Ziopharm Drug Stymies Lethal Tumors 77% Longer Than Standard Treatment

An experimental drug from Ziopharm Oncology Inc. helped keep fast-growing sarcomas, lethal tumors that can grow to the size of basketballs, in check 77% longer than a standard treatment, a company-sponsored study found.

Soft tissue sarcoma is a cancer that develops in body fat, muscle or other tissue. Ziopharm’s palifosfamide combined with doxorubicin, a standard therapy, increased to 7.8 months the time patients lived without seeing their cancer worsen, from 4.4 months with doxorubicin alone, the researchers said. Results from the study, released today, will be presented at a meeting of the American Society of Clinical Oncology next month.

Each year, about 10,000 people in the U.S. are diagnosed with soft tissue sarcoma, and half don’t survive five years, according to the National Cancer Institute in Bethesda, Maryland. If palifosfamide makes it to market, it will be the first new medication approved for this illness in the U.S. in 20 years, said Jonathan Lewis, New York-based Ziopharm’s chief executive officer.

“There isn’t really anything that works in that disease setting,” Simos Simeonidis, an analyst at Rodman & Renshaw Inc. in New York, said in an interview. “Even if ultimately you don’t double survival but you increase it by 50 or 60 percent, that would be very significant.”

Most Advanced Product

Ziopharm has no marketed products and three drugs in testing. Palifosfamide, its most advanced experimental drug, is a variation on ifosfamide, a type of chemotherapy. While ifosfamide, sold by Deerfield, Illinois-based Baxter International Inc. under the name Ifex, works in sarcoma, the drug has potentially fatal side effects, including brain toxicity and bleeding in the bladder.

“The old treatments for sarcoma are really toxic and hard to give,” said David D’Adamo, a sarcoma specialist at Memorial Sloan-Kettering Cancer Center in New York. If palifosfamide improves on that, it’s “a huge step forward,” he said.

The American Society of Clinical Oncology, based in Alexandria, Virginia, released 4,500 abstracts today in advance of the organization’s conference in Chicago, which begins June 4. The Ziopharm trial included 62 adult patients with soft- tissue tumor types that were inoperable.

The study, from the second of three rounds of testing required for approval by U.S. regulators, was halted early, on the recommendation of an independent data-monitoring committee, because palifosfamide prolonged survival significantly, Simeonidis wrote in a note investors.

“This is very good data in an area where it’s been a struggle to move the needle,” Ziopharm’s Lewis said in an interview. “The first time I saw it, I didn’t believe it.”

Sales Potential

The U.S. sales potential of palifosfamide in soft tissue sarcoma is about $250 million a year, according to Lewis. Because palifosfamide addresses an unmet medical need, it has orphan-drug status, meaning it will get seven years of immunity from competition from similar drugs if U.S. regulators clear it for sale. Expanded use in other cancers, such as lymphoma, may drive up annual revenue to $400 million, Lewis said.

Two other drugs are in late-stage testing for sarcoma: Votrient, from London-based GlaxoSmithKline Plc, and ridaforolimus, from Whitehouse Station, New Jersey-based Merck & Co. and Cambridge, Massachusetts-based Ariad Pharmaceuticals Inc. Both work by inhibiting angiogenesis -- the formation of new cancer-feeding blood vessels -- preventing tumors from expanding.

“In the sarcomas, these can be some of the largest tumors you’ll see in oncology,” D’Adamo said. “One of my physicians operated on a tumor that was 100 pounds. We need drugs that work to not only stop the tumors from growing, but to shrink them.”

To contact the reporters on this story: Ellen Gibson in New York at egibson9@bloomberg.net;

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