In its first foray in treating light chain (AL) amyloidosis, Alexion Pharmaceuticals has purchased an equity stake in Caelum Biosciences and gained an option to acquire the company based on Phase II data for Caelum’s lead asset, CAEL-101. In a Phase Ia/Ib study, the drug was well-tolerated and led to organ responses, particularly in the heart and kidneys. The deal adds to the string of deals Alexion has been signing lately with Complement Pharma, Syntimmune and Dicerna Pharmaceuticals in a bid to find new growth drivers aside from its blockbuster drug, Soliris® (eculizumab).