Abstract
Long-term survival in previously treated patients with advanced melanoma receiving single-agent nivolumab (a PD-1 inhibitor) in the phase 1 CA209-003 study was comparable to that seen with current standard-of-care agents. Responses occurred early and were durable.
The 107 advanced melanoma patients enrolled had received between one and five prior lines of systemic therapy. Their mean age was 61 years (range, 29–58); 67% were male. Most patients (62%) had received two or more systemic regimens, of which 65% were immunotherapies (but not CTLA-4 or PD-1 inhibitors). At baseline, visceral metastases were present in 78% of patients, and elevated lactate dehydrogenase levels were found in 36%. Dr. Hodi emphasized that the median follow-up of 55 months in this study is longer than that of any other study of an anti-PD-1 agent.
Patients received up to 96 weeks of nivolumab at doses between 0.1 mg/kg and 10 mg/kg intravenously every two weeks. While safety and tolerability were the study’s primary objectives, preliminary efficacy was a secondary objective, and the protocol was amended to collect OS and retreatment outcomes data as well, Dr. Hodi said.
The overall response rate for all doses was 32% (34 of 107), with a median response duration of 23 months (range, 4–32). For the 3-mg/kg dose ultimately selected for phase 3 studies, the overall response rate was 41% (7 of 17), and the median duration of response was 22 months (range, 9–27).
Among responding patients, 44% (15 of 34) showed a response at the week 8 first tumor assessment. In addition, among responders who discontinued for reasons other than disease progression, responses lasted for 16 months or longer in 21 patients. Responses are ongoing in 14 patients.
OS rates with the 3-mg/kg dose (n = 17) in years 1 to 4 are 65%, 47%, 41%, and 35%, respectively, and for all the cohorts are 63%, 48%, 42%, and 32%, respectively. Dr. Hodi noted, “There is a suggestion of a plateau in the curve at this point … but further confirmation will obviously be needed in continued follow-up.”
For all cohorts, median OS was 17.3 months (95% CI, 12.5–37.8). For the 3-mg/kg dose, it was 20.3 months (7.2, NE). Median PFS was longest in the 3-mg/kg group (10 months; CI, 2–16). Median OS in this cohort was 20 months (CI, 7, NE).
Investigators also conducted an exploratory analysis of patients who entered the follow-up period with ongoing disease control (CR, partial response, or stable disease). Retreatment was permitted in these patients after confirmed disease progression at the same dose assigned for up to a total of three years. Prolonged response or stabilization of disease was observed among five patients who were retreated; an increased adrenal mass was successfully excised in one patient. “We need prospective analyses to evaluate the efficacy and safety of nivolumab retreatment,” Dr. Hodi said.
Treatment-related immune-mediated adverse events were reported in 58% of patients, with 5% of grade 3 or 4. They included skin (38%), gastrointestinal (19%), endocrine (14%), and infusion reactions (6%). Dr. Hodi noted that immune- mediated adverse events with potential immunological etiologies require more frequent monitoring and/or unique interventions. In general, Dr. Hodi said, nivolumab treatment was well tolerated, with no new safety signals after a year of follow-up.
Three ongoing phase 3 trials are evaluating nivolumab 3 mg/ kg in patients with advanced melanoma.
American Heart Association Scientific Sessions
This year’s American Heart Association (AHA) Scientific Sessions drew an estimated 17,835 cardiologists, researchers, and other health care professionals to Chicago from November 15 to 19, with 6,421 international visitors among them. Sessions of particular interest covered the thorny issue of duration of anticoagulation therapy during procedures, a novel alternative to statins, and the risks of endocarditis when dental antibiotic prophylaxis is dropped.