Johnson & Johnson is paying $125 million to acquire rights to a Xencor bispecific antibody in development for B-cell cancers, a deal that puts the pharma giant in the mix with competitors pursuing the same cancer targets, but with a drug that could offer a dosing advantage.
Bispecific antibodies are drugs designed to hit two targets at the same time. The Xencor drug, plamotamab, targets CD20, an antigen on B-cell tumors, and CD3, a receptor on T cells that plays a role in activating them. The competition in this space is heating up as Roche and Regeneron Pharmaceuticals both have early-stage bispecific antibodies that go after the same targets. But the drugs from those companies are intravenous infusions. Xencor is preparing to test a version of its drug given as a subcutaneous injection, a route of administration that’s easier for both patients and physicians. That formulation could set plamotamab apart from competitors.
According to terms announced Monday, J&J subsidiary Janssen Biotech is paying $100 million up front for global rights to plamotamab. Furthermore, Johnson & Johnson Innovation – JJDC, will purchase $25 million worth of Xencor’s stock. The partners will share in the costs of developing plamotamab; 80% covered by Janssen and the remaining 20% by Xencor. Those costs include the projected 2022 start of a clinical trial evaluating the subcutaneous formulation of plamotamab. A Phase 1 dose-escalation is already underway testing the IV version of the drug in patients with blood cancers expressing CD20.
The deal also includes a two-year collaboration under which Monrovia, California-based Xencor will apply its technology to create additional bispecific antibodies addressing another antigen target on B-cell tumors, CD28. Janssen will have exclusive worldwide rights to develop selected molecules in combination with plamotamab and other drugs. Depending on the progress of the research, Xencor could earn milestone payments approaching $1.18 billion dollars, plus royalties from sales if the drugs from the collaboration reach the market. For antibodies commercialized outside of a combination with plamotamab, Xencor keeps an option to co-found development costs in exchange for higher royalties and the right to share in the commercialization of products in the U.S.
“The treatment landscape in B-cell lymphoma will potentially be redefined by CD20 x CD3 bispecific antibodies, such as plamotamab, and the best outcomes for patients will require creative combination approaches using complementary mechanisms of action,” Xencor President and CEO Bassil Dahiyat said in a prepared statement.
Janssen is already acquainted with Xencor’s antibody technology. Last year, the J&J subsidiary struck up an agreement to develop bispecific antibodies against CD28 and an undisclosed prostate tumor target as a way to potentially treat prostate cancer. Janssen paid $50 million up front; Xencor could receive up to $662.5 million in milestone payments.
Had things worked out differently, plamotamab might have been continuing its development under Novartis. That bispecific antibody and another one were part of a 2016 collaboration with the Swiss pharmaceutical giant. Three years later, the drug did not make the cut in a strategic review of pipeline candidates, and Novartis returned the drug’s rights to Xencor. The other drug from the 2016 pact targets CD123 and CD3. Now called vibecotamab, that bispecific antibody remains in development under the Novartis partnership.
Plamotamab is already part of a different collaboration. Last year, Xencor struck up an alliance with MorphoSys to test the bispecific antibody and MorphoSys drug Monjuvi in combination with another drug, lenalidomide, in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma. That collaboration is continuing, with Xencor funding that research at its own expense. A Phase 2 trial in relapsed or refractory DLBCL is expected to start late this year or early next year.
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