At the American Society of Clinical Oncology (ASCO) Annual Meeting this week, the results from a phase 3 study looking at the effect of adjuvant therapy with everolimus, a type of mTOR inhibitor were presented. The people in this study had cancer that had not yet spread but who were at high risk of their cancer coming back.
There were 1545 patients in the study. Half of these patients were randomly allocated to be given everolimus, the other half were given a placebo tablet. All patients had an intermediate to high risk of their cancer returning. Most patients had clear cell kidney cancer, 17% had non-clear cell kidney cancer.
Patients were followed for an average of more than 6 years. During this time, everolimus improved cancer-free survival compared to placebo, but the difference was not significant (64% compared to 61% at 6 years). Overall survival time was similar for both the everolimus group and the placebo group. More people withdrew due to side effects from everolimus (37% versus 5%), most being serious or life-threatening.
In conclusion, everolimus improved cancer-free survival after nephrectomy in people with kidney cancer that was at intermediate or high risk of returning, but the difference compared to placebo was not significant. This was despite a high rate of people stopping treatment due to side effects. In patients with a very high risk of their cancer returning, there was a 21% improvement in cancer-free survival with everolimus treatment. Adjuvant therapy with everolimus may be most relevant in this group of people.