The drug discoveries of Memphis biopharmaceutical company GTx.
illustration by Vasyl Dudenko | Dreamstime
A small Memphis company, GTx, is looking ahead to some big business pending approval of a new drug. It’s been a long road toward profitability for the company as it has guided product candidates through the lengthy and expensive regulatory processes.
Scientists at the company began years ago developing two compounds aimed at a specific type of cancer. One compound was believed to have the potential to prevent prostate cancer, the other to lessen the side effects of chemotherapy used to treat prostate cancer.
Due to stumbling blocks in the U.S. Food and Drug Administration approval process, company executives decided to pull the plug on that project.
“It would have meant spending millions of dollars, and the patent life [of the compound] was running out,” says Henry Doggrell, GTx vice president.
GTx scientists then turned their attention to two new compounds. The goal is for these compounds to be approved by the FDA to be sold as drugs for commercial use. One of them, Ostarine GTx-024 was assigned the name enobosarm by the United States Adopted Name Council.
Final clinical trials required by the FDA have just been completed on enobosarm, which diminishes muscle wasting in patients with newly diagnosed cases of non-small cell lung cancers, who are receiving chemotherapy.
When people undergo chemotherapy, they generally lose about 5 percent of muscle mass. “The ability to withstand chemotherapy is in part dependent on a person’s physical stamina,” says Doggrell, who also wears the hats of chief legal counsel and secretary at GTx.
Enobosarm acts as a selective androgen receptor modulator (SARM) and is engineered to regulate androgenic activity by triggering or blocking them. Testosterone is one such androgen, which affects the development and maintenance of male characteristics. Modulating the level of androgens can reduce the loss of muscle mass in cancer patients.
At least that’s what GTx principals are expecting the clinical trial of enobosarm to prove. These Phase III trials involved 325 subjects in each of two testing groups made up of lung cancer patients about to receive initial chemotherapy treatments. The patients were then followed to measure their performance. The trial subjects are located throughout eight countries, including the U.S. and Russia and in Europe and South America.
These clinical trials were double-blind tests, meaning that neither the patients nor the prescribing physicians know who was receiving the drug and who was receiving a placebo. The testing involved beginning the patients on a baseline dose of enobosarm, after which they were timed on an electronic stair-stepping machine. The last group of patients was scheduled to complete the study in May 2013. “The people who were on the drug have been able to keep or improve their performance levels,” Doggrell says.
Topline data — basic results — are expected in the third quarter of 2013. “If the data is good, our plan is to meet with the FDA and file a new drug application at the beginning of 2014,” Doggrell explains. That would put the drug on the market by mid-2014, a speedy time frame by FDA standards. The approval process has been accelerated because the drug received a “fast-track,” designation, which is given to compounds for an unmet medical need. “It’s a much more open interaction with the FDA,” Doggrell says.
Marc Hanover, President and COO of GTx, says he is hoping the drug his company is developing will change lives.
We are excited about the prospect of bringing to market a new class of drugs to improve muscle mass and physical performance in lung cancer patients who struggle to retain a semblance of a normal life as they undergo the rigors of chemotherapy to fight their cancer,” Hanover says. “We believe enobosarm will prove to be another necessary component among the treatments available to medical oncologists to fight cancer.”