KEYNOTE-427 is an open-label, single-arm, phase II study to look at the effectiveness of pembrolizumab as a first-line treatment for people with advanced clear cell RCC. At ESMO this year, updated efficacy, and safety results after a minimum follow-up of 41 months were presented.
This study looked at the treatment of people with RCC with pembrolizumab as their first medicine. The patients were grouped according to whether they had clear cell RCC (cohort A) or non-clear cell RCC (cohort B).
This poster presentation updated efficacy and safety results after a minimum of 41 months (nearly three and a half years) of follow-up in people with clear cell RCC (cohort A).
There were 110 patients in the study, most of whom had intermediate or poor risk RCC (61.8%). The average duration of treatment was 8.5 months, and the study continues. The data for this presentation were taken after an average of 47 months from patients entering the study.
More than a third of patients (36.4%) responded to treatment with pembrolizumab and their cancer got smaller. The average duration of this response was 19 months, and it was estimated that in 43.5% of these patients the response lasted for at least 2 years. Overall, more than two thirds (69%) had a reduction in the total number of tumours, and 19.1% had a reduction of 80% or more. Patients with intermediate or poor risk disease responded better to treatment than patients with favourable disease (39.7% versus 31%, respectively).
The average time to when the pembrolizumab stopped working and the cancer started growing again (progression-free survival) was 7.1 months and average overall survival time was 40.7 months. Nearly 20% of patients had a progression-free survival of at least 30 months and nearly two thirds (62.6%) had an overall survival time of 30 months. Both progression-free survival and overall survival time were better in patients with favourable risk disease than those with intermediate or poor risk disease.
After a minimum of 41 months follow-up, pembrolizumab was well tolerated and continues to show promising results as a first-line medicine for advanced RCC. No new or unexpected side effects to pembrolizumab were reported.