Cephalon Inc., of Frazer, said today it has submitted a new drug application to the Food and Drug Administration seeking approval for its experimental cancer drug, Treanda.

The injectable drug is designed to help treat patients with indolent B-cell non-Hodgkin's lymphoma who have progressed using another drug, rituximab.

The 20-year-old biopharmaceutical company has been working to lessen its reliance on sales of Provigil, a therapy prescribed for narcolepsy, sleep apnea and shift work sleep disorder. Provigil, which faces generic competition in 2012, accounted for 49 percent of Cephalon's revenues of $1.3 billion for the three quarters ended Sept. 30.

This is the second NDA submitted for Treanda by Cephalon. The first, filed in September, seeks FDA approval for it as a treatment for chronic lymphocytic leukemia. Regulators granted "orphan drug" status for that use because it is a rare disease with about 15,000 cases diagnosed each year.

In contrast, about 30,000 cases of indolent non-Hodgkin's lymphoma are diagnosed in the United States each year.

If approved, Treanda would be Cephalon's first oncology product.

Cephalon shares were trading down 47 cents, or 0.7 percent, at $71.93 in late morning trading on the Nasdaq.