The Salisbury South company, which also has significant operations in the United States, said it expected the combined oral contraceptive pill – called Nextstellis – to hit the US market by June 30.

The short-acting oestrogen and progestin contraceptive pill was developed by Belgian women’s health biotech company Mithra, and contains 15mg of estetrol, a native oestrogen, and 3mg of drospirenone.

Mayne Pharma said the use of estetrol signalled the first new oestrogen introduced into the US in more than 50 years.

It is also the publicly listed company’s first novel combined oral contraceptive to be sold in the US and follows the launch of a string of generic contraceptives in America earlier this year.

Mayne Pharma CEO Scott Richards said the contraceptive’s chemical entity had a “unique mode of action” that showed “positive outcomes in efficacy and safety and also showed good bleeding profile, cycle control and tolerability” during trials.

Richards said the FDA approval represented an “important milestone” for reproductive health choice.

“We are delighted to be introducing a new oestrogen and bringing to market this novel, safe and effective option for women to consider with their healthcare providers,” he told the ASX.

Mithra CEO Leon Van Rompay echoed Richards comments saying he believed Nextstellis represented “a new era in contraception”.

“The approval of Nextstellis represents a huge achievement for a biotech company such as Mithra and all the teams who made this ambition project come to fruition,” he said.

“This is a critical step in Mithra’s journey to bring innovative medicines to the US women’s health market.”

In an announcement to shareholders on Friday morning, Mayne Pharma said it would pay $14.19 million (US$11 million) in cash and 85.8 million ordinary shares to Mithra for the 20-year product licence, giving Mithra a 9.6 per cent stake in the business.

It follows a long-term licence and supply agreement between the companies last year to develop and sell the pill in Australia, with an intention to launch the product in New Zealand as well.

If approved, the European manufactured contraceptive will join a $130 million market in Australia, of which short-acting oral contraception was estimated at $70 million in 2020.

Mayne Pharma said Nextsetllis was under review with the Australian Therapeutics Goods Administration and anticipated it will be approved by early next year.

The company hopes the deal will help turn its fortunes around after reporting a significant fall to revenue over the past 12 months, due to lower patient visits to physicians during coronavirus lockdowns resulting in decreased prescription numbers.

As part of the deal, a Mithra representative will sit on the Mayne Pharma board, subject to shareholder approval in November.

The board changes are set to coincide with the departure of Mayne Pharma chairman and Australian businessman Roger Corbett and non-executive director and hotel heavyweight Bruce Mathieson, who will step down as part of a “renewal process”.

A US chairperson is expected to lead the company, with an Australian deputy chair.