Exhibit (a)(1)(B)

LETTER OF TRANSMITTAL

To Tender Shares of Common Stock

Entasis Therapeutics Holdings Inc.

Pursuant to the Offer to Purchase

dated June 7, 2022

Innoviva Merger Sub, Inc.

A Wholly-Owned Subsidiary of

Innoviva, Inc.

THE OFFER AND WITHDRAWAL RIGHTS EXPIRE AT 5:00 P.M., NEW YORK CITY TIME, ON

JULY 7, 2022, UNLESS THE OFFER IS EXTENDED.

The undersigned represents that I (we) have full authority to surrender without restriction the certificate(s) for exchange. You are hereby authorized and instructed to prepare in the name of and deliver to the address indicated below (unless otherwise instructed in the boxes on the following page) a check representing a cash payment for shares tendered pursuant to this Letter of Transmittal. Such cash payment shall equal $2.20 per share of common

stock tendered.

Total Shares

Need not be completed by stockholders tendering by book-entry transfer.

Unless otherwise indicated, it will be assumed that all Shares described above are being tendered. See Instruction 4.

Mail or deliver this Letter of Transmittal, together with the certificate(s) representing your shares, to the Depositary

for this Offer:

By Mail:			By Overnight Courier:
Computershare c/o Voluntary Corporate Actions P.O. Box 43011 Providence, RI 02940-3011			Computershare Trust Company, N.A. c/o Voluntary Corporate Actions 150 Royall Street, Suite V Canton, MA 02021

ALL QUESTIONS REGARDING THE OFFER SHOULD BE DIRECTED TO THE INFORMATION AGENT, D.F. KING & CO., AT ITS ADDRESS AND TELEPHONE NUMBERS AS SET FORTH ON THE BACK COVER PAGE OF THE OFFER TO PURCHASE.

DELIVERY OF THIS LETTER OF TRANSMITTAL TO AN ADDRESS OTHER THAN AS SET FORTH ABOVE FOR THE DEPOSITARY WILL NOT CONSTITUTE A VALID DELIVERY.

THIS LETTER OF TRANSMITTAL AND THE INSTRUCTIONS ACCOMPANYING THIS LETTER OF TRANSMITTAL SHOULD BE READ CAREFULLY BEFORE THIS LETTER OF TRANSMITTAL IS COMPLETED.

This Letter of Transmittal is to be used if certificates are to be forwarded herewith or, unless an Agent’s Message (as defined herein) is utilized, if delivery of any outstanding shares of common stock, par value $0.001 per share (the “Shares”) of Entasis Therapeutics Holdings Inc. is to be made by book-entry transfer to the Depositary’s account at The Depository Trust Company, pursuant to the procedures set forth in Section 3 of the offer to purchase, dated June 7, 2022.

NOTE: SIGNATURES MUST BE PROVIDED BELOW

PLEASE READ ACCOMPANYING INSTRUCTIONS CAREFULLY

☐	CHECK HERE IF TENDERED SHARES ARE BEING DELIVERED BY BOOK-ENTRY TRANSFER TO THE DEPOSITARY’S ACCOUNT AT THE BOOK-ENTRY TRANSFER FACILITY AND COMPLETE THE FOLLOWING:

Name of Tendering Institution

Account Number

Transaction Code Number

Additional Information if Shares Have Been Lost

If certificates for Shares you are tendering with this Letter of Transmittal have been lost, stolen, destroyed or mutilated, you should contact Computershare Trust Company, N.A., in its capacity as transfer agent (the “Transfer Agent”), toll-free at (800) 546-5141 or at (781) 575-2765 regarding the requirements for replacement. You may be required to post a bond to secure against the risk that the certificates may be subsequently recirculated. You are urged to contact the Transfer Agent immediately in order to receive further instructions for a determination of whether you will need to post a bond and to permit timely processing of this documentation. See Instruction 9.

Ladies and Gentlemen:

The undersigned hereby tenders to Innoviva Merger Sub, Inc. (“Purchaser”), a Delaware corporation and a wholly-owned subsidiary of Innoviva, Inc., a Delaware corporation (“Parent”), the above-described shares of common stock, par value $0.001 per share (the “Shares”), of Entasis Therapeutics Holdings Inc., a Delaware corporation (“Entasis”), pursuant to Purchaser’s offer to purchase all outstanding Shares at a price of $2.20 per Share, net to the seller in cash, without interest thereon and less any applicable withholding taxes, upon the terms and subject to the conditions set forth in (i) the offer to purchase dated June 7, 2022 (as it may be subsequently amended or supplemented from time to time, the “Offer to Purchase”), receipt of which is hereby acknowledged, and in (ii) this letter of transmittal (the “Letter of Transmittal” which, together with the Offer to Purchase, and any other related materials, as each may be amended or supplemented from time to time, collectively constitute the “Offer”). The Offer expires at 5:00 p.m., New York City time, on July 7, 2022, unless extended as described in the Offer to Purchase (such date and time, as it may be extended in accordance with the terms of the Merger Agreement (as defined herein), the “Expiration Date”). Purchaser reserves the right to transfer or assign, in whole or in part, to one or more of its affiliates the right to purchase Shares tendered pursuant to the Offer, but any such transfer or assignment will not relieve Purchaser of its obligations under the Offer or prejudice your rights to receive payment for Shares validly tendered and accepted for payment. The Offer is being made pursuant to the Agreement and Plan of Merger, dated as of May 23, 2022 (as it may be amended or supplemented from time to time in accordance with its terms, the “Merger Agreement”), by and among Parent, Purchaser and Entasis. The Merger Agreement provides, among other things, that as promptly as practicable following the acceptance for payment of Shares pursuant to and subject to the conditions to the Offer, and subject to the satisfaction or waiver of conditions set forth in the Merger Agreement, Purchaser will be merged with and into Entasis (the “Merger”), with Entasis continuing as the surviving corporation in the Merger and a wholly-owned subsidiary of Parent.

Upon the terms and subject to the conditions of the Offer and effective upon acceptance for payment of the Shares tendered herewith, the undersigned hereby sells, assigns and transfers to, or upon the order of, the Purchaser all right, title and interest in and to all the Shares that are being tendered hereby (and any and all other Shares or other securities or rights issued or issuable in respect thereof on or after the commencement of the Offer and appoints Computershare Trust Company, N.A. (the “Depositary”) the true and lawful agent and attorney-in-fact of the undersigned with respect to such Shares (and all such other Shares or securities), with full power of substitution (such power of attorney being deemed to be an irrevocable power coupled with an interest), to (i) deliver certificates for such Shares (and all such other Shares or securities), or transfer ownership of such Shares (and all such other Shares or securities) on the account books maintained by The Depository Trust Company (the “DTC”), together, in any such case, with all accompanying evidences of transfer and authenticity, to or upon the order of the Purchaser, (ii) present such Shares (and all such other Shares or securities) for transfer on the books of Entasis, and (iii) receive all benefits and otherwise exercise all rights of beneficial ownership of such Shares (and all such other Shares or securities), all in accordance with the terms of the Offer.

The undersigned hereby irrevocably appoints Purchaser and its officers, and each of them, and any other designees of the Purchaser, the attorneys and proxies of the undersigned, each with full power of substitution, to exercise all voting and other rights of the undersigned in such manner as each such attorney and proxy or its, his or her substitute shall in its, his or her sole discretion deem proper, with respect to all of the Shares tendered hereby which have been accepted for payment by Purchaser prior to the time of any vote or other action (and any and all other Shares or other securities or rights issued or issuable in respect thereof on or after the commencement of the Offer, at any meeting of stockholders of Entasis (whether annual or special and whether or not an adjourned meeting), or otherwise. This proxy is irrevocable and is granted in consideration of, and is effective upon, the acceptance for payment of such Shares by Purchaser in accordance with the terms of the Offer. Such acceptance for payment shall revoke any other proxy granted by the undersigned at any time with respect to such Shares (and all such other Shares or securities), and no subsequent proxies will be given by the undersigned (and if given, will not be deemed to be effective). This proxy will be governed by and construed in accordance with the laws of the State of Delaware and applicable federal securities laws.

The undersigned hereby represents and warrants that the undersigned has full power and authority to tender, sell, assign and transfer the Shares tendered herein (and any and all other Shares or other securities or rights

issued or issuable in respect thereof on or after the commencement of the Offer and that when the same are accepted for payment by Purchaser, Purchaser will acquire good and unencumbered title thereto, free and clear of all liens, restrictions, charges and encumbrances and not subject to any adverse claims.

The undersigned will, upon request, execute and deliver any additional documents deemed by the Depositary or Purchaser to be necessary or desirable to complete the sale, assignment and transfer of the Shares tendered hereby (and all such other Shares or securities).

All authority herein conferred or agreed to be conferred shall survive the death or incapacity of the undersigned, and any obligation of the undersigned hereunder shall be binding upon the heirs, personal representatives, successors and assigns of the undersigned. Except as stated in the Offer, this tender is irrevocable.

The undersigned understands that tenders of Shares pursuant to any one of the procedures described in Section 3 of the Offer to Purchase and in the instructions hereto will constitute an agreement between the undersigned and Purchaser upon the terms and subject to the conditions of the Offer.

Unless otherwise indicated under “Special Payment Instructions,” please issue the check for the purchase price of any Shares purchased, and return any Shares not tendered or not purchased, in the name(s) of the undersigned (and, in the case of Shares tendered by book-entry transfer, by credit to the account at the DTC). Similarly, unless otherwise indicated under “Special Delivery Instructions,” please mail the check for the purchase price of any Shares purchased and any certificates for Shares not tendered or not purchased (and accompanying documents, as appropriate) to the undersigned at the address shown below the undersigned’s signature(s). In the event that both “Special Payment Instructions” and “Special Delivery Instructions” are completed, please issue the check for the purchase price of any Shares purchased and return any Shares not tendered or not purchased in the name(s) of, and mail said check and any certificates to, the person(s) so indicated. The undersigned recognizes that Purchaser has no obligation, pursuant to the “Special Payment Instructions,” to transfer any Shares from the name of the registered holder(s) thereof if Purchaser does not accept for payment any of the Shares so tendered.

	SPECIAL PAYMENT INSTRUCTIONS (See Instructions 1, 5, 6 and 7)
	To be completed ONLY if the check for the purchase price of Shares purchased (less any applicable withholding taxes) or certificates for Shares not tendered or not purchased are to be issued in the name of someone other than the undersigned.

	Issue ☐ check ☐ certificates to:

	Name
	(Please Print)

	Address




	(Zip Code)


	Taxpayer Identification Number

	SPECIAL DELIVERY INSTRUCTIONS (See Instructions 1, 5, 6 and 7)
	To be completed ONLY if the check for the purchase price of Shares purchased (less any required withholding taxes) or certificates for Shares not tendered or not purchased are to be mailed to someone other than the undersigned or to the undersigned at an address other than that shown below the undersigned’s signature(s).

	Mail ☐ check ☐ certificates to:

	Name
	(Please Print)

	Address




	(Zip Code)

SIGN HERE

(PLEASE COMPLETE ENCLOSED FORM W-9)

(Signature(s) of Stockholder(s) must be provided above)

Dated

, 2022

Name(s)

(Please Print on the line above)

Capacity (Full Title)

Address

(Zip Code)

Area Code and Telephone Number

(Must be signed by registered holder(s) exactly as name(s) appear(s) on stock certificate(s) or on a security position listing or by person(s) authorized to become registered holder(s) by certificates and documents transmitted herewith. If signature is by a trustee, executor, administrator, guardian, attorney-in-fact, agent, officer of a corporation or other person acting in a fiduciary or representative capacity, please set forth full title and see Instruction 5.)

Guarantee of Signature(s)

(If required; see Instructions 1 and 5)

(For use by Eligible Institutions only.

Place medallion guarantee in space below)

Name of Firm

Address

(Zip Code)

Authorized Signature

Name

(Please Print)

Area Code and Telephone Number

Dated

, 2022

INSTRUCTIONS

Forming Part of the Terms and Conditions of the Offer

1. Guarantee of Signatures. No signature guarantee is required on the Letter of Transmittal (a) if this Letter of Transmittal is signed by the registered holder(s) (which term, for purposes of this Instruction, includes any participant in the DTC whose name appears on a security position listing as the owner of the Shares) of the Shares tendered herewith, unless such registered holder has completed either the box entitled “Special Payment Instructions” or the box entitled “Special Delivery Instructions” on this Letter of Transmittal or (b) if the Shares are tendered for the account of a financial institution (including most commercial banks, savings and loan associations and brokerage houses) that is a member in good standing of the Securities Transfer Agents Medallion Program or any other “eligible guarantor institution,” as such term is defined in Rule 17Ad-15 of the Exchange Act (each an “Eligible Institution” and collectively “Eligible Institutions”). In all other cases, all signatures on this Letter of Transmittal must be guaranteed by an Eligible Institution. See Instruction 5.

2. Delivery of Letter of Transmittal and Shares. This Letter of Transmittal is to be used either if certificates are to be forwarded herewith or, unless an Agent’s Message is utilized, if delivery of Shares is to be made by book-entry transfer pursuant to the procedures set forth in Section 3 of the Offer to Purchase. Certificates for all physically delivered Shares, or a confirmation of a book-entry transfer into the Depositary’s account at the DTC of all Shares delivered electronically (“Book-Entry Confirmation”), as well as a properly completed and duly executed Letter of Transmittal and any other documents required by this Letter of Transmittal, must be received by the Depositary at one of its addresses set forth on the front page of this Letter of Transmittal by the Expiration Date.

The term “Agent’s Message” means a message, transmitted by the DTC to and received by the Depositary and forming a part of a Book-Entry Confirmation, that states that the DTC has received an express acknowledgment from the participant in the DTC tendering the Shares that are the subject of such Book-Entry Confirmation, that such participant has received and agrees to be bound by the terms of the Letter of Transmittal and that Purchaser may enforce such agreement against such participant.

The method of delivery of Shares, this Letter of Transmittal and all other required documents, including through the Book-Entry Transfer Facility, is at the sole option and risk of the tendering stockholder, and delivery of the Shares will be deemed made only when actually received by the Depositary (including, in the case of a book-entry transfer, by book-entry confirmation). If certificates for Shares are sent by mail, we recommend registered mail with return receipt requested, properly insured, in time to be received on or prior to the Expiration Date.

No alternative, conditional or contingent tenders will be accepted, and no fractional Shares will be purchased. By executing this Letter of Transmittal, the tendering stockholder waives any right to receive any notice of the acceptance for payment of the Shares.

3. Inadequate Space. If the space provided herein is inadequate, the certificate numbers and/or the number of Shares should be listed on a separate schedule attached hereto.

4. Partial Tenders (not applicable to stockholders who tender by book-entry transfer). If fewer than all of the Shares represented by any certificate delivered to the Depositary are to be tendered, fill in the number of Shares which are to be tendered in the box entitled “Total Number of Shares Tendered.” In such case, a new certificate for the remainder of the Shares represented by the old certificate will be issued and sent to the person(s) signing this Letter of Transmittal, unless otherwise provided in the boxes entitled “Special Payment Instructions” or “Special Delivery Instructions,” as the case may be, on this Letter of Transmittal, as promptly as practicable following the expiration or termination of the Offer. All Shares represented by certificates delivered to the Depositary will be deemed to have been tendered unless otherwise indicated.

5. Signatures on Letter of Transmittal; Stock Powers and Endorsements. If this Letter of Transmittal is signed by the registered holder(s) of the Shares tendered hereby, the signature(s) must correspond with the name(s) as written on the face of the certificates without alteration, enlargement or any change whatsoever.

If any of the Shares tendered hereby are held of record by two or more persons, all such persons must sign this Letter of Transmittal.

If any of the Shares tendered hereby are registered in different names on different certificates, it will be necessary to complete, sign and submit as many separate Letters of Transmittal as there are different registrations of certificates.

If this Letter of Transmittal is signed by the registered holder(s) of the Shares tendered hereby, no endorsements of certificates or separate stock powers are required unless payment of the purchase price is to be made, or Shares not tendered or not purchased are to be returned, in the name of any person other than the registered holder(s). Signatures on any such certificates or stock powers must be guaranteed by an Eligible Institution.

If this Letter of Transmittal is signed by a person other than the registered holder(s) of the Shares tendered hereby, certificates must be endorsed or accompanied by appropriate stock powers, in either case, signed exactly as the name(s) of the registered holder(s) appear(s) on the certificates for such Shares. Signature(s) on any such certificates or stock powers must be guaranteed by an Eligible Institution.

If this Letter of Transmittal or any certificate or stock power is signed by a trustee, executor, administrator, guardian, attorney-in-fact, officer of a corporation or other person acting in a fiduciary or representative capacity, such person should so indicate when signing, and proper evidence satisfactory to the Purchaser of the authority of such person so to act must be submitted.

6. Stock Transfer Taxes. The Purchaser will pay any stock transfer taxes with respect to the sale and transfer of any Shares to it or its order pursuant to the Offer. If, however, payment of the purchase price is to be made to, or Shares not tendered or not purchased are to be returned in the name of, any person other than the registered holder(s), or if a transfer tax is imposed for any reason other than the sale or transfer of Shares to the Purchaser pursuant to the Offer, then the amount of any stock transfer taxes (whether imposed on the registered holder(s), such other person or otherwise) will be deducted from the purchase price unless satisfactory evidence of the payment of such taxes, or exemption therefrom, is submitted herewith.

7. Special Payment and Delivery Instructions. If the check for the purchase price of any Shares purchased is to be issued, or any Shares not tendered or not purchased are to be returned, in the name of a person other than the person(s) signing this Letter of Transmittal or if the check or any certificates for Shares not tendered or not purchased are to be mailed to someone other than the person(s) signing this Letter of Transmittal or to the person(s) signing this Letter of Transmittal at an address other than that shown above, the appropriate boxes on this Letter of Transmittal should be completed. Stockholders tendering Shares by book-entry transfer may request that Shares not purchased be credited to such account at the DTC as such stockholder may designate under “Special Payment Instructions.” If no such instructions are given, any such Shares not purchased will be returned by crediting the account at the DTC designated above.

8. Tax Information. Payments made to certain stockholders pursuant to the Offer may be subject to backup withholding. To avoid backup withholding, each U.S. Holder (as defined in Section 5 of the Offer to Purchase), and, if applicable, each other payee, must provide the Depositary with such stockholder’s or payee’s correct taxpayer identification number and certify that such stockholder or payee is not subject to such backup withholding by completing the enclosed Form W-9. In general, if a stockholder or payee is an individual, the taxpayer identification number is the social security number of such individual. If the Depositary is not provided with the correct taxpayer identification number, the stockholder or payee may be subject to a $50 penalty imposed by the Internal Revenue Service. Certain stockholders or payees (including, among others, all corporations and certain persons or entities who are not U.S. Holders) are not subject to these backup withholding and reporting requirements. In order to avoid backup withholding, a person or entity who is not a U.S. Holder should submit a properly completed Form W-8BEN (or other applicable IRS Form W-8), including certification of such holder’s foreign status, signed under penalty of perjury. Such certificates can be obtained from the Depositary or at http://www.irs.gov.

Failure to complete the enclosed Form W-9 or any other applicable form will not, by itself, cause Shares to be deemed invalidly tendered, but may require the Depositary to withhold 24% of the amount of any payments made pursuant to the Offer. Backup withholding is not an additional U.S. federal income tax. Rather, the U.S. federal income tax liability of a person subject to backup withholding will be reduced by the amount of tax withheld. If withholding results in an overpayment of taxes, a refund may be obtained provided that the required

information is furnished to the Internal Revenue Service. We recommend that you consult your own tax advisor or the Depositary for further guidance regarding the completion of the enclosed Form W-9 or Form W-8BEN (or other applicable IRS Form W-8) to claim exemption from backup withholding.

9. Mutilated, Lost, Stolen or Destroyed Certificates. If the certificate(s) representing Shares to be tendered have been mutilated, lost, stolen or destroyed, stockholders should promptly notify the Computershare Trust Company, N.A., in its capacity as transfer agent toll-free at (800) 546-5141 or at (781) 575-2765. The stockholder will then be instructed as to the steps that must be taken in order to replace such certificate(s). This Letter of Transmittal and related documents cannot be processed until the procedures for replacing lost, stolen, destroyed or mutilated certificates have been followed.

10. Irregularities. All questions as to the validity, form, eligibility (including time of receipt) and acceptance for payment of any tender of Shares will be determined by Purchaser, in its sole discretion, which determination shall be final and binding on all parties. Purchaser reserves the absolute right to reject any and all tenders determined by it not to be in proper form or the acceptance for payment of which may, in the opinion of Purchaser’s counsel, be unlawful. Purchaser also reserves the absolute right to waive any defect or irregularity in the tender of any Shares of any particular stockholder, whether or not similar defects or irregularities are waived in the case of other stockholders. No tender of Shares will be deemed to have been validly made until all defects and irregularities have been waived or cured within such time as Purchaser shall determine. None of Purchaser, the Depositary, the Information Agent (as set forth below) or any other person will be under any duty to give notice of any defects or irregularities in tenders or incur any liability for failure to give any such notice. Purchaser’s interpretation of the terms and conditions of the Offer (including the Letter of Transmittal and the instructions thereto) will be final and binding.

11. Requests for Assistance or Additional Copies. Requests for assistance or additional copies of the Offer to Purchase and this Letter of Transmittal may be obtained from the Information Agent at its addresses or telephone numbers set forth below.

The Information Agent for the Offer is:

D.F. King & Co., Inc.

48 Wall Street

New York, New York 10005

Shareholders Call (Toll-Free): (877) 478-5040

Banks and Brokers Call: (212) 269-5550

By Email: ETTX@dfking.com