Protherics has started a Phase II study for Prolarix, a targeted prodrug chemotherapy which is being developed for the treatment of primary liver cancer.

The move into Phase II follows promising data from a Phase I trial of Prolarix, presented at the American Society of Clinical Oncology meeting in June. The proof-of-concept study is designed to evaluate tumour response in addition to safety and tolerability of the drug in 14 patients with non-resectable hepatocellular carcinoma who have not been treated with Bayer/Onyx’ Nexavar (sorafenib).

The study has been initiated at a site in Belgium and additional sites in East Asia have been identified for inclusion in the trial, Protherics noted. The results are expected in the second half of 2009.

Chief executive Andrew Heath said that Prolarix “offers renewed hope for the many patients with primary liver cancer for whom there are very few treatment options”. If the results from the study are positive, “a licensing partner will be sought for Asia where the incidence of this type of cancer is highest," he added.

HCC is the sixth most common cause of cancer in the world and despite the recent approval of Nexavar, which Protherics noted is being adopted as the standard of care for the disease, life expectancy remains less than 12 months from diagnosis. Less than 20% of patients survive beyond one year, and less
than 5% live for more than five years.

AstraZeneca bid unlikely, says analyst
Meantime, Protherics shares have slipped back from the previous heights they enjoyed after the firm announced a fortnight ago after the company noted that it had received several approaches regarding a takeover.

AstraZeneca and Nycomed have both been linked with Protherics, but Paul Cuddon, an analyst at KBC Peel Hunt, told the Financial Times that AstraZeneca rarely risked buying companies with unproven drugs, while Nycomed had little strategic use for Protherics' cancer and cardiovascular treatments.

A more likely scenario, Mr Cuddon said, would be an all-share offer from a peer such as BTG. "If indeed a cash bid has been made in excess of our 29p target price, we would urge investors to accept," he told the newspaper.