AstraZeneca Wins EU Committee Backing for Enhertu and Klygefa

Genmab A/S announced that its investigational antibody-drug conjugate rinatabart sesutecan, known as Rina-S, achieved a confirmed objective response rate of 45.9% among 109 treated patients with platinum-resistant ovarian cancer in Part C of the Phase 1/2 RAINFOL-01 trial. The results, presented in a Late-Breaking Oral Session at the International Gynecologic Cancer Society Congress 2026 in Montreal, Canada, included five complete responses and a median duration of response of 12.1 months, with 51% of responders still in response at one year. The study also reported a median progression-free survival of 9.5 months, and antitumor activity was observed regardless of folate receptor alpha expression levels, including in patients with low expression and non-expressors, and regardless of prior treatment with mirvetuximab. More than half of patients, 53%, had received three or four prior lines of therapy, all had received prior bevacizumab and taxane therapy, 49.5% had received a prior PARP inhibitor, and 33% had received prior mirvetuximab soravtansine. The most common treatment-emergent adverse events were fatigue at 57.8% and low-grade gastrointestinal events including nausea at 67.9%, while serious adverse events were reported in approximately one-third of participants and treatment discontinuation due to adverse events occurred in 5.5%. Rina-S is being evaluated across four Phase 3 trials in platinum-resistant ovarian cancer, endometrial cancer, platinum-sensitive ovarian cancer maintenance, and second-line platinum-sensitive ovarian cancer, plus additional Phase 1/2 and Phase 2 studies.

AstraZeneca PLC, Daiichi Sankyo and Summit Therapeutics announced clinical collaboration agreements to test ivonescimab in combination with Datroway and sonesitatug vedotin across multiple tumour types, starting with a planned Phase III trial in first-line triple-negative breast cancer and gastrointestinal cancer. AstraZeneca's approximately US$2.00 billion equity investment via convertible preferred stock, alongside the co-funded oncology trials, prices the preferred stock at an implied US$18.36 per common share and targets roughly a 12% ownership stake in Summit. All parties retain full rights to their respective medicines. The investment strengthens Summit's funding and combination profile ahead of the HARMONi and HARMONi-3 readouts, though the U.S. FDA decision on the HARMONi BLA remains the key near-term catalyst and central source of risk. Summit's narrative projects $1.3 billion revenue and $223.0 million earnings by 2029, while some optimistic analysts model about US$2.7 billion of revenue and nearly US$289 million of earnings by 2029.

AstraZeneca and Daiichi Sankyo have entered a clinical trial collaboration agreement with Summit Therapeutics to evaluate Datroway, also known as datopotamab deruxtecan, in combination with Summit's ivonescimab across multiple tumor types. The companies plan to begin with a phase 3 trial in first-line triple negative breast cancer. Datroway is a specifically engineered TROP2 directed DXd antibody drug conjugate discovered by Daiichi Sankyo and jointly developed and commercialized by Daiichi Sankyo and AstraZeneca. Under the agreement, each company will contribute its respective compound for the planned combination trials, which will be sponsored by AstraZeneca or Daiichi Sankyo. AstraZeneca, Daiichi Sankyo and Summit will each contribute to trial costs, and each company will retain development and commercial rights to its respective medicines.