'However, it is well-established that, compared with other conventional treatments, immunotherapy shows unique efficacy kinetics such as delayed clinical effect and long-term favorable outcome.3 These characteristics may lead to the prolongation of trial duration and make it difficult to accelerate the drug development process.'

https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(23)00333-4/fulltext#secsectitle0100