Regeneron Pharmaceuticals Advances with ALN-CFB Study for PNH Treatment

Regeneron Pharmaceuticals ((REGN)) announced an update on their ongoing clinical study.

Regeneron Pharmaceuticals is conducting a pivotal study titled ‘A Randomized, Double-Blind, Placebo-Controlled, First-In-Human Study of the Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of ALN-CFB, an Investigational siRNA Therapeutic Against Complement Factor B, in Participants With Paroxysmal Nocturnal Hemoglobinuria and Persistent Anemia on Approved C5-Inhibitor Therapy.’ This study aims to assess the safety and tolerability of ALN-CFB in adults with Paroxysmal Nocturnal Hemoglobinuria (PNH) who continue to experience anemia despite being on a C5 inhibitor. The study’s significance lies in its potential to offer a new therapeutic option for this patient population.

The intervention being tested is ALN-CFB, a small interfering RNA (siRNA) designed to target Complement Factor B, potentially reducing anemia in PNH patients. The study compares ALN-CFB to a placebo to evaluate its effectiveness and safety.

This is an interventional study with a randomized, sequential intervention model. It employs a quadruple masking approach, meaning that the participant, care provider, investigator, and outcomes assessor are all blinded to the treatment allocation. The primary purpose is treatment-focused, aiming to establish the therapeutic potential of ALN-CFB.

The study is not yet recruiting, with the first submission date recorded as September 18, 2025. This date marks the beginning of the study’s timeline, with further updates expected as the study progresses.

From a market perspective, this study could significantly impact Regeneron’s stock performance and investor sentiment. If successful, ALN-CFB could position Regeneron as a leader in the treatment of PNH, potentially affecting competitors in the rare disease treatment market.

The study is ongoing, and further details are available on the ClinicalTrials portal.