Harpoon Therapeutics Announces Updated Interim Tolerability and Response Data from Phase 1/2 Clinical Trial of T Cell Engager HPN328 at ESMO Congress 2023
- Confirmed response rate 35% (11/31), across all tumor types and patient cohorts treated with 1 mg priming dose, including three confirmed, complete responses
- 32% (6/19) confirmed response rate in patients with small cell lung cancer (SCLC), including one confirmed complete response
- 42% (5/12) confirmed response rate in other neuroendocrine tumor types, including two confirmed complete responses
- Generally well tolerated; cytokine release syndrome (CRS) most common, predominantly low-grade, with no Gr3 CRS in 1 mg priming dose cohorts
- Enrollment in monotherapy dose cohorts nearing completion, on track to select Phase 2 dose(s) by end of 2023
- Results will be presented in a poster session at
ESMO Congress2023 on Monday, October 23, 2023and management will hold a webcast at 8:00 a.m. ET/ 2:00 p.m. CESTto review the data, following the poster presentation
HPN328 was generally well tolerated across all dose cohorts (N=71). Treatment-related adverse events (TRAEs) occurred in 67 patients (94%), and Grade ≥ 3 TRAEs in 18 patients (25%). CRS was most common (59%) and was primarily Grade 1 or 2. No dose limiting toxicities (DLT) occurred at target doses, and the target maximum tolerated dose (MTD) has not been reached as of the data cut off on
The preliminary response data for evaluable patients treated in 1 mg priming dose cohorts showed confirmed response rate of 35% (11/31) across all tumor types. In SCLC, the confirmed response rate was 32% (6/19) with one confirmed complete response. In patients with other neuroendocrine tumor types, such as prostate cancer, small cell cervical, small cell bladder, and large cell lung cancer, 42% (5/12) confirmed response rate was observed, including two confirmed complete responses in small cell bladder and small cell cervical tumor types. The duration of response data in the 1 mg priming dose cohorts continues to mature.
“HPN328’s antitumor activity and tolerability profile are promising given the aggressive nature of SCLC and other neuroendocrine tumor types included in the study. The preliminary response data from the 1 mg priming dose cohorts suggests HPN328’s activity in a broad spectrum of tumor types with similar histology,” said
“The interim data provides a solid foundation for the next steps in our future clinical development plans for HPN328, underscoring its potential to serve patients with high unmet medical needs. It enables us to rapidly move towards identifying the recommended Phase 2 regimen(s) in the monotherapy setting by the end of this year and supports the initiation of potential registrational studies in multiple tumor types in 2024,” said
The poster (presentation #698P) is now available on the ESMO website and under the Publications section on Harpoon’s website.
Webcast Registration Information
The live webcast will take place on
HPN328 targets delta-like canonical Notch ligand 3 (DLL3) and is based on Harpoon’s proprietary Tri-specific T cell Activating Construct (TriTAC®) platform designed to recruit a patient’s own immune cells to kill tumor cells. HPN328 is being evaluated as monotherapy in an ongoing open-label, multicenter two-part study to assess the safety, tolerability, and pharmacokinetics in patients with advanced cancers associated with expression of DLL3.
Harpoon Therapeutics is a clinical-stage immunotherapy company developing a novel class of T cell engagers that harness the power of the body’s immune system to treat patients suffering from cancer and other diseases. T cell engagers are engineered proteins that direct a patient’s own T cells to kill target cells that express specific proteins, or antigens, carried by the target cells. Using its proprietary Tri-specific T cell Activating Construct (TriTAC®) platform, Harpoon is developing a pipeline of novel TriTACs initially focused on the treatment of solid tumors and hematologic malignancies. Harpoon has also developed a proprietary ProTriTAC™ platform, which applies a prodrug concept to its TriTAC platform to create a therapeutic T cell engager that remains inactive until it reaches the tumor. Harpoon’s third proprietary technology platform, extended release TriTAC-XR, is designed to mitigate cytokine release syndrome. For additional information about
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Source: Harpoon Therapeutics Inc.