London : AstraZeneca shares hit a record high, breaching for the first time the 55 pounds a share level offered by Pfizer in 2014 during the U.S. group's abortive $100 billion attempt to buy the drug maker.

The British firm's stock has been on a roll recently, helped by a falling pound and speculation that Switzerland's Novartis might be next to launch a bid. However, the shares were lifted to a high of 55.05 pounds by the misfortunes of Bristol-Myers Squibb.

The failure of Bristol's immunotherapy drug Opdivo to slow disease progression in previously untreated patients with lung cancer as hoped was seen by investors as good news for rivals Merck & Co (MRK.N) and AstraZeneca.

Analysts at Leerink, Jefferies and Deutsche Bank said the negative result with Opdivo increased the potential market opportunity for AstraZeneca's keenly watched combination of durvalumab and tremelimumab.

Crucial clinical trial results with durvalumab, both on its own and in combination with tremelimumab, are due next year.

Chief Executive Pascal Soriot believes AstraZeneca can become a major player in cancer drugs that bolster the immune system. And its ability to carve out billions of dollars in potential sales hinges not only on the effectiveness of its own products but on the competitive profile of rivals.

Cancer is currently the hottest area of research across the drugs industry and some analysts believe this could make AstraZeneca a takeover target once again, with speculation turning last week to Novartis as a bidder.