A new drug to treat one of the most common sexual health problems in women of childbearing age could be available early next year.

Melbourne biotech Starpharma (ASX:SPL) has cleared its last US clinical trial for VivaGel BV, a drug that treats bacterial vaginosis.

VivaGel BV had already passed all US clinical trials for short term treatments for bacterial vaginosis, and has now been given the nod to also treat recurrent infections. The company says the drug could be worth up to $300 million.

CEO Jackie Fairley told Stockhead she estimated VivaGel BV could be available in the US and other major markets by the second quarter of 2018.

The third clinical trial gave Vivagel BV or a placebo to 1223 women with a history of recurrent bacterial vaginosis for 16 weeks. The treatment showed sustained benefits three months after treatment had stopped.

Ms Fairley said the global market for bacterial vaginosis was worth about $1 billion. About 30 per cent of women in the US and 20 per cent in Australia deal with this infection, and of those about half will experience recurrent bouts.

“Bacterial vaginosis is the most common cause of vaginal infection for women of childbearing age and can lead to infertility, premature birth delivery, HIV (BV increases chance of acquiring HIV/STIs from infected sexual partners), as well as unpleasant odours and vaginal discharge,” the company said in a statement.

It’s the world’s most common vaginal disorder, yet until now the only treatment was to go on a course of general antibiotics, meaning that women with recurrent infections effectively had untreatable conditions.

Ms Fairley said VivaGel BV, a topical gel that can’t be absorbed into the bloodstream, will be the only non-antibiotic drug on the market.

“Anti-infectives as a category are not very attractive for major pharmaceutical companies,” she said. “The market size is smaller (than longer-use drugs for conditions such as diabetes or cancer), and most antibiotics can’t be used prophylactically.”

Starpharma will lodge a final submission to the FDA for both the recurrent and short term use of VivaGel by the end of 2017, and Ms Fairley said she expected licencing negotiations to be finalised by then too. Starpharma received a fast-track designation for the drug earlier this year, so the final approval should only take up to eight months.

The company’s other products are DEP drug delivery platform, which was licenced to Astra Zeneca in 2015 and yielded a $2.6 million milestone payment in June, and the VivaGel antibacterial condom which is licenced to Ansell and other global condom manufacturers.

In July the company said it had full year cash inflows of $15.7 million, which it said was strong enough to commercialise the VivaGel BV product.

Starpharma’s shares closed about 10 per cent up at 84c at close of market on Monday August 7.