Exelixis will pay the French immuno-oncology biotech $5 million upon signing the agreement, as well as addition payments upon completion of closing conditions and extra milestone payments after closing, contingent upon certain events.

“GamaMabs has generated a compelling body of preclinical data supporting the potential of AMHR2 as a target for novel oncology therapies and demonstrated the safety of an anti-AMHR2 monoclonal antibody in human clinical trials,” said Peter Lamb, executive vice president, scientific strategy and chief scientific officer at Exelixis. “Based on these data,” he said, “we believe that applying our ADC capabilities to GamaMabs’ panel of antibodies against AMHR2 could yield a promising new addition to our biotherapeutics portfolio. Acquiring GamaMabs’ extensive know-how related to this target, as well as existing drug product and related manufacturing cell lines, will allow us to reduce significantly the development timeline compared with starting an AMHR2 program de novo.”

Once the deal has closed, Exelixis will control GamaMabs’ entire AMHR2 franchise technology, including all assets related to the monoclonal antibody drug murlentamab.

While GamaMabs stopped developing murlentamab in early 2021 after the “modest” efficacy shown in phase 1 and 2 trials, Exelixis said it is encouraged by its potential as the California-based company further develops novel biologics.

“The preclinical and clinical data generated to date for murlentamab support its first-in-class potential in a variety of cancer indications, and we expect that Exelixis’ ADC capabilities and expertise in the development and commercialization of novel cancer therapies will help to realize the full potential of this antibody in addressing unmet patient need,” said Stéphane Degove, GamaMabs’ CEO. “We believe that placing our AMHR2 franchise with Exelixis will enable rapid and effective development of AMHR2-targeting cancer therapies while providing us with near-term revenue that can support development of our other pipeline programs and technologies.”

While AMHR2 expression is usually restricted to ovary, testis and adrenal tissues, it is also expressed in ovarian, endometrial, renal, liver, colon and lung tumors.

Author: Elaine Burridge, Freelance Journalist