RETREATMENT WITH NIVOLUMAB IN PATIENTS WITH R/R CLASSICAL HODGKIN LYMPHOMA AFTER DISCONTINUATION OF THE THERAPY WITH IMMUNE CHECKPOINT INHIBITORS. (12th June 2019) - Fedorova, L.; Lepik, K.; Mikhailova, N.; Kondakova, E.; Zalyalov, Y.; Baykov, V.; Babenko, E.; Borzenkova, E.; Tsvetkova, L.; Stelmakh, L.; Afanasyev, B.