By Alan Sverdlik
AnorMED Inc. said AstraZeneca plc will take a second look at the design and timetable of the Phase III trial of the platinum-based anticancer agent ZD0473 after a new batch of data showed a lower response rate among platinum-resistant ovarian cancer patients than previously reported.
The development sliced AnorMED¿s stock in half Friday, even though AnorMED officials said the trial still could begin, as scheduled, in the fourth quarter of this year.
¿I¿m very limited as to what I can tell you,¿ Michael Abrams, president and CEO of Vancouver, British Columbia-based AnorMED, told BioWorld Today.
Abrams said new data that arose out of an efficacy statistical study ¿questions the response rate previously seen in platinum-resistant ovarian cancer patients¿ treated with ZD0473, which was 14 percent. He would not give the percent of the updated response rate, other than to say it was lower.
AstraZeneca, of London, initiated a Phase III trial of ZD0473 last April, which triggered the $4 million AnorMED milestone called for by their development and commercialization agreement. The multicenter, open-label trial was set up to evaluate the drug¿s safety and efficacy compared to L-doxorubicin in patients with ovarian cancer who had failed previous platinum-based therapy. (See BioWorld Today, April 6, 2001.)
¿We talked about the end of the year as a milestone,¿ Abrams said.
He said AstraZeneca is in the process of ¿reassessment and reevaluation¿ of protocols. ¿There may be other indications to go after, particularly where you see response rates that are encouraging,¿ he said. ¿This project is very much alive at AstraZeneca, and there are a number of ways to go forward with it. The problem is we can¿t give any guidance on the probabilities¿ of what the company may do.
Assuming there are only ¿minor amendments¿ needed, a Phase III could still be on for the end of the year.
There was some good news amid the disappointing response rate. Abrams, who called ZD0473 ¿a good compound, our flagship compound and one I¿m confident has a clinical role,¿ said that emerging data from Phase I and II trials in a variety of indications, including non-small-cell lung cancer, prostate cancer, breast cancer and bladder cancer, are promising. ¿They continue to support the conclusion that the compound is an active drug with manageable toxicity,¿ he said.
Completion of the Phase I and II trials is conceivable by the third quarter of 2002, Abrams said.
Also, he said, ¿the response rate in second-line platinum-sensitive ovarian patients has been maintained and remains encouraging.¿ As well, ZD0473 has elicited antitumor responses as both a monotherapy and in combination therapy when used to treat ovarian cancer, hormone-refractory prostate cancer, sarcoma and pancreatic cancer, he said.
AnorMED has other ongoing partnerships, most notably with Shire Pharmaceuticals Group plc, of Andover, UK, which filed for European marketing approval for Foznol (lanthanum carbonate) in March. Foznol is designed to manage phosphate levels in chronic renal failure patients.
AnorMED¿s stock (TSE:AOM) fell C$5.90 Friday, or 55 percent, to close at C$4.85.