The latest news on mergers and acquisitions featuring GSK/Boston Pharmaceuticals and bluebird bio/Carlyle/SK Capital Partners. Highlights below. 

* GSK To Acquire Liver Disease Drug from Boston Pharmaceuticals in $2-Bn Deal
* Investment Firms Up Offer for bluebird bio 

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GSK To Acquire Liver Disease Drug from Boston Pharmaceuticals in $2-Bn Deal 
GSK has agreed to acquire a liver-disease drug from Boston Pharmaceuticals, a Cambridge, Massachusetts-based bio/pharmaceutical company, in a deal worth up to $2 billion ($1.2 billion upfront and $800 million in milestone payments). 

Boston Pharmaceuticals’ lead asset, efimosfermin alfa, is a Phase III-ready, investigational specialty medicine to treat and prevent progression of steatotic liver disease (SLD), a condition where excessive fat accumulates in the liver. Efimosfermin is a once-monthly fibroblast growth factor 21 (FGF21) analog therapeutic in clinical development for treating metabolic dysfunction-associated steatohepatitis, including cirrhosis, and future development in alcohol-related liver disease, both forms of SLD.  

Under the agreement, GSK will pay $1.2 billion upfront, with potential for additional success-based milestone payments totaling $800 million. 

Source: Boston Pharmaceuticals 

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Investment Firms Up Offer for bluebird bio 
bluebird bio, a Somerville, Massachusetts-based bio/pharma company specializing in gene therapies, reports that the investment firms, Carlyle and SK Capital Partners, have upped their offer to acquire bluebird bio. The investment firms had first made an offer that was announced in February (February 2025). 

Under the amended agreement bluebird stockholders can elect to receive either the original offer of $3.00 per share in cash plus a contingent value right of $6.84 per share in cash payable upon achievement of a net sales milestone, or $5.00 per share in cash. Any shares tendered for which no election is made will receive the original consideration of $3.00 per share in cash and a contingent value right per share. 

The bluebird bio Board of Directors unanimously approved the amended agreement and recommends that all stockholders tender their shares in support of the transaction with financial urgency. The company said that the amended agreement “represents the only viable option for stockholders to receive consideration for their shares,”  in a May 14, 2025, press statement. “Absent a majority of stockholders tendering, bluebird is at significant risk of defaulting on its loan agreements with Hercules Capital, and it is extremely unlikely that stockholders would receive any consideration for their shares in a bankruptcy or liquidation.” 

As previously reported earlier this month (May 2025), Carlyle and SK Capital reported that they have received all required regulatory approvals to complete the transaction, and all parties expect the transaction to be completed following the successful completion of the ongoing tender offer.  

Source: bluebird bio