Merck (MSD), through a subsidiary, has agreed to acquire immunotherapy company Harpoon Therapeutics for $680 million.
The acquisition includes HPN328, an investigational delta-like ligand 3 (DLL3) targeting T-cell engager being evaluated in certain patients with small cell lung cancer and neuroendocrine tumours.
The announcement follows the news that Merck agreed a deal with Inspirna for colorectal cancer drug ompenaclid (RGX-202).
“At Merck, we continue to enhance our oncology pipeline through strategic acquisitions that complement our current portfolio and advance breakthrough science to help address the needs of people with cancer worldwide,” said Dr Dean Li, President, Merck Research Laboratories. “This agreement reflects the creativity and commitment of scientists and clinical development teams at Harpoon. We look forward to further evaluating HPN328 in innovative combinations with other pipeline candidates.”
Harpoon has a portfolio of T-cell engagers developed using the Tri-specific T cell Activating Construct (TriTAC) platform, designed to direct a patient’s own immune cells to kill tumour cells, and ProTriTAC platform, applying a prodrug concept to create a therapeutic T-cell engager that is designed to remain inactive until it reaches the tumour.
“At Harpoon, we have always been committed to advancing our cancer immunotherapy candidates to improve the lives of patients. With Merck’s recognised leadership in oncology clinical development and global commercial footprint, our lead candidate, HPN328, is well positioned moving forward,” said Julie Eastland, President and Chief Executive Officer, Harpoon Therapeutics.
Harpoon’s oncology pipeline
Harpoon’s lead candidate, HPN328, is a T-cell engager targeting delta-like ligand 3 (DLL3), an inhibitory canonical Notch ligand that is expressed at high levels in small cell lung cancer (SCLC) and neuroendocrine tumours.
HPN328 is currently being evaluated in a Phase I/II clinical trial evaluating HPN328 monotherapy in patients with advanced cancers associated with expression of DLL3. The study is also evaluating HPN328 in combination with atezolizumab in patients with SCLC.
In October 2023, Harpoon announced the presentation of positive interim tolerability and response data for HPN328 in certain patients with SCLC and neuroendocrine tumours.
Additional pipeline candidates include HPN217 targeting B-cell maturation antigen (BCMA), currently in Phase I clinical development for relapsed/refractory multiple myeloma, and several preclinical stage candidates, including HPN601, a conditionally activated targeting epithelial cell adhesion molecule (EpCAM) for EpCAM expressing tumours.