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.