Cortecs plans to use the three-month data, part of an ongoing two-year trial, to register the drug for approval in Europe. Analysts expect a launch in Europe by the year-end. Trials in the US are about two years behind.
The best existing treatments for brittle bone disease are injected or nasal forms of calcitonin. However, no one has yet been able to make a more user-friendly pill version to treat the illness, which affects around 200 million people worldwide.
Glen Travers, chairman, said that that an effective calcitonin pill could decimate rivals' share of the nasal and injectible market, worth some $800m (pounds 493m) a year world-wide and growing fast. "This is a very important day for us", he said.
Mr Travers said the result validated the effectiveness of Cortecs' oral drug delivery system, which enables large molecules to be taken into the stomach without being destroyed. The group is also using it to develop an insulin pill.
The brittle bone data, taken from 212 post-menopausal women, showed that patients taking Macritonin had dramatically lower levels of a chemical associated with bone breakdown in their urine compared to those on a dummy pill.
Crucially, the study also showed that Macritonin was equally as good as the current nasal spray. Cortecs' filing in Europe depends on it proving the drug is "equivalent" to existing treatments.
Analysts welcomed the data, but were concerned that a quarter of the patient sample were discarded due to "exceptional responses". Nomura analyst Nick Woolf said: "It's news that everyone wanted to hear. But things look tight. Cortecs need 30 patients per group to register for approval and they have 24. This is also just three months' data".
He added that the group would need a marketing partner to hit his share price target of 400p. Obvious candidates are Swiss drug giant Novartis, which makes nasal calcitonin, and French group RPR.
A spokesman for Novartis said: "Cortecs' study is obviously something we are aware of."Reuse content