Promising interim results of a double-blind placebo-controlled trial of the monoclonal antibody OvaRex in 345 patients with
Promising interim results of a double-blindplacebo-controlled trial of the monoclonal antibodyOvaRex in 345 patients with ovarian cancer were presented at the 37th annualmeeting of the American Society of Clinical Oncology (ASCO) in San Francisco.Dr. Jonathan Berek, MD, PhD, professor and vice chair at the University ofCalifornia-Los Angeles Medical Center and coprincipal investigator of thestudy made the presentation.
High-Risk Patients Show Greatest Benefit
Among the highlights of Dr. Berek’s presentation was therecent breakthrough in the understanding of the correlation between circulatinglevels of the ovarian tumor marker CA-125 and the efficacy of OvaRex.Specifically:
At the initiation of the trial, the CA-125 levels ofparticipants were assumed to be in the normal range for this patient population.One notable observation was that patients on the high end of this range are atsignificantly increased risk of relapsing. OvaRex is proving to be mostbeneficial in these patients.
The proportion of high-risk patients who achieved adisease-free survival of 6 months is significantly higher (P = .0397) amongthose treated with OvaRex (79%) than among those receiving placebo (39%).
Approximately 50% of patients developed a specific immuneresponse to OvaRex that correlated directly with clinical benefit.
Results of Phase II Trials
In addition to the interim analysis, AltaRex Inc (manufacturerof OvaRex) has analyzed final data from two phase II trials. These resultsdemonstrate that in late-stage ovarian cancer patients with recurrent disease,treatment with OvaRex can provide comparable efficacy to salvage chemotherapiesbut without the associated toxicities.
An analysis of the primary end point of time to disease relapsefor all 345 patients in the lead trial is scheduled to begin in thethird-quarter of this year. Clinical data from this trial and five othercomplementary and supporting trials will form the basis for a simultaneousfiling for product approval with both the United States and Canadian regulatoryauthorities.