Key Takeaways

  • VRDN-008 achieved a 74% peak IgG reduction and sustained suppression through 8 weeks after dosing in healthy volunteers

  • The investigational FcRn inhibitor demonstrated a 15- to 18-day half-life and was generally well tolerated, with no serious adverse events

  • Viridian plans to initiate a registrational trial in myasthenia gravis in mid-2027, evaluating dosing every 4 or 8 weeks

Viridian Therapeutics announced positive phase 1 results for VRDN-008, an investigational, half-life-extended FcRn inhibitor, demonstrating sustained immunoglobulin G (IgG) reductions and a pharmacokinetic profile that could support subcutaneous dosing every 8 weeks.

The phase 1 trial evaluated VRDN-008 in healthy volunteers who received 2 subcutaneous doses, administered at baseline and week 4. Results showed a 74% peak reduction in IgG levels, with sustained suppression through 8 weeks after dosing.

VRDN-008 demonstrated an extended half-life of 15 to 18 days, approximately 6 times longer than first-generation Fc fragments, according to the company.

The treatment was generally well tolerated, with no serious adverse events or dose-limiting toxicities reported. Viridian also reported that VRDN-008 did not adversely affect albumin or low-density lipoprotein (LDL) levels.

VRDN-008 is a bifunctional FcRn inhibitor licensed from Paragon Therapeutics. It combines an Fc fragment with an albumin-binding domain designed to extend drug half-life and prolong IgG suppression.

Viridian plans to advance VRDN-008 into registrational development beginning with myasthenia gravis (MG) in mid-2027, pending regulatory feedback. The proposed multi-arm trial will evaluate subcutaneous VRDN-008 administered every 4 weeks or every 8 weeks compared with placebo.

The company intends to administer VRDN-008 using Enable Injections' EnFuse, a hands-free, wearable injector designed to support at-home self-administration.

Although Viridian has established a development focus in thyroid eye disease, the company plans to expand its pipeline into additional autoantibody-mediated autoimmune diseases through VRDN-008.