Phase II Study Shows That Significantly Fewer rhIL-11 Treated Patients Require Platelet Transfusions

Genetics Institute, Inc. announced positive results of a phaseII study of recombinant human interleukin-eleven (rhIL-11). Inthe study, rhIL-11 restored platelets in thrombocytopenic patientsundergoing cancer chemotherapy to the extent that significantlyfewer patients required platelet transfusions when compared topatients on placebo.

Based on this favorable outcome, Genetics Institute said thatit plans to begin a phase III study of rhIL-11 by the end of 1995.In addition, the company expects to have results from two additionalphase II studies later this year.

"We are extremely pleased with the results of this study,"said Patrick Gage, PhD, Chief Operating Officer for Genetics Institute."We have now completed a rigorous, 'real world' test of rhIL-11in patients who, on entry into the study, were already platelettransfusion-dependent and were being treated with a wide varietyof chemotherapy regimens. Despite these challenges, rhIL-11 achieveda statistically significant outcome for a meaningful clinicalendpoint--eliminating platelet transfusions. Our goal now is toproceed expeditiously to a phase III study and, assuming continuedpositive results, complete the regulatory review process to makethis highly promising product available to physicians and patients."

In the double-blind, randomized, placebo-controlled study, involvingmore than 80 patients from 20 medical centers, 30% of the patientswho received a daily 50- mcg/kg dose of rhIL-11 did not requirea platelet transfusion. These results were statistically significantwhen compared to the placebo group, of which only 4% avoided platelettransfusions. Of the patients who received a daily 25-mcg/kg dose,18% also did not require a platelet transfusion, suggesting adose-response relationship for rhIL-11 in this study. In addition,the rhIL-1-treated patients who did have to be transfused showeda trend toward requiring fewer transfusions than those on placebo.

Study investigator Michael Gordon, MD, Director, Clinical CytokineProgram, Indiana University Medical Center, Indianapolis, whoalso studied rhIL-11 in phase I trials, said: "This studysignificantly advances our knowledge of ways to reduce platelettransfusions, a key concern for patients being treated with dose-intensivechemotherapy. If similar results are demonstrated in phase IIIstudies, rhIL-11 therapy could lead to better treatments for cancerpatients, reduce the risks associated with platelet transfusions,and offer the potential to conserve healthcare resources."

"This phase II study is important because it is a double-blind,randomized, placebo-controlled trial and it clearly shows promisingresults in a very difficult patient population at risk for thrombocytopenia,"commented another study investigator, Joseph Moore, MD, of DukeUniversity Medical Center.

In the study, the patients had a wide range of solid tumors orlymphomas and were being treated with a variety of chemotherapyregimens. All patients were treated on an outpatient basis. Treatmentwith rhIL-11 was administered by subcutaneous injection.

In general, rhIL-11 was well-tolerated by the study patients.The side effects profile was similar to that observed in phaseI studies, and included mild constitutional complaints and symptomsbelieved to be related to fluid retention, including a low incidenceof transient atrial arrhythmias. These effects were reversed whenthe treatment was completed or discontinued, and caused no significantclinical consequences. In addition, rhIL-11 treatment was notassociated with an increased incidence of neutropenic fevers,which has been seen with several other cytokines.