A month after filing a new drug application for Treanda in chronic lymphocytic leukemia, Cephalon Inc. said the drug met its endpoint in a pivotal trial in indolent non-Hodgkin's lymphoma patients who are refractory to rituximab.

Results from the 100-patient Phase III, single-arm study showed an overall response rate of 75 percent, as assessed by an independent radiological committee, a "fairly impressive" outcome particularly given a "difficult-to-treat population," said Jenifer Antonacci, senior manager of public relations for Frazer, Pa.-based Cephalon. Overall response includes patients in the trial who had complete, unconfirmed complete or partial response to treatment.

The drug also showed a median duration of response of 40 weeks, or 9.2 months. Antonacci said that detailed data from the study will be submitted at the American Society of Hematology meeting in December, but the company remains "on track to file an NDA before the end of the year" in relapsed, rituximab-refractory NHL. "Hopefully, we'll have a new treatment option for patients in 2008," she told BioWorld Today.

News of the Phase III data lifted Cephalon's stock (NASDAQ:CEPH) $2.71 Wednesday to close at $73.79.

About 30,000 patients in the U.S. are diagnosed each year with indolent NHL, a slow-growing cancer of the lymphatic system, and many are treated with Rituxan, a monoclonal antibody from South San Francisco-based Genentech Inc. and Cambridge, Mass.-based Biogen Idec Inc. While Treanda, if approved, would be used to treat those patients whose diseases relapse following Rituxan treatment, the bigger market potential for Cephalon's drug likely would be as a first-line therapy in combination with Rituxan.

Analyst Megan Murphy, of New York-based Lazard Capital Markets LLC, wrote in a research note that "the majority of our NHL forecast is predominately driven by combination use" in that earlier setting.

Lazard predicts that Treanda sales could reach $107 million in 2013, assuming a label expansion for combination use in 2010, as well as approval in first-line CLL. Murphy maintained a "hold" rating for the company, and investors await further Treanda data, including results from an ongoing Phase II/III study in combination with Rituxan, later this year.

Cephalon picked up rights to Treanda (bendamustine) through its 2005 acquisition of San Diego-based Salmedix Inc., which previously licensed the compound from Fujisawa Deutschland GmbH, of Munich, Germany. The drug, a purine analogue/alkylator hybrid, is designed to damage the DNA in cancer cells, while also preventing cancer cell division. It's approved outside the U.S. in multiple cancer indications, and Cephalon might investigate the product in other hematologic and solid tumor indications. "But right now, we're really focused on" CLL and NHL as near-term opportunities, Antonacci said.

The company submitted the CLL NDA last month and awaits the FDA's acceptance. Treanda previously gained orphan status in that indication and, if approved, would have seven years of marketing exclusivity. (See BioWorld Today, Sept. 24, 2007.)

Treanda's approval would give Cephalon two oncology products. The firm already markets Trisenox (arsenic trioxide) injection in relapsed or refractory acute promyelocytic leukemia. In its development pipeline, Cephalon continues advancing CEP-701, an oral, small-molecule tyrosine kinase inhibitor, which is in Phase III development for acute myeloid leukemia.

Separately, Cephalon and the FDA notified health care professionals Wednesday that the "Warning" section of the labeling for Provigil (modafinil) was updated to alert prescribers and patients about serious rash, hypersensitivity reactions and psychiatric symptoms associated with the drug. Rare cases of serious or life-threatening rash, including Stevens-Johnson syndrome, toxic epidermal necrolysis and drug rash with eosinophilia and systemic symptoms have been reported in adults and children in worldwide postmarketing experience, according to Cephalon and the FDA.

Angioedema and multi-organ hypersensitivity reactions also been have reported in postmarketing experience. Psychiatric adverse experiences, including anxiety, mania, hallucinations, and suicidal ideation, also have been reported in patients treated with Provigil.