Exhibit 4.2


 


REGISTRATION RIGHTS AGREEMENT


 


This Registration Rights Agreement (this
 “Agreement”) is made and entered into as of April [•], 2020, by and between Entasis Therapeutics Holdings
Inc., a Delaware corporation (the “Company”), and Innoviva, Inc. (the “Holder”). The Company
and the Holder are referred to each as a “Party” and collectively herein as the “Parties.”
Capitalized terms used herein and not otherwise defined herein shall have the respective meanings set forth in the Securities Purchase
Agreement.


 


In consideration of the mutual covenants
and agreements set forth herein and for good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged
by each Party, the Parties agree as follows:


 


1.                 
Definitions. As used in this Agreement, the following terms shall have the respective meanings set forth in this
Section 1:


 


“Affiliate” means, with
respect to any Person, any other Person, that directly or indirectly, Controls or is Controlled by or is under common Control with,
such Person; provided, however, that for purposes of this Agreement, the Holder shall not be deemed an Affiliate
of the Company or any of its Subsidiaries. “Affiliates” has a correlative meaning.


 


“Board” means the board
of directors of the Company.


 


“Business Day” means
any day that is not a Saturday, a Sunday or other day on which banks are required or authorized by law to remain closed for the
entirety of such day in New York, New York.


 


“Chosen Courts” has the
meaning set forth in Section 7(d).


 


“Close of Business” means
5:00 p.m. Eastern Time.


 


“Commission” means the
U.S. Securities and Exchange Commission or any other federal agency then administering the Securities Act or Exchange Act.


 


“Company Common Stock”
means the shares of common stock, par value $0.001 per share, of the Company.


 


“Company Indemnified Persons”
has the meaning set forth in Section 5(a).


 


“Control” means, with
respect to any Person, the possession, directly or indirectly, of the power to direct or cause the direction of the management
policies of such Person, whether through the ownership of voting securities, by contract or otherwise. “Controlled”
has a correlative meaning.


 


“Exchange Act” means
the Securities Exchange Act of 1934, as amended.


 


“FINRA” means the Financial
Industry Regulatory Authority.


 









     


     


    

 


“Form S-1 Shelf” has
the meaning set forth in Section 2(a).


 


“Form S-3 Shelf” has
the meaning set forth in Section 2(a).


 


“Holder” has the meaning
set forth in the preamble.


 


“Holder Indemnified Persons”
has the meaning set forth in Section 5(b).


 


“Indemnified Persons”
has the meaning set forth in Section 5(b).


 


“Losses” has the meaning
set forth in Section 5(a).


 


“Parties” has the meaning
set forth in the preamble.


 


“Person” means any individual,
partnership, corporation, company, association, trust, limited liability company, organization, entity or division, or any government,
governmental department or agency or political subdivision thereof.


 


“Proceeding” means any
action, claim, suit, proceeding or investigation (including a preliminary investigation or partial proceeding, such as a deposition)
pending or known to the Company to be threatened.


 


“Prospectus” means the
prospectus included in a Registration Statement (including a prospectus that includes any information previously omitted from a
prospectus filed as part of an effective Registration Statement in reliance upon Rule 430A), all amendments and supplements to
the Prospectus, including post-effective amendments, all material incorporated by reference or deemed to be incorporated by reference
in such Prospectus.


 


“Registrable
Securities” means (a) any Company Common Stock issued to the Holder pursuant to the Securities Purchase Agreement,
(b) any Company Common Stock issuable to the Holder upon exercise of warrants issued to the Holder pursuant to the Securities
Purchase Agreement, (c) any securities issued or issuable with respect to, on account of or in exchange for Company Common
Stock described in clauses (a) and (b), whether by stock split, stock dividend, recapitalization, merger, consolidation or
other reorganization, charter amendment or otherwise, (d) any warrants issued to the Holder pursuant to the Securities
Purchase Agreement and (e) any options, warrants or other rights to acquire, and any securities received as a dividend or
distribution in respect of, any of the securities described in clauses (a), (b), (c) and (d) above, in each case that are
held by the Holder and its Affiliates or any transferee or assignee of the Holder or its Affiliates, all of which securities
are subject to the rights provided herein until such rights terminate pursuant to the provisions of this Agreement. As to any
particular Registrable Securities, such securities shall not be Registrable Securities when (i) a Registration Statement
registering such Registrable Securities under the Securities Act has been declared effective and such Registrable Securities
have been sold, transferred or otherwise disposed of by the Holder thereof pursuant to such effective Registration Statement,
(ii) such Registrable Securities are sold, transferred or otherwise disposed of pursuant to Rule 144, (iii) such securities
cease to be outstanding or (iv) such securities have become eligible for sale by the Holder pursuant to Rule 144 without any
restriction on the volume or manner of such sale and all restrictive legends and stop transfer instructions have been removed
with respect to all book entries representing the applicable Registrable Securities.


 






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“Registration Expenses”
means all expenses incurred by the Company in complying with this Agreement, including, without limitation, all registration, qualification
and filing fees, printing expenses, escrow fees, fees and expenses of counsel for the Company and one counsel for the Holder, blue
sky fees and expenses and the expense of any special audits incident to or required by any such registration.


 


“Registration Statement”
means a registration statement of the Company filed with or to be filed with the Commission under the Securities Act that covers
the resale of any of the Registrable Securities pursuant to the provisions of this Agreement, and including any Prospectus, amendments
and supplements to each such registration statement or Prospectus, including pre- and post-effective amendments, all exhibits thereto,
and all material incorporated by reference or deemed to be incorporated by reference in such registration statement.


 


“Related Person” has
the meaning set forth in Section 7(m).


 


“Representatives” of
the Holder means its partners, shareholders, members, directors, officers, employees, agents, counsel, accountants, consultants,
investment advisers or other professionals or representatives, or its affiliates or wholly owned subsidiaries.


 


“Rule 144” means Rule
144 promulgated by the Commission pursuant to the Securities Act, or any similar rule or regulation hereafter adopted by the Commission
having substantially the same effect as such Rule.


 


“Rule 405” means Rule
405 promulgated by the Commission pursuant to the Securities Act, or any similar rule or regulation hereafter adopted by the Commission
having substantially the same effect as such Rule.


 


“Rule 415” means Rule
415 promulgated by the Commission pursuant to the Securities Act, or any similar rule or regulation hereafter adopted by the Commission
having substantially the same effect as such Rule.


 


“Rule 424” means Rule
424 promulgated by the Commission pursuant to the Securities Act, or any similar rule or regulation hereafter adopted by the Commission
having substantially the same effect as such Rule.


 


“Rule 430A” means Rule
430A promulgated by the Commission pursuant to the Securities Act, or any similar rule or regulation hereafter adopted by the Commission
having substantially the same effect as such Rule.


 


“Seasoned Issuer” means
an issuer eligible to use Form S-3 under the Securities Act and who is not an “ineligible issuer” as defined in Rule
405.


 


“Securities Act” means
the Securities Act of 1933, as amended.


 


“Selling Expenses” means
all underwriting fees, discounts, selling commissions and stock transfer taxes applicable to the sale of Registrable Securities
and related legal and other fees of the Holder not included within the definition of Registration Expenses.


 






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“Securities Purchase Agreement”
means that certain Securities Purchase Agreement, dated April 12, 2020, by and between the Company and the Holder, as may be amended,
restated, supplemented or otherwise modified from time to time.


 


“Shelf Period” has the
meaning set forth in Section 2(a).


 


“Shelf Registration”
means the registration of an offering of Registrable Securities on a Form S-1 Shelf or a Form S-3 Shelf, as applicable, on a delayed
or continuous basis under Rule 415, pursuant to Section 2(a).


 


“Shelf Registration Statement”
has the meaning set forth in Section 2(a).


 


“Subsidiary” means, when
used with respect to any Person, any corporation or other entity, whether incorporated or unincorporated, (a) of which such Person
or any other Subsidiary of such Person is a general partner (excluding partnerships, the general partnership interests of which
held by such Person or any Subsidiary of such Person do not have a majority of the voting interests in such partnership) or (b)
at least a majority of the securities or other interests of which having by their terms ordinary voting power to elect a majority
of the board of directors or others performing similar functions with respect to such corporation or other entity is directly or
indirectly owned or controlled by such Person or by any one or more of its Subsidiaries, or by such Person and one or more of its
Subsidiaries.


 


“Suspension Period” has
the meaning set forth in Section 2(b).


 


“Trading Market” means
the principal national securities exchange in the United States on which Registrable Securities are (or are to be) listed.


 


Unless the context requires otherwise:
(a) any pronoun used in this Agreement shall include the corresponding masculine, feminine or neuter forms; (b) references to
Sections, paragraphs and clauses refer to Sections, paragraphs and clauses of this Agreement; (c) the terms
 “include,” “includes,” “including” or words of like import shall be deemed to be followed
by the words “without limitation”; (d) the terms “hereof,” “herein” or
 “hereunder” refer to this Agreement as a whole and not to any particular provision of this Agreement; (e) unless
the context otherwise requires, the term “or” is not exclusive and shall have the inclusive meaning of
 “and/or”; (f) defined terms herein will apply equally to both the singular and plural forms and derivative forms
of defined terms will have correlative meanings; (g) references to any law or statute shall be deemed to refer to such law or
statute as amended or supplemented from time to time and shall include all rules and regulations and forms promulgated
thereunder, and references to any law, rule, form or statute shall be construed as including any legal and statutory
provisions, rules or forms consolidating, amending, succeeding or replacing the applicable law, rule, form or statute; (h)
references to any Person include such Person’s successors and permitted assigns; and (i) references to
 “days” are to calendar days unless otherwise indicated. Each of the Parties hereto acknowledges that each Party
was actively involved in the negotiation and drafting of this Agreement and that no law or rule of construction shall be
raised or used in which the provisions of this Agreement shall be construed in favor or against any Party hereto because one
is deemed to be the author thereof.


 






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2.                 
Registration.


 


(a)               Shelf
Registration. No later than thirty (30) days after the date hereof, the Company shall file a Registration Statement for a
Shelf Registration covering the resale of the Registrable Securities with the SEC for an offering to be made on a continuous
basis pursuant to Rule 415, or if Rule 415 is not available for offers and sales of the Registrable Securities, by such other
means of distribution of Registrable Securities as the Holder may reasonably specify (the “Initial Registration
Statement”). The Initial Registration Statement shall be on Form S-3 (or any successor to Form S-3) covering the
resale of all of the Registrable Securities held by the Holder (the “Form S-3 Shelf”), or if the Company
is not a Seasoned Issuer at the time of filing, the Company shall file a Registration Statement for a Shelf Registration on
Form S-1 (or any successor to Form S-1) (the “Form S-1 Shelf” and, together with the Form S-3 Shelf, the
 “Shelf Registration Statement”). Subject to the terms of this Agreement, including any applicable
Suspension Period, the Company shall cause the Shelf Registration Statement to be declared effective under the Securities Act
as promptly as possible after the filing thereof, but in any event (x) no later than the fifteenth (15th) day following the
filing of the Shelf Registration Statement in the event of no “review” by the Commission, (y) no later than the
sixtieth (60th) day following the filing of the Shelf Registration Statement in the event of “limited review” by
the Commission, or (z) in the event of a “full review” by the Commission, the one hundred and twentieth (120th)
day following the filing of the Shelf Registration Statement (the number of days in (x), (y) and (z) each being a
 “Review Period,” depending on the nature of the Commission’s review, and provided, for any
days during the period following the initial filing of the Shelf Registration Statement and prior to the effectiveness of the
Shelf Registration Statement that the Commission is unable to review or declare effective registration statements filed with
the Commission due to a shutdown or partial shutdown of the U.S. government (such days, “Tolled Days”),
the applicable number of days in such Review Period shall be extended by the number of Tolled Days), and shall use its
reasonable best efforts to keep such Shelf Registration Statement continuously effective under the Securities Act until the
date that all Registrable Securities covered by such Registration Statement are no longer Registrable Securities, including
(the period during which the Company shall use its reasonable best efforts to keep the Shelf Registration Statement
continuously effective under the Securities Act in accordance with this clause (i), the “Shelf Period”).
The Company shall notify the Holder by e-mail with electronic confirmation of the effectiveness of the Shelf Registration
Statement as promptly as practicable, and in any event within twenty-four (24) hours, after the Company telephonically or
otherwise confirms effectiveness with the Commission. The Company shall file a final Prospectus with the Commission to the
extent required by Rule 424. The “Plan of Distribution” section of such Shelf Registration Statement shall
provide for all permitted means of disposition of Registrable Securities, including firm-commitment underwritten public
offerings, agented transactions, sales directly into the market, purchases or sales by brokers and sales not involving a
public offering. Notwithstanding anything to the contrary contained herein, in the event the Commission informs the Company
that all of the Registrable Securities cannot, as a result of the application of Rule 415, be registered for resale as a
secondary offering on a single registration statement, the Company agrees to promptly (A) inform the Holder, (B) file
amendments to the Initial Registration Statement as required by the Commission and/or (C) withdraw the Initial Registration
Statement and file a new Registration Statement (a “New Registration Statement”), in either case covering
the maximum number of Registrable Securities permitted to be registered by the Commission, on Form S-3 or, if the Company is
ineligible to register for resale the Registrable Securities on Form S-3, such other form available to register for resale
the Registrable Securities as a secondary offering; provided, however, that prior to filing such amendment or
New Registration Statement, the Company shall be obligated to use its reasonable efforts to advocate with the Commission for
the registration of all of the Registrable Securities. In the event the Company amends the Initial Registration Statement or
files a New Registration Statement, as the case may be, under clauses (B) or (C) above, the Company will use its reasonable
efforts to file with the Commission, as promptly as allowed by the Commission, one or more Registration Statements on Form
S-3 or, if the Company is ineligible to register for resale the Registrable Securities on Form S-3, such other form available
to register for resale those Registrable Securities that were not registered for resale on the Initial Registration
Statement, as amended, or the New Registration Statement (the “Remainder Registration Statements”).


 






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(b)              
Suspension Period. Notwithstanding any other provision of this Section 2, the Company shall have the right,
but not the obligation, to defer the filing of (but not the preparation of), or suspend the use by the Holder of, any Registration
Statement for the shortest period possible, in no event to exceed thirty (30) days (i) upon issuance by the Commission of a stop
order suspending the effectiveness of such Registration Statement with respect to Registrable Securities or the initiation of proceedings
with respect to such Registration Statement under Section 9(d) or 8(e) of the Securities Act; or (ii) if the Company believes in
good faith that any such registration or offering would require the Company (after consultation with external legal counsel), under
applicable securities laws and other laws, to make disclosure of material nonpublic information that would not otherwise be required
to be disclosed at that time that would be materially adverse to the Company (any such period, a “Suspension Period”);
provided, that in no event shall the Company declare Suspension Periods lasting more than 60 days in the aggregate in any
twelve (12) month period. The Company shall (i) give prompt written notice to the Holder of its declaration of a Suspension Period
and of the expiration or termination of the relevant Suspension Period and (ii) promptly resume the process of filing or requesting
for effectiveness, or update the suspended Registration Statement, as the case may be, as may be necessary to permit the Holder
to offer and sell its Registrable Securities in accordance with applicable law.


 


(c)              
Required Information. The Company may require the Holder of Registrable Securities as to which any Registration Statement
is being filed or sale is being effected to furnish to the Company such information regarding the intended method of distribution
of such securities and such other information relating to the Holder and its ownership of Registrable Securities as the Company
may from time to time reasonably request in writing (provided that such information shall be used only in connection with
such registration). The Holder agrees to furnish such information to the Company and to cooperate with the Company as reasonably
necessary to enable the Company to comply with the provisions of this Agreement.


 


(d)              
Cessation of Registration Rights. All registration rights granted under this Section 2 shall continue to be
applicable with respect to the Holder until the Holder no longer holds any Registrable Securities.


 






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3.                 
Registration Procedures. The procedures to be followed by the Company and the Holder to register the sale of
Registrable Securities pursuant to a Registration Statement in accordance with this Agreement, and the respective rights and obligations
of the Company and the Holder with respect to the preparation, filing and effectiveness of such Registration Statement, are as
follows:


 


(a)              
The Company shall (i) prepare and file a Registration Statement with the Commission (within the time period specified in
Section 2(a)) which Registration Statement (A) shall be on a form required by this Agreement (or if not so required, selected
by the Company) for which the Company qualifies, (B) shall be available for the sale of the Registrable Securities in accordance
with the intended method or methods of distribution, and (C) shall comply as to form in all material respects with the requirements
of the applicable form and include and/or incorporate by reference all financial statements required by the Commission to be filed
therewith, (ii) use its reasonable best efforts to cause such Registration Statement to become effective and remain effective for
the period provided under Section 2(a), (iii) use its reasonable best efforts to prevent the occurrence of any event that
would cause a Registration Statement to contain a material misstatement or omission or to be not effective and usable for resale
of the Registrable Securities registered pursuant thereto (during the period that such Registration Statement is required to be
effective as provided under Section 2(a)), and (iv) cause each Registration Statement and the related Prospectus and any
amendment or supplement thereto, as of the effective date of such Registration Statement, amendment or supplement, (x) to comply
in all material respects with any requirements of the Securities Act and the rules and regulations of the Commission and (y) not
to contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary
to make the statements therein not misleading (provided, however, the Company shall have no liability for any information
furnished in writing by or on behalf of the Holder to the Company specifically for inclusion in (including by incorporation by
reference) any such Registration Statement that has not been corrected in a subsequent writing to the Company prior to the filing
or other disclosure of such information). The Company will, (1) at least three (3) Business Days prior to the anticipated filing
of a Registration Statement or any related Prospectus or any amendment or supplement thereto (including any documents incorporated
by reference therein), furnish to the Holder and its counsel copies of all such documents proposed to be filed and make such representatives
of the Company as shall be reasonably requested by the Holder available for discussion of such documents, (2) use its reasonable
best efforts to address in each such document prior to being so filed with the Commission such comments as the Holder or its counsel
reasonably shall propose within two (2) Business Days of receipt of such copies by the Holder and (3) not file any Registration
Statement or any related Prospectus or any amendment or supplement thereto containing information regarding the Holder to which
the Holder objects, unless such information is required to comply with any applicable law or regulation.


 


(b)               The
Company will as promptly as reasonably practicable (i) prepare and file with the Commission such amendments, including
post-effective amendments, and supplements to each Registration Statement and the Prospectus used in connection therewith as
(A) may be reasonably requested by the Holder of Registrable Securities covered by such Registration Statement necessary to
permit the Holder to sell in accordance with its intended method of distribution, including as may be required in connection
with any underwritten distribution of Registrable Securities or (B) may be necessary under applicable law to keep such
Registration Statement continuously effective with respect to the disposition of all Registrable Securities covered thereby
for the period provided under Section 2(a) in accordance with the intended method of distribution and, subject to the
limitations contained in this Agreement, prepare and file with the Commission such additional Registration Statements in
order to register for resale under the Securities Act all of the Registrable Securities held by the Holder, (ii) cause the
related Prospectus to be amended or supplemented by any required prospectus supplement, and as so supplemented or amended, to
be filed pursuant to Rule 424, (iii) respond to any comments received from the Commission with respect to each Registration
Statement or Prospectus or any amendment thereto, (iv) as promptly as reasonably practicable, provide the Holder true and
complete copies of all correspondence from and to the Commission relating to such Registration Statement or Prospectus other
than any comments that the Company determines in good faith would result in the disclosure to the Holder of material
non-public information concerning the Company that is not already in the possession of the Holder and (v) enter into such
customary agreements (including, as applicable, underwriting agreements in customary form) and take all such other actions as
the Holder the underwriters, if any, reasonably request in order to expedite or facilitate the disposition of Registrable
Securities under such Registration Statement or Prospectus and otherwise to facilitate, cooperate with and participate in
each proposed offering contemplated herein and customary selling efforts related thereto. The Company will comply in all
material respects with the provisions of the Securities Act and the Exchange Act (including Regulation M under the Exchange
Act) with respect to each Registration Statement and the disposition of all Registrable Securities covered by each
Registration Statement.


 






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(c)               The
Company will notify the Holder as promptly as practicable: (i)(A) when a Registration Statement, any pre-effective amendment,
any Prospectus or any prospectus supplement or post-effective amendment to a Registration Statement is proposed to be filed;
(B) when the Commission notifies the Company whether there will be a “review” of such Registration Statement and
whenever the Commission comments on such Registration Statement (in which case the Company shall provide true and complete
copies thereof and all written responses thereto to the Holder and its counsel, other than information which the Company
determines in good faith would constitute material non-public information that is not already in the possession of the
Holder); and (C) with respect to each Registration Statement or any post-effective amendment thereto, when the same has been
declared effective; (ii) of any request by the Commission or any other federal or state governmental or regulatory authority
for amendments or supplements to a Registration Statement or Prospectus or for additional information (whether before or
after the effective date of the Registration Statement) or any other correspondence with the Commission or any such authority
relating to, or which may affect, the Registration Statement; (iii) of the issuance by the Commission or any other
governmental or regulatory authority of any stop order, injunction or other order or requirement suspending the effectiveness
of a Registration Statement covering any or all of the Registrable Securities or preventing or suspending the use of any
Prospectus or the initiation or threatening of any Proceedings for such purpose; (iv) of the receipt by the Company of any
notification with respect to the suspension of the qualification or exemption from qualification of any of the Registrable
Securities for sale in any jurisdiction, or the initiation or threatening of any Proceeding for such purpose; or (v) of the
occurrence of any event that makes any statement made in such Registration Statement or Prospectus or any document
incorporated or deemed to be incorporated therein by reference untrue in any material respect or if, as a result of such
event or the passage of time, such Registration Statement, Prospectus or other documents requires revisions so that, in the
case of such Registration Statement or the Prospectus, as the case may be, it will 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
(in the case of the Prospectus, in light of the circumstances under which they were made) not misleading, or if, for any
other reason, it shall be necessary during such time period to amend or supplement such Registration Statement or Prospectus
in order to comply with the Securities Act, which shall correct such misstatement or omission or effect such compliance.


 


(d)              
The Company will use its reasonable best efforts to avoid the issuance of, or, if issued, obtain the withdrawal of (i) any
stop order or other order suspending the effectiveness of a Registration Statement, or preventing or suspending the use of any
Prospectus, or (ii) any suspension of the qualification (or exemption from qualification) of any of the Registrable Securities
for sale in any jurisdiction, as promptly as practicable, or if any such order or suspension is made effective during any Suspension
Period, as promptly as practicable after the Suspension Period is over.


 


(e)              
During the Shelf Period, upon request of the Holder and without charge, the Company shall furnish to the Holder and its
counsel, (i) promptly after the same is prepared and filed with the SEC, at least one copy of the Registration Statement and any
amendment(s) thereto, including all documents incorporated therein by reference and all exhibits to the extent requested by the
Holder or its counsel, (ii) upon the effectiveness of any amendment(s) to a Registration Statement, a copy of the prospectus included
in such Registration Statement and all amendments and supplements thereto (or such other number of copies as the Holder may reasonably
request) and (iii) such other documents, including copies of any preliminary or final prospectus, as the Holder may reasonably
request from time to time in order to facilitate the disposition of the Registrable Securities owned by the Holder.


 


(f)               
The Company will promptly deliver to the Holder and its counsel as many copies of each Prospectus or Prospectuses (including
each form of prospectus) and each amendment or supplement thereto as the Holder or its counsel may reasonably request in order
to facilitate the disposition of the Registrable Securities by the Holder. The Company hereby consents to the use of such Prospectus
and each amendment or supplement thereto by the Holder in connection with the offering and sale of the Registrable Securities covered
by such Prospectus and any amendment or supplement thereto, so long as the same are used in compliance with the Securities Act
and all other applicable laws and regulations.


 


(g)               To
the extent that the Company has certificated shares of Company Common Stock, the Company will cooperate with the Holder to
facilitate the timely preparation and delivery of certificates representing Registrable Securities to be delivered to a
transferee pursuant to a Registration Statement, which certificates shall be free of all restrictive legends indicating that
the Registrable Securities are unregistered or unqualified for resale under the Securities Act, Exchange Act or other
applicable securities laws, and to enable such Registrable Securities to be in such denominations and registered in such
names as the Holder may request in writing. In connection therewith, if required by the Company’s transfer agent, the
Company will promptly, after the effective date of the Registration Statement, cause an opinion of counsel as to the
effectiveness of the Registration Statement to be delivered to and maintained with such transfer agent, together with any
other authorizations, certificates and directions required by the transfer agent which authorize and direct the transfer
agent to issue such Registrable Securities without any such legend upon sale by the Holder of such Registrable Securities
pursuant to the Registration Statement.


 






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(h)              
Upon the occurrence of any event contemplated by Section 3(d)(v), as promptly as practicable, the Company will prepare
a supplement or amendment, including a post-effective amendment, if required by applicable law, to the affected Registration Statement
or a supplement to the related Prospectus or any document incorporated or deemed to be incorporated therein by reference, and file
any other required document so that, as thereafter delivered, no Registration Statement nor any Prospectus will contain an untrue
statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements
therein (in the case of a Prospectus, in light of the circumstances under which they were made) not misleading, such that the Holder
can resume disposition of such Registrable Securities covered by such Registration Statement or Prospectus.


 


(i)                
The Company will comply with all applicable rules and regulations of the Commission, the Trading Market and FINRA.


 


(j)                
The Holder agrees by its acquisition of Registrable Securities that, upon receipt of a notice from the Company of the occurrence
of any event of the kind described in clauses (ii) through (v) of Section 3(d) or the occurrence of a Suspension Period,
the Holder will forthwith discontinue disposition of such Registrable Securities under the applicable Registration Statement until
the Holder’s receipt of the copies of the supplemental Prospectus or amended Registration Statement or until it is advised
in writing by the Company that the use of the applicable Prospectus may be resumed, and, in either case, has received copies of
any additional or supplemental filings that are incorporated or deemed to be incorporated by reference in such Prospectus or Registration
Statement. In the event the Company shall give any such notice, the period during which the applicable Registration Statement is
required to be maintained effective shall be extended by the number of days during the period from and including the date of the
giving of such notice to and including the date when the Holder either receives the copies of the supplemented Prospectus or amended
Registration Statement or is advised in writing by the Company that the use of the Prospectus may be resumed.


 


(k)              
If such Registrable Securities are to be sold by any method or in any transaction other than on a national securities exchange
or in the over-the-counter market, in privately negotiated transactions, or in a combination of such methods, the Holder shall
notify the Company at least five (5) Business Days prior to the date on which the Holder first offers to sell any such Registrable
Securities.


 


4.                 
Registration Expenses. All Registration Expenses incurred in connection with any registration, qualification,
exemption or compliance pursuant to Section 2.1(a) hereof shall be borne by the Company.








 






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5.                 
Indemnification.


 


(a)               To
the fullest extent permitted by law, the Company shall indemnify and hold harmless the Holder, its partners, stockholders,
equity holders, general partners, managers, members and Affiliates and each of their respective officers and directors and
any Person who controls the Holder (within the meaning of the Securities Act or the Exchange Act) and any employee or
Representative thereof (each, a “Company Indemnified Person” and collectively, “Company
Indemnified Persons”), from and against any and all losses, claims, damages, liabilities, joint or several, costs
(including reasonable costs of preparation and reasonable attorneys’, accountants’ and experts’ fees) and
expenses, judgments, fines, penalties, interest, settlements or other amounts arising from any claims, demands, actions,
suits or proceedings, whether civil, criminal, administrative or investigative, in which any Company Indemnified Person may
be involved, or is threatened to be involved, as a party or otherwise, under the Securities Act, the Exchange Act or
otherwise (collectively, “Losses”), as incurred, arising out of, based upon, resulting from or relating to
(i) any untrue or alleged untrue statement of a material fact contained in any Registration Statement under which any
Registrable Securities were registered, Prospectus (including in any preliminary prospectus (if used prior to the effective
date of such Registration Statement)), or in any summary or final prospectus or in any amendment or supplement thereto or in
any documents incorporated or deemed incorporated by reference in any of the foregoing or (ii) any omission or alleged
omission to state therein a material fact required to be stated therein or necessary to make the statements made therein (in
the case of the Prospectus, in light of the circumstances under which they were made) not misleading, or (iii) any violation
or alleged violation by the Company or any of its Subsidiaries of the Securities Act, the Exchange Act, any state securities
law or any rule or regulation promulgated under the Securities Act, the Exchange Act or any federal, state, foreign or common
law rule or regulation in connection with such Registration Statement, disclosure document or related document or report or
any offering covered by such Registration Statement, and the Company shall reimburse such Company Indemnified Person for any
reasonable legal or other expenses reasonably incurred by it in connection with investigating or defending any such Loss,
claim, damage, liability, demand, action, suit or proceeding (the matters in the foregoing clauses (i) through (iii) being,
collectively, “Company Violations”). Notwithstanding anything to the contrary contained herein, the
indemnification agreement contained in this Section 5(a): (A) shall not apply to a Loss by a Company Indemnified Person
arising out of or based upon a Company Violation which occurs in reliance upon and in conformity with information furnished
in writing to the Company by the Holder or such Company Indemnified Person expressly for use in connection with the
preparation of such Registration Statement, such preliminary, summary or final prospectus or such amendment or supplement, or
other disclosure document; (B) with respect to any superseded prospectus, shall not inure to the benefit of any such person
from whom the person asserting any such Loss purchased the Registrable Securities that are the subject thereof (or to the
benefit of any other Company Indemnified Person) if the untrue statement or omission of material fact contained in the
superseded prospectus was corrected in the revised prospectus, as then amended or supplemented, if such revised prospectus
was timely made available by the Company pursuant to Section 3(f), and the Company Indemnified Person was promptly advised in
writing not to use the incorrect prospectus prior to the use giving rise to a violation; (C) shall not be available to the
extent such Loss is based on a failure of the Holder to deliver, or to cause to be delivered, the prospectus made available
by the Company, if such prospectus was theretofore made available by the Company pursuant to Section 3(f); and (D) shall not
apply to amounts paid in settlement of any Loss if such settlement is effected without the prior written consent of the
Company, which consent shall not be unreasonably withheld, conditioned or delayed.


 






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(b)              
In connection with any Registration Statement filed by the Company pursuant to Section 2(a) hereof in which the Holder
has registered for sale its Registrable Securities, the Holder agrees to indemnify and hold harmless, to the fullest extent permitted
by law, the Company, its directors and officers, employees, agents and each Person who controls the Company (within the meaning
of the Securities Act or the Exchange Act) (collectively, “Holder Indemnified Persons,” and together with the
Company Indemnified Persons, each an “Indemnified Person,” and collectively, the “Indemnified Persons”)
from and against any Losses resulting from (i) any untrue or alleged untrue statement of a material fact contained in any Registration
Statement under which such Registrable Securities were registered or sold under the Securities Act, Prospectus (including in any
preliminary prospectus (if used prior to the effective date of such Registration Statement)), or in any summary or final prospectus
or in any amendment or supplement thereto or in any documents incorporated by reference in any of the foregoing, (ii) any omission
or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein
(in the case of the Prospectus, in light of the circumstances under which they were made) not misleading, or (iii) any violation
or alleged violation by the Holder of any federal, state or common law rule or regulation relating to action or inaction in connection
with any information provided by the Holder in such registration, disclosure document or related document or report in the case
of clauses (i) and (ii) to the extent, but only to the extent, that such untrue statement or omission occurs in reliance upon and
in conformity with any information furnished in writing by or on behalf of the Holder specifically for inclusion in such registration,
disclosure document or related document or report and has not been corrected in a subsequent writing prior to the sale of the Registrable
Securities thereunder, and the Holder will reimburse the Company for any legal or other expenses reasonably incurred by it in connection
with investigating or defending such Losses. In no event shall the liability of the Holder hereunder be greater in amount than
the dollar amount of the net proceeds (after deducting the underwriters’ discounts and commissions) received by the Holder
under the sale of Registrable Securities giving rise to such indemnification obligation.


 


(c)               Any
Indemnified Person under paragraph (a) or (b) of this Section 5 shall (i) give prompt written notice to the
indemnifying person under paragraph (a) or (b) of this Section 5 of any claim with respect to which it seeks
indemnification (provided that any delay or failure to so notify the indemnifying person shall not relieve the
indemnifying party of its obligations hereunder except to the extent, if at all, that the indemnifying person’s ability
to defend such claim (through the forfeiture of substantive rights or defenses) is actually and materially prejudiced by
reason of such delay or failure) and (ii) permit such indemnifying person to assume the defense of such claim with counsel
reasonably satisfactory to the Indemnified Person; provided, however, that any Indemnified Person shall have
the right to select and employ separate counsel and to participate in the defense of such claim, but the fees and expenses of
such counsel shall be at the expense of such Indemnified Person unless (A) the indemnifying person has agreed in writing to
pay such fees or expenses, (B) the Indemnified Person has reasonably concluded (based upon advice of its counsel) that there
may be legal defenses available to it or other Indemnified Persons that are different from or in addition to those available
to the indemnifying person, or (C) in the reasonable judgment of any such Indemnified Person (based upon advice of its
counsel) a conflict of interest may exist between such Indemnified Person and the indemnifying person with respect to such
claims (in which case, if the Indemnified Person notifies the indemnifying person in writing that such Indemnified Person
elects to employ separate counsel at the expense of the indemnifying person, the indemnifying person shall not have the right
to assume the defense of such claim on behalf of such Indemnified Person). If any action is settled or if there be a final
judgment for the plaintiff, the indemnifying person agrees to indemnify each Indemnified Person from and against any Losses
by reason of such settlement or judgment. No action may be settled without the written consent of the Indemnified Person, provided
that the consent of the Indemnified Person shall not be required if (x) such settlement includes an unconditional release of
such Indemnified Person in form and substance satisfactory to such Indemnified Person from all liability on the claims that
are the subject matter of such settlement; (y) such settlement provides solely for the payment by the indemnifying person of
money as the sole relief for such action and (z) such settlement does not include any statement as to or any admission of
fault, culpability or a failure to act by or on behalf of any Indemnified Person. It is understood that the indemnifying
person or persons shall not, except as specifically set forth in this Section 5(c), in connection with any proceeding
or related proceedings in the same jurisdiction, be liable for the reasonable fees, disbursements or other charges of more
than one separate firm (in addition to any local counsel that is required to effectively defend against any such proceeding)
for all Indemnified Persons and that all such fees and expenses shall be paid or reimbursed promptly.


 






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(d)              
If the indemnification provided for in this Section 5 is held by a court of a competent jurisdiction to be unavailable
to an Indemnified Person with respect to any loss, damage, claim or liability, the indemnifying party, in lieu of indemnifying
such Indemnified Person thereunder, shall to the extent permitted by law, contribute to the amount paid or payable by such Indemnified
Person as a result of such loss, damage, claim or liability in such proportion as is appropriate to reflect the relative fault
of the indemnifying party on the one hand and of the Indemnified Person on the other in connection with the actions that resulted
in such loss, claim, damage or liability, as well as any other relevant equitable considerations. The relative fault of the indemnifying
person and of the Indemnified Person shall be determined by a court of law by reference to, among other things, whether the untrue
or alleged untrue statement of a material fact or the omission to state a material fact relates to information supplied by the
indemnifying person or Indemnified Person and the parties’ relative intent, knowledge, access to information and opportunity
to correct or prevent such statement or omission. The Parties agree that it would not be just and equitable if contribution pursuant
to this Section 5(d) were determined by pro rata allocation or by any other method of allocation that does not take account
of the equitable considerations referred to in the immediately preceding sentences. Notwithstanding the provisions of this Section
5(d), the Holder shall not be required to contribute any amount in excess of the net proceeds (after deducting the underwriters’
discounts and commissions) received by the Holder under the sale of Registrable Securities giving rise to such indemnification
obligation. 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.


 


(e)              
The remedies provided for in this Section 5 are not exclusive and shall not limit any rights or remedies which may
otherwise be available to any Indemnified Person at law or in equity. The obligations of the Company and the Holder under this
Section 5 shall survive completion of any offering of Registrable Securities pursuant to a Registration Statement and the
termination of this Agreement.


 


6.                  Facilitation
of Sales Pursuant to Rule 144. The Company shall timely file the reports required to be filed by it under the
Exchange Act or the Securities Act and the rules adopted by the Commission thereunder (including the reports under Sections
13 and 15(d) of the Exchange Act referred to in subparagraph (c)(1) of Rule 144), all to the extent required from time to
time to enable the Holder to sell Registrable Securities without registration under the Securities Act within the limitations
of the exemption provided by Rule 144. Upon the written request of the Holder in connection with that Holder’s sale
pursuant to Rule 144, the Company shall deliver to the Holder a written statement as to whether it has complied with such
requirements.


 


7.                 
Registration Rights Covenant. The Company covenants that it will not, and it will cause its Subsidiaries not
to, grant any right of registration under the Securities Act to any Person other than pursuant to this Agreement, unless the rights
so granted to another Person do not limit or restrict the rights of the Holder hereunder.


 






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8.                 
Miscellaneous.


 


(a)              
Remedies. In the event of a breach by the Company or the Holder of any of its obligations under this Agreement, any
Party, in addition to being entitled to exercise all rights granted by law and under this Agreement, including recovery of damages,
will be entitled to specific performance of its rights under this Agreement. The Parties agree that monetary damages would not
provide adequate compensation for any losses incurred by reason of a breach by the Company of any of the provisions of this Agreement
and further agree that, in the event of any action for specific performance in respect of such breach, the Company shall waive
the defense that a remedy at law would be adequate and shall waive any requirement for the posting of a bond. No failure or delay
by any Person in exercising any right, power or privilege hereunder shall operate as a waiver thereof nor shall any single or partial
exercise thereof preclude any other or further exercise thereof or the exercise of any other right, power or privilege. The rights
and remedies herein provided shall be cumulative and not exclusive of any rights or remedies provided by law.


 


(b)              
Amendment; Modification; Waivers. This Agreement may be amended or waived if, and only if, such amendment or waiver
is in writing and signed by the Company and the Holder, which writing shall specifically reference this Agreement, specify the
provision(s) hereof that it is intended to amend or waive and further specify that it is intended to amend or waive such provision(s).


 


(c)         
Notices. All notices and other communications in connection
with this Agreement shall be in writing and shall be deemed given if delivered personally, sent via electronic mail (with confirmation),
mailed by registered or certified mail (return receipt requested) or delivered by an express courier (with confirmation) to the
Parties at the following addresses (or at such other address for a Party as may be specified by like notice):


 


If to the Company:


 


Entasis Therapeutics Holdings Inc.


35 Gatehouse Drive


Waltham, MA 02451





Attn: Elizabeth Keiley


Tel: (781) 870-0120


Email: betzy.keiley@entasistx.com


 






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with a copy (which shall not constitute
notice) to:


 


Covington & Burling LLP


The New York Times Building


620 Eighth Avenue


New York, NY 10018


Attn: Jack S. Bodner


Tel: (212) 841-1079


Fax:(646) 441-9079


Email: jbodner@cov.com


 


If to the Holder:


 


Innoviva, Inc.


1350 Old Bayshore Highway Suite 400

Burlingame, CA 94010

Attention: Chief Executive Officer

Email: Geoffrey.hulme@inva.com


 


with a copy (which shall not constitute notice) to:




Willkie Farr & Gallagher LLP


787 Seventh Avenue


New York, New York 10019


Attn: Russell Leaf


         Jared Fertman


Tel: (212) 728-8593


       (212) 728-8670


Email: rleaf@willkie.com


           jfertman@willkie.com


 


(d)              
Governing Law; Jurisdiction; Waiver of Jury Trial. This Agreement shall be governed by, and construed in accordance
with, the laws of the State of Delaware, regardless of the laws that might otherwise govern under applicable principles of conflicts
of laws. In any action or proceeding between any of the parties arising out of or relating to this Agreement, each of the parties:
(a) irrevocably and unconditionally consents and submits to the exclusive jurisdiction and venue of the Delaware Chancery Court
or, to the extent such court does not have subject matter jurisdiction, the United States District Court sitting in the State of
Delaware; (b) agrees that all claims in respect of such action or proceeding shall be heard and determined exclusively in accordance
with clause (a) of this Section 7(d); (c) waives any objection to laying venue in any such action or proceeding in such
courts; (d) waives any objection that such courts are an inconvenient forum or do not have jurisdiction over any party hereto;
and (e) irrevocably and unconditionally waives the right to trial by jury.


 









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(e)              
Successors and Assigns. This Agreement shall be binding upon and inure to the benefit of the Parties hereto and their
respective heirs, executors, administrators, successors, legal representatives and permitted assigns. The Holder may not assign
its rights under this Agreement without the prior written consent of the Company


 


(f)               
Waiver of Venue. The Parties irrevocably and unconditionally waive, to the fullest extent permitted by applicable
law, (i) any objection that they may now or hereafter have to the laying of venue of any action or proceeding arising out of or
relating to this Agreement in any court referred to in Section 7(d) and (ii) the defense of an inconvenient forum to the
maintenance of such action or proceeding in any such court.


 


(g)              
Waiver of Trial by Jury. EACH PARTY ACKNOWLEDGES AND AGREES THAT ANY CONTROVERSY WHICH MAY ARISE UNDER THIS AGREEMENT
IS LIKELY TO INVOLVE COMPLICATED AND DIFFICULT ISSUES, AND THEREFORE EACH SUCH PERSON HEREBY IRREVOCABLY AND UNCONDITIONALLY WAIVES
ANY RIGHT SUCH PERSON MAY HAVE TO A TRIAL BY JURY WITH RESPECT TO ANY LITIGATION DIRECTLY OR INDIRECTLY ARISING OUT OF OR RELATING
TO THIS AGREEMENT. EACH PARTY CERTIFIES AND ACKNOWLEDGES THAT (i) NO REPRESENTATIVE, AGENT OR ATTORNEY OF THE OTHER PERSON HAS
REPRESENTED, EXPRESSLY OR OTHERWISE, THAT SUCH OTHER PERSON WOULD NOT, IN THE EVENT OF LITIGATION, SEEK TO ENFORCE THE FOREGOING
WAIVER, (ii) SUCH PERSON UNDERSTANDS AND HAS CONSIDERED THE IMPLICATIONS OF THIS WAIVER, (iii) SUCH PERSON MAKES THIS WAIVER VOLUNTARILY,
AND (iv) SUCH PERSON HAS BEEN INDUCED TO ENTER INTO THIS AGREEMENT AND EACH ANCILLARY AGREEMENT BY, AMONG OTHER THINGS, THE MUTUAL
WAIVERS AND CERTIFICATIONS IN THIS SECTION.


 


(h)              
Severability. The provisions of this Agreement shall be deemed severable and the invalidity or unenforceability of
any provision hereof shall not affect the validity or enforceability of any other provision. Whenever possible, each provision
or portion of any provision of this Agreement shall be interpreted in such manner as to be effective and valid under applicable
law, but if any provision of this Agreement, or the application thereof to any Person or any circumstance, is invalid or unenforceable,
(i) a suitable and equitable provision shall be substituted therefor to carry out, so far as may be valid and enforceable, the
intent and purpose of such invalid or unenforceable provision and (ii) the remainder of this Agreement and the application of such
provision to other Persons or circumstances shall not be affected by such invalidity or unenforceability, nor shall such invalidity
or unenforceability affect the validity or enforceability of such provision, or the application thereof, in any other jurisdiction;
provided, that, if any one or more of the provisions contained in this Agreement shall be determined to be excessively broad
as to activity, subject, duration or geographic scope, it shall be reformed by limiting and reducing it to the minimum extent necessary,
so as to be enforceable under applicable law.


 


(i)                
Business Days. If the last or appointed day for the taking of any action or the expiration of any right required
or granted herein shall be a day other than a Business Day, then such action may be taken or such right may be exercised on the
next succeeding Business Day.


 









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(j)                
Entire Agreement. This Agreement constitutes the entire agreement among the Parties with respect to the subject matter
hereof and supersedes all prior contracts or agreements with respect to the subject matter hereof and supersedes any and all prior
or contemporaneous discussions, agreements and understandings, whether oral or written, that may have been made or entered into
by or among any of the Parties or any of their respective Affiliates relating to the transactions contemplated hereby.


 


(k)              
Execution of Agreement. This Agreement may be executed and delivered (by facsimile, by electronic mail in Adobe Portable
Document Format (.pdf) or otherwise) in any number of counterparts, each of which, when executed and delivered, shall be deemed
an original, and all of which together shall constitute the same agreement.


 


(l)                
Determination of Ownership. In determining ownership of Company Common Stock hereunder for any purpose, the Company
may rely solely on the records of the transfer agent for the Company Common Stock from time to time, or, if no such transfer agent
exists, the Company’s stock ledger.


 


(m)            
No Recourse. Notwithstanding anything that may be expressed or implied in this Agreement, each Party covenants, agrees
and acknowledges that no recourse under this Agreement or any documents or instruments delivered in connection with this Agreement
shall be had against any of the Company’s or the Holder’s former, current or future direct or indirect equity holders,
controlling persons, stockholders, directors, officers, employees, agents, Affiliates, members, financing sources, managers, general
or limited partners or assignees (each, a “Related Person” and collectively, the “Related Persons”),
in each case other than the Company, the Holder or any of their respective permitted assigns under this Agreement, whether by the
enforcement of any assessment or by any legal or equitable proceeding, or by virtue of any applicable law, it being expressly agreed
and acknowledged that no personal liability whatsoever shall attach to, be imposed on or otherwise be incurred by any of the Related
Persons, as such, for any obligation or liability of the Company or the Holder under this Agreement or any documents or instruments
delivered in connection herewith for any claim based on, in respect of or by reason of such obligations or liabilities or their
creation; provided, however, nothing in this Section 7(m) shall relieve or otherwise limit the liability of
the Company or the Holder, as such, for any breach or violation of its obligations under this Agreement or such agreements, documents
or instruments. For the avoidance of doubt, none of the Parties will have any recourse, be entitled to commence any proceeding
or make any claim under this Agreement or in connection with the transactions contemplated hereby except against any of the Parties
or their respective successors and permitted assigns, as applicable.


 


(n)              
Third-Party Beneficiaries. Nothing in this Agreement, express or implied, is intended to confer upon any Person other
than a Party and its successors and permitted assigns any rights, benefits or remedies of any nature whatsoever.


 


(o)              
Headings; Section References; Signatories. All heading references contained in this Agreement are for convenience
purposes only and shall not be deemed to limit or affect any of the provisions of this Agreement.


 


[Signature Pages Follow]





 






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IN WITNESS WHEREOF, the undersigned Parties
have executed this Agreement as of the date first written above.


 


	 	ENTASIS THERAPEUTICS HOLDINGS INC.
	 	 
	 	 
	 	By:	 
	 	Name:   	Michael Gutch, Ph.D.
	 	Title: 	Chief Financial and Business Officer


 


	 	INNOVIVA, INC.
	 	 
	 	 
	 	By:	 
	 	Name:    	Geoffrey Hulme
	 	Title: 	Interim Principal Executive Officer


 





[Signature Page to Registration Rights
Agreement]