Cerulean Pharma Inc., of Cambridge, Mass., reported that an ongoing phase Ib/II trial of its lead nanoparticle-drug conjugate, CRLX101, in combination with Avastin (bevacizumab, Roche AG) in relapsed renal cell carcinoma (RCC) achieved its primary endpoint of at least 50 percent of patients achieving four months of progression-free survival (PFS).