Brain metastases resulting from the spread of renal cell carcinoma (RCC) are especially difficult to treat because drugs are stopped from getting to the brain by a membrane called the blood-brain barrier. Most patients with brain metastases have, therefore, been excluded from phase 3 clinical trials. In the phase 3/4 CheckMate 920 study, presented at the American Society for Clinical Oncology (ASCO)Annual Meeting at the weekend, the combination of nivolumab/ipilimumab was assessed in patients with advanced RCC for the treatment of brain metastases.
This study looked at 28 previously untreated patients with brain metastases from RCC that were not causing symptoms (asymptomatic). Of these patients, 14.3% had sarcomatoid RCC. Patients were treated with the nivolumab/ipilimumab combination for up to 2 years. In 31% of patients the brain metastases reduced in size, there were no complete responses, 8 partial responses and 10 patients had stable disease. The average time to response was 2.8 months and the average duration of response was two years. A quarter of patients had progression of their brain metastases. The average time to when the treatment stopped working and the cancer started growing again was 9 months. The trial remains ongoing to collect more information on overall survival times.
There were a few serious or life-threatening side effects to treatment, such as diarrhoea/colitis (7.1%), inflammation of the pituitary gland (3.6%), rash (3.6%), hepatitis (3.6%), and diabetes (3.6%).
This study showed that in patients with previously untreated metastatic RCC and brain metastases, patients with a high unmet medical need, the nivolumab/ipilimumab combination followed by nivolumab had manageable side effects and promising anti-cancer activity with longer follow-up.