Novogen claims four-leaf result from cancer drug trial

Sydney oncology drug developer Novogen (ASX:NRT, NASDAQ:NVGN) can smell the clover across the width of the Pacific, after its Connecticut-based subsidiary Marshall Edwards (LSE AIM:MSH and NASDAQ:MSHL) reported outstanding preliminary results from a trial of its clover-derived cancer drug phenoxodiol.

Marshall Edwards is trialling phenoxodiol as a re-sensitising agent in female volunteers with ovarian tumours who were no longer responding to first-line platinum and taxane chemotherapy drugs.

Of the 40 women recruited into the two-site trial at Melbourne's Royal Women's Hospital and the Yale-Newhaven Hospital in Connecticut, 32 (80 per cent) showed either a complete or partial response to combination therapies incorporating phenoxodiol.

The 40 patients were selected because their ovarian tumours had become refractory, or resistant to, the platinum drugs cis-platin and carboplatin, or the taxane agents paclitaxel and docetaxel. Patients whose tumours continued growing on these drugs were defined as refractory, while those who exhibited disease progression within seven months of treatment were classed as resistant.

They were divided into two groups of 20, one with high-level resistance to platins, the other to taxanes, and treated with a combination of phenoxodiol and the drugs that had failed them

Of the 40 patients on either treatment, 11 per cent had a complete response, involving full tumour regression, 22 per cent showed some regression, and 44 per cent of tumours stabilised.

Both groups of patients tolerated the treatments well, with no unexpected toxic effects.

Such responses are "very unusual" and the preliminary results support evidence for the drug's chemo-sensitising potential," said Marshal Edwards' executive chairman, Dr Graham Kelly.

"What gives us particular confidence to go forward into a registration trial is the level of stringency that we have used in our study," he said. "Most of the patients in our trial previously had shown disease recurrence during chemotherapy, with the rest showing disease recurrence within six months of therapy.

"Importantly, we also took those patients within a relatively short time after disease recurrence, meaning that we have selected a group of patients with tumors that we can be confident would normally have a very low level of sensitivity to platinums and taxanes," he said.

The study is now recruiting a similar patient cohort for the second stage of the two-part trial, in which 20 patients will be divided into groups and re-administered paclitaxel or cis-platin. Phenoxodiol will be added to their treatment regime if their tumours begin to grow.

Kelly said this level of stringency represents the highest level of challenge in chemo-sensitisation yet tested.

The ovarian-cancer trial is part of the Ovature (Ovarian Tumor Response) study, which is proceeding in Australia, the US and Japan. Ovature is a Phase IIb/IIIa registration study under way in Australia and the UK, that was based on evidence from the first part of the IIb study of phenoxodiol's remarkable capacity to re-potentiate standard chemotherapy agents.

Patients with platinum-resistant ovarian, fallopian tube or primary peritoneal cancers will be re-challenged with weekly carboplatin, then have phenoxodiol introduced into their treatment regime one they exhibit disease progression.

Novogen's investigational new drug is being trialled at five sites in Australia, four in the UK, and Marshall Edwards will seek approval to trial it at eight hospitals in the US.