The deal worth up to $576m gives Merck what Calporta founding investor Avalon believes is the most advanced program targeting TRPML1, a lysosomal ion channel implicated in neurodegenerative diseases when the lysosome stops clearing debris from cells.

Celiac disease specialist Sitari was the first company formed under the six-year collaboration. Three were shut down and Avalon controls the other four, which aren't compatible with GSK's new R&D focus.

Two companies in the biopharma space began trading publicly this week, one to pay off debt, the other to fund an early-stage pipeline.