8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 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 21, 2022

SPERO THERAPEUTICS, INC.

(Exact name of registrant as specified in its charter)

Delaware	001-38266	46-4590683
(State or other jurisdiction<br>of incorporation)	(Commission<br>File Number)	(IRS Employer<br>Identification No.)
675 Massachusetts Avenue, 14^th^ Floor<br> <br>Cambridge, Massachusetts	02139
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(Address of principal executive offices)	(Zip Code)

Registrant’s telephone number, including area code: (857) 242-1600

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)
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☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
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☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))
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Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading<br>Symbol(s)	Name of each exchange<br>on which registered
Common Stock, $0.001 par value per share	SPRO	The Nasdaq Global Select 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. ☒

Item 1.01	Entry into a Material Definitive Agreement.

Tebipenem HBr License Agreement with GSK

On September 21, 2022, Spero Therapeutics, Inc. (the “Company” or “Spero”) entered into a license agreement (the “License Agreement”) with GlaxoSmithKline Intellectual Property (No. 3) Limited (“GSK”). Pursuant to the terms of the License Agreement, the Company granted GSK an exclusive royalty-bearing license, with the right to grant sublicenses, under the Company’s intellectual property and regulatory documents and a sublicense under certain intellectual property of Meiji Seika Pharma Co., Ltd. (“Meiji”) and Meiji’s regulatory documents to develop, manufacture and commercialize tebipenem pivoxil and tebipenem HBr and products that contain tebipenem pivoxil and tebipenem HBr (the “GSK Licensed Products”) in all territories, except certain Asian countries previously licensed to Meiji (Japan, Bangladesh, Brunei, Cambodia, China, Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, South Korea, Taiwan, Thailand and Vietnam, or the “Meiji Territory”) (the “GSK Territory”). If Spero’s license with Meiji is terminated, or if Meiji forfeits or loses its rights to develop, manufacture and commercialize tebipenem HBr and products that contain tebipenem HBr in any countries in the Meiji Territory, then GSK will have an exclusive first right to negotiate with Spero to add any such countries to the GSK Territory.

Under the terms of the License Agreement, Spero will receive an upfront payment of $66 million for GSK to secure rights to the medicine. Remaining potential payments are milestone based, and are as follows:

Event	Milestone payments (up to)
Delivery of phase III programme	$150m
Total commercial milestone payments based on first sale (US/EU)	$150m
Sales milestone events
Net sales greater than $200m	$25m
Net sales greater than $300m	$25m
Net sales greater than $400m	$25m
Net sales greater than $500m	$50m
Net sales greater than $750m	$50m
Net sales greater than $1,000m	$50m
Total sales milestone payments:	$225m
Royalties	Low-single digit to low-double digit (if<br>sales exceed $1bn) tiered royalties<br>on net product sales.

Royalties are subject to reduction in the event of third-party licenses, entry of a generic product or expiration of patent and regulatory exclusivity prior to the tenth (10^th^) anniversary of the first commercial sale of a GSK Licensed Product in a particular country.

Spero will be responsible for the execution and costs of the follow-up Phase III clinical trial of tebipenem HBr. GSK will be responsible for the execution and costs of additional further development, including Phase III regulatory filing and commercialization activities for tebipenem HBr in the balance of the GSK Territory outside of the United States. Spero will also be responsible for providing and paying for the clinical supply of tebipenem HBr while GSK will be responsible for the costs of the commercial supply of tebipenem HBr. A joint development committee will be established between GSK and Spero to coordinate and review development activities for tebipenem HBr in the United States.

Unless earlier terminated due to certain material breaches of the License Agreement or by GSK for convenience, or otherwise, the License Agreement will expire on a jurisdiction-by-jurisdiction and GSK Licensed Product-by-GSK Licensed Product basis on the latest to occur of (i) loss of patent exclusivity, (ii) loss of regulatory exclusivity or (iii) ten (10) years following the date of the first commercial sale of such licensed product in such country (the “Royalty Term”). During the Royalty Term, Spero has agreed not to develop, manufacture or commercialize any oral carbapenem for any indication or any oral antibiotic for cUTI; this restriction does not apply to any third party which acquires control of Spero after the date of the License Agreement if certain conditions are met.

The Company has the right to terminate the License Agreement upon a material breach by, or bankruptcy of, GSK. GSK has the right to terminate the License Agreement at any time upon a specified number of days’ notice or upon a material breach by, or bankruptcy of, Spero. In addition, in the event that GSK has the right to terminate the License Agreement due to a breach by Spero, GSK may elect not to terminate the License Agreement and in lieu thereof may assume the responsibility and expense of development of tebipenem HBr in the United States, in which event GSK’s obligation to make further development payments to Spero would cease, and/or to reduce all subsequent commercial and sales milestone payments and royalty payments otherwise due by GSK to Spero under the License Agreement by fifty percent (50%).

The License Agreement contains representations and warranties, other covenants, indemnification provisions and other terms and conditions customary for transactions of the type contemplated by the License Agreement. In support of certain of its rights to indemnification, GSK also has certain rights to suspend payments otherwise owed to Spero, as well as the right to offset payments otherwise owed to Spero against certain indemnifiable claims.

The consummation of the transactions under the License Agreement is subject to the satisfaction of customary closing conditions, including the expiration or termination of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (the “HSR Act”); provided, that either Spero or GSK may terminate the License Agreement if expiration or termination of the applicable waiting period under the HSR Act has not occurred by March 21, 2023. The parties expect the transactions contemplated by the License Agreement and the SPA (as described below) to close in the fourth quarter of 2022.

Share Purchase Agreement

Concurrently with the execution of the License Agreement, on September 21, 2022 (the “Effective Date”), the Company entered into a stock purchase agreement (the “SPA”) with Glaxo Group Limited (“GGL”), an affiliate of GSK, pursuant to which GGL will purchase, at the closing of the transactions contemplated by the SPA (the date thereof, the “Closing Date”), 7,450,000 shares (the “Shares”) of the Company’s common stock, par value $0.001 per share (the “Common Stock”), at a purchase price of approximately $1.20805 per share, for an aggregate purchase price of $9.0 million. In the event that the number of Shares to be purchased by GGL, when taken together with shares of Common Stock beneficially owned by GGL and its affiliates, would exceed 19.99% of the outstanding shares of Common Stock following such purchase, then GGL shall only be required to purchase such number of Shares that would result in GGL and its affiliates beneficially owning of 19.99% of the outstanding shares of Common Stock.

The SPA contains the following standstill, lock-up and registration rights provisions:

•	Standstill. Prior to the one-year anniversary of the Effective Date, GGL and its affiliates shall not, without the Company’s prior written consent, among other things, directly or indirectly acquire additional shares of Common Stock, seek or propose a tender or exchange offer, merger or other business combination involving the Company, seek, propose or cause any recapitalization, restructuring, liquidation, dissolution or other extraordinary transaction with respect to the Company, solicit proxies or consents with respect to any matter, or undertake other specified actions related to the potential acquisition of additional equity interests in the Company, in each case, subject to customary exceptions.
•	Lock-Up. From and including the Effective Date until the date that is twenty-four (24) months from and after the Effective Date (the “Lock-up Period”), and subject to customary exceptions, neither GGL nor its affiliates shall sell or otherwise dispose of the Shares, or any other shares of Common Stock owned beneficially by GGL and/or its affiliates (collectively, the “Locked-Up Shares”), provided, however, such Lock-up Period shall expire from and after eighteen (18) months after the Effective Date, with respect to 50% of the Locked-Up-Shares.
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•	Registration Rights. If, following the fifteen (15) month anniversary of the Closing Date, GGL or any of its affiliates proposes to publicly resell any or all of the shares of Common Stock then held by them (the “Registrable Securities”) (subject to the lock-up periods described above) pursuant to Rule 144 (“Rule 144”) under the Securities Act of 1933, as amended (the “Securities Act”), and GGL or any of its affiliates in good faith believes they will be unable to sell all of their respective shares of Common Stock proposed to be sold by them pursuant to Rule 144 without volume or manner-of-sale restrictions, then GGL shall have the right to require the Company to file as promptly as practicable a secondary only registration statement on Form S-3 (or any successor form to Form S-3) promulgated under the Securities Act (the “Registration Statement”), registering the resale of such shares of Common Stock. The Company shall use commercially reasonable efforts to cause the Registration Statement to become effective as promptly as practicable and to cause the Registration Statement to remain effective until the earlier of (i) the date on which GGL and its affiliates have disposed of all of the Registrable Securities, (ii) such time as Rule 144 is available for the disposition of all Registrable Securities without volume or manner-of-sale restrictions and (iii) the eighth (8^th^) anniversary of the effectiveness date of the Registration Statement. The Company shall bear all expenses incurred in connection with the performance of the foregoing obligations and such rights shall apply to any shares in the capital of the Company issued or issuable with respect to the Registrable Securities as a result of any stock split, stock dividend, recapitalization, exchange or similar event. For the avoidance of doubt, GGL and its affiliates shall remain subject to the lock-up restrictions described above, even if the Registration Statement becomes effective before the eighteen (18) month anniversary of the Effective Date.
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The consummation of the transactions under the SPA is subject to the satisfaction of customary closing conditions, including the expiration or termination of the applicable waiting period under the HSR Act and the License Agreement becoming effective.

The Shares will be issued and sold without registration under the Securities Act in reliance on the exemptions provided by Section 4(a)(2) of the Securities Act and/or Regulation D promulgated thereunder and in reliance on similar exemptions under applicable state laws.

The foregoing is only a summary of the material terms of the License Agreement and SPA and does not purport to be a complete description of the rights and obligations of the parties thereunder and is qualified in its entirety by reference to the License Agreement and the SPA, copies of which the Company intends to file with its Quarterly Report on Form 10-Q for the fiscal quarter ending September 30, 2022, requesting confidential treatment for certain portions thereof.

Item 3.02	Unregistered Sales of Equity Securities.

The description set forth in the section titled “Share Purchase Agreement” in Item 1.01 of this Current Report is incorporated by reference into this Item 3.02. The Shares sold and issued in connection with the SPA have not been registered under the Securities Act or any state securities laws and may not be offered or sold in the United States absent registration under the Securities Act or an applicable exemption from the registration requirements.

Item 8.01	Other Events.

On September 22, 2022, the Company issued a press release announcing the matters reported herein. A copy of the press release is filed as Exhibit 99.1 hereto and is incorporated into this Item 8.01 by reference.

Item 9.01	Financial Statements and Exhibits.

(d)    Exhibits.

99.1	Press Release, dated September 22, 2022
104	Cover Page Interactive Data File (embedded within the Inline XBRL document)

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.

	SPERO THERAPEUTICS, INC.
	By:	/s/ Tamara Joseph
		Tamara Joseph
Date: September 22, 2022		Chief Legal Officer

EX-99.1

Exhibit 99.1

GSK and Spero Therapeutics Announce Exclusive License Agreement for Late-Stage Antibiotic Asset, Tebipenem HBr

The exclusive license allows GSK to commercialize tebipenem HBr in all territories, except Japan and certain other Asian countries

Spero Therapeutics receives $66 million upfront, with potential for future milestone payments, and tiered royalties.

GSK to purchase $9 million in shares of Spero common stock

London, UK and CAMBRIDGE, Mass., September 22, 2022 — GSK (LSE/NYSE: GSK) and Spero Therapeutics, Inc. (Nasdaq: SPRO) today announced they have entered into an exclusive license agreement for Spero’s late-stage antibiotic asset, tebipenem HBr. Tebipenem HBr is being developed as the first oral carbapenem antibiotic for the treatment of complicated urinary tract infections (cUTI), including pyelonephritis, caused by certain bacteria.

Luke Miels, Chief Commercial Officer, GSK said, “There is a high unmet medical need for a novel oral antibiotic as an alternative to intravenous hospital therapy for drug-resistant complicated urinary tract infections. Tebipenem HBr complements GSK’s infectious disease strategy and is consistent with our commitment to find value-enhancing opportunities to build a strong late-stage portfolio. Tebipenem HBr has a clear US FDA regulatory path to potential approval, which could significantly benefit patients with complicated urinary tract infections.”

“Spero’s agreement with GSK provides a critical step towards fully realizing the value tebipenem HBr can potentially provide to physicians, payors, and patients,” said Ankit Mahadevia, M.D., Chief Executive Officer of Spero. “We are thrilled to collaborate with GSK on developing tebipenem HBr for patients suffering from cUTI. With their antibiotic expertise and global commercial reach, GSK is ideally positioned to launch tebipenem HBr following regulatory approval as the first oral treatment for cUTI, providing patients with an alternative to in-hospital intravenous (IV) therapy. Tebipenem HBr’s potential as an at-home, oral option can potentially be of significant benefit by reducing hospital resource utilization. In addition, our partnership with GSK strengthens our balance sheet and shareholder base.”

Spero expects to start a new phase 3 clinical trial in 2023, following encouraging US FDA regulatory feedback on the proposed clinical trial design.

Financial Terms

GSK will receive an exclusive license to develop and commercialize tebipenem pivoxil and tebipenem pivoxil HBr in all territories, except Japan, and certain other Asian countries, territories which will be retained by Spero partner, Meiji Seika. Under the license agreement, Spero will be responsible for the execution and costs of the follow-up Phase 3 clinical trial of tebipenem HBr. GSK will be responsible for the execution and costs of additional development, including Phase III regulatory filing and commercialization activities for tebipenem HBr outside of the Meiji Seika territory.

Under the terms of the license agreement, Spero will receive an upfront payment of $66 million for GSK to secure rights to the medicine. Remaining potential payments are milestone based, and are as follows:

Event	Milestone payments (up to)
Delivery of phase III programme	$150m
Total commercial milestone payments based on first sale (US/EU)	$150m
Sales milestone events
Net sales greater than $200m	$25m
Net sales greater than $300m	$25m
Net sales greater than $400m	$25m
Net sales greater than $500m	$50m
Net sales greater than $750m	$50m
Net sales greater than $1,000m	$50m
Total sales milestone payments:	$225m
Royalties	Low-single digit to low-double digit<br>(if sales exceed $1bn) tiered<br>royalties on net product sales.

In connection with the license agreement and pursuant to a stock purchase agreement between GSK and Spero, GSK has agreed to make a $9 million common stock investment in Spero, purchasing 7,450,000 shares of Spero’s common stock at a purchase price of approximately $1.20805 per share, not to exceed 19.99% beneficial ownership of Spero by GSK and its affiliates.

The transactions are expected to close in the fourth quarter of 2022, subject to customary closing conditions, including expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended. The closing of the equity investment is conditioned upon the effectiveness of the license following Hart-Scott-Rodino clearance.

As of June 30, 2022, Spero had cash, cash equivalents, and marketable securities of $45.4 million. Based on the previously announced restructuring and the cessation of commercialization activities for the tebipenem HBr program, along with the initial cash payment of $66 million from the GSK licensing transaction, Spero believes that its current cash runway will be sufficient to fund the company beyond 2024.

About Tebipenem HBr

Tebipenem HBr (tebipenem pivoxil hydrobromide; formerly SPR994) is Spero’s novel late-stage development asset, an oral formulation of tebipenem pivoxil, a carbapenem antibiotic of the ß-lactam class marketed by Meiji Seika Pharma Co. Ltd. (Meiji) in Japan as Orapenem^®^ since 2009 for pediatric infections limited to pneumonia, otitis media and sinusitis. Carbapenems are an important subclass of antibiotics because they have been observed to be safe and effective in the treatment of drug-resistant Gram-negative bacterial infections. Tebipenem HBr is being developed for the treatment of complicated urinary tract infections, including acute pyelonephritis (AP), caused by certain bacteria. If approved, tebipenem HBr would be the first oral carbapenem antimicrobial to receive marketing approval in the United States. Tebipenem HBr has been granted Qualified Infectious Disease Product (QIDP) and Fast Track designations by the US Food and Drug Administration (FDA) for the treatment of cUTI and AP. Following feedback from the FDA, at Spero’s recent Type A meeting, Spero will conduct an additional Phase 3 trial to support the regulatory file.

Tebipenem HBr Research Support

Select tebipenem HBr studies have been funded in part with federal funds from the Department of Health and Human Services; Office of the Administration for Strategic Preparedness and Response; Biomedical Advanced Research and Development Authority, under contract number HHSO100201800015C.

About GSK

GSK is a global biopharma company with a purpose to unite science, technology, and talent to get ahead of disease together. Find out more at gsk.com/company

GSK in Antibiotics

GSK has been developing and supplying antibiotics for more than 70 years, and research and development continues to investigate new tools to prevent and mitigate infectious disease – and get ahead of antimicrobial resistance. GSK is already a leader on the Antimicrobial Resistance Benchmark of the Access to Medicine Foundation and participates in the AMR Action Fund, which aims to bring 2-4 new antibiotics to patients by 2030, through sustainable investment in the antibiotic pipeline.

About Spero Therapeutics

Spero Therapeutics, headquartered in Cambridge, Massachusetts, is a multi-asset, clinical-stage biopharmaceutical company focused on identifying, developing, and commercializing novel treatments for bacterial infections, including multi-drug resistant bacterial infections and rare diseases.

•	Spero Therapeutics is developing SPR720 as a novel oral therapy candidate for the treatment of a rare,<br>orphan pulmonary disease caused by non-tuberculous mycobacterial infections.
•	Spero Therapeutics also has an IV-administered next generation polymyxin<br>product candidate, SPR206, developed from its potentiator platform, which is in development to treat multi-drug resistant Gram-negative infections in the hospital setting.
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•	Tebipenem HBr is an investigational drug in the United States being developed for the treatment of cUTI,<br>including pyelonephritis, caused by certain bacteria, in adult patients who have limited treatment options; tebipenem HBr is not FDA-approved.
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For more information, visit https://sperotherapeutics.com.

GSK Forward Looking Statements

GSK cautions investors that any forward-looking statements or projections made by GSK, including those made in this announcement, are subject to risks and uncertainties that may cause actual results to differ materially from those projected. Such factors include, but are not limited to, those described in the Company’s Annual Report on Form 20-F for 2021, GSK’s Q2 Results for 2022 and any impacts of the COVID-19 pandemic

Spero Therapeutics Forward LookingStatements

This press release may contain forward-looking statements. These statements include, but are not limited to, statements about the timing of the closing of the license and equity investment transactions, the regulatory path forward for tebipenem HBr and potential FDA approval, the potential commercialization of tebipenem HBr and its future value, the potential receipt of milestone payments, and royalties on future sales under the license agreement and Spero’s cash runway. In some cases, forward-looking statements can be identified by terms such as “may,” “will,” “should,” “expect,” “plan,” “aim,” “anticipate,” “could,” “intent,” “target,” “project,” “contemplate,” “believe,” “estimate,” “predict,” “potential” or “continue” or the negative of these terms or other similar expressions. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including Spero’s and GSK’s ability to obtain antitrust clearance and close the proposed transactions in a timely manner; whether tebipenem HBr will advance through the clinical trial process on a timely basis, or at all, taking into account the effects of possible regulatory delays, slower than anticipated patient enrollment, manufacturing challenges, clinical trial design and clinical outcomes; whether the results of such trials will warrant submission for approval from the FDA or equivalent foreign regulatory agencies; whether the FDA will ultimately approve tebipenem HBr and, if so, the timing of any such approval; whether the FDA will require any additional clinical data or place labeling restrictions on the use of tebipenem HBr that would delay approval and/or reduce the commercial prospects of tebipenem HBr; whether a successful commercial launch can be achieved and market acceptance of tebipenem HBr can be established; whether Spero’s cash resources will be sufficient to fund its continuing operations for the periods and/or trials anticipated; and other factors discussed in the “Risk Factors” set forth in filings that Spero periodically makes with the U.S. Securities and Exchange Commission. The forward-looking statements included in this press release represent Spero’s views as of the date of this press release. Spero anticipates that subsequent events and developments will cause its views to change. However, while Spero may elect to update these forward-looking statements at some point in the future, it specifically disclaims any obligation to do so. These forward-looking statements should not be relied upon as representing Spero’s views as of any date subsequent to the date of this press release.

Investor Relations:

Ted Jenkins

Vice President, Investor Relations

TJenkins@sperotherapeutics.com

(617) 798-4039

Media Inquiries:

Matt Dick, Health Media Relations

Zeno Group

matt.dick@zenogroup.com

301-509-8532