Dere Willard H has filed 24 insider transactions across 4 companies since May 2023.
Most recent transaction: a disposition of 1000 shares of Mersana Therapeutics, Inc. ($MRSN) on January 06, 2026.
| Transaction Date | Company | Ticker | Insider Name | Title | Transaction Type | Security | Shares | Price | Shares Owned Following | Total Shares Outstanding | % of Owned | % of Outstanding |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Jan. 6, 2026 | Mersana Therapeutics, Inc. | $MRSN | Dere Willard H | Director | D | Stock Option (right to buy) | 1000 | $0.00 | 0.0000 | 4,998,750 | 100.00% | 0.02% |
| Jan. 6, 2026 | Mersana Therapeutics, Inc. | $MRSN | Dere Willard H | Director | D | Stock Option (right to buy) | 2200 | $0.00 | 0.0000 | 4,998,750 | 100.00% | 0.04% |
| Jan. 6, 2026 | Mersana Therapeutics, Inc. | $MRSN | Dere Willard H | Director | D | Stock Option (right to buy) | 734 | $0.00 | 0.0000 | 4,998,750 | 100.00% | 0.01% |
| Jan. 6, 2026 | Mersana Therapeutics, Inc. | $MRSN | Dere Willard H | Director | D | Stock Option (right to buy) | 1800 | $0.00 | 0.0000 | 4,998,750 | 100.00% | 0.04% |
| Jan. 6, 2026 | Mersana Therapeutics, Inc. | $MRSN | Dere Willard H | Director | D | Stock Option (right to buy) | 513 | $0.00 | 0.0000 | 4,998,750 | 100.00% | 0.01% |
| Jan. 6, 2026 | Mersana Therapeutics, Inc. | $MRSN | Dere Willard H | Director | D | Stock Option (right to buy) | 1002 | $0.00 | 0.0000 | 4,998,750 | 100.00% | 0.02% |
| Jan. 6, 2026 | Mersana Therapeutics, Inc. | $MRSN | Dere Willard H | Director | D | Stock Option (right to buy) | 125 | $0.00 | 0.0000 | 4,998,750 | 100.00% | 0.00% |
| Jan. 6, 2026 | Mersana Therapeutics, Inc. | $MRSN | Dere Willard H | Director | D | Stock Option (right to buy) | 368 | $0.00 | 0.0000 | 4,998,750 | 100.00% | 0.01% |
| Jan. 6, 2026 | Mersana Therapeutics, Inc. | $MRSN | Dere Willard H | Director | D | Stock Option (right to buy) | 450 | $0.00 | 0.0000 | 4,998,750 | 100.00% | 0.01% |
| Jan. 6, 2026 | Mersana Therapeutics, Inc. | $MRSN | Dere Willard H | Director | U | Common Stock | 1567 | $0.00 | 0.0000 | 4,998,750 | 100.00% | 0.03% |
| Jan. 6, 2026 | Mersana Therapeutics, Inc. | $MRSN | Dere Willard H | Director | D | Stock Option (right to buy) | 2460 | $0.00 | 0.0000 | 4,998,750 | 100.00% | 0.05% |
| Jan. 6, 2026 | Mersana Therapeutics, Inc. | $MRSN | Dere Willard H | Director | D | Stock Option (right to buy) | 800 | $0.00 | 0.0000 | 4,998,750 | 100.00% | 0.02% |
| Jan. 6, 2026 | Mersana Therapeutics, Inc. | $MRSN | Dere Willard H | Director | D | Stock Option (right to buy) | 544 | $0.00 | 0.0000 | 4,998,750 | 100.00% | 0.01% |
| June 12, 2025 | Mersana Therapeutics, Inc. | $MRSN | Dere Willard H | Director | A | Stock Option (right to buy) | 61500 | $0.00 | 61,500.0000 | 124,631,339 | 9999.99% | 0.05% |
| June 10, 2025 | Metagenomi Therapeutics, Inc. | $MGX | Dere Willard H | Not found | A | Stock Option (Right to Buy) | 21000 | $0.00 | 21,000.0000 | 1,870,923 | 9999.99% | 1.12% |
| May 20, 2025 | BIOMARIN PHARMACEUTICAL INC | $BMRN | Dere Willard H | Director | A | Common Stock | 6650 | $0.00 | 38,950.0000 | 196,708,000 | 20.59% | 0.00% |
| April 10, 2025 | Seres Therapeutics, Inc. | $MCRB | Dere Willard H | Not found | A | Stock Option (right to buy) | 100000 | $0.00 | 100,000.0000 | 174,358,753 | 9999.99% | 0.06% |
| June 11, 2024 | Mersana Therapeutics, Inc. | $MRSN | Dere Willard H | Director | A | Stock Option (right to buy) | 55000 | $0.00 | 55,000.0000 | 0 | 9999.99% | 0.00% |
| May 21, 2024 | BIOMARIN PHARMACEUTICAL INC | $BMRN | Dere Willard H | Director | A | Common Stock | 4720 | $0.00 | 32,300.0000 | 191,595,000 | 17.11% | 0.00% |
| April 4, 2024 | Seres Therapeutics, Inc. | $MCRB | Dere Willard H | Not found | A | Stock Option (right to buy) | 60000 | $0.00 | 60,000.0000 | 0 | 9999.99% | 0.00% |
| April 1, 2024 | Metagenomi Therapeutics, Inc. | $MGX | Dere Willard H | Not found | A | Stock Option (Right to Buy) | 78636 | $0.00 | 78,636.0000 | 3,884,740 | 9999.99% | 2.02% |
| Jan. 2, 2024 | Mersana Therapeutics, Inc. | $MRSN | Dere Willard H | Director | A | Common Stock | 6112 | $0.00 | 39,182.0000 | 0 | 18.48% | 0.00% |
| June 22, 2023 | Seres Therapeutics, Inc. | $MCRB | Dere Willard H | Director | A | Stock Option (right to buy) | 35000 | $0.00 | 35,000.0000 | 0 | 9999.99% | 0.00% |
| May 23, 2023 | BIOMARIN PHARMACEUTICAL INC | $BMRN | Dere Willard H | Director | A | Common Stock | 4190 | $0.00 | 27,580.0000 | 188,963,000 | 17.91% | 0.00% |