Phase Ib data indicate enduring responses to pembrolizumab in advanced melanoma
A preview of a major study to be presented at the 2016 Annual Meeting of the American Society of Clinical Oncology (ASCO) has highlighted how long-term follow-up of the KEYNOTE-001 study indicates that pembrolizumab offers a long-term survival benefit in advanced melanoma.
The follow-up data from this Phase Ib trial in advanced melanoma describe overall survival in both newly diagnosed and previously treated individuals, revealing that 40% of patients were alive 3 years after initiating therapy with pembrolizumab, with 36-month overall survival rates in both groups.
“Advanced melanoma is still a very challenging cancer, which is why it is so remarkable that such a large proportion of patients see a long-term survival benefit from this therapy,” commented lead study author Caroline Robert of the Institut Gustave-Roussy (Paris, France). “The results of this study further demonstrate the potential for long-term benefit with pembrolizumab.”
The ASCO press release gives further details on these new data in terms of remissions, with 15% of patients in this study experiencing complete remissions according to immune-related response criteria – of these individuals, 89% remain in remission.
KEYNOTE-001 involved 655 patients with advanced melanoma, 75% of whom had already received prior therapy for the disease (inclusive of individuals who had previously received therapy with ipilimumab). Those enrolled on the trial received pembrolizumab at 2 or 10 mg / kg every 3 weeks, or 10 mg / kg every 2 weeks. During the trial, 2 mg / kg every 3 weeks was determined to be the optimal dose. Patients remained on treatment until disease progression, intolerable toxicity or investigator decision.
New survival data portray a 3-year overall survival rate of 40% and median overall survival of 24.4 months. There was no difference in 3-year survival rate between individuals previously treated with ipilimumab and those who has not received the treatment (41%).
Patients within the KEYNOTE-001 trial received pembrolizumab for an average of 11.3 months. The treatment was well tolerated, with the most common adverse events reported as fatigue (40%), itchiness (28%) and rash (23%). Within the trial, 8% of patients stopped the treatment because of side effects related to pembrolizumab.
A total of 61 (9%) patients stopped pembrolizumab after a complete response was achieved, and 97% remained in remission at time of analysis.
Of the individuals who remained in remission after stopping pembrolizumab, the median time they remained in remission after stopping pembrolizumab was 10 months and ongoing.
While they caution that it is hard to make any definitive conclusions based on this single-arm, early phase trial, the researchers state that these encouraging survival data suggest that advanced melanoma patients can benefit from pembrolizumab regardless of whether they received previous treatments.
Source: ASCO press release
