Calico's lead drug candidate is fosigotifator, which targets eIF2B, a guanine nucleotide exchange factor that is essential for protein synthesis and a key regulator of the ISR. 

As of Q1 2025, Calico and AbbVie are conducting a Phase Ib/II trial of fosigotifator to evaluate the safety, tolerability, and pharmacokinetics of fosigotifator in participants diagnosed with VWM disease. This study is the first time an eIF2B activator has been administered to people with VWM disease.

Fosigotifator is also being investigated as a potential treatment for people with amyotrophic lateral sclerosis (ALS) in two ongoing studies.