The Impact of a Humanized CCR4 Antibody (Mogamulizumab) on Patients with Aggressive-Type Adult T-Cell Leukemia-Lymphoma Treated with Allogeneic Hematopoietic Stem Cell Transplantation

Understanding the Immunopathology of HTLV-1-Associated Adult T-Cell Leukemia/Lymphoma: A Comprehensive Review

Human T-cell leukemia virus type-1 (HTLV-1) causes adult T-cell leukemia/lymphoma (ATL). HTLV-1 carriers have a lifelong asymptomatic balance between infected cells and host antiviral immunity; however, 5-10% of carriers lose this balance and develop ATL. Coinfection with Strongyloides promotes ATL development, suggesting that the immunological status of infected individuals is a determinant of HTLV-1 pathogenicity. As CD4+ T cells play a central role in host immunity, the deregulation of their function and differentiation via HTLV-1 promotes the immune evasion of infected T cells. During ATL development, the accumulation of genetic and epigenetic alterations in key host immunity-related genes further disturbs the immunological balance. Various approaches are available for treating these abnormalities; however, hematopoietic stem cell transplantation is currently the only treatment with the potential to cure ATL. The patient's immune state may contribute to the treatment outcome. Additionally, the activity of the anti-CC chemokine receptor 4 antibody, mogamulizumab, depends on immune function, including antibody-dependent cytotoxicity. In this comprehensive review, we summarize the immunopathogenesis of HTLV-1 infection in ATL and discuss the clinical findings that should be considered when developing treatment strategies for ATL.

Zidovudine and Interferon Alfa based regimens for the treatment of adult T-cell leukemia/lymphoma (ATLL): a systematic review and meta-analysis

BACKGROUND

ATLL (Adult T-Cell Leukemia/Lymphoma) is an aggressive hematological malignancy. This T-cell non-Hodgkin lymphoma, caused by the human T-cell leukemia virus type 1 (HTLV-1), is challenging to treat. There is no known treatment for ATLL as of yet. However, it is recommended to use Zidovudine and Interferon Alfa-based regimens (AZT/IFN), chemotherapy, and stem cell transplant. This study aims to review the outcome of patients with different subtypes of ATLL treated with Zidovudine and Interferon Alfa-based regimens.

METHODS

A systematic search was carried out for articles evaluating outcomes of ATLL treatment by AZT/IFN agents on human subjects from January 1, 2004, until July 1, 2022. Researchers assessed all studies regarding the topic, followed by extracting the data. A random-effects model was used in the meta-analyses.

RESULTS

We obtained fifteen articles on the AZT/IFN treatment of 1101 ATLL patients. The response rate of the AZT/IFN regimen yielded an OR of 67% [95% CI: 0.50; 0.80], a CR of 33% [95% CI: 0.24; 0.44], and a PR of 31% [95% CI: 0.24; 0.39] among individuals who received this regimen at any point during their treatment. Our subgroup analyses' findings demonstrated that patients who received front-line and combined AZT/IFN therapy responded better than those who received AZT/IFN alone. It is significant to note that patients with indolent subtypes of disease had considerably higher response rates than individuals with aggressive disease.

CONCLUSION

IFN/AZT combined with chemotherapy regimens is an effective treatment for ATLL patients, and its use in the early stages of the disease may result in a greater response rate.

Clinical significance of soluble CADM1 as a novel marker for adult T-cell leukemia/lymphoma

Adult T-cell leukemia/leukemia (ATLL) is an aggressive peripheral T-cell malignancy, caused by infection with the human T-cell leukemia virus type 1 (HTLV-1). We recently showed that the cell adhesion molecule 1 (CADM1), a member of the immunoglobulin superfamily, is specifically and consistently overexpressed in ATLL cells, and functions as a novel cell surface marker. In this study, we first show that a soluble form of CADM1 (sCADM1) is secreted from ATLL cells by mainly alternative splicing. After developing the Alpha linked immunosorbent assay (AlphaLISA) for sCADM1, we show that plasma sCADM1 concentrations gradually increased during disease progression from indolent to aggressive ATLL. Although other known biomarkers of tumor burden such as soluble interleukin-2 receptor α (sIL-2Rα) also increased with sCADM1 during ATLL progression, multivariate statistical analysis of biomarkers revealed that only plasma sCADM1 was selected as a specific biomarker for aggressive ATLL, suggesting that plasma sCADM1 may be a potential risk factor for aggressive ATLL. In addition, plasma sCADM1 is a useful marker for monitoring response to chemotherapy as well as for predicting relapse of ATLL. Furthermore, the change in sCADM1 concentration between indolent and aggressive type ATLL was more prominent than the change in the percentage of CD4⁺CADM1⁺ ATLL cells. As plasma sCADM1 values fell within normal ranges in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients with higher levels of serum sIL-2Rα, the measurement of sCADM1 may become a useful tool to discriminate between ATLL and other inflammatory diseases, including HAM/TSP.

Pralatrexate in patients with recurrent or refractory peripheral T-cell lymphomas: a multicenter retrospective analysis

Peripheral T-cell lymphomas (PTCL) are a heterogeneous group of non-Hodgkin’s lymphomas with poor clinical outcomes. Pralatrexate showed efficacy and safety in recurrent or refractory PTCLs. The purpose or this study was to investigate the efficacy and safety of pralatrexate in relapsed or refractory PTCLs in real-world practice. This was an observational, multicenter, retrospective analysis. Between December 2012 and December 2016, a total of 38 patients with relapsed or refractory PTCLs were treated with pralatrexate at 10 tertiary hospitals in Korea. Patients received an intravenous infusion of pralatrexate at a dose of 30 mg/m²/week for 6 weeks on a 7-week schedule. Modified dosing and/or scheduling was allowed according to institutional protocols. Median patient age was 58 years (range, 29–80 years) and the most common subtype was peripheral T-cell lymphoma, not otherwise specified (n = 23, 60.5%). The median dosage of pralatrexate per administration was 25.6 mg/m²/wk (range, 15.0–33.0 mg/m²/wk). In intention-to-treat analysis, 3 patients (7.9%) showed a complete response and 5 patients (13.2%) showed a partial response, resulting in an overall response rate (ORR) of 21.1%. The median duration of response was 7.6 months (range, 1.6–24.3 months). The median progression-free survival (PFS) was 1.8 months (95% confidence interval [CI], 1.7–1.8 months) and the median overall survival was 7.7 months (95% CI, 4.4–9.0 months). The most common grade 3/4 adverse events were thrombocytopenia (n = 13, 34.2%), neutropenia (n = 7, 23.7%), and anemia (n = 7, 18.4%). Our study showed relatively lower ORR and shorter PFS in patients with recurrent or refractory PTCLs treated with pralatrexate in real-world practice. The toxicity profile was acceptable and manageable. We also observed significantly lower dose intensity of pralatrexate in real-world practice.

Discussion on the indication of allogeneic stem cell transplantation for advanced cutaneous T cell lymphomas

Advanced cutaneous T cell lymphoma (CTCL) patients have a dismal prognosis, especially those relapsing or progressing after systemic therapy. No curative therapies are available, but some new agents have prolonged disease-free survival time with a good toxicity profile. Allogeneic stem cell transplantation (allo-SCT) offers the longest disease-free survival, potentially representing the best therapeutic option for eligible patients. In the present article, we discuss current evidence about allo-SCT for CTCL patients, timing, and new therapeutic options before allo-SCT, taking into account some considerations that may impact clinical outcome.

The clinical impact of human T-lymphotrophic virus type 1 (HTLV-1) infection on the development of adult T-cell leukemia-lymphoma (ATL) or HTLV-1-associated myelopathy (HAM) / atypical HAM after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and renal transplantation

Because there are limited clinical reports on the impact of human T-lymphotropic virus type 1 (HTLV-1) on organ transplantation, its effects on the development of adult T-cell leukemia-lymphoma (ATL), post-transplantation lymphoproliferative disorder (PTLD) and HTLV-1–associated myelopathy (HAM) or atypical HAM after organ transplantation remain unclear.

We retrospectively analyzed the impact of HTLV-1 in 54 allogeneic hematopoietic stem cell transplantation (allo-HSCT) cases and 31 renal transplantation cases between January 2006 and December 2016.

Among the 54 allo-HSCT cases, nine recipients with ATL tested positive for HTLV-1, and one was found to be an HTLV-1 carrier. All donors tested negative for HTLV-1. Only one HTLV-1 carrier did not present with ATL or HAM development after allo-HSCT. Among nine ATL cases after allo-HSCT, four eventually relapsed due to proliferation of recipient-derived ATL cells. However, in one ATL case, atypical HAM developed rapidly at 5 months after allo-HSCT.

Among the 31 renal transplantation cases, all donors tested negative for HTLV-1, and only recipients tested positive. Only one HTLV-1 carrier recipient did not present with ATL or HAM development after renal transplantation. However, one HTLV-1-negative recipient developed PTLD in the brain 10 years after renal transplantation.

In clinical practice, careful follow-up of HTLV-1 infected recipients after organ transplantation is important because atypical HAM can develop in ATL patients after allo-HSCT. Furthermore, to clarify the risk of ATL or HAM development in HTLV-1 infected recipients, we prospectively followed up our cohort.

Highlights from the HTLV-1 symposium at the 2017 Australasian HIV and AIDS Conference held jointly with the 2017 Australasian Sexual Health Conference, November 2017, Canberra, Australia

We are pleased to report on the inaugural HTLV-1 symposium at the 2017 Australasian HIV and AIDS Conference joint with 2017 Australasian Sexual Health Conference in Canberra, Australia. Our understanding of HTLV-1 epidemiology, pathogenesis, laboratory diagnostics and treatment options for HTLV-1 diseases has advanced tremendously over the last 40 years. However, the awareness of healthcare providers and the general population about HTLV-1, and the effective promotion and implementation of HTLV-1 transmission-prevention strategies, lag behind current knowledge. Here we present a summary of the symposium, plenary and poster presentations on HTLV-1.