Halting Tumors’ Growth by Targeting Their ‘Achilles Heel’
Joseph Schlessinger is one of the world’s leading cellular biologists and cancer-treatment inventors.
Widely known for pioneering studies of how cells grow and divide, and how aberrant cell signals can lead to cancer, he has made discoveries that have led to an entire field of cancer research, producing a new class of targeted anti-cancer drugs — multi-kinase inhibitors — that combat the disease by retarding both tumor growth and blood supply.
Before coming to Yale in 2001, Schlessinger invented a treatment for various types of deadly cancers; it was called SU11248, or Sutent. He co-founded a company and the FDA approved the drug in 2006 to treat gastrointestinal and kidney cancers. Pfizer Inc. ultimately acquired the firm, and Sutent is now is being tested for other types of cancer.
More recently at Yale, where he is chair of pharmacology at the School of Medicine, he invented a novel approach for development of antibody drugs to treat cancers that have escaped conventional therapies.
His discovery was the basis for a New Haven company he founded with Yale called Kolltan Pharmaceuticals, which recently secured $35 million in financing. Kolltan is developing monoclonal antibodies against various cancers that the company hopes to move rapidly into human clinical trials toward FDA approval.
Schlessinger’s latest breakthroughs were the result of painstaking research into cellular signals that switch on the growth of tumors — and how to stop that growth. “When you really understand how these receptors work, you can find new Achilles’ heels that you can use in order to block activity in cancer and other diseases,” he said.
By targeting these sites, drugs can block receptors and overcome resistance that develops when patients undergo lengthy treatment with current cancer drugs.
Schlessinger, who has turned down offers to run drug companies, savors the freedom of academia. “I think you have to use your imagination and come up with the big questions,” he said, “and then try to answer them.”
Known to friends and colleagues as “Yossi,” Schlessinger said he has been fascinated by science since boyhood but remains haunted by war. Born in the former Yugoslavia at the very end of World War II, his parents were Jewish partisans fighting the Nazis. Many of his extended family members were murdered, he noted.
His parents fled communism with him after the war and settled in Israel, but there was no escape from conflict, said Schlessinger. He was an officer in Israel’s elite Golani brigade, laying or removing mines in the 1967 Six-Day War, the 1973 Yom Kippur War and the 1982 invasion of Lebanon.