** The Nasdaq biotechnology index .NBI touches a record high and is up 1.2% on Fri, putting the index on track for a roughly 4.8% gain this week

** That would be its biggest weekly pct increase since the week starting September 29

** Biotechs picked up momentum this week, thanks in part to M&A deals or talk

** Shares of Avadel Pharmaceuticals AVDL.O up 21.5% on Fri after Avadel disclosed it had received an unsolicited takeover proposal from Danish pharmaceutical company Lundbeck. Lundbeck's up to $23 per share offer is being compared against Alkermes' ALKS.O up to $20 per share deal. Avadel's stock is up about 25% for the week and up 122% for the YTD

** Also, shares of Mersana Therapeutics MRSN.O are up more than 200% for the week, and up ~1% on Fri. The stock had already soared more than 200% on Thurs after it said Day One Biopharmaceuticals DAWN.O agreed to acquire Mersana in a deal that could be worth up to $285 mln

** In addition, Cogent Biosciences COGT.O is up more than 100% for the week after the co said on Monday that its experimental combo drug significantly delayed disease progression in patients with an advanced form of stomach cancer in a late-stage study

(Reporting by Caroline Valetkevitch )

((caroline.valetkevitch@thomsonreuters.com))