“As I shared when I joined, I had a relapse of my neuroimmune condition a few weeks before starting the job,” Simo said in a note which was shared in OpenAI’s “core” Slack channel. “It’s been a bit of a rollercoaster since, and the last month has been particularly rough health-wise. For my entire time here, I’ve postponed medical tests and new therapies to stay completely focused on the job and not miss a single day of work. I took time off for the first time two weeks before the break for some medical tests, and it’s now clear that I’ve pushed a little too far and I really need to try new interventions to stabilize my health.”
Simo is expected to take “several weeks” of leave according to her internal post.
In his new role, Lightcap will be in charge of the company’s forward-deployed engineers, which embed within enterprise organizations and help integrate OpenAI’s technology.
OpenAI will begin searching for a new CMO, Simo said. The company is also looking for a chief communications officer to replace Hannah Wong, who left her position in January. Chris Lehane has taken over as the leader of the communications team in the interim.
Simo joined OpenAI in August 2025, where she took over many of the company’s consumer-facing products, including ChatGPT, Codex, and the social-video app Sora. She recently shuttered the Sora app and told staff that the company needed to cut side projects and refocus around its core products.
This is a developing story. Please check back for updates.