Merck and AiCuris today announced that they have entered into an exclusive worldwide licensing agreement for AiCuris' portfolio of investigational medicines targeting Human Cytomegalovirus (HCMV), including letermovir (AIC246), an oral, late-stage antiviral candidate being investigated for the treatment and prevention of HCMV infection in transplant recipients.

Under the agreement, Merck, through a subsidiary, will gain worldwide rights to develop and commercialize candidates in AiCuris' HCMV portfolio. AiCuris will receive a €110 million upfront payment and is eligible for milestone payments of up to €332.5 million based on successful achievement of development, regulatory and commercialization goals for HCMV candidates, including letermovir, an additional back-up candidate as well as other Phase I candidates designed to act via an alternate mechanism.

In addition, AiCuris will be entitled to receive royalty payments reflecting the advanced stage of the clinical program on any potential products that result from the agreement, Merck will be responsible for all development activities and costs.

Closing of the transaction is contingent upon obtaining clearance from the relevant authorities.