Spero Therapeutics Announces Inducement Grant Under Nasdaq Listing Rule 5635(c)(4)

CAMBRIDGE, Mass., Nov. 28, 2025 (GLOBE NEWSWIRE) — Spero Therapeutics, Inc. (Nasdaq: SPRO), a clinical-stage biopharmaceutical company focused on identifying and developing novel treatments for rare diseases and multi-drug resistant (MDR) bacterial infections, today announced that on November 3, 2025, the Compensation Committee of Spero’s Board of Directors approved the grant of an aggregate of 90,000 restricted stock unit awards (RSUs) to one new employee under the Spero Therapeutics, Inc. 2019 Inducement Equity Incentive Plan, as amended (2019 Inducement Plan). The RSUs are being granted as an inducement material to Spero’s new employee in accordance with Nasdaq Listing Rule 5635(c)(4).

The 2019 Inducement Plan is used exclusively for the grant of equity awards to individuals who were not previously employees of Spero (or following a bona fide period of non-employment), as a material inducement for such individuals entering into employment with Spero, pursuant to Rule 5635(c)(4) of the Nasdaq Listing Rules.

The RSUs will vest in four equal annual installments beginning on December 1, 2025, subject to the employees‘ continued employment with Spero on such vesting dates. The RSUs are subject to the terms and conditions of the 2019 Inducement Plan and an RSU agreement covering the grant.

About Spero Therapeutics
Spero Therapeutics, headquartered in Cambridge, Massachusetts, is a clinical-stage biopharmaceutical company focused on identifying and developing novel treatments for rare diseases and MDR bacterial infections with high unmet need. For more information, visit www.sperotherapeutics.com.

Investor Relations Contact:
Shai Biran, PhD
Spero Therapeutics
IR@Sperotherapeutics.com

Media Inquiries:
media@sperotherapeutics.com