Pharmos Corporation (Pink Sheets: PARS) announced today the results of its Phase 2b Dextofisopam clinical trial to evaluate safety and efficacy of the compound in irritable bowel syndrome.
Although the primary efficacy variable (% of weeks responding for adequate overall relief of IBS symptoms) did not reach statistical significance, the percentage responding for the Dextofisopam 200 mg group was higher than that observed for the Phase 2a trial. However, the placebo response rate was higher than expected compared to the Phase 2a placebo response.
This result was similarly demonstrated across all other secondary efficacy variables associated with the adequate overall relief question. In all cases except at Month 1, the response rates for the Dextofisopam 200 mg group were essentially the same as or in most cases better than the response rates observed for the Phase 2a trial.
Secondary response variables of adequate relief of abdominal pain and discomfort and overall IBS symptoms ratings showed statistical significance and trends favoring the Dextofisopam 200 mg group compared to placebo.
Further secondary analysis, as well as sub group analysis, is ongoing and will be reported when available.
The Phase 2b double-blind, randomized, placebo-controlled study evaluated the clinical safety, tolerability and efficacy of multiple doses of Dextofisopam. Female outpatients with diarrhea predominant and alternating diarrhea and constipation IBS (according to Rome III Criteria for IBS) were randomized into each of four treatment groups: 100mg, 200mg, and 300mg BID dextofisopam or placebo. A total of 324 patients were enrolled using approximately 70 US centers. The patients participated for up to 19 weeks, including a screening period, a 12-week treatment period, and a 28-day post treatment period. The primary endpoint was "adequate overall relief" of IBS symptoms during the 12-week treatment period.
In the Phase 2b study, of the 324 patients randomized, 311 (96%) were evaluated in the Intent to Treat (ITT) analysis. Patients who completed the full study numbered 225 (69%), a similar percentage to the Phase 2a study, and 99 patients discontinued the study. The majority of patients who discontinued did so due to withdrawal of consent or a non serious adverse event.
Demographics and baseline calculations were compatible among the four treatment groups. The mean age was between 44 and 45 years of age. The duration of IBS disease symptoms ranged from 9 to 11 years, and the majority of patients were white.
The most bothersome IBS symptom reported at baseline was abdominal pain and discomfort, followed by a sense of urgency and stool frequency.
This Phase 2b study followed a successful 141-patient Phase 2a study in which Dextofisopam with a dose of 200 mg BID demonstrated a statistically significant improvement over placebo on the primary endpoint of adequate overall relief>
Additionally, dextofisopam has been evaluated in three randomized, double-blind, placebo-controlled Phase 1 trials comprising healthy volunteers. Clinical data from the Phase 1 studies demonstrated that dextofisopam appears to be safe and well tolerated at doses up to 600 mg BID.
As previously communicated, the Company's strategy is now to seek a pharmaceutical partner with the appropriate GI scientific expertise for further development of Dextofisopam. Interested parties should contact the Company.