By Karen Pihl-Carey

Aronex Pharmaceuticals Inc. plans to expand its Phase II trial of Atragen in hormone-refractory metastatic prostate cancer, based on preliminary results from 14 patients.

It is the second time this summer Aronex, of The Woodlands, Texas, has expanded a trial of the drug. It expanded its Phase II study in relapsed or refractory non-Hodgkin's lymphoma patients in June. (See BioWorld Today, June 29, 1999, p. 1.)

Meanwhile, the company is continuing discussions with the FDA over deficiencies in its new drug application (NDA) to market Atragen for the treatment of patients with acute promyelocytic leukemia (APL). The agency said earlier this month that the Oncologic Drugs Advisory Committee would not consider the drug on Sept. 17 as originally expected, but it did not detail the deficiencies. (See BioWorld Today, Aug. 6, 1999, p. 1.)

Aronex's stock fell 35 percent to $4.50 that day. It closed Wednesday unchanged at $4 per share.

"I can't really comment on what affects our stock. We were affected by the announcement that we felt we needed to make," said Connie Stout, associate director of corporate communications at Aronex. "We are having ongoing communications with the FDA, but other than to say that there is dialogue, we are really not commenting further."

Atragen is Aronex's lead product, and is being tested in a number of cancers. It is a liposomal formulation of all-trans-retinoic acid. The APL NDA was submitted in December based on Phase II data, which met the FDA's criteria for submission. On Aug. 5, the company learned the FDA found problems with the NDA.

"Once everything becomes more clear to us, we certainly will share that with the community and begin taking the necessary steps to solve the problem," Stout said.

Meanwhile, Aronex is expanding the Phase II trial for prostate cancer, which affects 184,500 people a year, according to the American Cancer Society. The trial was initiated in November 1998. Patients taking the drug, which is administered intravenously three times a week, noticed an improved quality of life, said Anthony Williams, vice president of medical affairs at Aronex.

Stout said a number of pilot studies of Atragen are under way.

"One of the things that we're trying to do for the clinical development program for Atragen is to take a look at the product for a larger number of indications," she told BioWorld Today. It is being developed for hematologic malignancies and solid tumors found not only in non-Hodgkin's lymphoma, but in renal cell carcinoma and superficial bladder cancer.

Stout did not want to speculate as to when the company might file NDAs for these other indications because testing still is in the early stages.

Aronex, however, does plan to file an NDA in Europe to market Atragen for patients with APL. "That's something that we want to do this year and certainly we'll take steps to get that done," Stout said. "That is our target."

Aronex has five products in clinical development, including Nyotran, an injectable liposomal formulation of nystatin for treating fungal infections. The company expects to file an NDA this year for Nyotran, Stout said.