Physicochemical and functional assessment of messenger RNA 5′Cap-end impurities under forced degradation conditions

using model mRNAs with elevated impurity levels. mRNA 5'Cap degradation impurities significantly impacted protein expression but did not trigger innate immune response pathways. 5'Cap degradation impurities should be considered as a critical quality attribute of mRNA therapeutics and should be monitored during production, purification, formulation, and storage.