Celator Pharmaceuticals raised $20 million in a Series D private equity financing. Proceeds will support ongoing clinical trials and activities related to advancing the company's lead product, CPX-351 (cytarabine:daunorubicin) Liposome Injection as a treatment for acute myeloid leukemia (AML).
The round was led by a new investor, Thomas, McNerney & Partners, with participation by current investors Domain Associates, Ventures West Capital, Quaker BioVentures, TL Ventures, GrowthWorks Capital, and BDC Venture Capital. Joining Celator's Board of Directors is Alex Zisson, partner, Thomas, McNerney & Partners.
"Earlier this year we announced that CPX-351 achieved a statistically significant improvement in complete remissions in newly diagnosed, elderly AML patients compared to the standard of care in a randomized Phase II study,” notes Scott Jackson, CEO of Celator. “We look forward to disclosing these results and other data later this year."
CPX-351 represents a new approach to developing combinations of drugs in which drug molar ratios with synergistic antitumor activity are encapsulated in a drug delivery vehicle to maintain the desired ratio following administration. For most patients with cancer, standard of care usually involves the use of combinations of individual drugs. Therapies are usually combined at their maximum tolerated dose (MTD) but do not always result in treatments with maximum clinical benefit. For example, combining drugs at their synergistic ratio is not enough, Celator reports. Without technology to maintain that ratio in patients, the individual drugs will be metabolized independently and at different rates. As a result, the ratio of drugs will change over time and may negatively impact their effectiveness.
Based on the concept of synergistic ratios, Celator has identified a number of ratio-dependent chemotherapy drug combinations. Celator uses its CombiPlex technology, which incorporates high-throughput screening and mathematical algorithms for synergy analysis, to screen and measure the synergistic benefit of drug ratios in panels of tumor cells. A key advantage of the CombiPlex technology platform, the company points out, is the ability to overcome the inherently dissimilar pharmacokinetics of individual drugs. This makes it possible to maintain synergistic ratios after administration to patients. The technology’s particulate delivery system uses liposomes, polymers, and nanotechnologies specially formulated to control the distinct pharmacokinetics of individual drugs.
CPX-351 has been granted orphan drug status by the FDA for AML. Celator is currently conducting two randomized Phase II studies with CPX-351. One compares CPX-351 versus the standard "7+3" regimen of cytarabine:daunorubicin in patients between 60 and 75 years with newly diagnosed AML. The primary efficacy endpoint of the study, the rate of patients achieving a complete remission with CPX-351 compared to "7+3," achieved statistical significance. In addition, the company reported a reduction in the 30-day and 60-day mortality with CPX-351 versus the "7+3" regimen.
The second randomized Phase II study is comparing CPX-351 versus intensive salvage therapy in patients between 18 and 65 years with AML in first relapse. Enrollment is expected to be completed in 2010. This study is supported by The Leukemia & Lymphoma Society.
Celator's clinical-stage pipeline also includes CPX-1 (irinotecan:floxuridine) Liposome Injection, which is in Phase II development as a treatment for colorectal cancer. The firm has two preclinical candidates: CPX-571 (irinotecan:cisplatin) for small-cell lung cancer and CPX-8XY, which has not yet been designated to an indication. Celator also has research collaborations with Cephalon and the NCI's Nanotechnology Characterization Laboratory.