Extending both progression-free and overall survival, Genmab’s Rina-S “sets a high bar for future competition” in a market served by AbbVie, analysts said.
Genmab’s FRα-directed antibody-drug conjugate has improved survival in a Phase 3 study, putting the biotech on track to challenge AbbVie for an ovarian cancer market.
The clinical trial, RAINFOL-02, compared Genmab’s rinatabart sesutecan (Rina-S) to the investigator’s choice of chemotherapy in 584 people with platinum-resistant ovarian cancer (PROC). In the intent-to-treat (ITT) population, the company linked Rina-S to a 71% reduction in the risk of disease progression or death, hitting its primary progression-free survival (PFS) endpoint, according to Genmab’s Friday announcement.
Genmab also reported a 57% reduction in the risk of death on Rina-S, meeting the trial’s key secondary endpoint of overall survival (OS). The magnitude of effect on PFS and OS “exceeds investor expectations and sets a high bar for future competition in ovarian cancer,” William Blair analysts said in a Friday note to investors.
Genmab’s stock popped more than 8% Friday and continued climbing over the weekend, now sitting at $43.70, as compared to $39.84 at market open on Oct. 23.
Truist Securities analysts compared Genmab’s results favorably to data on Elahere, AbbVie’s FRα-directed ADC. In the Phase 3 MIRASOL trial, researchers linked Elahere to a 35% reduction in the risk of disease progression or death and a 33% reduction in the risk of death.
Genmab’s Phase 3 Rina-S data “underpins our confidence that this drug will escalate in status to be the dominant ADC in Gyn Onc indications,” Leerink Partners analysts said in a Friday note to investors. Truist analysts were similarly bullish, telling investors the same day that the data “establish Rina-S as a potential new standard of care across broad PROC.”
The prediction that Rina-S will be used “across broad PROC” is underpinned by the patient population in RAINFOL-02. Genmab’s ITT population included patients regardless of FRα expression. Elahere is used in FRα-positive patients identified using a companion diagnostic. Winning approval across FRα levels would double the addressable population compared to Elahere, Raghuram Selvaraju, managing director of Healthcare Equity Research at H.C. Wainwright, recently told BioSpace by email.
Genmab plans to discuss the Phase 3 results with regulatory authorities worldwide. Encouraged by the data, Leerink analysts raised their probability of success for Rina-S in PROC from 90% to 100%. The analysts are increasingly confident that Genmab can secure priority FDA review, positioning the biotech to file for approval in the first quarter of 2027 and launch Rina-S in the U.S. late next year.
Genmab is also developing Rina-S in platinum-sensitive and earlier-line ovarian cancer, as well as endometrial cancer, non-small cell lung cancer and advanced gastrointestinal cancers.
The RAINFOL-02 victory means Genmab has made a winning start to a sequence of three key readouts. Facing the loss of royalties from Darzalex, its Johnson & Johnson–partnered cancer drug, toward the end of the decade, Genmab has invested in Rina-S and two other programs to establish new growth drivers.
One of the programs, the AbbVie-partnered Epkinly, recently delivered positive Phase 3 data. Genmab is closing in on Phase 3 data on the third asset, the EGFR/LGR5 bispecific petosemtamab, in head and neck squamous cell carcinoma.
The company shared Phase 2 data on petosemtamab in colorectal cancer (CRC) at the European Society of Medical Oncology meeting in Madrid. Leerink analysts raised their probability of success in first- and second-line CRC from 0% to 40% in response to the update.
