By Jim Shrine
ILEX Oncology Inc. began enrolling patients in the third pivotal trial of its apoptotic drug, DFMO, this one testing the compound's ability to prevent recurrence of superficial bladder cancer after surgery.
DFMO (eflornithine) is one of five oncology products ILEX has in the clinic and the second furthest along in development. Campath, a monoclonal antibody partnered with LeukoSite Inc., has completed pivotal studies and a biologics license application may be filed by mid-year, ILEX spokeswoman Deborah Sibley said.
The new DFMO study is a randomized, double-blind, placebo-controlled Phase III trial to test the orally delivered compound's ability to prevent recurrence after transurethral resection, the standard treatment for bladder cancers. The National Cancer Institute-sponsored trial will involve 450 patients at 39 sites, and is scheduled to end in 2002.
Sibley said interim analyses are scheduled in 2000 and 2001, the first of which will be held after cancer recurrence would be evident. "So we should know whether it's working or not [at the first interim analysis] and choose to file with the FDA at that time."
Urologist Michael Sarosdy, co-chairman of the study, said superficially invasive neoplasms occur in about two-thirds of the 54,000 new cases of bladder cancer diagnosed in the U.S each year. But early-stage cancers usually are not treated initially because there are no products that provide enough benefit to outweigh the toxicity.
ILEX is a San Antonio-based company that focuses on licensing or acquiring cancer drugs for development. It doesn't have research and discovery capabilities but rather concentrates on taking compounds through the clinic. It also offers drug development services to others on a contract basis.
ILEX licensed worldwide oncology rights for DFMO from Hoechst Marion Roussel AG, of Frankfurt, Germany. The drug initially was used to treat African sleeping sickness.
Sibley said DFMO decreases cellular polyamine concentrations, thereby decreasing proliferation of cancer cells.
Phase III studies of DFMO are ongoing in colon cancer and non-melanoma skin cancer, with one in advanced breast cancer expected to get under way soon, Sibley said. Results from a recently completed Phase II study in prostate cancer are not available. The National Cancer Institute is conducting five separate DFMO studies.
The third drug in ILEX's pipeline is oxypurinol, an active metabolite of allopurinol, which is used in treating a variety of cancers. ILEX's drug is used for those who can't tolerate allopurinol. A Phase III protocol is being reviewed, Sibley said.
The other two ILEX drugs in the clinic are aminopterin - in two Phase II trials and one Phase I - and SR-45023A, an orally active biophosphonate ester derivative just taken into Phase I in metastatic cancers.
Sibley said several potential partners have expressed interest in marketing Campath on behalf of ILEX and Cambridge, Mass.-based LeukoSite, and one likely will be chosen in the next few months. The assumption is that a marketing partner will be sought for DFMO, she said, though it may be too early to say.
ILEX's stock (NASDAQ:ILXO) closed down 25 cents Tuesday at $9.625.