Preliminary results from a mid-stage trial of Phynova’s PYN17 have provided more evidence that the agent is safe and well-tolerated in patients with chronic hepatitis C (HCV).

The Phase II trial, which enrolled 39 patients at five sites across the USA, showed no serious side effects and a low level of relatively minor adverse events identical to those seen in the placebo group, confirming previous safety data from a similar study conducted in London, the company noted.

Currently, standard treatment for chronic HCV, which affects around 170 million across the globe, involves injections of pegylated interferon and oral doses of ribavirin. Response rates are around 40%-50% in patients with the harder-to-treat genotype 1, and 70%-90% in those with genotype 2.

But the severity of side effects means that around 20%-25% of patients stop treatment, Dr John Efthimiou, Chief Medical Officer of Phynova, told delegates at a meeting earlier this year. Interferon causes tiredness, fever and depression, while Ribavirin can give patients anaemia, skin rashes, a funny taste in the mouth and a dry cough. Persuading patients to remain on therapy is a big challenge, and a lot aren’t cured because they don’t complete treatment.

Important advantage
So Phynova, which is focused on developing drugs based on Chinese plant-based medicines, is clearly delighted with this latest round of safety results. “This is a very important attribute for patients suffering from this serious chronic condition since current treatments for hepatitis C have a notoriously high level of drug-related toxicity”, commented chief executive Robert Miller.

Aside from this potential benefit over existing therapies, PYN17 is currently the only product being tested in clinical trials that is designed to treat both the debilitating symptoms and impaired health affecting patients’ quality of life as well as the liver inflammation associated with the condition, the group claims.

A pivotal, Phase IIb study for the drug has been scheduled in the first half of 2008. This dose-ranging trial will involve around 200-300 patients, but final details are being fleshed out and will only be known fully in the next month or so, a spokesman for the company told PharmaTimes UK News. But key endpoints for the study will be health related quality of life, fatigue and liver inflammation, he said.

PYN17 is based on a novel formulation of four plant extracts which have proven to be safe and effective in the treatment of liver ailments in Asia and the West, according to the firm, and, unlike current antiviral therapy, offers a multivalent approach to treating HCV, being an antiviral, anti-inflammatory, antioxidant, and antifibrotic all rolled into one.

Ticking time bomb
Experts have warned that the National Health Service is likely facing a ticking time bomb with HCV, and it has been estimated that the market for will hit $9 billion by 2010. In the UK, there are currently around 600,000 people carriers of HCV in the country. According to Professor Foster, most of these were infected in the 1970s through drug abuse and, as it takes 30-40 years to develop liver cirrhosis, we could on the brink of an explosion of patients needing expensive therapy to try and combat the disease.

Liver transplants are needed in 5%-10% of patients with cirrhosis every year, costing the health service as much as £30,000 per patient per year at £29,938, a cost “which will dominate healthcare thinking over the next 15 years,” according to Prof Foster. And this coupled with the hefty expense of treating patients in other stages of the disease, further underscores the need for new, more effective treatments.