https://orcid.org/0000-0003-0521-2005
Key Points
PIRT is a novel prognostic model for patients with R/R mature T-cell and NK-cell lymphomas that defined risk groups with differing outcomes.
Small molecule inhibitors offer survival advantage relative to chemotherapy in AITL warranting continued investigation in clinical trials.
Variances in global access to drugs and treatment practices make it challenging to understand the benefit of contemporary therapies in patients with relapsed and refractory (R/R) mature T-cell and NK-cell lymphomas (MTCL and MNKCL). We conducted an international retrospective cohort study of 925 patients with R/R MTCL and MNKCL. In PTCL-NOS and ALK- ALCL, patients with relapsed lymphoma demonstrated a superior median overall survival (OS) relative to refractory from the time of second-line treatment. We identified several independent predictors of OS for R/R lymphoma including age >60, primary refractory disease, histological subtype other than AITL, extranodal sites >1, Ki67 ≥40%, and absolute lymphocyte count <LLN. A multivariable model incorporating these formed the basis for a prognostic index for R/R TCL (PIRT), in which patients are stratified into low-risk (0-1 risk factor), intermediate-risk (2-3 risk factors), or high-risk (≥4 risk factors) groups, which were associated with 3-year OS of 57.14% (95% CI: 17.1-83.7), 23.3% (8.7-41.9), and 7% (0.4-26.9), respectively. Patients received either a "novel" single agent (SA, 35%) or cytotoxic chemotherapy (CC, 60%) for their second line treatment. Higher progression-free survival was observed with SA over CC for the entire cohort with a higher 3-year OS in AITL and ALK- ALCL. Among the SA, small molecule inhibitors demonstrated OS advantage relative to CC in AITL. Our results underscore efficacy of novel drugs and the potential of a new prediction model in informing heterogeneous prognosis within the R/R population of MTCL and MNKCL.
