitle the Holder to any of the rights of a shareholder of the Company.

6.      Reservation of Stock.  The Company will reserve from its authorized and unissued Common Stock a sufficient number of shares to provide for the issuance of Warrant Stock upon the exercise of this Warrant.  Issuance of this Warrant shall constitute full authority to the Company’s officers who are charged with the duty of executing stock certificates to execute and issue the necessary certificates for shares of Warrant Stock issuable upon the exercise or conversion of this Warrant.

7.      Exercise of Warrant.  This Warrant may be exercised at any time prior to its termination and prior to the expiration of the thirty (30) days Notice of Redemption, in case the warrants have been called pursuant to 4A above, by the surrender of this Warrant, together with the Notice of Exercise and the Investment Representation Statement in the forms attached hereto as Attachments 1 and 2, respectively, duly completed and executed at the principal office of the Company, specifying the portion of the Warrant to be exercised and accompanied by payment in full of the Warrant Price in cash or by check with respect to the shares of Warrant Stock being purchased.  This Warrant shall be deemed to have been exercised immediately prior to the close of business on the date of its surrender for exercise as provided above, and the person entitled to receive the shares of Warrant Stock issuable upon exercise shall be treated for all purposes as Holder of such shares of record as of the close of business on such date.  As promptly as practicable after such date, the Company shall issue and deliver to the person or persons entitled to receive the same a certificate or certificates for the number of full shares of Warrant Stock issuable upon such exercise.  If the Warrant shall be exercised for less than the total number of shares of Warrant Stock then issuable upon exercise, promptly after surrender of the Warrant upon such exercise, the Company will execute and deliver a new Warrant, dated the date hereof, evidencing the right of the Holder to the balance of the Warrant Stock purchasable hereunder upon the same terms and conditions set forth herein.

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8.      Adjustment of Exercise Price and Number of Shares.  The number of shares issuable upon exercise of this Warrant (or any shares of stock or other securities or property at the time receivable or issuable upon exercise of this Warrant) and the Warrant Price therefor are subject to adjustment upon the occurrence of the following events:

(a)           Adjustment for Stock Splits, Stock Dividends, Recapitalizations, etc.  The Warrant Price and the number of shares issuable upon exercise of this Warrant shall each be proportionally adjusted to reflect any stock dividend, stock split, reverse stock split, combination of shares, reclassification, recapitalization or other similar event altering the number of outstanding shares of the Company’s capital stock.

(b)           Adjustment for Other Dividends and Distributions.  In case the Company shall make or issue, or shall fix a record date for the determination of eligible holders entitled to receive, a dividend or other distribution with respect to the shares payable in securities of the Company then, and in each such case, the Holder, on exercise of this Warrant at any time after the consummation, effective date or record date of such event, shall receive, in addition to the Warrant Stock (or such other stock or securities) issuable on such exercise prior to such date, the securities of the Company to which such Holder would have been entitled upon such date if such Holder had exercised this Warrant immediately prior thereto (all subject to further adjustment as provided in this Warrant).

9.      Adjustment for Capital Reorganization, Consolidation or Merger.  If any capital reorganization of the capital stock of the Company, or any consolidation or merger of the Company with or into another corporation, or the sale of all or substantially all of the Company’s assets to another corporation shall be effected in such a way that holders of the Company’s capital stock will be entitled to receive stock, securities or assets with respect to or in exchange for the Company’s capital stock, and in each such case the Holder, upon the exercise of this Warrant, at any time after the consummation of such capital reorganization, consolidation, merger, or sale, shall be entitled to receive, in lieu of the stock or other securities and property receivable upon the exercise of this Warrant prior to such consummation, the stock or other securities or property to which such Holder would have been entitled upon such consummation if such Holder had exercised this Warrant immediately prior to the consummation of such capital reorganization, consolidation, merger, or sale, all subject to further adjustment as provided in this Section 9; and in each such case, the terms of this Warrant shall be applicable to the shares of stock or other securities or property receivable upon the exercise of this Warrant after such consummation.

10.    “Market Stand-Off” Agreement.  The Holder agrees in connection with any underwritten registration of the Company’s securities (other than a registration of securities in a Rule 415 of the Securities Act of 1933, as amended, (“Securities Act”) transaction or with respect to an employee benefit plan), upon request of the Company or the underwriters managing any underwritten offering of the Company’s securities, not to sell, make any short sale of, loan, pledge (or otherwise encumber or hypothecate), grant any option for the purchase of, or otherwise directly or indirectly dispose of any of its shares of Common Stock (other than those included in the registration) without the prior written consent of the Company and such managing underwriters for 180 days following the effective date of the registration statement for such offering under the Securities Act; provided, however, that such agreement shall not be required unless all officers and directors of the Company enter into similar agreements, and provided further that such agreement shall not be required with respect to shares underlying the warrant if the warrant has been called for redemption under paragraph 4A within 30 days before or 180 days after the filing of the registration statement with respect to such underwritten offering.

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11.    Transfer of Warrant.  This Warrant may be transferred or assigned by the Holder hereof in whole or in part, provided that the transferor provides, at the Company’s request, an opinion of counsel satisfactory to the Company that such transfer does not require registration under the Securities Act and the securities law applicable with respect to any other applicable jurisdiction.

12.    Amendments and Waivers.  This Warrant and any term hereof may only be amended, waived, discharged or terminated by a written instrument signed by the Company and the holders of at least 66 2/3% of the shares issuable upon exercise of the Callable Warrants then outstanding.

13.    Miscellaneous.  This Warrant shall be governed by the laws of the State of California, as such laws are applied to contracts to be entered into and performed entirely in California by California residents.  The headings in this Warrant are for purposes of convenience and reference only, and shall not be deemed to constitute a part hereof.  Neither this Warrant nor any term hereof may be changed or waived orally, but only by an instrument in writing signed by the Company and the Holder of this Warrant.  All notices and other communications from the Company to the Holder of this Warrant shall be delivered, personally or mailed by first class mail, postage prepaid, to the address furnished to the Company in writing by the last Holder of this Warrant who shall have furnished an address to the Company in writing, and if mailed shall be deemed given three days after deposit in the United States mail.

HALOZYME THERAPEUTICS, INC.

By: /s/ David Ramsey

David Ramsay

Chief Financial Officer

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Attachment 1

NOTICE OF EXERCISE

TO:

HALOZYME THERAPEUTICS, INC.

1.           The undersigned hereby elects to purchase ________ shares of the Warrant Stock of Halozyme Therapeutics, Inc. pursuant to the terms of the attached Warrant, and tenders herewith payment of the purchase price in full, together with all applicable transfer taxes, if any.

2.           Please issue a certificate or certificates representing said shares of Warrant Stock in the name of the undersigned or in such other name as is specified below:

____________________________________
(Name)

____________________________________

(Address)

(Date) (Authorized Signature of Warrant Holder)

Attachment 2

INVESTMENT REPRESENTATION STATEMENT

Shares of Warrant Stock (as defined in the attached Warrant) of

HALOZYME THERAPEUTICS, INC.

In connection with the purchase of the above-listed securities, the undersigned hereby represents to Halozyme Therapeutics, Inc. (the “Company”) as follows:

(a)           The securities to be received upon the exercise of the Warrant (the “Warrant Stock”) will be acquired for investment for its own account; not as a nominee or agent, and not with a view to the sale or distribution of any part thereof, and the undersigned has no present intention of selling, granting participation in or otherwise distributing the same, but subject, nevertheless, to any requirement of law that the disposition of its property shall at all times be within its control.  By executing this Statement, the undersigned further represents that it does not have any contract, undertaking, agreement or arrangement with any person to sell, transfer, or grant participation to such person or to any third person, with respect to any Warrant Stock issuable upon exercise of the Warrant.

(b)           The undersigned understands that the Warrant Stock issuable upon exercise of the Warrant at the time of issuance may not be registered under the Securities Act, and applicable state securities laws, on the ground that the issuance of such securities is exempt pursuant to Section 4(2) of the Securities Act and state law exemptions relating to offers and sales not by means of a public offering, and that the Company’s reliance on such exemptions is predicated on the undersigned’s representations set forth herein.  If the Warrant Stock is registered under the Securities Act at the time of exercise, the undersigned represents that it will sell the Warrant Stock in accordance with the terms of such registration statement or in accordance with some other applicable exemption from registration.

(c)           The undersigned acknowledges that an investment in the Company is highly speculative and represents that it is able to fend for itself in transactions of this type, has such knowledge and experience in financial and business matters as to be capable of evaluating the merits and risks of its investments, and has the ability to bear the economic risks (including the risk of a total loss) of its investment.

(d)           The undersigned acknowledges that the Warrant Stock issuable upon exercise of the Warrant must be held indefinitely unless registered under the Securities Act or an exemption from such registration is available.  The undersigned is aware of the provisions of Rule 144 promulgated under the Securities Act which permit limited resale of shares purchased in a private placement subject to the satisfaction of certain conditions, including, among other things, the availability of certain current public information about the Company, certain holding periods for the security to be sold, certain manner of sale restrictions and certain volume of sale restrictions.

(Date) (Authorized Signature of Warrant Holder)