Background: Peripheral T-cell lymphoma (PTCL) is a clinically and biologically heterogeneous disease with poor prognosis. The response rate of standard CHOP regimen (cyclophosphamide, doxorubicin, vincristine, and prednisolone) is only 50-60%, with a poor long-term survival rate of 10-30%. The addition of etoposide to CHOP increases response rate, but not progression free survival (PFS) or overall survival (OS). Recent study reported that nuclear factor kappa B (NF-κB) pathway plays a critical role in PTCL. Bortezomib, a potent and reversible proteasome inhibitor, can induce tumor cell apoptosis by inhibiting activation of NF-κB pathway and has been recommended as single agent option in relapse/refractory PTCL. We aimed to study the efficacy and safety of bortezomib in combination with cyclophosphamide, doxorubicin, etoposide, and prednisone (BCHEP) in newly diagnosed PTCL patients for the first time.

METHODS: A prospective, single arm, phase 2 study was conducted (NCT04061772). This is an interim analysis. Patients with newly diagnosis of PTCL were treated with up to 6 cycles of BCHEP regimen every 3 weeks. Bortezomib was subcutaneously administered on Days 1 and 8 at a dose of 1.3 mg/m 2 in combination with CHEP, consisting of 100 mg/m 2 etoposide on Days 1 to 3, 750mg/m 2 cyclophosphamide on Day 1, 75mg/m 2 epirubicin on Day 1 and 100mg prednisone on Days 1 to 5. The primary endpoint of the study was ORR including complete response (CR) and partial response (PR). The secondary endpoints included progression free survival (PFS), overall survival (OS) and adverse events (AEs).

RESULTS: Between February 2019 and January 2021, a total of twenty-six patients were enrolled. Median age was 57 years (range 37-69) and six (23.1%) were female. Pathological subtypes included ALK-positive anaplastic cell lymphoma (ALCL, n=2), ALK-negative ALCL (n=4), PTCL, not otherwise specified (PTCL-NOS, n=9) and angioimmunoblastic T-cell lymphoma (AITL, n=11). Nineteen patients had stage III/IV disease and eleven had B symptoms, including weight loss in three cases and fever in eight. Ten patients had elevated serum lactate dehydrogenase (LDH), eleven had IPI score higher than 2. All patients had completed BCHEP treatment for at least two cycles and received imaging evaluation. Ten patients received prophylaxis of intrathecal chemotherapy with methotrexate at least once. Three patients received consolidated radiotherapy for metabolic residuals after chemotherapy, while one received autologous hematopoietic stem cell transplantation as consolidation treatment. This study had reached the primary end point at this interim analysis. The ORR was 92.3% (24/26) with a CR rate of 57.7% (15/26). Two patients had progression of disease within two cycles of chemotherapy. After a median follow-up of 16.3 months, twelve patients had disease progression, and six died. Median PFS was 10.9 months and 1-year PFS rate was 65.4%. Median OS was 14.6 months and 1-year OS rate was 88.5%. No patient presented with Grade 5 AE. The most frequent all-grade hematological toxicity was leucopenia (42.3%,11/26), anemia (50%,13/26) and thrombocytopenia (23.1%, 6/26). Other common toxicity included intestinal infection or pneumonia (19.2%, 5/26), Grade 1 peripheral neuropathy (15.4%, 4/26) and nausea (7.7%, 2/26). Dose reduction was performed in eight patients.

CONCLUSIONS: Interim results showed that bortezomib in combination with CHEP is associated with high response rate and manageable toxicity in patients with previously untreated PTCL. The BCHEP regimen may serve as a novel first-line treatment option for patients with PTCL. The study is going on to enroll patients and updating results, including the prognostic value of serum inflammatory factors. Larger trials will be necessary to further verify the efficacy of this regimen in treatment naïve PTCL patients and to overcome relapse after remission.

Disclosures

No relevant conflicts of interest to declare.

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