Rather than accepting his year-end 2017 ease into retirement by Alexion Pharmaceuticals Inc., Martin Mackay is adding another page to his storied biopharma career as one of the trio of co-founders at startup Rallybio LLC. The Farmington, Conn.-based company, which landed a $37 million series A to target rare disease therapies, was "born out of lots of failures and mistakes in the past," said Mackay, who serves as executive leader. "Fortunately, along the way we were able to develop some good medicines, and we hope to bring that experience to bear in a positive way."