Investigational Rinatabart Sesutecan (Rina-S) Shows Promising Anti-Tumor Activity as Single Agent in Heavily Pretreated Patients with Ovarian and Endometrial Cancers in Phase 1/2 Clinical Trial

Media Release

COPENHAGEN, Denmark; September 15, 2024

• Treatment with rinatabart sesutecan (Rina-S) showed encouraging response rate in heavily pretreated patients with ovarian cancer in dose expansion cohort
• Responses with Rina-S were observed across FRα expression levels
• Phase 3 trial will further evaluate the safety and efficacy of Rina-S at 120 mg/m² in patients with advanced ovarian cancer
  
  

Genmab A/S (Nasdaq: GMAB) announced today new data from the Phase 1/2 study of rinatabart sesutecan (Rina-S), an investigational folate receptor-alpha (FRα)-targeted, Topo1 antibody-drug conjugate (ADC), demonstrated a confirmed objective response rate (ORR) of 50.0% (95% CI) in ovarian cancer patients treated with Rina-S 120 mg/m² once every 3 weeks (Q3W), regardless of FRα expression levels. These data were from the dose expansion part of a multi-part study evaluating the safety and efficacy of single-agent Rina-S in ovarian cancer (OC) and endometrial cancer (EC). These results, and additional findings from the study, were presented at the European Society of Medical Oncology Congress 2024 (ESMO) in Barcelona, Spain.

Part B of the study randomized 42 previously-treated patients with histologically or cytologically confirmed advanced OC (epithelial ovarian cancer, primary peritoneal cancer or fallopian tube cancer) to Rina-S 100 mg/m² (n=22) or Rina-S 120 mg/m² (n=20). Ninety-five percent of patients in the 120 mg/m² group were identified as platinum-resistant ovarian cancer (PROC) as were 90.9% of patients in the 100 mg/m² group. In patients receiving Rina-S 100 mg/m², results showed a confirmed ORR of 18.2% compared with 50.0% among patients receiving 120 mg/m². Results for 100 mg/m² and 120 mg/m² respectively also included: complete response: 0 (0%) and 1 (5.6%); partial response in 4 (18.2%) and 8 patients (44.4%); stable disease in 15 (68.2%) and 7 patients (38.9%); disease progression in 3 patients (13.6%) and 1 patient (5.6%). Only one patient in the 120 mg/m² treatment arm was not evaluable. With a median on study follow-up of 24 weeks, all confirmed responses with the 120 mg/m² dose were ongoing at the time of data cutoff. The disease control rate (DCR) was 86.4% and 88.9% (95% CI: 65.3-98.6), respectively. Based on these results, Rina-S 120 mg/m² has been selected for further evaluation in a Phase 3 trial for patients with advanced ovarian cancer, which is expected to start in 2024.