Addex Pharmaceuticals has announced positive results for a Phase II trial of ADX10059, a new monotherapy for patients with gastroesophageal reflux disease (GERD), a leading cause of heartburn.

The new monotherapy is a first-in-class reflux inhibitor that may address the actual cause of GERD rather than simply addressing symptoms.

ADX10059 works by reducing activation of the metabotropic glutamate receptor 5 through negative allosteric modulation.

Addex chief medical officer Charlotte Keywood said that the number of symptom-free days increased five-fold, an exciting and clinically meaningful effect.

“The magnitude of the effect, along with the tolerability profile, indicates that ADX10059 has the potential to be a useful therapy for GERD management,” Keywood said.

The results were based on a double-blind, placebo-controlled, multi-centre European Phase IIb trial in 103 GERD patients.

During the study ADX10059 was shown to significantly increased the mean number of GERD symptom-free days in week two 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.

In addition to the primary endpoints, the treatment also showed superiority over placebo for a variety of secondary variables including an increase in heartburn-free days, a reduction in sleep disturbance and a reduction in the requirement for antacid medication.