SAN DIEGO, Feb. 7 /PRNewswire/ -- Phase 2A clinical studies have indicated that Optimer’s lead antibiotic candidate, OPT-80/PAR-101, appears to be efficacious in the treatment of Clostridium difficile-associated diarrhea (CDAD). The Company has recently received FDA approval of its Phase 2B/3 clinical trial protocols and plans to begin these trials in April 2006.
In a Phase 2A dose ranging study, OPT-80/PAR-101 was evaluated in 45 CDAD patients. The evaluation included cure rates, relief of symptoms of CDAD, time to resolution of diarrhea, and clinical recurrence. OPT-80/PAR-101 was well tolerated by all subjects, and the clinical response was very promising with a 41/45, >91% cure rate overall. Of the subjects that completed therapy, 2/41 (<5%) patients had recurrence of symptoms.
Clostridium difficile-associated diarrhea (CDAD)
Clostridium difficile (C. difficile) is a major cause of diarrhea in hospitals and long-term care facilities worldwide. When patients are treated with broad-spectrum antibiotics, including oral vancomycin, the normal gut flora can be disrupted and C. difficile can flourish in the bowel, produce toxins, and cause severe diarrhea or CDAD. In addition, about 20% of patients treated with these antibiotics suffer a recurrence of symptoms (or relapse). An ideal treatment for CDAD would be a safe effective antibiotic that selectively inhibits the pathogen, prevents recurrence, and allows the gut flora to maintain a healthy level.
“CDAD is a condition characterized by painful severe diarrhea and can become life-threatening with the development of fulminant colitis and toxic megacolon. Due to the spread of a hypervirulent epidemic C. difficile strain, more CDAD cases with increasing severity are being reported,” said Pam Sears, Senior Director of Biology at Optimer. “Moreover, the current therapies are losing their effectiveness against this disease.”
“OPT-80/PAR-101, the first in a new class of antibiotics with a novel mechanism, has demonstrated encouraging results for efficacy with low blood levels due to the apparent limited absorption from the GI tract in the proof-of-principle Phase 2A trial in CDAD patients,” stated Youe-Kong Shue, Vice President of Clinical Development at Optimer. “The FDA reviewed and commented favorably on the Phase 2B/3 protocol on January 18, 2006. This trial will include sites in the US, Canada and Europe, and is to start this March. We are working closely with our partner, Par Pharmaceutical, to accelerate the development of this compound to treat this dreadful disease.”
Is it OPT-80 or PAR-101? Answer: Yes, it is.
In August 2003, Optimer Pharmaceuticals filed an Investigational New Drug (IND) application for its lead drug candidate, OPT-80, for the treatment of CDAD. Shortly thereafter, OPT-80 was granted Fast Track designation by the FDA.
In April 2005, Par Pharmaceutical Companies, Inc. and Optimer entered into a collaborative agreement to jointly develop OPT-80. Both parties agreed to change the drug codename from “OPT-80" to “PAR-101" for future regulatory filings in the United States. However, Optimer currently plans to retain “OPT-80" for use in the rest of the world.
In this collaboration, Par has exclusive rights to market, sell and distribute the product in the United States and Canada, while Optimer has exclusive rights to market, sell and distribute OPT-80/PAR-101 to the rest of the world. Optimer is sponsoring the clinical trials, while Par has overall responsibility for clinical development, regulatory interactions, manufacturing, and filing the NDA in the United States. OPT-80/PAR-101 may be commercially available as soon as 2008.
This press release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, including statements related to Optimer’s plans to pursue clinical development of product candidates and the timing thereof and the potential efficacy of product candidates. Any statements contained in this press release that are not statements of historical fact may be deemed to be forward-looking statements. Words such as “plans,” “intends,” “expects” and similar expressions are intended to identify these forward-looking statements. There are a number of important factors that could cause Optimer’s results to differ materially from those indicated by these forward-looking statements, including risks associated with the timing and success of pre-clinical studies and clinical trials.
Media Contact: Christina Donaghy (858) 909-0736 cdonaghy@optimerpharma.com
Optimer Pharmaceuticals
CONTACT: Christina Donaghy of Optimer Pharmaceuticals, +1-858-909-0736,cdonaghy@optimerpharma.com
