By Randall Osborne
West Coast Editor
Genta Inc.¿s antisense chemotherapy booster, G3139, entered a pivotal study for advanced melanoma ¿ the malignant skin cancer for which there is ¿practically nothing¿ useful on the market today, said President and CEO Raymond Warrell.
¿The state of the art is quite poor,¿ Warrell noted. Dacarbazine (DTIC), with which G3139 will be used in the trials, ¿gives you about a 10 percent to 15 percent response rate in advanced melanoma,¿ he said. Vaccines are being developed for early-stage melanoma.
G3139, soon to be renamed, was designed to reduce the bcl-2 protein level in cancer cells by way of an antisense mechanism targeting messenger RNA produced by the bcl-2 gene.
¿A central factor in the pathogenesis of most types of cancer is the overexpression of bcl-2,¿ Warrell said, and the bcl-2 protein is believed to inhibit apoptosis, or programmed cell death, thus possibly contributing to resistance against cancer treatments.
The randomized controlled pivotal Phase III trial will be conducted at multiple sites in North America and Europe, Warrell said.
Genta, of Lexington, Mass., plans to further develop the compound for other cancers.
¿We¿ve finished a Phase II trial in malignant lymphoma,¿ Warrell said. ¿The other diseases pegged for a decision to go or no go in Phase III this year are prostate cancer, small-cell lung cancer and probably colorectal cancer.¿
Completion of the Phase III trial in melanoma ¿obviously depends on the rate of accrual, but a reasonable estimate is 14 to 16 months, with a short period of follow-up,¿ he said.
Gerald Schimmoeller, chief financial officer, said the compound would be the first antisense cancer drug approved by the FDA.
¿By itself, [the market for the melanoma treatment] is between $100 million and $200 million, but when you add up all the indications we could go after, you¿re talking about the billion dollar range,¿ Schimmoeller said.
¿We¿re pretty much focused on the cancer area,¿ he added. ¿There are other drugs in the pipeline, but not nearly as far along as this one.¿
Genta¿s stock (NASDAQ:GNTA) closed Thursday at $12.562, up 68.75 cents.