Achillion Reports Positive Data from Phase 2 Study of Danicopan

Achillion Pharmaceuticals (NASDAQ:ACHN) has announced topline results from its Phase 2 trial of its oral small molecule factor D inhibitor danicopan (ACH-4471) in paroxysmal nocturnal hemoglobinuria (PNH) patients.

As quoted in the press release:

Data from the Phase 2 trial were presented in a poster presentation today at the 61^st American Society of Hematology (ASH) Annual Meeting in Orlando, FL.

The primary endpoint of the trial was an increase in hemoglobin from baseline. A mean increase of 2.4 g/dL at 24 weeks of treatment was achieved in this proof-of-concept trial. Danicopan, in combination with eculizumab, resulted in a significant reduction in blood transfusions with 10 patients receiving 34 transfusions (58 units) in the 6 months prior to screening to 1 patient receiving 1 transfusion (2 units) during the 24-week trial.

“C5 inhibition, the current standard of care, is an effective treatment approach for patients with PNH. While this treatment approach shows control of intravascular hemolysis and improved overall survival, many patients remain anemic and some may continue to be transfusion dependent due to persistent extravascular hemolysis,” stated Dr. Austin Kulaskeraraj MBBS, MD, MRCP, FRCPath, lead author of this Phase 2 poster presentation at ASH and consultant hematologist at Kings College Hospital in London. “In this clinical trial, the addition of danicopan, a factor D inhibitor that addresses the extravascular hemolysis caused by PNH, to C5 inhibitor therapy resulted in a greater than 2-gram increase in hemoglobin, and significant reduction of transfusions.”

In addition to improvements in hemoglobin and transfusions, there were also meaningful improvements in markers of hemolysis including bilirubin, reticulocytes, and PNH red blood clone size (%). “The increase in PNH specific red blood cell clone size, and reduction of reticulocytes, is likely due to the prevention of C3-mediated extravascular hemolysis, a result of targeting upstream in the Alternative Pathway, while retaining the control of MAC-mediated intravascular hemolysis,” said Dr. Steven Zelenkofske, Chief Medical Officer of Achillion. “The mean increase of 11 points on the FACIT Fatigue scale, relative to the baseline on eculizumab monotherapy, demonstrates the potential impact the addition of danicopan can have on a patient’s quality of life.”

In this clinical trial, danicopan was generally well tolerated. All treatment emergent adverse events were considered mild to moderate in severity except for Grade 3 severe adverse events that occurred in two patients. Both patients had resolution of their events, remained on danicopan, and completed the study.

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