Insider holders · CIK 0001701108
Spero Therapeutics, Inc. · SPRO
Every insider with a reported Table I holding at this company, ranked by their last-reported share count. A balance is only as fresh as its filing — the report date sits next to every row on purpose. ← Back to activity
| Insider | Direct shares | Indirect shares | Total reported | Last report (ET) | From |
|---|---|---|---|---|---|
| Jean Francois FormelaDirector | — | 2,408,128 | 2,408,128 | Nov 7, 2017 · 4:08 pm EST | Form 4 |
| GLAXOSMITHKLINE PLC10% Owner | — | 1,934,006 | 1,934,006 | Jul 17, 2018 · 5:01 pm EDT | Form 4 |
| Vikas GoyalDirector | — | 1,854,006 | 1,854,006 | Nov 7, 2017 · 4:06 pm EST | Form 4 |
| Casper BreumDirector | — | 1,091,774 | 1,091,774 | Nov 7, 2017 · 4:05 pm EST | Form 4 |
| Debra ZackChief Medical Officer | 162,311 | — | 162,311 | Aug 6, 2026 · 6:49 pm EDT | Form 4 |
| Ankit MahadeviaSee Remarks | 65,817 | 65,817 | 131,634 | Jul 6, 2018 · 9:41 pm EDT | Form 4 |
| Milind DeshpandeDirector | 101,454 | — | 101,454 | Jun 25, 2026 · 7:26 pm EDT | Form 4 |
| Kathleen TregoningDirector | 85,000 | — | 85,000 | Jun 25, 2026 · 7:17 pm EDT | Form 4 |
| Cynthia SmithDirector | 85,000 | — | 85,000 | Jun 25, 2026 · 7:14 pm EDT | Form 4 |
| Scott Thomas JacksonDirector | 85,000 | — | 85,000 | Jun 25, 2026 · 6:57 pm EDT | Form 4 |
| Patrick V.J.J. VinkDirector | 85,000 | — | 85,000 | Jun 25, 2026 · 7:12 pm EDT | Form 4 |
| John C Pottage Jr.Director | 85,000 | — | 85,000 | Jun 25, 2026 · 6:55 pm EDT | Form 4 |
| Frank E ThomasDirector | 85,000 | — | 85,000 | Jun 25, 2026 · 6:59 pm EDT | Form 4 |
| Atlas Venture Fund IX, L.P.10% Owner | 42,781 | — | 42,781 | Nov 1, 2017 · 7:50 pm EDT | Form 3 |
| Atlas Venture Associates IX, L.P.10% Owner | 42,781 | — | 42,781 | Nov 1, 2017 · 7:50 pm EDT | Form 3 |
| Atlas Venture Associates IX, LLC10% Owner | 42,781 | — | 42,781 | Nov 1, 2017 · 7:50 pm EDT | Form 3 |
| Joel SendekChief Financial Officer | 15,181 | 10,181 | 25,362 | Jul 6, 2018 · 9:44 pm EDT | Form 4 |
| Cristina LarkinChief Operating Officer | 1,500 | — | 1,500 | Jul 6, 2018 · 9:45 pm EDT | Form 4 |
Balances come from each insider’s most recent filing that reports a Table I holding; an insider who left the company years ago still appears with their last-known figure and its date. Indirect totals collapse multiple vehicles (trusts, LLCs) into one number — open the filing for the breakdown. Shares as filed, not split-adjusted.