SEC Form 4 · accession 0001193125-26-283230
Spero Therapeutics, Inc. · SPRO
Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗
Reporting owner
Cynthia Smith
Director
Period of report
Jun 23, 2026
Accepted (ET)
Jun 25, 2026 · 7:14 pm EDT
Rule 10b5-1 plan
box not checked
Issuer CIK
0001701108
Table I — non-derivative securities
| Security | Date | Code | Shares | Price | A/D | Owned after | D/I | Nature of ownership |
|---|---|---|---|---|---|---|---|---|
| Common StockF1 | Jun 23, 2026 | A | 10,000 | $0.00 | A | 85,000 | D |
Table II — derivative securities
| Security | Conv. / exercise price | Date | Code | Shares | A/D | Exercisable | Expires | Underlying | Underlying shares | Owned after | D/I |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Stock Option (right to buy)F2 | $2.15 | Jun 23, 2026 | A | 20,000 | A | — | Jun 23, 2036 | Common Stock | 20,000 | 20,000 | D |
Explanation of responses
- F1Consists of restricted stock units ("RSUs"). Each RSU represents the right to receive one share of common stock upon vesting. The RSUs vest on June 23, 2027, subject to the Reporting Person's continued service through the applicable vesting date.
- F2The shares underlying this option will vest and become exercisable in full on June 23, 2027 subject to the Reporting Person's continued service as a director through the vesting date.