Phase II study of novel orally PI3Kα/δinhibitor TQ-B3525 in relapsed and/or refractory follicular lymphoma

This registration study assessed clinical outcomes of TQ-B3525,the dual phosphatidylinositol-3-kinase(PI3K)α/δinhibitor,in relapsed and/or refractory follicular lymphoma(R/R FL).This phase II study(ClinicalTrials.gov NCT04324879.Registered March 27,2020)comprised run-in stage and stage 2.R/R FL patients after≥2 lines therapies received oral 20 mg TQ-B3525 once daily in a 28-day cycle until intolerable toxicity or disease progression.Primary endpoint was independent review committee(IRC)-assessed objective response rate(ORR).Based on results(ORR,88.0%;duration of response[DOR],11.8 months;progression-free survival[PFS],12.0 months)in 25 patients at run-in stage,second stage study was initiated and included 82 patients for efficacy/safety analysis.Patients received prior-line(median,3)therapies,with 56.1%refractory to previous last therapies;73.2%experienced POD24 at baseline.At stage 2,ORR was 86.6%(71/82;95%CI,77.3-93.1%),with 28(34.2%)complete responses.Disease control rate was 95.1%due to 7(8.5%)stable diseases.Median time to response was 1.8 months.Among 71 responders,median DOR was not reached;18-month DOR rate was 51.6%.with median follow-up of 13.3 months,median PFS was 18.5(95%CI,10.2-not estimable)months.Median overall survival(OS)was not reached by cutoff date;24-month OS rate was estimated as 86.1%.Response rates and survival data were consistent across all subgroups.Grade 3 or higher treatment-related adverse events were observed in 63(76.8%)cases,with neutropenia(22.0%),hyperglycemia(19.5%),and diarrhea(13.4%)being common.TQ-B3525 showed favorable efficacy and safety for R/R FL patients after≥2 lines prior therapies.