CHICAGO, IL— Nivolumab appears to be safe and shows some promise of efficacy against advanced ovarian cancer, according to data from a small phase 2 clinical study presented at the 2014 American Society of Clinical Oncology (ASCO) Annual Meeting.
Nivolumab at 1 mg/kg “is well tolerated for platinum resistant recurrent or refractory and has encouraging clinical efficacy for advanced or relapsed, platinum-resistant [patients with] ovarian cancer,” reported lead author Junzo Hamanishi, MD, PhD, of Kyoto University in Kyoto, Japan, and coauthors.
This is the first clinical trial of nivolumab treatment against ovarian cancer, Dr. Hamanishi noted.
PD-1 is a co-inhibitory receptor expressed on activated immune T cells, and regulates antitumor immune response. Nivolumab is a fully-humanized anti-PD-1 antibody. A total of 18 evaluable patients were treated with nivolumab: 10 patients were administered 1mg/kg and eight patients were administered 3 mg/kg, each every 2 weeks for 1 year. Starting at week 8, patients were assessed every 8 weeks and patients with disease progression were taken off study.
Median treatment duration was 14 weeks. There were two serious treatment-related adverse events (AEs): one patient in the 1 mg/kg group experienced grade 3 fever, disorientation, and gait disorder; and one patient in the 3 mg/kg category experienced grade 3 fever and deep-vein thrombosis. Other grade 3/4 treatment-related AEs included hypothyroidism (two patients, both in the 1 mg/kg group); heart arrhythmia (one patient, in the 3 mg/kg group); and lymphocytopenia (one patient, in the 1 mg/kg group).
“The total objective response rate was 17%” as of March 31, 2014, Dr. Hamanishi said. “The 3 mg/kg dose may be more favorable (25%) than 1 mg/kg (10%).”
Two patients in the 3 mg/kg group experienced complete response (CR; response rate 25%). Among the 10 patients receiving 1 mg/kg nivolumab, one experienced a partial response (10% response rate) and two patients experienced stable disease (SD).
“Biomarkers predicting response or adverse effect are being explored now,” Dr. Hamanishi said.
- Hamanishi J, Mandai M, Ikeda T et al. Abstract 5511. Presented at: 2014 American Society of Clinical Oncology (ASCO) Annual Meeting; May 30-June 3, 2014; Chicago, IL.