4.3. Future directions
The optimal dose range of astodrimer gel is yet to be determined, despite the available evidence suggest astodrimer 1% gel is associated with the best efficacy and safety outcomes. More large-sized, placebo-controlled, clinical trials are needed to solidly draw definitive conclusions about the efficacy and safety profiles of astodrimer gel for treatment of patients with bacterial vaginosis. Additionally, head-to-head comparative clinical trials challenging astodrimer gel against conventional antibiotics are warranted to establish therapeutic superiority. Moreover, whether astodrimer gel used as an adjunct to (or in combination with) conventional antibiotics will be beneficial is a question that merits an investigation.
Recurrence of bacterial vaginosis is a major management issue and it remains a plausible question as whether astodrimer gel is effective in preventing recurrence of bacterial vaginosis on the long-term. To that end, a phase 3, placebo-controlled study was completed (but not yet published in a peer-reviewed journal) to investigate the efficacy and safety of astodrimer gel in preventing recurrence of bacterial vaginosis up to four months post successful cure with oral metronidazole. In this trial, a total of 586 patients were cured with metronidazole and randomized to receive astodrimer 1% gel (n=294) or placebo (n=291) at a dose of 5 g vaginally every second day for four months. Overall, astodrimer 1% gel was superior to placebo for the primary and secondary endpoints. Specifically, administration of astodrimer 1% gel resulted in lower percentage of patients with recurrence (based on clinical cure and Amsel criteria), prolonged time to recurrence and decreased percentage of patients with self-reported recurring symptoms of vaginal odor/discharge. All in all, this study proved the superiority of astodrimer 1% gel in decreasing the probability of recurrence of bacterial vaginosis in women with a history of recurrent bacterial vaginosis. Nonetheless, while this study is strongly powered, additional comparative studies are needed to harden the efficacy and safety of monotherapy or combination astodrimer 1% gel in preventing long-term recurrence.