Moderna is not the only recent case of the FDA reversing previous guidance. For example, Uniqure has a drug that in trials reduced the progression rate of Huntington's Disease by 75% against propensity-matched controls, along with excellent biomarker data (NfL levels, a marker of neuron death, actually fell, which unheard of in Huntington's patients, where neuron death rises relentlessly until death). It claims the FDA had previously told it that this data would be sufficient. However, it just got told to go back and run a full RCT (problematic for various reasons), delaying treatment availability for this uniformly fatal disease by several years. RegenexBio has a similar story.
Moderna is not the only recent case of the FDA reversing previous guidance. For example, Uniqure has a drug that in trials reduced the progression rate of Huntington's Disease by 75% against propensity-matched controls, along with excellent biomarker data (NfL levels, a marker of neuron death, actually fell, which unheard of in Huntington's patients, where neuron death rises relentlessly until death). It claims the FDA had previously told it that this data would be sufficient. However, it just got told to go back and run a full RCT (problematic for various reasons), delaying treatment availability for this uniformly fatal disease by several years. RegenexBio has a similar story.