Dere Willard H (CIK 1311569) reported 2 SEC Form 4 insider transactions across 2 companies over the past 18 months (most recent 2026-01-06). Recent activity: Sell MRSN (1,567 shares), Buy BMRN (6,650 shares). Source: SEC Form 4.
| Date | Company | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-01-06 | Mersana Therapeutics, Inc. (MRSN) | Director | Sell | 1,567 | $0 |
| 2025-05-22 | BIOMARIN PHARMACEUTICAL INC (BMRN) | Director | Buy | 6,650 | $0 |
Source: SEC Form 4 filings · as of 2026-01-06