Blockbuster oncology deal

LEXINGTON, Mass.—GlaxoSmith-Kline (GSK) has finalized a deal with Synta Pharmaceuticals Corp. on a global collaboration agreement for the joint development and commercialization of STA-4783, a first-in-class, small-molecule, oxidative stress inducer that is entering Phase III clinical development for the treatment of metastatic melanoma—a deal with the potential for more than $1 billion in payments to Synta.

Under the terms of the agreement, Synta will receive an upfront cash payment of $80 million. Synta will also be eligible to receive potential milestone payments of up to $135 million for events leading to approval of STA-4783 in metastatic melanoma, further development and regulatory milestones of up to $450 million across various indications and up to $300 million in potential commercial milestone payments based on achieving certain net sales thresholds.

The companies will share responsibility for developing and commercializing STA-4783 in the United States and GSK will have exclusive responsibility for development and commercialization of the compound in other countries. Synta will continue to fund all development for metastatic melanoma in the United States and the companies will share responsibility and costs for development of STA-4783 in other indications.

"We've structured this deal in a very interesting way which I think reflects GSK's confidence in Synta as a company in that we are taking the lead role in metastatic melanoma for NDA in the United States," says Dr. Safi R. Bahcall, president and CEO of Synta, adding that the milestone payments of $135 million leading up to an approval application with the FDA should more than cover Synta's clinical costs going forward.

Synta and GSK will jointly commercialize STA-4783 in the U.S. for other indications  with Synta receiving a tiered profit share based on levels of annual net sales. The parties will share development costs outside of the U.S. and Synta will receive double-digit tiered royalties on net sales. In addition, GSK may, subject to Synta's agreement, purchase as much as $45 million of Synta's common stock upon the future achievement of specified development and regulatory milestones.

"[This agreement] further strengthens our late-stage oncology pipeline, which currently includes 10 Phase III programs, and also demonstrates our commitment to identifying compounds that have the potential to deliver real benefit to patients," said Moncef Slaoui, chairman of R&D for GSK, in a news release about the deal. "The data we have seen from the Phase II trials conducted by Synta have given us confidence in the potential of STA-4783 as a novel means of treating metastatic melanoma, a disease for which there is high unmet medical need."

GSK's commitment to the oncology market is one of the key reasons the company won out in the competitive bidding process for STA-4783, Bahcall notes. Aside from the money alone, which he says means Synta is "really in a position to not need to access the public market for quite a while," working with a company like GSK on development, sales and marketing is going to be a boon for all of Synta's oncology drugs, the next set of which are "advancing rapidly." The deal is also transformative for Synta, Bahcall says, moving it "one step closer to a fully integrated discovery, development and commercial engine."

In preclinical models, STA-4783 showed potent killing of a broad range of cancer cell types at high doses, and an ability to strongly enhance the efficacy of certain chemotherapy agents, with minimal additional toxicity, at moderate doses. In addition to the pivotal, confirmatory Phase III clinical trial in metastatic melanoma beginning soon for STA-4783, the drug is now entering Phase II trials in other oncology indications, and for uses in combination with other agents. STA-4783 has received "Fast Track" designation from the FDA for development in metastatic melanoma.