Spero Therapeutics, Inc. — Director's Dealing 2021

Aug 18, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Spero Therapeutics, Inc. (SPRO)
CIK: 0001701108
Period of Report: 2021-08-17

Reporting Person: FORMELA JEAN FRANCOIS (Director)

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2021-08-17	Stock Option (right to buy)	$13.69	A	7500	Acquired	2031-08-17	Common Stock (7500)	Direct

Footnotes

F1: The shares underlying this option will vest and become exercisable in full on August 17, 2022 subject to the Reporting Person's continued service as a director through the vesting date.

F2: The reporting person is a member of Atlas Venture Associates IX, LLC and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon exercise of the equity grants to Atlas Venture Advisors, L.P. As such, the Reporting Person disclaims beneficial ownership to the securities reported herein for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, except to the extent of his pecuniary interest therein, if any.