Achillion Pharmaceuticals

The company's business model centered on the discovery and clinical development of novel drug candidates. Initially, Achillion concentrated on antivirals for chronic hepatitis C before pivoting to complement-mediated diseases. Its primary market was patients suffering from rare nephrology, hematology, ophthalmology, and neurology conditions with inadequate or no approved treatments. The company's revenue generation strategy was predicated on advancing its drug pipeline through clinical trials to eventually achieve commercialization or lucrative partnerships. A significant milestone was a collaboration with Janssen for a Hepatitis C program. A major turning point occurred on January 28, 2020, when Alexion Pharmaceuticals acquired Achillion for an upfront payment of approximately $930 million. This acquisition was driven by the strategic fit of Achillion's pipeline with Alexion's existing leadership in complement-mediated diseases.

Achillion's key assets at the time of acquisition were orally administered, small molecule Factor D inhibitors. The lead candidate, danicopan (ACH-4471), was in Phase II development for treating paroxysmal nocturnal hemoglobinuria (PNH) and C3 glomerulopathy (C3G), both rare and debilitating diseases. Danicopan, which received Breakthrough Therapy designation, works by targeting Factor D, a critical control point further upstream in the alternative pathway of the complement cascade than Alexion's existing C5 inhibitors like Soliris. This mechanism offered the potential to treat patients who were sub-optimal responders to C5 inhibitors and addressed uncontrolled complement activation while leaving other critical immune functions intact. A second-generation Factor D inhibitor, ACH-5228, was also in Phase I development, representing a broader platform with potential applications in other immune-related diseases.