Genmab (GMAB) said Saturday that its investigational rinatabart sesutecan, or Rina-S, treatment achieved a 45.9% confirmed objective response rate in a phase 1/2 study of patients with platinum-resistant ovarian cancer.

Among 109 treated patients, five had no detectable signs of cancer after treatment, and the median duration of response was 12.1 months, with 51% of responders remaining in response at one year, the company said.

Genmab reported median progression-free survival of 9.5 months. Common adverse events included nausea, vomiting and constipation, among others, the company said.

About one-third of patients experienced serious side effects, while 5.5% stopped treatment because of side effects, Genmab said.

Genmab said Rina-S is being tested in additional Phase 3 studies involving ovarian and endometrial cancers, as well as other solid tumors.

Genmab shares were 1.4% higher in Monday premarket activity.