Phase I study of bevacizumab and temsirolimus combination therapy in advanced malignancies: safety, efficacy, and ovarian cancer expansion.

BACKGROUND

Bevacizumab and temsirolimus target angiogenic and mTOR pathways in cancer progression.

METHODS

This phase I study enrolled 48 heavily pretreated patients with advanced solid tumors, including an ovarian cancer expansion cohort. Patients received bevacizumab biweekly plus temsirolimus weekly in a 3 + 3 design to assess safety, maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs). Exploratory analyses included tumor genomic profiling and dynamic contrast-enhanced MRI (DCE-MRI).

RESULTS

Patients had a median age of 59 and median four prior therapies. Common tumor types were ovarian (27%) and head and neck (15%). Treatment-related adverse events occurred in 93.8%, with 31.3% ≥grade 3. Five patients experienced DLTs, including grade 3 enteritis, fatigue, bowel obstruction/abdominal ileus/pulmonary embolism, bowel perforation and grade 3/4 elevated liver enzymes. MTD was bevacizumab 10 mg/kg biweekly plus temsirolimus 20 mg weekly. Overall, objective response rate (ORR) was 7.3% and 19.5% achieved stable disease ≥6 months (clinical benefit rate [CBR] 26.8%). In ovarian cohort, ORR was 16.7% and CBR 33.3%. Patients with tumor regression on DCE-MRI had lower ΔKtrans values.

CONCLUSION

Combination therapy showed acceptable safety and modest activity. Molecular and imaging findings were exploratory and limited. These preliminary observations could inform future biomarker studies. (ClinicalTrials.gov Identifier: NCT01552434).