Cerulean Announces Completion of Enrollment of a Phase 1b/2 Study of CRLX101 in Combination with Avastin® in Relapsed Renal Cell Carcinoma

Cerulean Pharma Inc. (Nasdaq:CERU), a leader in Dynamic Tumor Targeting™, today announced completion of enrollment of 22 patients in a Phase 1b/2 clinical proof of principle trial of its lead nanoparticle-drug conjugate, CRLX101, in combination with Avastin® in relapsed renal cell carcinoma (RCC). This study is an investigator-sponsored trial (IST) being conducted by the University of Pennsylvania and Thomas Jefferson University Hospital with support from Cerulean. The Principal Investigator is Dr. Stephen Keefe of the University of Pennsylvania Abramson Cancer Center.

“We have observed in interim data a response rate that is significantly higher than what has been seen historically with standard-of-care treatments and this response rate seems to be translating into clinical benefit for those patients,” said Dr. Keefe. “This trial continues to generate promising results, and I look forward to submitting final data for presentation at an upcoming medical meeting.”

Data previously presented from the first 11 patients from this study showed a 27% response rate (three RECIST responses) in a setting where standard of care historically provides only a 2-4% response rate. A 7.6 months median progression-free (PFS) survival was observed, which is double the roughly 3.5 months PFS achieved by standard-of-care in this setting. Based on these data, Cerulean launched a company-sponsored randomized Phase 2 trial of CRLX101 in combination with Avastin in 3rd and 4th line RCC in August 2014, which is currently ongoing.

About CRLX101

CRLX101 is a dynamically tumor-targeted nanoparticle-drug conjugate (NDC) designed to concentrate in tumors and slowly release its anti-cancer payload, camptothecin, inside tumor cells. CRLX101 inhibits topoisomerase 1 (topo 1), which is involved in cellular replication, and hypoxia-inducible factor-1α (HIF-1α), which research suggests is a master regulator of cancer cell survival mechanisms thought to promote drug and radiation resistance. CRLX101 has shown activity in four tumor types in late stage disease and in a front line setting, and it has shown activity as monotherapy and in combination with other cancer treatments. CRLX101 is currently in Phase 2 clinical development and has been dosed in more than 250 patients.

About Cerulean’s Dynamic Tumor Targeting™ Platform

Cerulean’s Dynamic Tumor Targeting Platform creates NDCs that are designed to provide safer and more effective cancer treatments. We believe our NDCs concentrate their anti-cancer payloads inside tumors while sparing normal tissue because they are small enough to pass through the “leaky” vasculature present in tumors but are too large to pass through the wall of healthy blood vessels. Once inside tumors, our NDCs enter tumor cells where they slowly release anti-cancer payloads from within the tumor cells.

About Cerulean Pharma

The Cerulean team is committed to improving treatment for people living with cancer. We apply our Dynamic Tumor Targeting Platform to create a portfolio of nanoparticle-drug conjugates, or NDCs, designed to selectively attack tumor cells, reduce toxicity by sparing the body’s normal cells, and enable therapeutic combinations. Our lead product candidate, CRLX101, is in multiple clinical trials in combination with other cancer treatments, all of which aim to unlock the power of combination therapy. For more information, please visit www.ceruleanrx.com.

Cautionary Note on Forward Looking Statements

Any statements in this press release about our future expectations, plans and prospects, including statements about the clinical development of our product candidates, statements about our estimated research and development expenses and sufficiency of cash to fund specified use of cash and other statements containing the words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “would,” and similar expressions, constitute forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including: the uncertainties inherent in the initiation of clinical trials, availability and timing of data from ongoing and future clinical trials and the results of such trials, whether preliminary results from a clinical trial will be predictive of the final results of that trial or whether results of early clinical trials will be indicative of the results of later clinical trials, expectations for regulatory approvals, availability of funding sufficient for our foreseeable and unforeseeable operating expenses and capital expenditure requirements and other factors discussed in the “Risk Factors” section of our Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 13, 2014 and in other filings that we make with the Securities and Exchange Commission. In addition, any forward-looking statements included in this press release represent our views only as of the date of this release and should not be relied upon as representing our views as of any subsequent date. We specifically disclaim any obligation to update any forward-looking statements included in this press release.

Avastin® is a trademark of Genentech Inc.