With Lykos CRL now public, FDA opens new era of accountability

MDMA-assisted therapy for PTSD and its FDA regulatory review become publicly contentious after the FDA publishes Lykos’ Complete Response Letter (CRL). On September 4, 2025, the FDA released a batch of 89 CRLs, including the CRL that had previously declined to approve Lykos’ MDMA-assisted therapy application. The article highlights what the FDA says was missing or insufficient, including safety reporting reliability, trial durability and longer-term evidence, and concerns around bias and maintaining blinding in psychedelic trials. It also notes earlier public signals from FDA-related deliberations in 2024, and that Lykos was told in August 2024 that approval was not granted. MAPS, which incubated Lykos, reacts by praising the FDA for making the CRL public but criticizing the agency’s content and accusing it of shifting trial expectations. The publication is framed as a broader shift toward transparency in drug regulation that could affect not only psychedelics but the accountability of FDA decision-making more generally.