Sustained remission of multi-line relapsed extranodal NK/T-cell lymphoma, nasal type, following sintilimab and chidamide: A case report.

INTRODUCTION: There is currently no optimal treatment modality for refractory or relapsed Extranodal NK/T-cell lymphoma, nasal type (ENKTL). In recent years, programmed cell death protein 1 (PD-1)/programmed cell - ligand 1 pathway blockade and histone deacetylase inhibitors have emerged as promising strategies for refractory or relapsed ENKTL. Accumulating evidence has shown that therapeutic effects of anti-PD-1 antibody could be enhanced by histone deacetylase inhibitors. PATIENT CONCERNS: A 52-year-old male patient was diagnosed with stage I ENKTL by biopsy on February 2010. DIAGNOSIS: positron emission tomography-computed tomography (PET-CT) and biopsy were used to diagnose relapsed ENKTL in 2014.
INTERVENTIONS: The patient was treated with radiotherapy and six cycles of etoposide, prednisone, vincristine (Oncovin), cyclophosphamide and doxorubicin hydrochloride and achieved complete remission (CR) by PET-CT in August 2010. In November 2014, the patient was diagnosed with relapsed stage IV ENKTL and was treated with six cycles of alternative chemotherapy with the regimen of steroid (dexamethasone), methotrexate, ifosfamide, L-asparaginase, and etoposide and pegaspargase plus Gemcitabine, Oxaliplatin along with radiotherapy. The patient achieved remission and was placed on thalidomide maintenance treatment. Upon suspicion of relapse suggested by PET-CT, Autologous stem cell transplant was performed after BCNU, etoposide, Ara-C, and melphalan preconditioning on February 2016. Following relapse again in December 2016, the lesions of left femur were treated with radiotherapy and he received anti-PD-1 antibody. He was treated with 4 cycles of pegaspargase plus Gemcitabine, Oxaliplatin on August 2017. The patient's condition improved. He received maintenance and consolidation therapy including lenalidomide, radiotherapy of the right nasal cavity and paranasal sinuses and antigen-specific reactive T cell infusions. PET-CT imaging showed there was high metabolic activity signal in the distal end of right femoral on August 2018 and the treatment regimen was adjusted to radiotherapy of the distal end of right femoral and systemic treatment of PD-1 antibody Sintilimab and chidamide 30 mg. After 5 months post-treatment, biopsy of nasopharynx showed no lymphoma cells. The patient continued the treatment of Sintilimab and chidamide 20 mg. OUTCOMES: PET-CT imaging showed his lesions obtained remission after 8 months post-treatment.
CONCLUSION: Thus, combination of sintilimab and chidamide can be used to treat relapsed ENKTL following treatment failure from chemo-, radio-, and immuno-therapy. A clinical trial has been launched.