ARIAD has provided the preliminary findings from two ongoing clinical trials. The study evaluated oral ridaforolimus in combination with trastuzumab (Herceptin) in patients with resistant, metastatic breast cancer and with bevacizumab (Avastin) in heavily pretreated patients with refractory, metastatic solid tumors.
The phase 2 clinical of Ridaforolimus combined with Trastuzumab trial was designed to test the hypothesis, that addition of ridaforolimus to trastuzumab in patients with metastatic breast cancer (who have become resistant to trastuzumab), would result in objective evidence of tumor shrinkage.
The trial is expected to enroll 33 patients. According to the protocol, the study will be considered positive if at least a 15% objective response rate (ORR) is achieved. Clinical-benefit response (CBR) will also be assessed, said the company.
Out of 28 refractory patients enrolled, 15 patients currently remain on study without disease progression, either with objective evidence of control of their disease or awaiting further assessment.
Reportedly, five partial responses have been observed, which would meet the trial’s pre specified criterion for a positive outcome, pending independent review of radiologic findings. The preliminary CBR rate in these patients with progressive, refractory disease is 35%.
Another, phase 1 clinical trial of Ridaforolimus combined with Bevacizumab in solid tumors, was designed to test the hypothesis that the addition of ridaforolimus to bevacizumab in heavily pretreated patients with metastatic solid tumors (who have become resistant to bevacizumab), could be achieved safely and would result in evidence of clinical benefit.
Over 17 patients were enrolled and treated in this study. Out of them, five patients currently remain on study without disease progression, evidence of the control of their disease. The preliminary CBR rate in these patients with progressive, refractory disease is 35%.
The longest duration of stable disease currently observed in the trial is ten cycles of therapy in a patient with advanced pancreatic cancer; this patient also had a 13% reduction in tumor size. The combination of oral ridaforolimus and bevacizumab at standard doses was well tolerated.
Harvey Berger, chairman and CEO of ARIAD, said: “We believe that the spectrum of clinical opportunities available to us continues to broaden as we obtain new data on ridaforolimus both as a single agent and in combination with various targeted agents.”
“The data from these two trials highlight the potential clinical activity of ridaforolimus in patients with difficult-to-treat, resistant and refractory cancers. Overcoming the development of drug resistance in patients with cancer represents an important challenge for new therapeutics,” he added.