Role of maintenance in unsustained MRD negativity. During the first 2 years after maintenance randomization (left), patients receiving KR maintenance vs R alone had a lower risk of unsustained MRD negativity (24-month CI, 20% vs 33%); this advantage is lost after the carfilzomib discontinuation (right, landmark analysis after 2 years of maintenance) (4-year CI, 17% vs 21%).