false --12-31 0001583107 0001583107 2026-09-23 2026-09-23 iso4217:USD xbrli:shares iso4217:USD xbrli:shares UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 23, 2026 THERAVANCE
BIOPHARMA, INC. (Exact Name of Registrant as Specified in its
Charter) Cayman Islands 001-36033 98-1226628 (State
    or Other Jurisdiction of (Commission
    File Number) (I.R.S.
    Employer Identification Incorporation) Number) c/o Theravance Biopharma US, LLC 901
Gateway Boulevard South
San Francisco , CA 94080 ( 650 ) 808-6000 (Addresses, including zip code, and telephone
numbers, including area code, of principal executive offices) Check the appropriate box below if the Form 8-K
filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General
Instruction A.2. below): ¨ Written communications pursuant
to Rule 425 under the Securities Act (17 CFR 230.425) ¨ Soliciting material pursuant to
Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ¨ Pre-commencement communications
pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ¨ Pre-commencement communications
pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each class Trading Symbol(s) Name of each exchange on which registered Ordinary
    Share $0.00001 Par Value TBPH Nasdaq Global Market Indicate by check mark whether the registrant
is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2
of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter). Emerging
growth company ¨ If
an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying
with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨ Introductory Note This Current Report on Form 8-K is being filed
in connection with the completion on September 23, 2026 of the transactions contemplated by that certain Agreement and Plan of Merger
(the “ Merger Agreement ”), dated as of June 28, 2026, by and among Theravance Biopharma, Inc., an exempted company with
limited liability incorporated under the Laws of the Cayman Islands (the “ Company ”), Zymeworks Inc., a Delaware corporation
(“ Parent ”), and Zymeworks Merger Sub 1, an exempted company with limited liability incorporated under the Laws of the
Cayman Islands and a wholly owned subsidiary of Parent (“ Merger Sub ”). On the terms and subject to the conditions of
the Merger Agreement, upon the consummation of the Merger (the “ Closing ”), Merger Sub merged with and into the Company
(the “ Merger ”), with the Company surviving the Merger as a wholly owned subsidiary of Parent (the “ Surviving
Company ”). Capitalized terms used but not otherwise defined in this Current Report on Form 8-K have the meanings set forth in
the Merger Agreement. Item 1.01 Entry into a Material Definitive Agreement. The information provided in the Introductory Note and Items 2.01 and
5.02 of this Current Report on Form 8-K is incorporated herein by reference. Item 2.01. Completion of Acquisition or Disposition of Assets. The information provided in the Introductory Note
of this Current Report on Form 8-K is incorporated herein by reference. Pursuant to the terms and conditions of the Merger
Agreement, among other things: · Company Ordinary Shares : At the effective time of the Merger (the “ Effective Time ”),
each ordinary share, par value $0.00001 per share, of the Company (“ Ordinary Share ”) issued and outstanding immediately
prior to the Effective Time (other than Canceled Shares and Dissenting Shares) was canceled and converted into the right to receive (i)
$17.00 in cash, without interest (the “ Per Share Cash Consideration ”), and (ii) one contingent value right, which represents
the right to receive the CVR Payment Amount (as defined below), if any, at the times and subject to the terms and conditions provided
for in the CVR Agreement (as defined and further described below), in cash, without interest (each, a “ CVR ” and, collectively,
the “ CVRs ” and each CVR together with the Per Share Cash Consideration, the “ Per Share Merger Consideration ”). · Company Options : At the Effective Time, each Company Option, whether vested or unvested, that was
outstanding, unexercised and not yet expired as of immediately prior to the Effective Time was canceled and converted into the right to
receive, in full satisfaction of the rights of such holder, an amount in cash, without interest, equal to (i) the excess, if any, of the
Per Share Cash Consideration over the exercise price of such Company Option, multiplied by (ii) the number of Ordinary Shares underlying
such Company Option (subject to any required tax withholdings as provided in the Merger Agreement) plus (iii) one CVR for each Ordinary
Share underlying such Company Option. However, any Company Option that had an exercise price per Ordinary Share that is greater than or
equal to the Per Share Cash Consideration ceased to be outstanding, was canceled and ceased to exist and the holder of any such Company
Option was not entitled to payment of the Per Share Merger Consideration. · Company RSU Awards : At the Effective Time, each Company RSU Award that was outstanding immediately
prior to the Effective Time, whether vested or unvested, was canceled and automatically converted into a right to receive an amount in
cash, without interest, equal to (i) the Per Share Cash Consideration multiplied by (ii) the number of Ordinary Shares underlying such
Company RSU Award (subject to any required tax withholdings as provided in the Merger Agreement) plus (iii) one CVR for each Ordinary
Share underlying such Company RSU Award. · Company PSU Awards : At the Effective Time, each Company PSU Award that was outstanding immediately
prior to the Effective Time, whether vested or unvested, was canceled in exchange for the right to receive an amount in cash, without
interest, equal to (i) the Per Share Cash Consideration multiplied by (ii) the number of Ordinary Shares with respect to such Company
PSU Award that remained outstanding and unreleased as of immediately prior to the Effective Time, plus (iii) one CVR for each Ordinary
Share underlying such Company PSU Award. The foregoing description of the Merger Agreement
and the transactions contemplated thereby does not purport to be complete and is subject to, and qualified in its entirety by, the full
text of the Merger Agreement, a copy of which is attached hereto as Exhibit 2.1, and the terms of which are incorporated herein by
reference. Item 3.01. Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing The information provided in Item 2.01 of this
Current Report on Form 8-K is incorporated herein by reference. On September 23, 2026, the Company notified the
Nasdaq Stock Market LLC (“ Nasdaq ”) of the Closing and requested that Nasdaq suspend trading of the Ordinary Shares
as of the close of business on September 23, 2026 and file with the U.S. Securities and Exchange Commission (the “ SEC ”)
a notification of removal from listing and registration on Form 25 to effect the delisting of the Ordinary Shares from Nasdaq and the
deregistration of the Ordinary Shares pursuant to Section 12(b) of the Securities Exchange Act of 1934, as amended (the “ Exchange
Act ”). The delisting of the Ordinary Shares from Nasdaq will be effective 10 days after the filing of the Form 25. Following
the effectiveness of the Form 25, the Company intends to file a certification and notice of termination of registration on Form 15 with
the SEC requesting the termination of registration of the Ordinary Shares under Section 12(g) of the Exchange Act and the suspension of
reporting obligations under Section 13 and 15(d) of the Exchange Act with respect to the Ordinary Shares. Item 3.03. Material Modification to Rights of Security Holders The information provided in the Introductory Note
and Items 2.01, 3.01, 5.01 and 5.03 of this Current Report on Form 8-K is incorporated herein by reference. At the Effective Time, each holder of shares of
the Ordinary Shares issued and outstanding immediately prior to the Effective Time ceased to have any rights as a shareholder of the Company
(other than the right of the holders of the Ordinary Shares to receive the Per Share Merger Consideration). Item 5.01. Changes in Control of Registrant The information provided in the Introductory Note
and Items 2.01, 5.02 and 5.03 of this Current Report on Form 8-K is incorporated herein by reference. As a result of the completion of the Merger, a
change in control of the Company occurred, and the Company became a wholly owned subsidiary of Parent. Parent obtained the funds necessary
to finance the Merger through a combination of cash on hand and new debt financing. Item 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment
of Certain Officers; Compensatory Arrangements of Certain Officers The information provided in the Introductory Note
and Item 2.01 of this Current Report on Form 8-K is incorporated herein by reference. In connection with the completion of the Merger
and as contemplated by the Merger Agreement, at the Effective Time, each of Rick E Winningham, Laurie Smaldone Alsup, Susannah Gray, Dean
J. Mitchell, Donal O’Connor and Deepa R. Pakianathan resigned from the Company’s Board of Directors, and Mr. Winningham resigned
as the Company’s Chief Executive Officer. These resignations were in connection with the Merger and not as a result of any disagreements
between the Company and the resigning individuals on any matters relating to the Company’s operations, policies or practices. As of the Effective Time and pursuant to the terms
of the Plan of Merger, Kristin Stafford, Scott Platshon and Paul Schneider became the directors of the Company. In connection with the Merger and pursuant to
the terms of the CVR Agreement, on September 22, 2026, the Company entered into a consultation agreement with Ms. Gray (the “ Consultation
Agreement ”), pursuant to which Ms. Gray has the primary responsibility of negotiating a CVR Product License for the twelve-month
period following the Closing. Pursuant to the terms of the Consultation Agreement, Ms. Gray will not be compensated by the Company for
any services performed pursuant to the Consultation Agreement. The foregoing description of the Consultation
Agreement does not purport to be complete and is subject to, and qualified in its entirety by, the full text of the Consultation Agreement,
a copy of which is attached hereto as Exhibit 10.1, and the terms of which are incorporated herein by reference. Item 5.03. Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year. The information provided in Item 2.01 of
this Current Report on Form 8-K is incorporated herein by reference. Pursuant to the terms of the Merger Agreement,
at the Effective Time, in accordance with the Plan of Merger, the memorandum and articles of association of Merger Sub, as in effect immediately
prior to the Effective Time, became the memorandum and articles of association of the Surviving Company, save and except that (i) all
references to the name “Zymeworks Merger Sub 1” were amended to “Theravance Biopharma, Inc.”; (ii) all references
to the share capital of the Surviving Company were amended to refer to the correct authorized share capital of the Surviving Company consistent
with the Plan of Merger, until thereafter amended in accordance with the applicable provisions of Part 16 of the Companies Act (as revised)
of the Cayman Islands and such memorandum and articles of association and (iii) such memorandum and articles of association include indemnification
provisions as required by Section 6.10(b) of the Merger Agreement. Copies of the memorandum and articles of association
are attached as Exhibit 3.1 to this Current Report on Form 8-K and are incorporated herein by reference. Item 8.01. Other Events. Contingent Value Rights Agreement On September 23, 2026, in connection with the
Merger Agreement, Parent entered into a contingent value rights agreement (the “ CVR Agreement ”) with Computershare
Inc., a Delaware corporation (“ Computershare ”), and its affiliate, Computershare Trust Company, N.A., a federally chartered
trust company, acting jointly with Computershare, as Rights Agent (as defined in the CVR Agreement). Each CVR issued by Parent under the CVR Agreement
represents a non-tradeable contractual contingent right to receive: · a pro rata share of 80% of the net proceeds received by Parent or its affiliates (including the Surviving
Company), if any, from any license, divestiture or other monetization transaction of ampreloxetine executed within the ten-year period
following the Effective Time (the “ CVR License Expiration Date ”); · a pro rata share of $50 million in cash upon the first commercial sale of ampreloxetine by Parent or its
affiliates (including the Surviving Company) in the U.S., UK, Spain, France, Germany or Italy on or prior to the CVR License Expiration
Date, if any; and · a pro rata share of 10% of the net sales received by Parent or its affiliates (including the Surviving
Company), if any, on a country-by-country basis, from the date of the first commercial sale until the later of the 10th anniversary of
such date, patent expiration or the loss of exclusivity. The CVRs and the possibility of receiving any
payment pursuant to the CVRs are highly speculative and subject to numerous factors outside the control of Parent or its affiliates. There
can be no assurance that any transaction that may give rise to any payment pursuant to the CVRs will be executed or that any payment pursuant
to the CVRs will ever be paid. The CVRs will not be evidenced by a certificate
or other instrument, will not have any voting or dividend rights, will not represent any equity or ownership interests in Parent or the
Surviving Company and will not be transferable except in limited circumstances. The foregoing description of the CVR Agreement
does not purport to be complete and is subject to, and qualified in its entirety by, the full text of the CVR Agreement, a copy of which
is attached hereto as Exhibit 10.2, and the terms of which are incorporated herein by reference. Item 9.01. Financial Statements and Exhibits. (d)        Exhibits. Exhibit No. Description 2.1 Agreement and Plan of Merger, dated as of June 28, 2026, by and among Theravance Biopharma, Inc., Zymeworks Inc. and Zymeworks Merger Sub 1 (incorporated by reference from Exhibit 2.1 to Theravance Biopharma, Inc.’s Current Report on Form 8-K, filed on June 29, 2026)* 3.1 Amended and Restated Memorandum and Articles of Association of Theravance Biopharma, Inc. 10.1 Consultation Agreement, dated September 22, 2026, by and between Susannah Gray and Theravance Biopharma, Inc. 99.1 Contingent Value Rights Agreement, dated as of September 22, 2026, by and among Zymeworks Inc., Computershare Inc. and Computershare Trust Company, N.A.* 104 Cover Page Interactive Data File (embedded within the Inline XBRL document) * Certain schedules and exhibits have been omitted pursuant to Item 601(a)(5) of Regulation S-K. A copy of any omitted schedule or exhibit will be furnished to the SEC upon request. SIGNATURE Pursuant to the requirements of the
Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly
authorized. THERAVANCE BIOPHARMA, INC. Date: September 23, 2026 By: /s/ Scott Platshon Scott Platshon Director

Zymeworks Inc. completed its acquisition of Theravance Biopharma, Inc. on September 23, 2026, with Theravance becoming a wholly owned subsidiary of Zymeworks. This strategic combination is intended to strengthen both companies' market positions in the biotechnology sector.

On September 23, 2026, Theravance Biopharma, Inc. completed a merger with Zymeworks Inc., as per the Agreement and Plan of Merger dated June 28, 2026. In this transaction, Zymeworks Merger Sub 1, a subsidiary of Zymeworks Inc., merged with and into Theravance Biopharma, which will now operate as a wholly owned subsidiary of Zymeworks. This merger reflects a strategic alignment aimed at strengthening their market positions. The details surrounding the financial terms of the transaction have not been disclosed in the filing.

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