M&A activity was continuing to drive the global pharmaceutical sector higher today after Pfizer confirmed it was working on its next move after its first tentative approach for AstraZeneca in January was rejected. Shares in the Anglo-Swedish group were up around 15% at 4,705p in afternoon trade after the US company said it is still "considering a possible transaction" despite its initial $100bn approach being rebuffed.Pfizer said that any potential transaction would offer AstraZeneca's shareholders a "highly compelling opportunity to realise a significant premium" to the recent share price and would include a "substantial" cash payment. The company is "confident a combination is capable of being consummated", it said in a statement.Other pharma stocks in London were making decent gains today, including Shire, BTG and GlaxoSmithKline.Meanwhile, AIM-listed GW Pharmceuticals jumped 8% after US regulators granted 'Fast Track' designation to its Sativex product, which treats pain in patients with advanced cancer. Fast Track status means that the drug is afforded greater access to the Food and Drug Administration "for the purpose of expediting the drug's development, review and potential approval".On the other side of the Pond, US drug development group Furiex Pharmaceuticals surged as much as 32% in pre-market trade in New York after a takeover offer from Forest Laboratories for $1.1bn in cash.US generic drug maker Mylan was also making headlines after sweetening its bid for Swedish pharma firm Meda, though the offer was rejected.Top performing sectors so far todayPharmaceuticals & Biotechnology 13,310.96 +6.00%Beverages 13,856.64 +0.85%Health Care Equipment & Services 5,168.67 +0.69%Food & Drug Retailers 3,870.76 +0.52%Insurance (non-life) 1,867.84 +0.43%Bottom performing sectors so far todayHousehold Goods & Home Construction 11,049.53 -1.61%Industrial Metals & Mining 1,143.06 -1.53%Industrial Transportation 3,021.47 -1.41%Forestry & Paper 10,399.75 -1.33%Mining 16,623.25 -1.33%BC