Biogen has registered a first-in-human Phase I/II trial of BIIB147, an investigational antisense oligonucleotide (ASO) that the company said targets stathmin-2 (STMN2) pre-mRNA, in adults with ALS who carry no pathogenic or uncertain variants in the SOD1 or FUS genes. According to a Biogen Q2 2026 SEC filing, the company exercised an option in Q2 2026 to obtain a worldwide exclusive, royalty-bearing licence from Ionis Pharmaceuticals to develop and commercialize BIIB147. ​

STMN2 plays an important role in maintaining and repairing motor neuron axons, but its production is disrupted by abnormal TDP-43 activity, a pathological feature of most ALS cases. Antisense therapies targeting STMN2 RNA processing aim to restore functional protein expression and potentially slow neuronal degeneration. Biogen enters a field already led by QurAlis, whose STMN2-targeting ASO QRL-201 demonstrated restoration of STMN2 expression and encouraging neuronal injury biomarker findings in the Phase I/II ANQUR study earlier this year, although clinical benefit remains unproven.

The study — registered as NCT07855211 — is a randomized, quadruple-masked, placebo-controlled multiple-ascending-dose study with an open-label extension, enrolling 69 adults at two US sites. Four cohorts receive intrathecal BIIB147 or placebo for 12–20 weeks before transitioning to an open-label maintenance phase lasting up to 340 weeks, with primary completion estimated for January 2034.

                                        Source: ALLSCI news biotech