By Randall Osborne

West Coast Editor

Cell Therapeutics Inc., with its drug Trisenox (arsenic trioxide) already approved for acute promyelocytic leukemia and more oncology products in the pipeline, filed to offer $150 million in convertible subordinated notes due in 2008.

Seattle-based CTI said the notes would be convertible into common stock at a price yet to be determined, and another $30 million in notes may be issued as overallotments.

The FDA approved Trisenox, which works by inducing apoptosis, or programmed cell death, last year, and CTI is marketing it without a partner while exploring other potential applications, including multiple myeloma and lymphoma, among other blood cell and solid tumor cancers. (See BioWorld Today, Sept. 27, 2000.)

A week before Trisenox was cleared, CTI raised about $137 million by selling 3.6 million shares. Proceeds included the exercise of an overallotment option by managers of the sale. (See BioWorld Today, Sept. 22, 2000.)

Proceeds of the convertible notes offering will pay for clinical trials, expansion of sales and marketing, potential acquisitions of companies or products, and general corporate purposes, including working capital.

The company has clinical trials under way with PG-TXL, a derivative of paclitaxel, the active ingredient of the well-known cancer drug Taxol; and Apra (CT-2584), for patients with cancers such as soft-tissue sarcoma and prostate cancer who have become resistant to conventional chemotherapy.

PG-TXL, in Phase II trials, works by delivering paclitaxel conjugated to polyglutamate, which apparently renders it inactive while circulating in the bloodstream (thus lowering toxicity) while increasing the percentage of drug that arrives in the tumor by way of blood vessels, the company said. CTI also began developing a novel PG-camptothecin and aims to submit an investigational new drug application to the FDA by the end of this year or early next.

Data from a pair of Phase II trials with Apra, CTI said, are expected this year. In November 1999, the company said results were encouraging with the first 24 evaluable patients with soft-tissue sarcomas who had failed conventional therapies, and the protocol was expanded from 40 patients to 80. Apra, which works by regulating the way cancer cells metabolize certain lipids, also is in a Phase II study in patients with prostate cancer who have failed hormonal and conventional chemotherapy.

CTI’s stock (NASDAQ:CTIC) closed Tuesday at $28.85, up $1.72.