ABBV-CLS-628 is a novel IV-infused drug from Calico Life Sciences (backed by Alphabet/Google) and AbbVie, entering the largest Phase 2 ADPKD trial to date with 240 patients across 11 countries.
Background
Calico Life Sciences, Alphabet's longevity research lab, has partnered with AbbVie to develop ABBV-CLS-628 — a drug whose exact mechanism remains undisclosed. What we know is that it's administered as an IV infusion every 4 weeks and targets kidney cyst growth. The trial, named ANCHOR, represents a massive bet: 240 patients across approximately 100 sites in 11 countries, making it one of the largest Phase 2 efforts specifically for ADPKD.
How It Works
The mechanism of action has not been publicly disclosed — unusual for a Phase 2 trial. Calico is known for applying computational biology and machine learning to drug discovery, suggesting this may be a first-in-class compound identified through AI-driven target discovery. The IV route (rather than oral) suggests it may be a biologic or large molecule that can't survive the GI tract.
Clinical Trial Details
The ANCHOR trial (NCT06902558) is a multicenter, randomized, double-blind, placebo-controlled study. Patients receive infusions every 4 weeks for 92 weeks (nearly 2 years). The primary endpoint is change in Total Kidney Volume (TKV) measured by MRI at Week 96. The trial began recruiting in June 2025 with estimated completion in December 2027.
Why It's Promising
The involvement of Calico/AbbVie — with deep pockets and computational biology expertise — plus the ambitious trial size suggests high confidence in preclinical data. If successful, this could reach Phase 3 by 2028 and potentially market by 2031–2032. The undisclosed mechanism means it could represent an entirely new approach to PKD.
Limitations & Concerns
The secrecy around the mechanism makes it difficult for patients and researchers to assess plausibility. IV administration every 4 weeks is a significant burden compared to oral drugs. No preclinical publications are available for independent evaluation.