PRINCETON, N.J., June 1 Medarex, Inc.(Nasdaq: MEDX) today announced updated long-term follow-up and overallsurvival (OS) results from a Phase 2 clinical study (MDX010-08) of 3 mg/kg ofipilimumab in combination with dacarbazine (DTIC) where 11.4%, or 4 of 35patients, were still alive at or greater than 4 years of follow-up. Thisincluded 1 patient that experienced a complete response (4.7 years), 1 patientthat experienced a partial response (4.2 years), 1 patient with stable disease(4.6 years) and 1 patient with RECIST defined progressive disease (4.4 years).The median OS for patients treated with ipilimumab in combination with DTICwas 15 months in this study. These results compare favorably with data inmedical literature, in which median OS ranges from 6 to 9 months for patientswith treated or previously untreated advanced melanoma treated with standardchemotherapy. These findings were presented at the Annual Meeting of theAmerican Society of Clinical Oncology (ASCO), being held in Chicago, IL May30-June 3, 2008. (Abstract # 9022)
"The long-term survival data suggests that ipilimumab in combination withDTIC may have long-lasting effects," said Geoffrey M. Nichol, MBChB, SeniorVice President of Product Development at Medarex. "With a median survival ofapproximately 15 months in the patients treated with 3 mg/kg of ipilimumab incombination with DTIC in this Phase 2 study, we look forward with interest tothe outcome of the ongoing Phase 3 study being performed by our collaboratorBristol-Myers Squibb Company, comparing 10 mg/kg of ipilimumab in combinationwith DTIC versus DTIC alone in previously-untreated patients with advancedmelanoma."
In the Phase 2 trial (MDX010-08), 72 chemotherapy-naive patients withadvanced melanoma were treated with 3 mg/kg of ipilimumab monthly for fourmonths and were randomized to receive either ipilimumab in combination withDTIC (n=35) or ipilimumab alone (n=37). Patients originally treated in theMDX010-08 study were subsequently enrolled into study MDX010-028 to determinelong-term follow-up data and OS. The disease control rate (proportion ofpatients with complete responses, partial responses or stable disease) forpatients treated with ipilimumab in combination with DTIC was 37.1%, or 13 of35 patients, with 2 complete responses, 3 partial responses and 8 patientswith stable disease. Two of 37 patients, or 5.4%, treated with 3 mg/kg ofipilimumab alone experienced partial responses, which were ongoing more than 4years and 4.2 years in duration, respectively. The disease control rate inthe ipilimumab alone treatment arm was 21.6%, or 8 of the 37 patients, withmedian OS of 12 months.
Ipilimumab is being developed through a joint partnership betweenBristol-Myers Squibb and Medarex. Based on preclinical and clinical studiesshowing that antibody blockade of CTLA-4 plays an important role in sustainingan active immune response to fight cancer, the companies are pursuing a broadclinical development program with ipilimumab. More than 2,000 patients havebeen treated in clinical trials with ipilimumab as a monotherapy or incombination with other agents. Patients in the ongoing Phase 3 study (BMSstudy CA184-024) are randomized to receive induction therapy with 10 mg/kg ofipilimumab in combination with DTIC or placebo. Eligible patients arepermitted maintenance dosing with ipilimumab or placebo after the inductionphase has been completed.
For further information about ipilimumab clinical trials, please visitwww.clinicaltrials.gov.
Ipilimumab is a fully human antibody that binds to CTLA-4 (cytotoxic Tlymphocyte-associated antigen 4), a molecule on T-cells that plays a criticalrole in regulating natural immune responses. The absence or presence ofCTLA-4 can augment or suppress the immune system's T-cell response in fightingdisease. Ipilimumab is designed to block the activity of C