A Study of Plitidepsin in Patients With Relapsed or Refractory Angioimmunoblastic T-cell Lymphoma

Prospective, multicenter, phase II clinical trial to determine the efficacy of plitidepsin in patients with relapsed/refractory (R/R) AITL. The primary endpoint will be overall response rate (ORR) according to the Lugano classification response criteria per independent review. Medical specialists (radiologists and hematologists) who are directly involved in the care of patients with AITL (but are not participating in this trial as investigators) will review all efficacy data (including radiological assessments, bone marrow biopsies) and will assign the best response and the date of objective response or progression/censoring according to their independent evaluation. Central pathological review of each patient's original diagnosis report(s) will be required before inclusion. Two futility analyses of the primary endpoint (ORR according to the Lugano classification criteria and per Independent Review Committee (IRC)) are planned around six months after approximately 25% and 50% of eligible patients (i.e., 15 and 30 patients respectively with AITL confirmed by central pathological review) have been treated. Two or less responders out of 15 patients or seven or less responders out of 30 patients, according to boundaries and sample size assumptions, will mean that the alternative hypothesis could be rejected, and thus recruitment might be stopped at the time of the first or second futility analysis, respectively. Otherwise, accrual will continue to 60 patients with AITL confirmed by central pathological review. This decision will be taken at the time by an Independent Data Monitoring Committee (IDMC). The IDMC, which will include specialists in peripheral T-cell lymphomas (PTCL) supported by a medical statistician, will review data provided by the Investigators, the IRC efficacy assessments and safety information and will advise whether the study should continue. Recruitment can continue during the review period. If there are 19 or more responders of 60 patients, the efficacy of plitidepsin will be considered as clinically relevant in AITL patients. Central pathological review will be conducted by experienced pathologists appointed by the Sponsor and available to the investigative sites for consultation about AITL diagnosis confirmation. Central pathological review is required for (a) local histopathology reports prior to patient treatment, and (b) tumor samples before each futility analysis and at the end of the study. The central laboratory pathologists will be responsible for (a) approving patient inclusion on the basis of investigative site pathology reports provided during screening, (b) analyzing tumor biopsies (initial diagnosis and/or relapses) to confirm the AITL diagnosis, and (c) analyzing blood samples to identify plasma biomarkers and extract DNA. Tumor samples (initial diagnosis and relapses) are required for central review to confirm AITL diagnosis but not to approve inclusion. Archived tissue samples of representative tumors must be sent for central review and biomarker analysis. If the diagnosis biopsy is not available (because the patient was diagnosed at another site, for example), the most recent representative biopsy (relapse and/or progression) will be used. Submitting both, however, is strongly recommended. Tumor blocks will be returned to the centers.