LOS ANGELES, Dec 6 (Reuters) - Allos Therapeutics Inc ALTH.O said on Saturday a small, but potentially pivotal, trial of its experimental drug pralatrexate found it helped curb cancer in 27 percent of patients with an aggressive type of lymphoma.
The trial involved previously treated patients with peripheral T-cell lymphoma — one of the most deadly and difficult-to-treat types of the white blood cell cancer. There are currently no approved treatments for PTCL.
Dr. Owen O’Connor, director of the lymphoma program at Columbia University Medical Center in New York and the trial’s lead investigator, said the study met its goals.
The 115-patient trial showed that 27 percent of patients responded to the drug and 11 percent achieved full remission.
O’Connor said 54 percent of patients enrolled in the trial had not responded to prior chemotherapy treatment.
Pralatrexate, or PDX, is designed to camouflage itself as a folic acid, which allows it to be absorbed by the tumor, where it attacks the cancer.
“The way to cure these patients is to get them into complete remission and then do a bone marrow transplant,” O’Connor said, noting PDX was also being studied as a front-line treatment in combination with chemotherapy drug gemcitabine.
Researchers found mouth sores to be a major side effect of PDX, but pre-treatment with folic acid limited the problem and allowed the use of higher doses, O’Connor said.
Side effects in the Phase 2 trial included drops in platelet counts and white blood cell function.
The trial was designed — in concert with the U.S. Food and Drug Administration — to provide enough data for a marketing application, said Allos Chief Executive Paul Berns.
He said the company planned to file for FDA approval of PDX during the first half of next year. The drug has been granted orphan status by the FDA, which gives developers a period of market exclusivity, and Allos will request a six-month priority review, Berns said.
He said Allos planned to retain U.S. rights for PDX, but was reviewing options for co-development and co-promotion outside of the United States. The company said in November it had enough cash on hand for 12 months of operations.
“There is a lot of consolidation in the industry right now. Our focus is on becoming a commercial enterprise,” Berns said.
Of the 65,000 Americans diagnosed each year with non-Hodgkin’s lymphoma, about 6,000 suffer from hard-to-treat PTCL.
Results of the trial were announced in San Francisco at a meeting of the American Society of Hematology. (Reporting by Deena Beasley; Editing by Peter Cooney)