Harpoon Therapeutics Inc. (HPTX) stock experienced a significant event on June 17, 2024, when it announced a definitive agreement to be acquired by AbbVie Inc. (ABBV) for $24.00 per share in cash, totaling approximately $1.0 billion [1]. This news led to a substantial increase in Harpoon Therapeutics' stock price following the announcement [1][2].
Why is AbbVie acquiring Harpoon Therapeutics?
AbbVie is acquiring Harpoon Therapeutics to gain access to its innovative pipeline of T-cell engagers, specifically its lead product candidate, HPN328. This therapy is designed to target DLL3 and is intended for patients with small cell lung cancer (SCLC) and other neuroendocrine tumors [1]. The acquisition is expected to bolster AbbVie's oncology portfolio [1][3].
What is Harpoon Therapeutics' lead product candidate?
Harpoon Therapeutics' lead product candidate is HPN328 [1]. This is a T-cell engager developed using the company's TriTAC technology [4]. HPN328 targets DLL3, a protein often found on cancer cells in SCLC and other neuroendocrine tumors [1][4].
What is the significance of HPN328 targeting DLL3?
DLL3 is a protein that is expressed at high levels on SCLC and other neuroendocrine tumor cells, but minimally on normal tissues [4]. This makes it an attractive target for therapies that can selectively eliminate cancer cells while sparing healthy ones. HPN328 is designed to bind to both DLL3 on cancer cells and CD3 on T-cells, bringing the T-cells into close proximity with the cancer cells to initiate an immune response and kill them [4].
How does Harpoon's TriTAC technology work?
Harpoon Therapeutics' TriTAC (Trifunctional T-cell Activating Conjugate) platform is designed to create therapies that bring T-cells into contact with cancer cells [4]. The TriTACs have three components: one that binds to the target antigen on the cancer cell (like DLL3), one that binds to CD3 on T-cells, and a third component that is designed to enhance T-cell activation and effector function [4].
What is the current status of HPN328's clinical development?
HPN328 is currently being evaluated in a Phase 1/2 clinical trial, called the "Discovery" study, in patients with DLL3-expressing SCLC and other neuroendocrine tumors [1][4]. Preliminary data from this study have shown promising signs of efficacy, including tumor responses and a manageable safety profile [1][4].
When is the AbbVie acquisition of Harpoon Therapeutics expected to close?
The acquisition of Harpoon Therapeutics by AbbVie is expected to close in the second half of 2024, subject to customary closing conditions, including the approval of Harpoon stockholders and regulatory approvals [1].
What are the implications of this acquisition for Harpoon's other programs?
While the primary focus of the acquisition is HPN328, AbbVie will also gain access to Harpoon's other product candidates, including HPN239, which targets PSMA for prostate cancer, and HPN424, targeting BCMA for multiple myeloma [1][3]. These programs also utilize Harpoon's T-cell engager technology [4].
Sources:
[1] https://www.drugpatentwatch.com/news/abbvie-to-acquire-harpoon-therapeutics-for-1-billion
[2] https://www.drugpatentwatch.com/companies/harpoon-therapeutics-inc
[3] https://www.drugpatentwatch.com/companies/abbvie-inc
[4] https://www.drugpatentwatch.com/news/harpoon-therapeutics-presents-updated-clinical-data-from-hpn328-discovery-trial