Genetics Institute officials said they could file a new drug application(NDA) by the end of 1996 for interleukin-11 (IL-11), their plateletgrowth booster for chemotherapy patients, if the product qualifies foraccelerated consideration under the FDA's new guidelines forspeeding approval of cancer drugs.

The Cambridge, Mass.-based company Wednesday released positiveresults from a second Phase II study of the drug, which is designed toreduce the need for cancer patients to undergo transfusions whentheir platelets are destroyed by chemotherapy treatments. Platelets areinvolved in blood clotting and their reduction can lead to excessivebleeding.

Genetics Institute's stock (NASDAQ:GENIZ) jumped $3 Wednesdayto $73.50, a 5 percent increase.

John Ryan, Genetics Institute's vice president of clinicaldevelopment, said the data revealed treatments with recombinant IL-11 reduced the risk of platelet transfusion by 60 percent. Thestatistically significant results, Ryan said, confirmed positive efficacyfindings of a Phase II trial reported last year. (See BioWorld Today,May 19, 1995, p. 2.)

Both Phase II studies also have shown the drug is safe. A Phase IIItrial, ongoing with 250 cancer patients, should reach the half-waypoint by the end of this year when an interim analysis will beconducted.

Ryan said Genetics Institute will meet with the FDA this summer todetermine whether the two Phase II studies would qualify the drug forconsideration under accelerated approval guidelines for cancer-related therapies announced by the agency in April 1996. (SeeBioWorld Today, April 23, 1996, p. 1.)

"If the FDA is strongly encouraged with the Phase II trials, we couldfile by the end of 1996 or early 1997," Ryan said. "If not, we couldfile later in 1997."

The standard treatment for restoring platelets destroyed bychemotherapy is a platelet transfusion, which is costly and presents arisk of infection. Competition is keen among biotechnologycompanies to develop a substitute. Analysts have estimated an initialannual market for a platelet growth drug at about $500 millionworldwide.

Genetics Institute's NDA for recombinant IL-11 would be the firstsuch submission to the FDA for a platelet booster.

Amgen Inc., of Thousand Oaks, Calif., and Genentech Inc., of SouthSan Francisco, have versions of thrombopoietin, which alsostimulates platelet growth, under development, but the products arenot as advanced as Genetics Institute's.

Amgen is scheduled to release the first clinical data from a Phase I/IItrial of its version of thrombopoietin, called megakaryocyte growthand development factor, at the American Society of ClinicalOncology meeting Sunday in Philadelphia.

Ryan said data from the second Phase II study of IL-11 was receivedtoo late for inclusion in Genetics Institute's presentation Saturday atthe same conference.

The study involved 62 breast cancer patients who received either IL-11 or a placebo after completing two cycles of chemotherapy. Of the33 patients who received the drug, only seven, or 21 percent,required platelet transfusions. Fifty-two percent of patients in theplacebo group needed donor platelets.

Ryan said patients enrolled in the second Phase II were at "relative"risk of requiring a transfusion.

In the first Phase II trial, he said, all 80 cancer patients enrolled wereat "absolute" risk of requiring transfusions after chemotherapy. Inthose studies, 30 percent receiving 50 micrograms per kilogram ofIL-11 did not require a transfusion compared with only 4 percent whodid not need a transfusion in the placebo group. Fifty microgramswas the higher of two doses evaluated in the first Phase II study andwas the same dose used for all treated patients in the second trial.

Ryan said the second Phase II study also revealed an improved safetyprofile for IL-11 from the first trial. n

-- Charles Craig

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