Cerulean Pharma has reported topline data from a phase Ib/II trial of its lead nanoparticle-drug conjugate CRLX-101 in combination with bevacizumab in relapsed renal cell carcinoma (RCC) (ClinicalTrials.gov Identifier NCT01625936). The ongoing 22-patient study is an investigator-sponsored trial conducted at the University of Pennsylvania and Thomas Jefferson University Hospital with support from Cerulean. The last patient was enrolled in December last year. The trial met its primary endpoint of at least 50% of patients achieving 4 months of progression-free survival (PFS). At the time of data collection last month, preliminary topline data showed a median PFS of 9.9 months.
The current standard of care in the third- and fourth-line setting for the treatment of relapsed RCC provides approximately 3.5 months of PFS. At data collection, the RECIST response rate from this trial was 23%, which compares with a response rate of 2-4% on standard of care. CRLX-101 and Avastin have been generally well tolerated with no unexpected toxicities. Seven patients were still being treated at the time of data collection. The median PFS supports the rationale for Cerulean's ongoing randomized phase II trial of CRLX-101 plus bevacizumab in third- and fourth-line RCC (ClinicalTrials.gov Identifier NCT02187302).
The company-sponsored trial will enroll up to 110 patients at approximately 30 U.S. centers. Up to 90 patients (45 in the treatment arm and 45 in the comparator arm) with clear cell RCC will be assessed to determine if the trial meets its primary endpoint. Up to 20 patients with non-clear cell RCC will be evaluated separately for response rate and PFS. For the primary endpoint, the trial is powered to show a 2.3-month improvement in median PFS over an expected 3.5 months in the comparator arm. Cerulean expects to release topline primary endpoint data and overall response rate data from this trial in the second quarter of next year (Cerulean Pharma News Release).