Maintenance therapy in adult T-cell acute lymphoblastic leukemia (T-ALL) is the longest phase but with limited option. The classic drugs used in the maintenance phase such as 6-mercaptopurine, methotrexate, corticosteroid and vincristine have potentially serious toxicities. Optimizing therapy in the modern age, chemo-free maintenance therapy regimens for patients with T-ALL may dramatically improve the maintenance therapeutic landscape. We report here the combination of Anti-programmed cell death protein 1 antibody and histone deacetylase inhibitor as chemo-free maintenance treatment in a T-ALL patient with literature review, thus providing a unique perspective in addition to valuable information which may inform novel therapeutic approaches.

Failure to CD19-targeted chimeric antigen receptor T-cell (CAR-T) therapy for patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL), is an emerging clinical problem. There is no consensus on the treatment for these patients and treatment remains empirical.
We reported a case of an elderly R/R DLBCL patient who had TP53 mutation and relapsed 12 months after initial response to CAR T-cell therapy. The patient did not respond to salvage chemotherapy with the GDP regimen and could not tolerate any aggressive chemotherapy. Thereafter, the patient was given chidamide and zanubrutinib. After two months of treatment, the patient achieved sustained complete remission. At the last follow-up, the patient remains in radiographic CR 22 months after CAR-T infusion and 10 months after the initiation of the combination treatment.
We report the first successful case of dual inhibition of HDAC and BTK for the treatment of R/R DLBCL after failure to CAR-T cell therapy, which opens a new therapeutic possibility for the future.

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare primary cutaneous lymphoma composed of CD8+ cytotoxic T-cell that is primarily localized in the subcutaneous tissue. No standard treatments are currently available for SPTCL due to its rarity. Chemotherapy, radiotherapy, immunosuppressive agents, and hematopoietic stem cell transplantation (HSCT) have been used frequently, however, the effects of these treatment approaches remain controversial. In this report, we present an unusual case of SPTCL in a 47-year-old woman whose initial symptoms were atypical. The patient was started on etoposide, vincristine, cyclophosphamide, doxorubicin, and prednisone (EPOCH) chemotherapy once diagnosed. After two cycles of chemotherapy, her clinical symptoms were not significantly improved. Subsequently, histone deacetylase (HDAC) inhibitor chidamide was added to the chemotherapy from the third cycle. She recovered gradually and achieved complete remission (CR) after four cycles of chemotherapy combined with chidamide, followed by chidamide monotherapy for maintenance. More than 1 year after the therapy, she remained in CR. Our case illustrates, for the first time, chidamide can be an effective agent to induce long-term remission for rare SPTCL.

BACKGROUND: Monomorphic epitheliotropic intestinal T cell lymphoma (MEITL) is a rare extra-nodal T-cell lymphoma that has uniformly aggressive features with a poor prognosis. No standardized treatment protocols have been established. Previous experience has demonstrated favorable outcomes with combination chemotherapy followed by autologous hematopoietic stem cell transplant. However, many patients are unable to tolerate the toxicities. Chidamide is a new histone deacetylase inhibitor that has shown preferential efficacy in mature T-cell lymphoma.
METHODS: We herein present two cases of MEITL who were both intermediate risk according to enteropathy-associated T cell lymphoma prognostic index. Case one was a 61-year-old man. He complained of upper abdominal pain and intermittent black stool for 2 mo. Imaging examination revealed that the intestinal wall was thickened. He received a partial excision of the small intestine. A chidamide-based combination regimen was given postoperatively. Eleven months later, he presented with recurrence in the bilateral lungs. He passed away 15 mo after his diagnosis. Case two was a 35-year-old woman who complained of abdominal distention for 1 mo. Positron emission tomography/computed tomography demonstrated wall thickening of the small intestine and upper sigmoid colon. Colon perforation and septic shock occurred on the fourth day of her admission. She was treated by sigmoid colostomy. Chidamide-based combination therapy was then provided. She was recurrence-free for 6 mo until lesions were found in the bilateral brain and lived for 17 mo since her diagnosis. Compared to historical data, chidamide seems to improve the prognosis of MEITL slightly.
CONCLUSIONS: MEITL is a type of aggressive lymphoma. Chidamide is a new promising approach for the treatment of MEITL.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive hematopoietic malignancy mainly affecting elderly patients. It is highly responsive to chemotherapy, but the median event-free survival is very short and has a high rate of relapse even after performing allogeneic stem cell transplantation; thus, the discovery of novel agents for the treatment of BPDCN is urgent. Chidamide is a new oral isotype-selective histone deacetylase inhibitor (HDACi). It is proved to exert a well-characterized anticancer property in a wide range of hematological malignancies, especially lymphoma. Here, we report a 41-year-old man who used oral chidamide 30 mg twice per week for maintenance therapy after receiving complete remission. For the first time in this field, we had explored the efficiency of chidamide in the treatment of BPDCN and tried to give more choices to the therapy of this disease.

Ewing sarcoma (ES) is a form of primary bone cancer, with few treatment options for patients who develop relapse with an overall 5-year survival of 13%. New treatment options are needed and histone deacetylase (HDAC) inhibitors show encouraging results in preclinical studies. Our patient developed inoperable progressive lung metastases and was treated with the HDAC inhibitor panobinostat. During 18 months of treatment, no new lesions appeared; the treatment was stopped due to progression. This clinical observation warrants further evaluation of HDAC inhibitors in ES. Combination with chemotherapy and biomarker studies could improve the therapeutic index of these classes of compounds.