Organon, the pharmaceutical unit of Dutch chemical group Akzo Nobel, said this morning that it has started Phase III trials of a new oral contraceptive based on natural oestrogen.

NOMAC/E2 is ‘the first major innovation in hormone content since the introduction of the pill in the 1960s’, according to Organon, because it contains a form of the hormone that is identical to the one found in women. All other oral contraceptives on the market use a synthetic version of oestrogen called ethinyl estradiol.

In addition, the contraceptive contains a novel progesterone component – NOMAC (nomegestrol acetate) – that is designed to mimic the natural form of the hormone more closely than compound used in rival products.

Organon was granted development and marketing rights of NOMAC/E2 by Merck KGaA affiliate Laboratoire Theramex last year. Phase II trials suggest that NOMAC/E2 provides good contraceptive efficacy with an expected cyclic bleeding pattern and an acceptable safety profile.

"Bringing this new contraceptive into Phase III adds value to Organon's strong late stage development pipeline," the company said in a statement.