OpenAI’s AGI chief, Fidji Simo, is leaving her full-time role and becoming a part-time advisor due to a severe flare-up of a chronic neuroimmune condition. She originally took medical leave in April, and after months of recovery, realized she needed to focus fully on her health. Her departure is part of a broader wave of C-suite changes at OpenAI, including former COO Brad Lightcap stepping down to work on special projects and CMO Kate Rouch leaving to prioritize her health. During Simo’s leave, president Greg Brockman took over product strategy, leading a reorganization to unify ChatGPT and Codex into a single “agentic platform.” Simo shared her struggle of building the future while battling a disabling disease with no cure, and CEO Sam Altman expressed sadness and gratitude. Why it matters: This high-level exit underscores the intense human cost behind cutting-edge AI development, as even top leaders can’t outpace their own biological limits.