Opdivo, a blockbuster anti-PD-1 immune checkpoint inhibitor, is already approved for many types of cancer, including non small-cell lung cancer and metastatic melanoma. It can be prescribed alone or in combination with Yervoy (ipilimumab), another checkpoint inhibitor. Opdivo competes with Merck’s Keytruda (pembrolizumab), also approved for many types of cancer.
DS-8201 is an investigational antibody-drug conjugate. It consists of an antibody that binds to a target protein (in this case, HER2), and releases a toxic compound when engulfed by the cancer cell. DS-8201 is currently in Phase 1 clinical trials for several cancer types; the U.S. Food and Drug Administration recently granted DS-8201 breakthrough therapy status for HER2+ breast cancer patients who had failed previous treatments.
With this partnership, investigators hope the two drugs will have a combined effect that improves outcomes for patients with HER2+ metastatic breast and bladder cancers.
“We are excited to evaluate if the combination of these two mechanisms of action – the ability of an anti-PD-1 to harness the immune system and the potential of DS-8201 to deliver chemotherapy directly to target cancer cells – may be able to improve the outcomes of patients with HER2-expressing advanced breast and bladder cancer,” Dr. Antoine Yver, executive vice president and global head of Daiichi Sankyo’s oncology research and development unit, said in a press release.
“Combination therapy with agents that target different and complementary pathways — in this case, the combination of a checkpoint inhibitor and innovative chemotherapy delivery — is a potential new approach for patients with difficult-to-treat cancers,” added Dr. Fouad Namouni, head of development at Bristol-Myers Squibb’s oncology division.
The Phase 1b trial will have two parts. The first dose-escalation study will determine the best DS-8201 dose to be used in combination with Opdivo in patients with HER2+ breast cancer who have failed standard treatments. The second dose-expansion study will assess efficacy, safety and tolerability of the established DS-8201 dose, together with Opdivo, in patients with HER2+ advanced metastatic breast cancer or bladder cancer. Eligible patients must have received prior chemotherapy treatment.
The study, led by Daiichi, will likely start in Europe and the United States early next year.