By Karen Pihl-Carey

Seattle-based NeoRx Corp. will move its skeletal targeted radiotherapy (STR) product to treat multiple myeloma into a Phase III trial to be funded through a $5 million credit line from PPD Inc.

The product demonstrated in Phase II trials its ability to eliminate myeloma cancer cells in 12 out of 27 patients evaluated, many of whom had failed to respond to chemotherapy or whom had relapsed after responding.

The Phase III pivotal trial will be a multicenter, randomized, open-label trial, expected to begin in the second quarter.

¿What we intend to do is to do a randomized trial in patients with multiple myeloma, treating half the patients with standard high-dose therapy and treating the other half with the same standard high-dose therapy, plus with 40Gy, or 4,000 rads, delivered to the bone marrow with our STR product,¿ said Paul Abrams, CEO of NeoRx. ¿And what we are powering the study to show is an improvement in the rate of complete remissions with the test agent compared to the standard treatment alone.¿

PPD, of Wilmington, N.C., will provide a $5 million credit line to help fund the trial. The principal and interest is not due until the STR product is either FDA approved or abandoned by NeoRx. In return, PPD will be issued a limited number of warrants to purchase NeoRx common stock at a premium to the current price, but no royalties are included in the deal.

NeoRx¿s stock (NASDAQ:NERX) closed Friday at $5.687, up about 28 cents.

The goal of the trial is to demonstrate if the addition of STR to high-dose therapy will increase the number of complete responses without adding significant toxicity. The safety data to date have not shown serious toxicity and have led researchers to raise the age limit of study participants in the pivotal trial.

¿Intensive therapy requiring stem cell reinfusion has in the past been restricted to patients who are relatively young, that is, 60 years and below,¿ Abrams told BioWorld Today. ¿The researchers who have been involved in this study have seen such a promising safety profile so far that they believe they can significantly raise the age limit and still be able to treat the patients safely.¿

Abrams said it will take about a year to accrue the 200 to 250 patients needed for the trial, and that the trial will start sometime this year at 15 to 20 sites in North America. Once all patients are accrued, he expects it will take six months to fully evaluate the data, taking a possible new drug application filing into 2002.

¿We¿re expecting to have this reviewed under fast-track [status] because it¿s a cancer drug for a life-threatening disease,¿ Abrams said.

STR is a small molecule designed to carry the radiation therapy known as a radionuclide to the site of the disease in the bone. In the Phase III study, the radionuclide used will be holmium-166-DOTMP. NeoRx believes the product can reduce exposure to normal organs by selectively delivering the radionuclide to the site of the disease.

Multiple myeloma is characterized by elevated plasma cells in the bone marrow, which can lead to anemia, erosion of bone and small tumors. There were about 13,700 new cases and about 11,400 people who died from the disease in 1999, estimated the American Cancer Society.