Collaborations announced for antibody-drug conjugate development

Two pharma giants have struck up international licensing collaborations involving antibody–drug conjugates (ADCs). ADCs use their antibody component to guide a drug payload to specific sites in the body.

Merck KGaA, in Germany, announced a licensing agreement Dec. 22 with Cambridge, Massachusetts–based Mersana Therapeutics to design and develop ADCs against two new cancer targets. The ADCs from this partnership will aim to activate the stimulator of interferon genes (STING) signaling pathway to rouse the immune system to fight cancer. Mersana will receive $30 million in cash from Merck KGaA and is eligible for an additional $800 million in global sales royalties and milestone payments.

On the same day, North America’s Merck & Co. announced that it obtained a near-global license from China-based Kelun-Biotech to develop seven ADC candidates to treat cancer. The smaller company will retain the rights to research, develop, and commercialize certain ADCs for the greater China region. Merck & Co. will front Kelun $175 million and stands to pay another $9.3 billion in royalties and milestones and if Kelun also hands over its rights to develop and commercialize select ADCs in the China region.On top of the deal, the pharma giant also announced its intention to purchase Kelun shares. The ADC licensing agreement is the third one this year between the two companies, and the most lucrative.

The ADC deals underscore the growth of this class of anticancer treatments. At least 12 ADCs are approved to treat cancer, and over 140 candidates are in clinical development, according to the European Pharmaceutical Review.