Merck & Co, Inc (WHITEHOUSE STATION, New Jersey) and Japan Tobacco Inc (TOKYO, Japan) announced a worldwide licensing agreement to develop and commercialize JTT-305, an investigational oral osteoanabolic agent for the treatment of osteoporosis.

Under the terms of the agreement, Merck gains worldwide rights, except for Japan, to develop and commercialize JTT-305. JT will receive an upfront payment and is eligible to receive additional cash payments upon achievement of certain milestones associated with the development and approval of a drug candidate covered by this agreement. JT will also be eligible to receive undisclosed royalties from sales of any drug candidates that receive marketing approval.

JTT-305 is investigational, oral, calcium sensing receptor (CaSR) antagonist that is currently being evaluated by JT in phase II clinical trials in Japan for its effect on increasing bone mineral density (BMD) and is in phase I clinical trials outside of Japan. The CaSR antagonist increases BMD and decreases new vertebral fractures by accelerating endogenous parathyroid hormone (PTH) secretion via antagonism of circulating calcium on CaSR in parathyroid cells.

The effective date of the collaboration agreement is subject to the expiration or earlier termination of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act.