Addex Reports Data For Phase IIb GERD Trial

Addex has achieved statistically significant efficacy on the primary endpoint, increasing the number of symptom free days in the Phase IIb trial of ADX10059 as a monotherapy in patients with gastroesophageal reflux disease (GERD).

ADX10059 is a first-in-class reflux inhibitor that works by reducing activation of the metabotropic glutamate receptor 5 (mGluR5) through negative allosteric modulation (NAM).

The study ADX10059-204 was a double-blind, placebo-controlled, multi-center European Phase IIb trial in 103 GERD patients known to respond well to proton pump inhibitors (PPIs). There was a two-week baseline symptom evaluation period followed by two weeks of administration of ADX10059 120mg twice daily. ADX10059 was used as a monotherapy so patients in the study did not use PPIs or other acid suppressant therapy during the baseline and study treatment periods.

The primary clinical endpoint was the patient reported number of GERD symptom free days in week 2 of treatment compared to the last 7 days of baseline. Objective measures of the effects of ADX10059 on esophageal function and reflux events were made in a subset of 24 patients on the day before starting treatment and on the last day of treatment using impedance pH monitoring and esophageal manometry.

ADX10059 significantly increased the mean number of GERD symptom free days in week 2 of treatment. At baseline the mean number of symptom free days was 0.46 in the ADX10059 group and 0.72 days in the placebo group. During treatment week 2 this increased to 2.5 days in the ADX10059 group and to 1.71 days in the placebo group (p = 0.0452)

In the subset of 24 patients who underwent mechanistic monitoring ADX10059 also achieved statistical significance in two mechanistic primary endpoints. ADX10059 significantly reduced total impedance measured reflux events and also acidic reflux events over the 24 hour monitoring period.

In the ADX10059 treated group the mean number of total reflux events decreased by 26% from 64.9 at baseline to 47.9 on treatment compared to no change in the placebo group with a mean of 77.0 reflux episodes at baseline and 78.4 on treatment (p = 0.0342). In the ADX10059 group the mean number of acidic reflux events in 24 hours decreased by 29% from 52.1 at baseline to 37.0 at end of treatment compared to a small increase in the placebo group with 55.7 episodes at baseline, and 59.7 at end of treatment (p = 0.0032).

In addition to the primary efficacy endpoints, ADX10059 showed statistical superiority over placebo for a variety of secondary variables including an increase in heartburn free days, a reduction in sleep disturbance, a reduction in the requirement for antacid medication, an improvement in a GERD symptom patient reported outcome questionnaire (p < 0.05 for all measures).

ADX10059 120mg twice-daily given for two weeks was well tolerated and the tolerability profile seen is compatible with use in the treatment of GERD.

Addex also announced today that enrollment has been completed in the second trial of ADX10059 in GERD patients. In the study ADX10059-205, the product is being used as an add-on therapy in patients who are partial responders to Proton Pump Inhibitors (PPIs), the standard therapy for GERD. Results are expected in January 2010. A third trial, where ADX10059 is being studied as a migraine prophylaxis in patients with frequent migraines is progressing as expected and data will be reported in the second quarter of 2010.