By Mary Welch

Cell Therapeutics Inc. filed a new drug application (NDA) for Arsenic Troxide (ATO) for the treatment of patients with relapsed or refractory acute promyelocytic leukemia.

The drug already has FDA fast-track status, meaning a decision should come before the end of the year.

Seattle-based Cell Therapeutics (CTI) gained the rights to ATO through its acquisition of New York-based PolaRx Biopharmaceuticals Inc. in a deal where Cell Therapeutics assumed up to $5 million in PolaRx liabilities. The company also issued 2 million shares of its common stock to PolaRx shareholders and possibly another 3 million shares upon FDA approval. (See BioWorld Today, Jan. 11, 2000, p. 1.)

At the time of the purchase, CTI said it intended to file the NDA by the second half of this year. Last month it raised $40 million in a private placement to help finance the filing. The company sold 3.33 million shares at $12 each. (See BioWorld Today, Feb. 18, 2000, p. 1.)

Because of the financial filing, CTI is in a SEC-imposed "quiet period" and was not available for comment.

"The company has reason to be excited," said Dayton Misfeldt, vice president and research analyst with Roth Capital Partners Inc., in Newport Beach, Calif. "They filed ahead of their schedule, which is always good. The real value of ArsenicTroxide is more in its potential off-label use. The refractory acute leukemia market isn't all that large, but there's been some promising evidence in other oncology areas. There are about 15 trials ongoing sponsored by the National Cancer Institute that use arsenic for indications like lymphoma, leukemia and multiple myeloma. Once it gets approved, it'll be available for other indications and that's where some excitement can happen."

In the pivotal trial, data showed ATO induced a high rate of complete remission among patients suffering from acute promyelocytic leukemia who had relapsed after prior therapy. The most common side effects were asymptomatic EKG changes, which were managed with steroids.

Cell Therapeutics' stock (NASDQ:CTIC) closed Wednesday at $25.75, down $2.75.