With $163M Deal, Tarveda Revives Synta Pharma’s Cancer Drug Work

Xconomy Boston — 

Earlier this year, Blend Therapeutics changed its name to Tarveda Therapeutics and spun what used to be its lead drug into a separate company, the latest steps in a strategic overhaul. The wheeling and dealing continued this morning for the Watertown, MA, company, which has cut a deal with Madrigal Pharmaceuticals—the firm that recently merged with now-defunct Synta Pharmaceuticals—to add another potential cancer drug to the mix.

Tarveda has agreed to pay Madrigal (NASDAQ: MDGL) as much as $163 million overall—including an unspecified upfront payment—for the rights to a drug called PEN-866 and potentially others like it. Much of that cash will be tied to the progress of PEN-866, an experimental cancer drug that, like Tarveda’s other experimental therapies, is composed of two chemically linked molecules.

Tarveda drugs, which it calls pentarins, are essentially tinier versions of antibody-drug conjugates, or ADCs, a type of cancer treatment that links antibodies to toxins to attack tumors. The difference is pentarins use peptides—much smaller molecules than antibodies—to shepherd the drug to tumor cells, which in theory might help them penetrate tumor tissue more easily than ADCs. Tarveda’s lead drug, known as PEN-221, binds to a protein on the surface of neuroendocrine cells called somatostatin receptor 2, carrying the chemotherapy drug DM1. It’s supposed to begin clinical testing this year.

Through the Madrigal deal, Tarveda now has a second experimental drug, PEN-866. The drug targets heat shock protein 90 (HSP90), a so-called chaperone protein that helps shuttle other proteins around—including some that cause cancer—inside cells. HSP90 has been a popular cancer drug target, but drugs that block the protein haven’t fared well. Novartis’ AUY922, Infinity Pharmaceuticals’ (NASDAQ: INFI) IPI-504, and Synta’s ganetespib are just a few examples of companies whose HSP90-blocking drugs have failed. (Check out this article in the journal Clinical Advances in Hematology & Oncology for more on the history of HSP90 inhibitors).

The failure of ganetespib is what doomed Synta, a Lexington, MA, company that in April merged with Madrigal following a strategic review. The surviving company, which kept the Madrigal name, is focused on cardiovascular and liver diseases and trying to shed all of Synta’s cancer drug work. This includes Synta’s intellectual property on HSP90, which has led to what Tarveda is carrying forward as PEN-866. Tarveda says PEN-866 is different than past failed HSP90 inhibitors because it’s a conjugate—it doesn’t just block HSP90, it carries a byproduct of the toxic chemotherapy irinotecan. That’ll have to be proven in clinical trials, however; the first human study of PEN-866 should begin early next year.

Tarveda CEO Drew Fromkin called PEN-866 an “ideal fit” for the company, which is trying to prove that pentarins can overcome some of the limitations of ADCs and other cancer drugs. Fromkin took over the company last year, when it was still called Blend and focused on a few disparate methods of developing cancer drugs. Since that time, Blend has spun out its old lead drug, a next-gen platinum-based chemotherapy drug called BTP-114, into a new company called Placon Therapeutics and sharpened its focus on pentarins. Blend changed its name to Tarveda in January.