Phase I study of selinexor in combination with dexamethasone, ifosfamide, carboplatin, etoposide chemotherapy in patients with relapsed or refractory peripheral T-cell or natural-killer/T-cell lymphoma

Selinexor is a selective inhibitor of nuclear export with anti-cancer properties. We performed a phase I study to determine the safety and maximum tolerated dose (MTD) of selinexor when combined with high-dose dexamethasone, ifosfamide, carboplatin and etoposide (DICE) in relapsed/refractory (R/R) T-cell lymphoma (TCL) and natural-killer/T-cell lymphoma (NKTL). Patients with R/R TCL and NKTL were treated with standard dose ICE, dexamethasone 20mg on days 3 to 7, and escalating doses of oral selinexor on days 3, 5 and 7 in a 3+3 design. Dose level (DL) 1, 2 and 3 were 40, 60 and 80mg respectively. Eleven patients with a median age of 60 were enrolled; 6 at DL1 and 5 at DL2. Patients had received a median of 2 (range 1-4) prior lines of treatment and 7 had primary refractory disease at study entry. Patients received a median of 3 cycles (range 1-6) of selinexor-DICE. The most common grade (G) 1/2 toxicities included nausea (64%), fatigue (55%), and anorexia (45%) and the most common G 3/4 toxicities included thrombocytopenia (82%), anemia (82%), neutropenia (73%), and hyponatremia (73%). Two patients developed doselimiting toxicities at DL2 and one at DL1. Five patients discontinued treatment for reasons other than disease progression or lack of response. Of the 10 evaluable patients, the overall and complete response rates were 91% and 82% respectively. The MTD of selinexor was 40mg when combined with DICE. The combination showed promising CR rates in patients with R/R TCL and NKTL but was poorly tolerated.