Pharmaceutical giant AstraZeneca on Tuesday set out its defence against a 63bn pounds takeover bid from US rival Pfizer as it urged Britain not to take sides in the affair.AstraZeneca issued a strategy update highlighting "excellent growth prospects, a rapidly progressing pipeline and the future delivery of shareholder value as an independent company."Last week, it rejected the bid from Pfizer as under-valuing it, but there has been speculation that Pfizer would increase its offer or take it directly to the British company's shareholders.AstraZeneca said on Tuesday that it was targeting annual revenue of more than $45bn by 2023, versus $25.7bn last year.A UK parliamentary group, the Business, Innovation and Skills committee, will call representatives from both companies to discuss the deal in the coming weeks, a committee spokesman said on Tuesday. The Anglo-Swedish group, which has been targeting new drug development to replace treatments whose patents have expired or are due to run out soon, said it had speeded up scientific research to boost its line-up of drugs in the late stages of development.It is focusing on five key growth areas including its Brilinta heart drug, which it said would be worth $3.5bn in 2023, as well as diabetes and respiratory treatments, Japan and emerging markets such as China.Chief Executive Pascal Soriot said: "We are continuing to create significant value for shareholders from our independent strategy."The move came as the company's Chairman, Leif Johansson, warned British Prime Minister David Cameron that active engagement with Pfizer would allow the group to suggest that Downing Street was in favour of the deal, the FT said.AstraZeneca has refused to enter talks with Pfizer, which said it was "very disappointed" and plans to keep options open for its next step. The group has until May 26th under UK takeover rules to persuade Astra to enter talks or, if it fails, to walk away.Analysts have said one of the reasons Pfizer - which on Tuesday posted a 9% year-on-year drop in first quarter sales to $11.4bn - is looking to buy the bio-medical group to boost its relatively weak line-up of drugs in development.As of 09:10, AstraZeneca's share price had dropped 114.5p or 2.4% to 4693.5p.WS/PW