Harpoon built small T-cell engager proteins that link a patient's T cells to tumour cells, including HPN328, which targets DLL3 on small cell lung cancer and neuroendocrine tumours. Merck bought the company in early 2024 for about $680 million.
Harpoon Therapeutics was a South San Francisco clinical-stage company that developed T-cell engagers on its Tri-specific T cell Activating Construct (TriTAC) platform and the ProTriTAC prodrug platform, which keeps the engager inactive until it reaches the tumour. Lead candidate HPN328 is a DLL3-targeting T-cell engager evaluated in patients with small cell lung cancer and neuroendocrine tumours. On 8 January 2024 Merck agreed to acquire Harpoon for $23.00 per share in cash, an approximate total equity value of $680 million, and the merger completed on 11 March 2024, after which Harpoon's Nasdaq listing (HARP) ended. Merck said it would evaluate HPN328 in combinations with its pipeline. The harpoontx.com domain now redirects to merck.com.
Investors not recorded; see the round sources.
| Round | Year | Amount | Source |
|---|---|---|---|
| Acquisition · $23.00 per share in cash, approximate total equity value $680 million; announced 8 January 2024, completed 11 March 2024 | 2024 | $680M | sec.gov |
Amounts only where the cited source states them. Rounds without a public source are not listed.
Shares DLL3, Small-cell lung cancer.
Shares DLL3, Small-cell lung cancer.
Shares CD3, T-cell engagers (bispecific).
Shares DLL3, T-cell engagers (bispecific), Small-cell lung cancer.
Shares T-cell engagers (bispecific), Small-cell lung cancer.
Shares T-cell engagers (bispecific), Small-cell lung cancer.
Shares DLL3, Small-cell lung cancer.
Shares CD3, T-cell engagers (bispecific).