A recent study has found that the combination of temozolomide (T), vincristine (V), and irinotecan (I), may be the best standard of care for all patients (children and adults) diagnosed with relapsed or refractory rhabdomyosarcoma. This Phase 2 study has been published in the Journal of Clinical Oncology.
The Study
The Phase 2 investigation included 120 patients who were given either VI (60 patients) or VIT (60 patients). There was a median age of 11 years. Additionally, 89% of the patients were diagnosed with relapsed disease at the start of the trial. All patients were given vincristine at 1.5mg/m2 on the first day and on day 8. They were given irinotecan at 50mg/m2 on day 1 through day 5. Those receiving temozolomide were given it at 125mg/m2 on the first day through day 5. On the 2nd cycle, this increased to 150mg/m2.
All patients were on a 21-day treatment cycle. Treatment was stopped if there was disease progression or high levels of toxicity. 55 patients did experience progressed disease and stopped the treatment before the trial was over. Further, 13 left the trial due to toxicity. 16 patients were able to receive at least 12 cycles of their treatment (VI or VIT). In total, 104 patients faced progression and 91 passed away during the trial. The researchers do note that no deaths were study-related or treatment-related.
The primary endpoint of this investigation was the overall response rate after 2 cycles had passed. Also analyzed were overall survival, progression-free survival, best response, and adverse effects. 98% of people in the VIT group experienced an adverse event grade 3 or higher. In the VI group, this was just 78%. In the VIT group, 93% of all participants had an AE that was related to the treatment. This was 69% of patients in the VI group. Toxicity was 81% in the VIT group and 61% in the VI group.
Objective response rate after 2 cycles for the VIT group was 44% compared to 31% in the VI group. The VIT group had a greater reduction in risk of progression or risk of relapse. Overall survival was stable and significant in the VIT group and there were more objective responses (57%) in the VIT group than in the VI group (38%).
You can read more about this combination therapy and this trial here.
