AMENDMENT NO. 1 TO NOTE AMENDMENT AND EXCHANGE AGREEMENT

Exhibit 10.1

AMENDMENT NO. 1

TO

NOTE AMENDMENT AND EXCHANGE AGREEMENT

Dated as of January 28, 2009

This Amendment No. 1 (the “Amendment”) to the Note Amendment and Exchange Agreement (the “Agreement”) dated November 17, 2003 by and among Oscient Pharmaceuticals Corporation (formerly known as Genome Therapeutics Corp.) (the “Parent”) and each of the holders set forth on Schedule A and Schedule B of the Agreement (the “Holders”) is entered into as of the date first written above. Capitalized terms used and not otherwise defined in this Amendment are used herein as defined in the Agreement.

1. Amendments to Article I . The definition of “Parent,” “Initial Conversion Price” and “Maturity Date” in Article I of the Agreement are hereby amended and restated in their entirety as follows:

“Parent” means Oscient Pharmaceuticals Corporation (formerly known as Genome Therapeutics Corp.)”

“Initial Conversion Price” means $1.10.

“Maturity Date” means December 1, 2009.

2. Amendment to Add Article XV . The Agreement is hereby amended to add a new Article XV which shall read in its entirety as follows:

ARTICLE XV

ADDITIONAL EXCHANGE PRIVILEGES

SECTION 15.1. Optional Exchange of Parent Note for 12.50% Convertible Guaranteed Senior Notes due 2011 .

(a) At anytime prior to two (2) Business Days before the Maturity Date a Holder of a Parent Note may exchange all, but not less than all, of its Parent Note for a 12.50% Convertible Guaranteed Senior Note due 2011 (“New Note”) of the Parent in a principal amount equal to the principal amount and accrued interest of such Parent Note. The New Notes shall be issued pursuant to the Indenture dated November 25, 2008 by and among the Parent, Guardian II Acquisition Corporation and U.S. Bank National Association (the “Indenture”) and shall be substantially in the form set out in Exhibit A . The exchange of a Parent Note into a New Note shall be deemed to be the satisfaction in full of the Parent’s obligations under such Parent Note.

(b) The New Notes will be issuable in denominations of $1,000 and any integral multiple of $1,000 above that amount (the amount, if any, in excess of such integral multiple, the “Excess Amount”). Any Excess Amount due to a Holder upon exchange will be settled by issuing to such Holder the number of shares of Common Stock of the Parent obtained by

dividing such Excess Amount by the then-effective Conversion Price. The Parent will not issue fractional shares of Common Stock and instead will deliver a check in an amount equal to the value of such fraction computed on the basis of the closing price of the Parent’s Common Stock on the date of the exchange.

(c) New Notes shall bear the following legend:

THIS SECURITY AND THE SECURITIES ISSUABLE UPON CONVERSION OR EXERCISE HEREOF HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED. THIS SECURITY AND THE SECURITIES ISSUABLE UPON CONVERSION OR EXERCISE HEREOF MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT WITH RESPECT HERETO OR THERETO UNDER SAID ACT OR AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED.

(d) Any shares of Common Stock issuable upon conversion of the New Notes shall bear the following legend:

THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED. THE TRANSFER OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE IS SUBJECT TO THE CONDITIONS SPECIFIED IN THE AMENDMENT NO. 1 TO THE NOTE AMENDMENT AND EXCHANGE AGREEMENT DATED NOVEMBER 17, 2003 BY AND AMONG OSCIENT PHARMACEUTICALS CORPORATION (THE “ COMPANY ”) AND THE OTHER PARTIES LISTED ON THE SIGNATURE PAGES THERETO, AND THE COMPANY RESERVES THE RIGHT TO REFUSE THE TRANSFER OF SUCH SECURITIES UNTIL SUCH CONDITIONS HAVE BEEN FULFILLED WITH RESPECT TO SUCH TRANSFER. A COPY OF SUCH CONDITIONS SHALL BE FURNISHED BY THE COMPANY TO THE HOLDER HEREOF UPON WRITTEN REQUEST AND WITHOUT CHARGE.

(e) Removal of legends.

(i) In connection with a sale of the New Notes or any shares of Common Stock that have been issued upon the conversion thereof pursuant to an effective registration statement governing such securities, the Parent agrees that it shall facilitate the delivery of such New Notes or certificates representing such shares of Common Stock, as applicable, which shall be free, to the extent permitted by this Amendment and under applicable law, of all restrictive legends.

(ii) If the New Notes or any shares of Common Stock issued upon the conversion thereof become eligible for sale pursuant to Rule 144, the Parent shall, without any request or action on the part of the Holders, remove the legends set forth on such securities pursuant to Rule 144 at the one year anniversary of the issuance of the New Notes. Notwithstanding the prior sentence, a Holder may request that the Parent remove the legends at any time prior to the one year anniversary of the New Notes. Any Holder requesting the removal of such legend shall deliver or cause to be delivered to the Parent a certificate executed by such Holder requesting removal of the legends and an opinion of such Holder’s counsel, such certificate and opinion to be in form and substance reasonably satisfactory to the Parent. Upon receipt of such certificate and opinion, Parent shall remove the legends set forth on such securities.

SECTION 15.2. Exchange Procedure .

(a) To exchange a Parent Note for a New Note, a Holder must (1) provide written notice to the Parent specifying that it is exchanging its Parent Note in the form provided on Exhibit B hereto, (2) surrender its Parent Note to the Parent at the following address: 1000 Winter Street, Suite 2200, Waltham, Massachusetts 02451 and (3) furnish to the Trustee under the Indenture a completed Internal Revenue Service Form W-9. The date on which a Holder satisfies the foregoing requirements is the date of the exchange (the “Exchange Date”). As soon as practicable, and in any event within ten (10) days following the Exchange Date, the Parent shall deliver or cause to be delivered to such Holder a New Note and, if applicable, any shares of Common Stock and a check in lieu of any fractional shares to which such Holder is entitled as a result of the exchange. Holders shall also be responsible for paying any transfer or similar tax, if required, in connection with the exchange of the Parent Notes for New Notes.

(b) For the avoidance of doubt, the last day a Holder may exchange is Parent Note is two Business Days prior to the Maturity Date.

3. Amendment to Add Article XVI . The Agreement is hereby amended to add a new Article XVI which shall read in its entirety as follows:

ARTICLE XVI

REGISTRATION RIGHTS

SECTION 16.1. Registration Rights .

The Parent shall:

(a) no later than twenty (20) days following the date of this Amendment (the “Filing Date”), prepare and file with the Commission a Registration Statement on Form S-1 (the “Registration Statement”) relating to the resale of the New Notes and the shares of Common Stock issuable upon the conversion thereof by the Holders;

(b) no later than ten (10) days following the date of this Amendment (the “Request Date”), provide a draft of the Registration Statement relating to the resale of the New Notes and the shares of Common Stock issuable upon the conversion thereof by the Holders, to the Holders (via e-mail addresses provided on Exhibit C ) and requesting the necessary information from the Holders to complete the Registration Statement within seven (7) days of the receipt of the Registration Statement;

(c) use its commercially reasonable efforts, subject to receipt of the necessary information from the Holders described in (b) above, to cause the Commission to declare the Registration Statement effective as promptly as practicable after the Registration Statement is filed by the Parent, but in no case later than 120 days after the Filing Date;

(d) promptly prepare and file with the Commission such amendments and supplements to the Registration Statement and the prospectus used in connection therewith as may be necessary to keep the Registration Statement effective until the earlier of (i) such time as all of the New Notes and shares of Common Stock issuable upon the conversion thereof have been sold pursuant to the Registration Statement, (ii) the one year anniversary date of the issuance of the New Notes; (iii) the date that is two Business Days prior to the Maturity Date of the Parent Notes, if at such time no Holders of Parent Notes have exchanged Parent Notes for New Notes; or (iv) such time as all New Notes and shares of Common Stock issuable upon the conversion thereof held by the Holders have been sold pursuant to an exemption from Registration;

(e) in consultation with its counsel, file documents required of the Parent for compliance with Blue Sky requirements in states specified in writing by the Holder; provided, however, that the Parent shall not be required to qualify to do business or consent to service of process in any jurisdiction in which it is not now so qualified or has not so consented;

(f) bear all expenses in connection with the procedures in paragraphs (a) through (d) of this Section 16.1, other than fees and expenses, if any, of counsel or other advisers to the Holders or underwriting discounts, brokerage fees and commissions incurred by the Holders, if any in connection with the offering of the New Notes and the shares of Common Stock issuable upon the conversion thereof pursuant to the Registration Statement;

(g) advise the Holder (via e-mail addresses provided on Exhibit C ) as promptly as reasonably possible following the time when: (i) the prospectus or any prospectus supplement or post-effective amendment has been filed, and, with respect to the Registration Statement or any post-effective amendment thereto, when the same has become effective; (ii) the Parent receives notice or obtains knowledge of the issuance of any stop order by the Commission delaying or suspending the effectiveness of the Registration Statement or of the initiation of any proceeding for that purpose, or any other order issued by any state securities commission or other regulatory authority suspending the qualification or exemption from qualification of the New Notes and shares of Common Stock issuable upon the conversion thereof under state securities or “blue sky” laws; and (iii) the financial statements included in any Registration Statement become ineligible for inclusion therein or the Parent receives notice or obtains knowledge of the existence of any fact or the happening of any event that makes any statement of a material fact in the Registration Statement, the prospectus, any amendment or supplement thereto, or any document incorporated by reference therein untrue, or which results in an omission of a material fact necessary in order to make the statement contained therein in light of the circumstances in which it was made not misleading;

(h) in order to enable the Holders to sell the Shares under Rule 144 to the Securities Act, for a period of one year from the issuance of the New Notes, use its commercially reasonable efforts to comply with the requirements of Rule 144, including without limitation, use its commercially reasonable efforts to comply with the requirements of Rule 144(c) with respect to public information about the Parent and to timely file all reports required to be filed by the Parent under the Exchange Act; and

(i) upon (A) the issuance by the SEC of a stop order suspending the effectiveness of the Registration Statement or the initiation of proceedings with respect to the Registration Statement under the Securities Act, (B) the occurrence of any event or the existence of any fact as a result

of which the Registration Statement or the related prospectus shall contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein not misleading, in the light of the circumstances under which they were made or (C) the occurrence or existence of any pending corporate development (a “Material Event”) that, in the reasonable discretion of the Parent, makes it appropriate to suspend the availability of the Registration Statement and the related prospectus, the Parent must promptly give notice to the Holders (via the e-mail addresses provided on Exhibit C ) that the availability of the Registration Statement is suspended (a “Suspension Notice”) and, upon receipt of any Suspension Notice, each Holder agrees not to sell any New Note or shares of Common Stock issuable upon the conversation therefore pursuant to the Registration Statement until such Holder’s is advised in writing by the Parent that the prospectus may be used, and has received copies of any additional or supplemental filings that are incorporated or deemed incorporated by reference in such prospectus (such period, the “Suspension Period”). The Parent will use its commercially reasonable efforts to ensure that the use of the prospectus may be resumed (x) in the case of clause (A) above, as promptly as is practicable, (y) in the case of clause (B) above, as soon as, in the judgment of the Parent, the Registration Statement or the prospectus does not contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein not misleading, in the light of the circumstances under which they were made and (z) in the case of clause (C) above, as soon as, in the reasonable discretion of the Parent, such suspension is no longer appropriate.

To the extent that (i) the Parent fails to comply with its obligations under Section 16.1(a) or 16.1(c) above or (ii) a Suspension Period extends more than an aggregate of ninety (90) days during the period during which the Registration Statement is required to be effective under Section 16.1(d) above (each event referred to in clause (i) and (ii) is referenced as an “Event” and the duration of any such Event, including the date of the Event but excluding the date on which the Event is no longer continuing is referred to as a “Damages Accrual Period”), then the Parent will make payments to the Holders, as liquidated damages and not as a penalty, in an amount (the “Liquidated Damages Amount”) equal to 0.5% of the aggregate principal value of the New Notes held by Holders as determined on the last business day for any 30-day Damages Accrual Period (or pro rata for any portion thereof during which an Event occurred), or, without duplication, in the case of shares of Common Stock received upon the Conversion of the New Notes, 0.5% of the aggregate Closing Sales Price as determined at the time the shares of Common Stock were exchanged for the New Notes times the number of such shares of Common Stock held by each Holder to be paid on the last business day of each 30-day Damages Accrual Period (or pro rata for any portion thereof during which an Event occurred). Notwithstanding the foregoing, the Parent will not be liable to any Holder for any Liquidated Damages Amounts once the aggregate number of days in all Damages Accrual Periods has exceeded 180 days. In addition, no Liquidated Damages Amounts shall accrue as to any New Note from and after the date on which the Registration Statement is no longer required to be effective under Section 16.1(d). The rate of accrual of the Liquidated Damages Amount with respect to any period shall not exceed the rate provided for in this paragraph notwithstanding the occurrence of multiple concurrent Events. Following the cure of all Events requiring the payment by the Parent of Liquidated Damages Amounts to the Holders pursuant to this Section, the accrual of Liquidated Damages Amounts shall cease (without in any way limiting the effect of any subsequent Event requiring the payment of Liquidated Damages Amount by the Parent).

SECTION 16.2. Transfer of Shares After Registration . Each Holder agrees that it will not effect any disposition of the New Notes and shares of Common Stock issuable upon the conversion thereof that would constitute a sale within the meaning of the Securities Act or pursuant to any applicable state securities laws, except as contemplated in the Registration Statement referred to in Section 16.1 or as otherwise permitted by law, and that it will promptly notify the Parent of any changes in the information set forth in the Registration Statement regarding the Holder or its plan of distribution.

SECTION 16.3. Indemnification .

(a) The Parent agrees to indemnify, defend and hold harmless each Holder, each person, if any, who controls any Holder within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act (a “Controlling Person”) and the respective officers, directors, partners, employees, representatives and agents of the Holders or any Controlling Person (each, an “Indemnified Party”), from and against any loss, damage, expense, liability, claim or any actions in respect thereof (including the reasonable cost of investigation) which such Indemnified Party may incur or become subject to under the Securities Act, the Exchange Act or otherwise, insofar as such loss, damage, expense, liability, claim or action arises out of or is based upon any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or prospectus, including the prospectus, financial statements and schedules, and all other documents filed as a part thereof, as amended at the time of effectiveness of the Registration Statement, including any information deemed to be a part thereof as of the time of effectiveness pursuant to paragraph (b) of Rule 430A of the Securities Act, or the prospectus, in the final form filed with the Commission pursuant to Rule 424(b) of the Securities Act, or filed as part of the Registration Statement at the time of effectiveness if no Rule 424(b) filing is required (the “Prospectus”), or any subsequent amendment or supplement thereto or arises out of or is based upon any omission or alleged omission to state a material fact required to be stated in the Registration Statement or the Prospectus or in any amendment or supplement thereto or necessary to make the statements therein not misleading, in the light of the circumstances under which they were made, and the Parent shall reimburse, as incurred, the Indemnified Parties for any legal or other expenses reasonably incurred by them in connection with investigating or defending any such loss, damage, expense, liability, claim or action in respect thereof; provided , however , that the Parent will not be liable in any such case to the extent that any such loss, claim, damage, liability or expense arises out of or is based upon (i) any untrue statement or alleged untrue statement or omission or alleged omission made in the Registration Statement, the Prospectus or any amendment or supplement thereto in reliance upon and in conformity with written information furnished to the Parent by or on behalf of the Holder expressly for use therein, or (ii) the failure of a Holder to comply with its covenants and agreements contained in this Amendment or the Agreement, or (iii) the inaccuracy of any representation or warranty made by a Holder in this Amendment or (iv) any statement or omission in any Prospectus that is corrected in any subsequent Prospectus that was delivered to the Holder prior to the pertinent sale or sales by the Holder.

(b) Each Holder, severally and not jointly, agrees to indemnify, defend and hold harmless the Parent, its directors, officers, employees, representatives, agents and any person who controls the Parent within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act (each, a “Parent Indemnified Party”) from and against any loss, damage, expense, liability, claim or any actions in respect thereof (including the reasonable cost of

investigation) which such Parent Indemnified Party may incur or become subject to under the Securities Act, the Exchange Act or otherwise, insofar as such loss, damage, expense, liability, claim or action arises out of or is based upon any untrue statement or alleged untrue statement of a material fact contained in information furnished in writing by or on behalf of such Holder to the Parent expressly for use in the Registration Statement or Prospectus or any amendment or supplement thereto, or arises out of or is based upon any omission or alleged omission to state a material fact required to be stated in the Registration Statement or Prospectus or in any amendment or supplement thereto or necessary to make the statements therein not misleading, in the light of the circumstances under which they were made, in each case in connection with such information furnished in writing by or on behalf of such Holder to the Parent expressly for such use; and, subject to the limitation set forth immediately preceding this clause, each Holder shall reimburse, as incurred, the Parent for any legal or other expenses reasonably incurred by the Parent or any such controlling person in connection with investigating or defending any loss, damage, expense, liability, claim or action in respect thereof. This indemnity agreement will be in addition to any liability which such Holder may otherwise have to the Parent or any of its controlling persons.

(c) If any action, suit or proceeding (each, a “Proceeding”) is brought against any person in respect of which indemnity may be sought pursuant to either subsection (a) or (b) of this Section 16.3, such person (the “Indemnified Party”) shall promptly notify the person against whom such indemnity may be sought (the “Indemnifying Party”) in writing of the institution of such Proceeding and the Indemnifying Party shall assume the defense of such Proceeding; provided , however , that the omission to notify such Indemnifying Party shall not relieve such Indemnifying Party from any liability which it may have to such Indemnified Party or otherwise. Such Indemnified Party shall have the right to employ its own counsel in any such case, but the fees and expenses of such counsel shall be at the expense of such Indemnified Party unless the employment of such counsel shall have been authorized in writing by such Indemnifying Party in connection with the defense of such Proceeding or such Indemnifying Party shall not have employed counsel to have charge of the defense of such Proceeding within thirty (30) days of the receipt of notice thereof or such Indemnified Party shall have reasonably concluded upon the written advice of counsel that there may be one or more defenses available to it that are different from, additional to or in conflict with those available to such Indemnifying Party (in which case such Indemnifying Party shall not have the right to direct that portion of the defense of such Proceeding on behalf of the Indemnified Party, but such Indemnifying Party may employ counsel and participate in the defense thereof but the fees and expenses of such counsel shall be at the expense of such Indemnifying Party), in any of which events such reasonable fees and expenses shall be borne by such Indemnifying Party and paid as incurred (it being understood, however, that such Indemnifying Party shall not be liable for the expenses of more than one separate counsel in any one Proceeding or series of related Proceedings together with reasonably necessary local counsel representing the Indemnified Parties who are parties to such action). An Indemnifying Party shall not be liable for any settlement of such Proceeding effected without the written consent of such Indemnifying Party, but if settled with the written consent of such Indemnifying Party, such Indemnifying Party agrees to indemnify and hold harmless an Indemnified Party from and against any loss or liability by reason of such settlement. Notwithstanding the foregoing sentence, if at any time an Indemnified Party shall have requested an Indemnifying Party to reimburse such Indemnified Party for fees and expenses of counsel as contemplated by the second sentence of this paragraph, then such Indemnifying Party agrees that

it shall be liable for any settlement of any Proceeding effected without its written consent if (i) such settlement is entered into more than sixty (60) Business Days after receipt by such Indemnifying Party of the aforesaid request, (ii) such Indemnifying Party shall not have reimbursed such Indemnified Party in accordance with such request prior to the date of such settlement and (iii) such Indemnified Party shall have given such Indemnifying Party at least thirty (30) days’ prior notice of its intention to settle. No Indemnifying Party shall, without the prior written consent of any Indemnified Party, effect any settlement of any pending or threatened Proceeding in respect of which such Indemnified Party is or could have been a party and indemnity could have been sought hereunder by such Indemnified Party, unless such settlement includes an unconditional release of such Indemnified Party from all liability on claims that are the subject matter of such Proceeding and does not include an admission of fault, culpability or a failure to act, by or on behalf of such Indemnified Party.

(d) If the indemnification provided for in this Section 16.3 is unavailable to an Indemnified Party under subsections (a) and (b) of this Section 16.3 in respect of any losses, damages, expenses, liabilities, claims or actions referred to therein, then each applicable Indemnifying Party, in lieu of indemnifying such Indemnified Party, shall contribute to the amount paid or payable by such Indemnified Party as a result of such losses, damages, expenses, liabilities, claims or actions (i) in such proportion as is appropriate to the reflect fault of the Parent on the one hand and of the Holders on the other in connection with the statements or omissions which resulted in such losses, damages, expenses, liabilities, claims or actions, as well as any other relevant equitable considerations. The relative fault of the Parent on the one hand and of the Holders on the other shall be determined by reference to, among other things, whether the untrue statement or alleged untrue statement of a material fact or omission or alleged omission relates to information supplied by the Parent or by the Holders and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. The amount paid or payable by a party as a result of the losses, damages, expenses, liabilities, claims and actions referred to above shall be deemed to include any reasonable legal or other fees or expenses reasonably incurred by such party in connection with investigating or defending any Proceeding.

(e) The Parent and the Holders agree that it would not be just and equitable if contribution pursuant to this Section 16.3 were determined by pro rata allocation or by any other method of allocation which does not take account of the equitable considerations referred to in subsection (d) above. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The Holders’ respective obligations to contribute pursuant to this Section 16.3 are several and not joint. The remedies provided for in this Section 16.3 are not exclusive and shall not limit any rights or remedies which may otherwise be available to any indemnified party at law or in equity.

(f) The indemnity and contribution provisions contained in this Section 16.3 shall remain operative and in full force and effect regardless of (i) any termination of this Agreement, (ii) any investigation made by or on behalf of any Holder or any person controlling any Holder or the Parent, or the Parent’s officers or directors or any person controlling the Parent and (iii) the sale of any New Notes and shares of Common Stock issuable upon the Conversion thereof by any Holder.

SECTION 16.4. Termination of Conditions and Obligations . The conditions precedent imposed by Section 16.2 upon the transferability of the securities purchased pursuant to this Amendment shall cease and terminate as to any particular number of securities upon the earlier of (i) the one year anniversary date of the issuance of the New Notes and (ii) at such time as an opinion of counsel satisfactory in form and substance to the Parent shall have been rendered to the effect that such conditions are not necessary in order to comply with the Securities Act.

SECTION 16.5. Information Available . The Parent, upon the reasonable request of the Holder, shall make available for inspection by each Holder and any attorney, accountant or other agent retained by the Holder, all financial and other records, pertinent corporate documents and properties of the Parent, and cause the Parent’s officers, employees and independent accountants to supply all information reasonably requested by the Holder or any such underwriter, attorney, accountant or agent in connection with the Registration Statement.

4. Amendment to Add Article XVII . The Agreement is hereby amended to add a new Article XVII which shall read in its entirety as follows:

ARTICLE XVII

PRIVATE PLACEMENT

REPRESENTATIONS AND WARRANTIES OF EACH HOLDER

SECTION 17.1. Private Placement . Each Holder hereby severally, and not jointly, represents and warrants to the Parent, as to itself and as to no other Person, as of the date hereof, as of the Exchange Date, and as of the date that the New Notes are converted into shares of Common Stock, as follows:

(a) Such Holder is (i) an “accredited investor” as defined in Rule 501 of Regulation D of the Securities Act and (ii) acquiring the New Notes and any shares of Common Stock issuable upon the conversion thereof, as the case may be, for its own account, for investment, and not with a view to the distribution thereof in violation of any securities laws.

(b) Such Holder understands (i) that the offering of the New Notes and any shares of Common Stock issued upon the conversion thereof are intended to be exempt from registration under the Securities Act pursuant to Section 4(2) and Regulation D thereof and (ii) that there is no existing public or other market for the New Notes.

(c) Such Holder (either alone or together with its advisors) has sufficient knowledge and experience in financial and business matters so as to be capable of evaluating the merits and risks of its investment in the New Notes and any shares of Common Stock issuable upon the conversion thereof, and is capable of bearing the economic risks of such investment.

(d) Such Holder understands that the New Notes and any shares of Common Stock issuable upon the conversion thereof will be issued in a transaction exempt from the registration or qualification requirements of the Securities Act and applicable state securities laws, and that such securities must be held indefinitely unless a subsequent disposition thereof is registered or qualified under the Securities Act and such laws or is exempt from such registration or qualification.

(e) Such Holder (i) has had full access to all of the information it considers necessary or appropriate to make an informed investment decision with respect to the New Notes and the shares of Common Stock issuable upon the conversion thereof, (ii) has had the opportunity to discuss with management of Parent the intended business and financial affairs of Parent and to obtain information (to the extent Parent possessed such information or could acquire it without unreasonable effort or expense) necessary to verify any information furnished to it or to which it had access and (iii) can bear the economic risk of (x) an investment in the New Notes and any shares of Common Stock issuable upon the conversion thereof indefinitely and (y) a total loss in respect of such investment, and has such knowledge and experience in business and financial matters so as to enable it to understand and evaluate the risks of and from an investment decision with respect to its investment in the New Notes and any shares of Common Stock issuable upon the conversion thereof and to protect its own interest in connection with such investment.

(f) Such Holder has not taken any action that would entitle any Person to any commission or broker’s fee in connection with the transactions contemplated by this Amendment.

SECTION 17.2. Enforceability . The execution and delivery by such Holder of this Amendment will result in legally binding obligations enforceable against it and the other parties hereto in accordance with the respective terms and provisions hereof.

5. Amendment to Add Article XVIII . The Agreement is hereby amended to add a new Article XVIII which shall read in its entirety as follows:

ARTICLE XVIII

LIMITATION ON COMMON STOCK OWNERSHIP BY MAVERICK ENTITIES

SECTION 18.1. Exercise Limitations; Holder’s Restrictions . Notwithstanding anything to the contrary contained in the Indenture, the Agreement, the Amendment or any New Note or any Parent Note and other than with respect to those event listed in Section 18.2 below, the Parent or its successor shall not effect any conversion of the New Note or Parent Note that is in the discretion of Maverick Fund II, Ltd., Maverick Fund USA, Ltd., Maverick Fund, L.D.C. and their affiliates (each a “Maverick Entity” and, together, the “Maverick Entities”), and the Maverick Entities shall not have the right to voluntarily convert any portion of the New Note or Parent Note, nor shall any Maverick Entity submit any notice of conversion (“Notice”), pursuant to Article 14 of the Indenture or Section 5 of the New Notes or Section 8.1 of the Agreement or the Parent Notes, to the extent that after giving effect to such voluntary conversion (together with any interest payment payable in shares of Common Stock under the Indenture or New Notes at the election of the Parent or its successor, a “Voluntary Conversion”), the Maverick Entities in the aggregate would beneficially own in excess of 9.99% (the “Maximum Percentage”) of the number of shares of Common Stock outstanding immediately after giving effect to such Voluntary Conversion. Each delivery of a Notice by a Maverick Entity of a Parent Note or New Note, as applicable, will constitute a representation by such Maverick Entity that it has evaluated the limitations set forth in this Section 18.1 and determined, based on the most recent public filings by the Parent with the Securities and Exchange Commission, that the issuance of the full number of shares of Common Stock to which the Maverick Entity is entitled upon submitting the Notice is permitted hereunder. For purposes hereof, beneficial ownership shall be calculated in

accordance with Section 13(d) of the Securities Exchange Act of 1934, as amended. For purposes of this paragraph, in determining the number of outstanding shares of Common Stock, a Maverick Entity may rely on the number of outstanding shares of Common Stock as reflected in (x) the Parent or its successor’s most recent Form 10-Q or Form 10-K, as the case may be, (y) a more recent public announcement by the Parent or its successor or (z) any other notice by the Parent or its successor or the Parent or its successor’s transfer agent setting forth t