Biogen Idec has entered an agreement to acquire UK-based Convergence Pharmaceuticals, a clinical-stage biopharma company with a portfolio of ion channel-modulating product candidates for neuropathic pain. Biogen will pay $200 million upfront and Convergence shareholders are eligible to receive additional milestone payments of as much as $475 million. Convergence will continue to operate out of Cambridge, UK, under the leadership of its chief scientific officer, Simon Tate, Ph.D.   Biogen gains C...