Why is Genmab stock rallying today?

Genmab stock experienced a significant 3.7% rise, reaching DKK 2,341, following the company's announcement of positive outcomes from Part C of its Phase 1/2 RAINFOL-01 study. This study, centered around rinatabart sesutecan (Rina-S), an antibody-drug conjugate targeting folate receptor alpha (FRα), showed promising results in patients with platinum-resistant ovarian cancer, a group with limited effective treatment options.

The data revealed a confirmed objective response rate of 45.9% among the 109 enrolled patients, including five complete responses. Notably, the antitumor activity of Rina-S was observed across all FRα expression levels, a feature that significantly expands the potential patient population when compared to existing FRα-targeted therapies.

The data from the study was initially presented at the International Gynecologic Cancer Society Congress in Montreal on October 3, 2026, with the Copenhagen market reacting when normal trading resumed. Despite the broader Danish equity market facing persistent selling pressure, Genmab's pipeline news was the primary driver of its stock movement.

The U.S. indices remained relatively stable, with no global market trends dampening the enthusiasm for the Rina-S data. An additional catalyst for the stock's rise came from an extraordinary general meeting scheduled for October 7. The robustness and long-lasting effects of the Rina-S response data, combined with the drug's activity regardless of FRα expression and four ongoing Phase 3 trials in ovarian and endometrial cancer, provided investors with compelling reasons to bid the shares to a new 52-week high, highlighting the growing confidence in Genmab's oncology pipeline.