FIRST SUPPLEMENTAL INDENTURE, dated as of September 21, 2023 (this
Supplemental Indenture), between PARATEK PHARMACEUTICALS, INC., a Delaware corporation, as issuer (the Company), and U.S. Bank Trust Company, National Association (f/k/a U.S. Bank National Association), a
national banking association, as trustee (the Trustee), supplementing the Indenture, dated as of April 23, 2018, between the Company and the Trustee (the Base Indenture and the Base Indenture, as amended
and supplemented by this Supplemental Indenture, and as it may be further amended, supplemented or otherwise modified from time to time with respect to the Notes, the Indenture).
W I T N E S S E T H
WHEREAS,
the Company executed and delivered the Indenture to the Trustee, providing for the issuance of the Companys 4.75% Convertible Senior Subordinated Notes due 2024 (the Notes);
WHEREAS, the Company, Resistance Acquisition, Inc., a Delaware corporation (Parent), and Resistance Merger Sub, Inc., a
Delaware corporation and a wholly-owned subsidiary of Parent (Merger Sub), have entered into that certain Agreement and Plan of Merger, dated as of June 6, 2023 (as the same may be amended, supplemented or otherwise modified
from time to time, the Merger Agreement), pursuant to which, among other things, on the date of the execution of this Supplemental Indenture, Merger Sub will merge with and into the Company, with the Company continuing as the
surviving corporation and as a subsidiary of Parent (the Merger);
WHEREAS, in connection with the Merger, each share
of common stock, $0.001 par value per share, of the Company (the Common Stock), outstanding immediately prior to the effective time of the Merger (the Effective Time), subject to certain exceptions set forth in
the Merger Agreement, will be automatically converted into the right to receive (i) an amount in cash equal to $2.15, without interest but subject to any applicable tax withholdings, plus (ii) one contractual contingent value right (a
CVR) that will represent the right to receive a contingent payment of $0.85, without interest thereon, upon the achievement of a specified milestone, pursuant to the Merger Agreement and the Contingent Value Rights
Agreement, dated as of the date hereof, by and between Parent and Equiniti Trust Company, LLC (the Contingent Value Rights Agreement) being entered into in connection with the Merger Agreement;
WHEREAS, Article 11 of the Indenture permits the Company to merge with or into another Person, subject to the satisfaction of certain
conditions set forth therein, which conditions the Company has determined have been satisfied and, further, the Company has determined that the Merger constitutes a Merger Event, a Fundamental Change and a Make-Whole
Fundamental Change under and as defined in the Indenture;
WHEREAS, pursuant to the Merger Agreement, the Effective Time shall occur
on September 21, 2023;
WHEREAS, Section 14.07 of the Indenture provides that the Company and the Trustee shall execute a
supplemental indenture providing that, at and after the effective time of a Merger Event, the right to convert each $1,000 principal amount of Notes shall be changed into a right to convert such principal amount of Notes into the kind and amount of
shares of stock, other securities or other property or assets (including cash or any combination thereof) that a holder of a number of shares of Common Stock equal to the Conversion Rate immediately prior to such Merger Event would have owned or
been entitled to receive (the Reference Property, with each unit of Reference Property meaning the kind and amount of Reference Property that a holder of one share of Common Stock is entitled to receive) upon
such Merger Event;