CytRx plans to begin its Phase IIb clinical trial in the second half of this year, subject to U.S. Food and Drug Administration (FDA) clearance. As previously announced, this trial, planned to include approximately 390 ALS patients enrolled at 30 to 35 U.S. and Canadian clinical sites, was designed to monitor changes in the progression of disease symptoms and would be completed about 18 months after the beginning of patient enrollment. Following consultation with the FDA, CytRx is now considering various options, including increasing the size and duration of the planned trial and/or conducting a second efficacy clinical trial for ALS, possibly in parallel with the Phase IIb trial, to provide additional data to support a possible approval decision by the FDA.
CytRx expects to announce results of its recently-completed six-month open-label extension trial with arimoclomol for ALS later this week.
"It is rewarding to see significant progress toward our goal of initiating the Phase IIb clinical trial for arimoclomol this year," stated CytRx's President and CEO Steven A. Kriegsman. "Based on the results of this clinical trial we plan to proceed with a dose that is four times greater than that used in our previous Phase IIa ALS clinical trials. These study results will help us optimize trial design to maximize our chances of demonstrating efficacy and supporting our commitment to help those who suffer from the devastating effects of ALS."
The double-blind, placebo-controlled rising multiple dose study, which was announced in February 2007, was designed to identify the highest safe and well-tolerated arimoclomol dose. Forty healthy volunteers were divided evenly into groups of 10 subjects. In each group three subjects received a placebo capsule without drug and seven received arimoclomol at either 100 mg (the highest dose provided in the Phase IIa double-blind and open-label extension studies), 200 mg, 400 mg, or 600 mg three times daily over a seven day period. Dose escalation proceeded carefully, with safety and tolerability demonstrated at lower dose levels prior to testing higher doses. The study indicated that all four doses were safe and well-tolerated. Based on these results and additional data, CytRx plans to proceed with a 400 mg dose of arimoclomol three times daily in its planned Phase IIb efficacy trial.
"While these results indicate that we could potentially use an even higher dose of arimoclomol, we selected 400 mg for our upcoming efficacy trial for several reasons," said Jack Barber, Ph.D., CytRx's Chief Scientific Officer. "First, the 400 mg dose resulted in drug serum exposures higher than those that have provided maximum therapeutic benefit in animals. Second, using less than the highest possible dose potentially provides a margin of safety for ALS patients. Finally, larger doses may not be practical in this population as the capsules could be too large for ALS patients who sometimes have difficulty swallowing."
CytRx is presently conducting a follow-up clinical trial in healthy volunteers to provide longer-term safety and tolerability information at the 400 mg dose. This double-blind, placebo-controlled study includes 16 healthy volunteers: four are receiving a placebo capsule without drug and 12 are receivi ng 400 mg of arimoclomol three times daily for 28 days. The results of this safety study will be reported early in the fourth quarter of this year, prior to the planned initiation of the Phase IIb efficacy trial.
About CytRx Corporation
CytRx Corporation is a biopharmaceutical research and development company engaged in the development of high-value human therapeutics. The Company owns three clinical-stage compounds based on its small molecule "molecular chaperone" co-induction technology. In September 2006, CytRx announced that arimoclomol was shown to be safe and well tolerated at all three doses tested in its Phase IIa clinical trial in patients with ALS. The Company plans to enter a Phase IIb clinical trial with arimoclomol in ALS in the second half of 2007, subject to FDA clearance. The FDA has granted Fast Track designation and Orphan Drug status to arimoclomol for the treatment of ALS and has also been granted orphan medicinal product status for the treatment of ALS by the European Commission. The Company has announced plans to commence a Phase II clinical trial for arimoclomol in stroke recovery in the first half of 2008, subject to FDA clearance. The Company has also announced plans to commence a Phase II clinical trial with its next drug candidate, iroxanadine, for diabetic foot ulcers in the first half of 2008, subject to FDA clearance. In addition, the Company plans to open a research and development facility in San Diego in the third quarter of 2007. For more information on the Company, visit www.cytrx.com.
About RXi Pharmaceuticals Corporation
Worcester, Massachusetts-based RXi Pharmaceuticals Corporation, a majority-owned subsidiary of CytRx, is a biopharmaceutical research and development company that focuses on developing RNAi-based therapeutics for the treatment of human disease. RXi's initial focus is on neurodegenerative diseases, oncology, type 2 diabetes and obesity. RXi has licenses to a diverse series of early pate nts and patent applications that were filed from 1998 to 2006 in the areas of RNAi target sequences, RNAi chemistry and RNAi delivery. The Company was founded by CytRx and RNAi pioneers Craig Mello, Ph.D., 2006 Nobel Laureate for discovering RNAi and inventing RNAi therapeutics; Tariq M. Rana, Ph.D., inventor of fundamental technology for stabilizing RNAi and of RNAi nanotransporters; Greg Hannon, Ph.D., discoverer of RNAi mechanism (RISC) and short hairpin RNAi (shRNAi); and Michael Czech, Ph.D., a leader in the application of RNAi to diabetes and obesity. RXi's CEO, Tod Woolf, Ph.D., previously co-invented and commercialized STEALTH(TM) RNAi, one of the most widely used second-generation RNAi research products.
This press release may contain forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended. Such statements involve risks and uncertainties that could cause actual events or results to differ materially from the events or results described in the forward-looking statements, including risks or uncertainties regarding regulatory approvals for future clinical testing of arimoclomol, including CytRx's planned Phase IIb clinical trial, and the scope of the clinical testing that may be required by regulatory authorities for arimoclomol, uncertainties regarding the timing and amount of revenues, if any, that will be realized by CytRx from the commercialization of arimoclomol, the significant time and expense that will be incurred in developing any of the potential commercial applications for arimoclomol and the potential need for additional capital to fund the development of arimoclomol, as well as other risks or uncertainties described in CytRx's most recently filed SEC documents, such as its most recent annual report on Form 10-K and any current reports on Form 8-K filed since the date of the last Form 10-K. All forward-looking statements are based upon information avail able to CytRx on the date the statements are first published. CytRx undertakes no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.
Dan Schustack, 212-732-4300