Seattle Genetics, Inc. (Nasdaq: SGEN) today announced that it will receive a milestone payment from GlaxoSmithKline (GSK) triggered by European Commission conditional marketing authorisation for GSK’s BLENREP™ (belantamab mafodotin), an antibody-drug conjugate (ADC) targeting B-cell maturation antigen (BCMA) that utilizes Seattle Genetics’ proprietary technology. BLENREP was developed and will be commercialized by GSK. In addition to the milestone payment, Seattle Genetics is entitled to royalties on BLENREP product sales. BLENREP was approved as monotherapy for the treatment of multiple myeloma in adult patients who have received at least four prior therapies and whose disease is refractory to at least one proteasome inhibitor, one immunomodulatory agent, and an anti-CD38 monoclonal antibody, and who have demonstrated disease progression on the last therapy.

“This is the second collaborator program utilizing our ADC technology to receive European Commission approval in 2020, and rapidly follows the FDA approval of BLENREP earlier this month, highlighting the potential of these novel therapies in the treatment of cancer patients globally,” said Clay Siegall, Ph.D., President and Chief Executive Officer of Seattle Genetics. “Our ADC collaborator progress, along with the growth of Seattle Genetics’ marketed ADCs, ADCETRIS and PADCEV, and recent positive results of tisotumab vedotin from our ADC pipeline, underscore our leadership in ADCs to treat cancer.”

BLENREP was granted PRIME (PRIority MEdicines) designation in 2017 and the application was reviewed under the European Medicines Agency’s (EMA) accelerated assessment procedure, which is given if the Committee for Medicinal Products for Human Use of the EMA determines the treatment is of major interest from a public health perspective and represents a therapeutic innovation.

Seattle Genetics’ ADC technology combines the specificity of monoclonal antibodies, innovative linker systems and potent cell-killing agents to treat cancer. The technology has been licensed to several companies. Under the terms of these agreements, each licensee company has rights to use the technology with antibodies against specified targets. The licensee is responsible for research, product development, manufacturing and commercialization. Seattle Genetics is entitled to receive fees, progress-dependent milestone payments and royalties on worldwide net sales of any resulting ADC products.