The combination of chidamide with the CHOEP regimen in previously untreated patients with peripheral T-cell lymphoma: a prospective, multicenter, single arm, phase 1b/2 study

Objective:To assess the efficacy and safety of the novel histone deacetylase inhibitor,chidamide,in combination with cyclophosphamide,doxorubicin,vincristine,etoposide,and prednisone(Chi-CHOEP)for untreated peripheral T-cell lymphoma(PTCL).Methods:A prospective,multicenter,single arm,phase 1 b/2 study was conducted.A total of 128 patients with untreated PTCL(18–70 years of age)were enrolled between March 2016 and November 2019,and treated with up to 6 cycles with the Chi-CHOEP regimen.In the phase 1 b study,3 dose levels of chidamide were evaluated and the primary endpoint was determination of the maximumtolerated dose and recommended phase 2 dose(RP2 D).The primary endpoint of the phase 2 study was 2-year progression-free survival(PFS).Results:Fifteen patients were enrolled in the phase 1 b study and the RP2 D for chidamide was determined to be 20 mg,twice a week.A total of 113 patients were treated at the RP2 D in the phase 2 study,and the overall response rate was 60.2%,with a complete response rate of 40.7%.At a median follow-up of 36 months,the median PFS was 10.7 months,with 1-,2-,and 3-year PFS rates of 49.9%,38.0%,and 32.8%,respectively.The Chi-CHOEP regimen was well-tolerated,with grade 3/4 neutropenia occurring in approximately two-thirds of the patients.No unexpected adverse events(AEs)were reported and the observed AEs were manageable.Conclusions:This large cohort phase 1 b/2 study showed that Chi-CHOEP was well-tolerated with modest efficacy in previously untreated PTCL patients.