Purchaser Status. At the time such Purchaser was offered the Securities, it was, and as of the date hereof it is, and on each date on which it exercises any Warrants, it will be either: # an “accredited investor” as defined in Rule 501(a)(1), (a)(2), (a)(3), (a)(7) or (a)(8) under the Securities Act or # a “qualified institutional buyer” as defined in Rule 144A(a) under the Securities Act.

Purchaser Deliverables. At the Closing and as a condition to Closing, Purchaser shall deliver the following:

Purchaser Representations. In connection with the issuance and acquisition of Shares under this Agreement, the Purchaser hereby represents and warrants to the Company as follows:

In the event a material breach of this Agreement, the non-breaching Party may deliver notice of such breach to the breaching Party, such notice containing full details of said breach. In such notice, the non-breaching Party shall identify (acting reasonably and in good faith) examples of the actions or conduct that such Party would consider to be an acceptable cure of such breach. The breaching Party shall have, subject to Section 10.2.2(b), ​ days to cure such breach (​ days in the case of a Party’s breach of its payment obligations). Subject to Section 10.2.2(b), if the Party receiving notice of breach fails to cure such breach within the ​ day period or ​ day period (as applicable), the Party originally delivering the notice may terminate this Agreement upon written notice to the other Party.

Material Breach. Subject to [Section 3.2.3], either Party may terminate this Agreement for cause at any time during the Term by giving written notice to the other Party in the event that such other Party commits a material breach of its obligations under this Agreement and such material breach remains uncured for ninety (90) days from the date of such notice; provided, however, that if any breach is not reasonably curable within ninety (90) days and if the breaching Party is making a bona fide effort to cure such breach, such termination shall be delayed for a time period to be agreed by both Parties in order to permit the breaching Party a reasonable period of time to cure such breach.

CytomX Breach. Regeneron will have the right to terminate this Agreement in the event of any material breach by CytomX of any terms and conditions of this Agreement ​; provided, however, that Regeneron has ​; provided further, however, that such termination will not be effective if such breach has been cured within ​ days after written notice thereof is given by Regeneron to CytomX specifying the nature of the alleged breach; provided further, however, if such breach is not reasonably subject to cure within ​ days after receipt of written notice thereof, then CytomX shall continue to use good faith efforts to cure such breach and shall have provided to Regeneron a written plan intended to cure (and that CytomX reasonably believes will cure) such breach as soon as reasonably practicable thereafter. Notwithstanding the foregoing in this [Section 13.3.1], in the event of a good faith dispute as to whether a material breach by CytomX has occurred, the foregoing cure period with respect thereto will be tolled pending final resolution of such dispute in accordance with the terms of this Agreement; provided, however, if such dispute relates to payment, such tolling of the cure period will only apply with respect to payment of the disputed amounts, and not with respect to any undisputed amount.

Should any Party materially breach any provisions of this Agreement and fail to remedy such breach within thirty (30) Business Days after receiving written notice from the other Party requiring such remedy, then the Party aggrieved by such breach shall be entitled, without prejudice to their other rights in law including any right to claim damages, to cancel this Agreement or to claim immediate specific performance of all of the defaulting Party’s obligations the due for performance at the time of breach.

Purchaser hereby agrees to indemnify and defend the Seller and its officers, directors, stockholders, employees, agents, representatives, affiliates, successors and assigns (“Indemnified Parties”) and

Resales Under Rule [[Unknown Identifier]]. It will take reasonable steps to inform persons acquiring Securities from the Initial Purchasers in the United States that the Securities # have not been and will not be registered under the Securities Act, # are being sold to them without registration under the Securities Act in reliance on Rule [[Unknown Identifier]] and # may not be offered, sold or otherwise transferred except # to the Company, # outside the United States in accordance with Regulation S or # inside the United States in accordance with # Rule [[Unknown Identifier]] to a person whom the seller reasonably believes is a QIB that is purchasing such Securities for its own account or for the account of a QIB to whom notice is given that the offer, sale or transfer is being made in reliance on Rule [[Unknown Identifier]] or # pursuant to another available exemption from registration under the Securities Act.

Purchaser Demand Rights. On or after January 1, 2021 and prior to December 31, 2025, the BlackRock Purchaser (on behalf of itself and any other Holders) shall have the right to dispose of Registrable Securities under a Registration Statement pursuant to an Underwritten Offering if the BlackRock Purchaser reasonably expects (for itself and/or any other Holders) # gross proceeds of at least $100 million from such Underwritten Offering or # gross proceeds of at least $50 million from such Underwritten Offering and such Registrable Securities represent 100% of the then-outstanding Registrable Securities held by the BlackRock Purchaser and any applicable Selling Holder. The BlackRock Purchaser (on behalf of itself and any other Holders) shall exercise its demand registration right by delivering a written notice to the Partnership specifying that # it is exercising a demand registration right, # the name of each Selling Holder, and # the amount of Registrable Securities to be included in the Underwritten Offering. Promptly upon receipt of the written notice, the Partnership shall enter into an underwriting agreement in a form that is customary in Underwritten Offerings of securities by the Partnership with the Managing Underwriter or Underwriters selected by the Partnership, which shall include, among other provisions, indemnities to the effect and to the extent provided in Section 2.08, and shall take all such other reasonable actions as are requested by the Managing Underwriter or Underwriters in order to expedite or facilitate the disposition of such Registrable Securities; provided, however, the BlackRock Purchaser shall have the right (on behalf of itself and the other Holders) to exercise the demand registration rights set forth in this Section 2.03 not more than three times (and not more frequently than once in any twelve-month period), and only in the event that either the Partnership has not conducted an Underwritten Offering of Common Units in the preceding twelve-month period in which the BlackRock Purchaser (on behalf of itself or other Holders) was eligible to exercise piggyback registration rights pursuant to Section 2.02 or, if the Partnership has conducted such an Underwritten Offering, the BlackRock Purchaser (on behalf of itself or other Holders) has been reduced in the amount of Registerable Securities included in such offering pursuant to Section 2.02(b) by 25% or more of the Included Registrable Securities; provided, further, the aggregate amount of Registerable Securities that may be included in an Underwritten Offering pursuant to a demand registration right exercised pursuant to this Section 2.03 shall not exceed one-third of aggregate number of Registrable Securities outstanding as of the latest Closing Date (or such larger number of Registrable Securities to the extent consented to by the Partnership in its sole and absolute discretion); provided, further, that if the Partnership or any of their respective Affiliates # is conducting or actively pursuing a merger, acquisition or disposition transaction with a third party, # is conducting or actively pursuing a securities offering of the Partnership’s Common Units with anticipated gross offering proceeds of at least $100 million (other than in connection with any at-the-market offering or similar continuous offering program), or # is in possession of material nonpublic information affecting the Common Units that the Partnership has determined, in the best interests of the Partnership, should not be publicly disclosed at that time, then the Partnership may suspend the BlackRock Purchaser’s right to require the Partnership to conduct an Underwritten Offering on the BlackRock Purchaser’s and such Selling Holder’s behalf pursuant to this Section 2.03; provided, however, that the Partnership may only suspend such demand registration right to require the Partnership to conduct an Underwritten Offering pursuant to this Section 2.03 once in any six-month period and in no event for a period that exceeds an aggregate of 90 days in any 180-day period or 120 days in any 365-day period.