Harpoon Therapeutics Announces Completion of Planned Patient Enrollment in Phase 1 Study of HPN217 in Relapsed/Refractory Multiple Myeloma

Harpoon Therapeutics, Inc. recently announced the completion of planned patient enrollment in the Phase 1 dose escalation study evaluating the safety, tolerability, and pharmacokinetics of HPN217 in patients with relapsed/refractory multiple myeloma. Additional patients currently in screening will also be allowed to enroll.

“Completing enrollment in the Phase 1 trial of HPN217 is an important step towards potentially bringing this therapy to patients with advanced disease who have progressed after prior treatments,” said Luke Walker, MD, Chief Medical Officer of Harpoon Therapeutics. “I would like to thank our patients and their caregivers, as well as our clinical partners and dedicated team of employees who have participated in this Phase 1 trial and advanced the development of HPN217.”

“We are pleased to have achieved this important milestone for Harpoon, with the enrollment of the first of our two TriTAC clinical compounds having completed dose escalation as planned,” added Julie Eastland, President and CEO of Harpoon Therapeutics. “The identification of the recommended dose(s) for Phase 2 and the presentation of Phase 1 data is anticipated by the end of 2023.”

HPN217 is being evaluated in an ongoing Phase 1, multicenter, open-label dose escalation study designed to evaluate safety, tolerability, pharmacokinetics (PK) and clinical activity in patients with relapsed/refractory multiple myeloma who have had at least three prior systemic treatments, including a proteasome inhibitor, an immunomodulatory drug and an anti-CD38 antibody, including patients with prior exposure to BCMA therapy. Primary objectives are characterization of safety, tolerability, PK and determination of the recommended Phase 2 dose. For additional information about the trial, please visit www.clinicaltrials.gov using the identifier NCT04184050.

HPN217 targets B-cell maturation antigen (BCMA) 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. HPN217 is being evaluated in an ongoing Phase 1, multicenter, open-label dose escalation study designed to evaluate safety, tolerability, pharmacokinetics (PK) and clinical activity in patients with relapsed/refractory multiple myeloma who have had at least three prior systemic treatments.

In November 2019, Harpoon Therapeutics and AbbVie announced a licensing agreement and option to advance HPN217 and expand an existing discovery collaboration. Under the terms of the agreement, AbbVie may exercise its option to license HPN217 after completion of the Phase 1 clinical trial. In March 2022, the FDA granted Fast Track designation to HPN217, underscoring its potential to address a serious unmet medical need for patients with relapsed, refractory multiple myeloma.

Harpoon Therapeutics is a clinical-stage immuno-oncology 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 more information, visit www.harpoontx.com.