Achillion Pharmaceuticals Inc. is reducing its workforce by about 20% as part of its operational restructuring plan to cut expenses and focus on developing its existing clinical and late-stage preclinical factor D inhibitors.

Factor D is an essential enzyme involved in the alternative pathway, a part of the innate immune system.

The New Haven, Conn.-based biopharmaceutical posted a net loss of $23.2 million and no recognized revenue in the fourth quarter of 2017. With the restructuring plan, Achillion expects to save about $10 million in 2018 over its 2017 expense levels.

For 2018, Achillion will focus on developing ACH-4471, for treating rare, kidney-related diseases, C3 glomerulopathy and immune-complex-mediated MPGN; ACH-4471 for treating paroxysmal nocturnal hemoglobinuria, a rare blood disease characterized by the destruction of red blood cells; as well as next-generation factor D inhibitors, ACH-5228 and ACH-5548.

In other news, Joseph Truitt has been promoted to president and will also continue to serve as COO, a position he has held since September 2017.