In the phase IIa dose ranging study, OPT-80/PAR-101 was evaluated in 45 patients with clostridium difficile-associated diarrhea (CDAD). 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 an overall cure rate above 91%. Of the subjects that completed the therapy, fewer than 5% had recurrence of symptoms.
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.
“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 IIa trial in CDAD patients,” stated Youe-Kong Shue, vice president of clinical development at Optimer. “We are working closely with our partner, Par Pharmaceutical, to accelerate the development of this compound to treat this dreadful disease.”
Optimer recently received FDA approval for its phase IIb/III clinical trial protocols and plans to begin these trials in April 2006.