SEATTLE, Oct. 2, 2012 /PRNewswire/ -- Cell Therapeutics, Inc. ("CTI") (NASDAQ and MTA: CTIC) announced that OPAXIO (paclitaxel poliglumex) has been granted orphan-drug designation by the U.S Food and Drug Administration ("FDA") for the treatment of glioblastoma multiforme ("GBM"), a malignant brain cancer.
Orphan designation was granted based on preliminary activity seen from phase 2 results of OPAXIO when added to standard therapy (temozolamide ("TMZ") plus radiation). In this study, progression-free and overall survival was encouraging among patients with GBM, including patients whose tumors expressed unmethylated MGMT. Current standard therapy is less effective in patients with tumors that have unmethylated MGMT, an important DNA repair enzyme. A randomized trial is now underway for patients with GBM with unmethylated MGMT comparing standard TMZ and radiation to OPAXIO and radiation.
According to the National Cancer Institute, GBM is the most common and deadliest type of primary brain tumor in adults. It is estimated that there will be 10,000-12,000 new cases of GBM diagnosed in the US this year alone. The standard of care for patients with GBM is a surgical resection, if possible, followed by radiation given with concurrent TMZ. The prognosis for the majority of patients with GBM is poor with less than 25% of patients surviving two years with current therapies. Survival is shorter for patients whose tumors have active (unmethylated) MGMT.
Orphan-drug designation is granted by the FDA to novel drugs that seek to treat a rare disease or condition. Orphan-drug designation provides substantial potential benefits to the drug developer, including seven years of market exclusivity for the product upon regulatory approval, fee waivers and tax incentives.Under the leadership of Dr. Howard Safran at Brown University Medical Center, a multicenter Phase 2 study (BrUOG 244) has been initiated comparing the efficacy of OPAXIO plus radiation with that of TMZ plus radiation in newly-diagnosed patients with GBM and unmethylated MGMT. In approximately 55% of patients with GBM, MGMT is unmethylated, thereby decreasing the efficacy of standard therapy with TMZ plus radiation therapy ("RT"). The randomized study seeks to determine whether OPAXIO plus radiation will improve progression free survival and overall survival when compared to TMZ plus radiation, the current treatment standard in this disease. "The current randomized trial is based on the encouraging results previously demonstrated with OPAXIO and radiation in patients with newly diagnosed malignant brain cancer and specifically targets GBM patients with a genomic marker, unmethylated MGMT, who are less likely to benefit from the current standard of care TMZ and radiation," stated Howard Safran, M.D., Medical Director of the Brown University Oncology Group. "We are pleased OPAXIO has been granted orphan-drug designation as patients with this disease have a serious unmet medical need for improved long-term survival particularly when MGMT is unmethylated." About the Study The study is expected to enroll up to 120 patients. Patients in the OPAXIO arm will receive OPAXIO once every week plus RT for six weeks. Patients in the TMZ arm will receive daily oral TMZ plus RT for six weeks. After completion of initial therapy, both arms will receive maintenance TMZ on day 1-5 and then every 28 days for up to 12 cycles for a total of 48 weeks. Participating institutions include Rhode Island Hospital of Brown University, Memorial Hospital of University of Massachusetts, Maine Medical Center, Upstate Medical Center of the State University of New York (Syracuse), the University of Washington, the University of California at San Diego and Penn State Hershey Medical Center. About OPAXIO™ OPAXIO™ (paclitaxel poliglumex, CT-2103), is an investigational, biologically enhanced, chemotherapeutic that links paclitaxel, the active ingredient in Taxol®, to a biodegradable polyglutamate polymer, which results in a new chemical entity. When bound to the polymer, paclitaxel is inactive, potentially sparing normal tissue's exposure to high levels of paclitaxel and its associated toxicities. Blood vessels in tumor tissue, unlike blood vessels in normal tissue, are porous to macromolecules such as OPAXIO. Based on preclinical studies, it appears that OPAXIO is preferentially distributed to tumors due to their leaky blood vessels and trapped in the tumor bed, allowing significantly more of the dose of chemotherapy to localize in the tumor than with standard paclitaxel. Once inside the tumor cell, enzymes metabolize the protein polymer, releasing active paclitaxel. Unlike standard radiosensitizing agents, OPAXIO appears tumor selective and does not appear to enhance radiation toxicity to normal tissues.