Shares in the biotechnology group Antisoma soared 19 per cent yesterday after the company announced promising results from a clinical trial of an experimental lung cancer medicine.

Antisoma said that a new Phase-II study of the drug, known as ASA404, supported earlier findings suggesting that its use in combination with chemotherapy had led to one of the biggest increases in survival reported in the treatment of nonsmall cell lung cancer.

Full results of the latest 31-patient trial, conducted in New Zealand and Germany, are being kept under wraps until September 5, when they will be presented at the World Lung Cancer Conference in Seoul, South Korea.

However, the earlier study of the drug published last year showed that lung cancer patients treated with ASA404 in combination with standard chemotherapy survived almost 60 per cent longer than patients who received chemotherapy alone – 14 months compared with 8.8 months.

“Today’s data confirms the spectacular increase in survival we saw in the 2006 study,” Glyn Edwards, Antisoma’s chief executive, said. “The data looks very strong and this increases the likelihood that the drug will get to market. It is much less likely to be a fluke.”

Novartis, the Swiss pharmaceuticals giant that is Antisoma’s partner on the drug, is preparing to launch a final-stage trial early next year. These Phase-III trials are likely to take at least three years, but the latest results have paved the way for millions of dollars in extra milestone payments to Antisoma from Novartis – possibly as much as $890 million (£445 million) if the drug eventually achieves a commercial launch.

Mr Edwards said that the drug was also being tested against prostate cancer and that further results on this were likely within the next two months. Nevertheless, some analysts remain sceptical about the drug’s prospects against other tumour types. Last month, Antisoma’s shares plunged after disappointing results against ovarian cancer.

Others questioned the magnitude of the rise in the company’s share price yesterday. “Antisoma is already a fully valued stock, so I don’t understand the strength of the market’s reaction,” Ibraheem Mahmood, an analyst for Investec, said.

If it succeeds, ASA404, Antisoma’s flagship product, which was discovered by two professors at the University of Auckland, New Zealand, would be the first of a new generation of anticancer drugs designed to starve tumour cells of blood. It was originally licensed by Antisoma from Cancer Research Ventures in August 2001 and worldwide rights were licensed to Novartis in April 2007.

Nonsmall cell lung cancer is the most common form of the disease, accounting for about 80 per cent of all cases. According to the World Health Organisation, there are more than 1.2 million cases worldwide of lung and bronchial cancer each year, causing approximately 1.1 million deaths. The 19 per cent rise priced Antisoma shares at 34p.

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