Subtype Of Peripheral T-cell Lymphoma Research Articles

NOT OTHERWISE SPECIFIED T-CELL LYMPHOMA: OUTCOMES OF A SINGLE CENTER STUDY.

The peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) is the most common subtype of peripheral T-cell lymphoma (PTCL). It constitutes approximately 25% of all PTCLs and accounts for more than 15% of all lymphomas. The results of the first Ukrainian prospective study of patients with PTCL-NOS are presented in the article. The aim of the study was to analyze the morbidity of PTCL patients and the treatment performed, to evaluate overall survival and progression-free survival, and to determine the factors that predict the treatment response. An analysis was performed on the data of 31 patients diagnosed with peripheral PTCL-NOS from February 2018 to the present. T-cell lymphoid neoplasms were diagnosed according to the 2016 WHO classification. The treatment regimens were in alignment with ESMO and NCCN guidelines. More than 90% of patients were prescribed anthracycline-based regimens (CHOP; CHOEP - cyclophosphamide, doxorubicin, etoposide, vincristine, prednisone). An initial treatment was performed with CHOP-based regimens in 38.70% (n = 12) of patients, with the addition of etoposide in 58.06% of patients (n = 18). The response was assessed according to the response criteria for malignant lymphoma (Cheson, 2008, 2014). The overall response to therapy was 58.06% (n = 18), with complete responses in 29.03% of patients and partial responses in 29.03% of patients. The stabilization of the disease occurred in 3.44%, while the disease progression in 41.37% of patients. The 12-month and 24-month survival rates were 75.44% and 50.81%, respectively. The 12-month and 24-month progression-free survivals were 47.68% and 33.1%, respectively. Ki-67 overexpression (> 65%) was a negative prognostic factor. The results of the treatment of PTCL obtained in a Ukrainian population study are similar to those in other European studies, all of which remain unsatisfactory. Further research is required to develop a new strategy for examination and therapy to improve treatment outcomes. The emphasis should be placed on the pragmatic clinical trials comparing the efficacy of first-line treatment in PTCL patients with both favorable and unfavorable clinical factors.

Aggressive T-cell lymphomas: 2024: Updates on diagnosis, risk stratification, and management.

Aggressive T-cell lymphomas continue to have a poor prognosis. There are over 30 different subtypes of peripheral T-cell lymphoma (PTCL), and we are now beginning to understand the differences between the various subtypes beyond histologic variations. Gene expression profiling and other molecular techniques have enabled deeper understanding of differences in various subtypes as reflected in the latest 5th WHO classification of PTCL. It is becoming increasingly clear that therapeutic approaches that target specific cellular pathways are needed to improve the clinical outcomes of PTCL. There are many targeted agents currently in various stages of clinical trials for PTCL that take advantage of the differential expression of specific proteins or receptors in PTCL tumors. This includes the CD30 directed antibody drug conjugate brentuximab vedotin. Other notable targets are phosphatidylinositol 3-kinase inhibitors, histone deacetylase inhibitors, CD25, and chemokine receptor 4. Anaplastic lymphoma kinase (ALK) inhibitors are promising for ALK expressing tumors. Allogeneic stem cell transplant continues to be the curative therapy for most aggressive subtypes of PTCL. The use of checkpoint inhibitors in the treatment of PTCL is still controversial, with best results seen in cases of extranodal natural killer cell/T-cell lymphoma. Bispecific antibody-based treatments and chimeric antigen receptor cell-based therapies are in clinical trials.

Efficacy and Safety of Valemetostat Monotherapy in Patients with Relapsed or Refractory Peripheral T-Cell Lymphomas: Primary Results of the Phase 2 VALENTINE-PTCL01 Study

Introduction: Peripheral T-cell lymphoma (PTCL) is an aggressive non-Hodgkin lymphoma (NHL), with limited available treatment options for patients (pts) with relapsed or refractory (R/R) disease. Valemetostat tosylate (valemetostat) is a novel and potent dual inhibitor of enhancer of zeste homolog (EZH)2 and EZH1, which is approved in Japan for the treatment of R/R adult T-cell leukemia/lymphoma (ATLL). Here, we report primary results for pts with R/R PTCL treated with valemetostat in the open-label, single-arm, global, phase 2 VALENTINE-PTCL01 study (DS3201-A-U202; NCT04703192). Methods: Pts were ≥ 18 years of age, had a confirmed diagnosis of PTCL, had R/R disease after ≥ 1 prior line of systemic therapy, and pts with anaplastic large cell lymphoma (ALCL) had received prior brentuximab vedotin treatment. Pts received oral valemetostat 200 mg/day in continuous 28-day cycles until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR), assessed by blinded independent central review of PTCL following computed tomography (CT)-based response assessment according to Lugano 2014 criteria. Secondary efficacy endpoints included duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Positron emission tomography (PET)-CT-based response assessment by Lugano 2014 criteria was an exploratory endpoint. Efficacy analyses included all pts who received ≥ 1 dose of valemetostat and had an eligible PTCL subtype confirmed by central hematopathology review; safety analyses included all pts who received ≥ 1 dose of valemetostat. Results: A total of 133 pts with R/R PTCL were enrolled and received ≥ 1 dose of valemetostat. Pts had a median age of 69 years (range 22-85) and 91 pts (68.4%) were male. Pts had received a median of 2 prior lines of therapy (range 1-12) and 35 pts (26.3%) received prior hematopoietic cell transplant (HCT; autologous, n = 32; allogeneic, n = 5). PTCL subtype eligibility was confirmed in 119 pts: 42 pts (31.6%) had angioimmunoblastic T-cell lymphoma (AITL), 41 (30.8%) had PTCL, not otherwise specified (PTCL, NOS), 9 (6.8%) had ALCL (7 [5.3%] ALK-negative and 2 [1.5%] ALK-positive), 8 (6.0%) had nodal PTCL with T follicular helper cell phenotype, and 19 (14.3%) had other PTCL subtypes. As of data cutoff (May 5, 2023), 32 pts (24.1%) were still receiving treatment; reasons for treatment discontinuation included progressive or relapsed disease in 46 pts (34.6%), clinical progression in 19 pts (14.3%), adverse event in 13 pts (9.8%), and 12 pts (9.0%) discontinued study drug to proceed with allogeneic HCT. Median treatment duration was 18 weeks (range 0.3-93.4) and median duration of follow-up was 10.5 months (range 0.2-21.5). Among 119 efficacy-evaluable pts, the CT-based ORR was 43.7% (n = 52) (95% confidence interval [CI], 34.6-53.1), including 17 pts (14.3%) achieving CR and 35 pts (29.4%) achieving PR as best overall response. Median DOR was 11.9 months (95% CI, 7.8-not evaluable [NE]) and median time to response was 8.1 weeks (range 5-37). ORR by PTCL subtype ranged from 31.7% for PTCL, NOS to 54.8% for AITL (Table 1). Using PET-CT-based response assessment, ORR was 52.1% (n = 62) (95% CI, 42.8-61.3), including 32 pts (26.9%) with a complete metabolic response. Median CT-based PFS was 5.5 months (95% CI, 3.5-8.3) and median OS was 17.0 months (95% CI, 13.5-NE). Of 133 pts in the safety analysis set, 128 pts (96.2%) experienced ≥ 1 treatment-emergent adverse event (TEAE) of any grade, 77 pts (57.9%) experienced grade ≥ 3 TEAEs, and 53 pts (39.8%) experienced serious adverse events. The most common all grade and grade ≥ 3 TEAE was thrombocytopenia (Table 2). Overall, 13 pts (9.8%) experienced a TEAE that led to treatment discontinuation, 21 pts (15.8%) had a TEAE that led to dose reduction, and 66 pts (49.6%) had a TEAE that led to dose interruption. Conclusions: Valemetostat demonstrated a high ORR of 43.7% with durable responses (median DOR of 11.9 months) in pts with R/R PTCL, and responses were observed across all PTCL subtypes. A valemetostat dose of 200 mg/day was tolerable; safety analysis showed that the most common TEAEs were cytopenias. These primary results from the VALENTINE-PTCL01 study suggest that valemetostat provides a clinically meaningful benefit for pts with R/R PTCL.

Epidemiology, Clinical Features and Outcomes of Peripheral T-Cell Lymphoma in Latin America

INTRODUCTION: Peripheral T-cell lymphomas (PTCL) represent a rare and heterogenous group of mature T-cell lymphomas often characterized by aggressive behavior. Previous studies evaluating the distribution of PTCL subtypes across Latin America (LATAM) were limited in their representation of most countries in the region. Additionally, a lack of standardized management for several subtypes and the absence of comprehensive lymphoma registries in LATAM suggests exploring real-world treatment patterns and clinical outcomes. We conducted an international pooled analysis to assess the distribution of PTCL across LATAM countries and report treatment outcomes. METHODS: We compiled data from patients aged ≥18 years with newly diagnosed PTCL from the retrospective registry of the Grupo de Estudio Latinoamericano de Linfoproliferativos (GELL, n=988, 1975-2023), the Brazilian T-cell Project (Brazilian TCP, 2015-2017, 168 cases retrospective; 2017-2023, 425 cases prospective) and the prospective registry of the International T cell Project (ITCP, n=529, 2006-2023). Data were abstracted from medical records in a standardized form. Survival data was only available from the GELL and Brazilian TCP. Overall survival (OS) was estimated from diagnosis to death from any cause, while progression-free survival (PFS) was defined from diagnosis to relapse, progression, or death from any cause. We used the Kaplan-Meier method and Log-rank test to estimate and compare survival probabilities. RESULTS: We enrolled 2110 patients from 11 LATAM countries. Overall, the median age at diagnosis was 54 years (range 18-95 years), most were male (59%), present with advanced stage disease (Ann Arbor III-IV, 67%), and had good performance status (ECOG ≤1, 71%) (Table 1). After PTCL not otherwise specified (NOS, 39%), adult T-cell leukemia/lymphoma (ATL, 18%) and extranodal NK/T cell lymphoma (ENKTL, 16%) were the most frequently diagnosed PTCL subtypes with varying distribution across LATAM countries. Peru had a higher prevalence of ATL (39%) and ENKTL was frequently diagnosed in Central America (43%). In contrast, ALK-negative (ALK-) anaplastic large T-cell lymphoma (ALCL) was the second more frequent subtype in Brazil (18%), Chile (16%), and Argentina (9%). The percentage of mature T-cell NOS was 27% in Argentina and 28% in Chile. A total of 1620 received chemotherapy. First-line chemotherapy varied across subtypes. Patients with ENKTL were frequently treated with asparaginase/platinum-based therapy (62%), while CHOP was more commonly used for ATL or PTCL NOS (46% for both). Chemotherapy with CHOEP/EPOCH was frequent for patients with ALK- ALCL (45%), ALK+ (ALCL 47%), or AITL (48%). With a median follow-up of 33 months, the 3-year OS and PFS for the overall cohort were 40% and 30%, respectively. ALK+ ALCL had superior survival estimates, with a 3-year OS of 77% and a 3-year PFS of 73%. The 3-year OS for patients with ENKTL was 48% and the PFS was 45%. Patients with ATL experienced the lowest survival rates (OS and PFS of 23% and 16% at 3 years, respectively). The use of asparaginase/platinum or CHOP-based therapy was associated with superior 3-year OS (61% and 52%, respectively; p=0.011) and PFS (57% and 49%, respectively; p=0.017) among patients with ENKTL. For ATL, the use of CHOEP/EPOCH was associated with improved 3-year OS (21%, p=0.009) and PFS (15%, p=0.024), but outcomes remained dismal. CONCLUSION: To our knowledge, we report the largest pooled cohort of PTCL subtypes across LATAM by leveraging the retrospective registry of the GELL consortium and data from the Brazilian TCP and ITCP. Our findings suggest a distinct distribution of PTCL subtypes across LATAM countries, with a higher prevalence of ATL and ENKTL compared to the epidemiological patterns in Western countries. This distribution underscores a unique opportunity to increase trial enrollment and accrual of rarer PTCL subtypes. The relatively high percentage of mature T-cell NOS suggests difficulties in providing specific lymphoma diagnoses in the region. The low survival rates for some subtypes indicate the need to develop novel therapies to improve patient outcomes. A larger prospective assessment of PTCL epidemiology and treatment outcomes is being planned to expand the ascertainment of cases, improve pathological classification of the different PTCL subtypes, and validate our results in the LATAM region.

Significance of the Rhoa G17V Mutation Detected By Ddpcr in Diagnostic and Monitor of Angioimmunoblastic T-Cell Lymphoma

Introduction Angioimmunoblastic T-cell lymphoma (AITL) is a subtype of peripheral T-cell lymphoma (PTCL) that originates from T follicular helper cells (TFH). RHOA G17V mutation is the most common hotspot locus which could be detected in 50%-70% of cases, showing its potential value for the diagnosis and clinical monitor of this disease. Methods RHOA G17V mutation were detected by Droplet digital PCR (ddPCR) in available samples from PTCL patients, at baseline and before every cycle. Response assessments were done by PET/CT and evaluated according to Lugano criteria after 3 cycles and end of first line chemotherapy(EOT), or at suspicious of disease progression. All data analyses were performed using SPSS 20.0 software (SPSS, Inc.) and GraphPad Prism 9.0 software (GraphPad software). p-Value < 0.05 was considered statistically significant. Results 30 patients with PTCL were included in our center from 2021-01-01 to 2023-07-01,21 were confirmed as AITL and 9 were PTCL-NOS by pathologist review. In whole cohort, RHOA G17V mutation could be detected in 46.7%(14/30) of all patients, also was positive in 61.9%(13/21) and negative in 38.1% (9/21) of patients with AITL. The sensitivity and specificity of RHOA G17V mutation in AITL by ddPCR is 61.9% and 88.9%, with a positive predictive value of 92.9%, and a negative predictive value of 50%. Hyperglobulinemia, positive direct Coombs test, elevated LDH, elevated β2-MG were founded in 76.9%(10/13),61.5%(8/13) ,61.5%(8/13) and 76.9% (10/13) of AITL patients with RHOA G17V mutation, which were significantly higher than those without RHOA G17V mutation(P=0.002,0.019,0.019,0.026). Furthermore, all of the of RHOA G17V mutated AITL patients were in clinical stage III or IV(100%, 13/13), 76.9%(10/13) of them with detectable whole-blood EBV-DNA(≥500 copies/mL) and all have three or more TFH markers(100%,13/13). We next evaluated the baseline and dynamical changes in RHOA G17V VAF-positive patients with AITL. Pretreatment VAF was significantly lower for patients who achieved complete remission or partial remission at EOT compared with that of patients with progressive disease or stable disease (mean VAF, 20.75% vs. 4.31%, p = 0.0028). (Figure 1). In addition, the median PFS in AITL patients with and without RHOA G17V mutation was 9.157 months and 15.154 months respectively(P=0.32).Finally, in 10 AITL patients with dynamic results of RHOA G17V mutation (Figure 2) , a good correlation was found in between dynamic changes of VAF of RHOA G17V mutation and response assessment by PET/CT, rerise of RHOA G17V mutation VAF could be detected prior to clinical progression in two patients，showing for the its protentional value for disease monitor. Conclusions Our study first reported the diagnostic value of single hotspot detection of G17V RHOA mutation by ddPCR in PTCL. Monitoring of G17V RHOA mutation in AITL has predictive value of assess tumor burden and response, also can complement the longitudinal supervise of disease.

Updated Results of a Prospective Study: Rituximab and Lenalidomide Plus Chidamide (RLC) for Patients with Relapsed/Refractory Angioimmunoblastic T-Cell Lymphoma

Introduction Angioimmunoblastic T-cell lymphoma (AITL) is the second most common subtype of peripheral T-cell lymphoma (PTCL). The therapeutic effect of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), the most common first-line chemotherapy regimen, is not satisfactory, and most patients experience relapse or disease progression. The 5-year progression-free survival (PFS) of AITL is 13%-23%, and 5-year overall survival (OS) is 33%-36%. The benzamide histone deacetylase inhibitor (HDACi) Chidamide and lenalidomide (a second-generation immunomodulatory compound) are both approved for the treatment of relapsed or refractory PTCL in China. About 70%-100% of the AITL patients have EBV infection, which may cause abnormal immune functions in hosts. EBV infects immunocytes such as B cells, T cells, and natural killer cells, and it impairs immune functions that can clear neoplastic cells from the body. Rituximab may eradicate EBV-B cells and activated B cells and may prevent the progression to AITL. When combined with rituximab, lenalidomide augmented antibody-dependent cell-mediated cytotoxicity by enhancing NK cells, which overcomes rituximab resistance in lymphoma patients. In this prospective phase II study, the efficacy and safety of a new regimen consisting of rituximab, lenalidomide and chidamide has been evaluated in relapsed/refractory AITL patients. We have reported the preliminary results (2022 ASH, poster 1600), and now we update the data of this study. Methods Patients with relapsed/refractory AITL after at least first-line chemotherapy were treated with up to 6 cycles of a rituximab and lenalidomide plus chidamide (RLC) regimen every 3 weeks. The initial dose of each drug has been reported. The primary endpoint of the study was PFS. The secondary endpoints included overall response rate (ORR), OS, and adverse events (AEs). Results Between Aug 2019 and May 2023, 24 patients with relapsed/refractory AITL were enrolled. The characteristics of these patients are listed in table 1. On enrollment, 16 (66.7%) patients had received 1st-line chemotherapy, 7 (29.1%) patients had received 2nd-line chemotherapy, and 1 (4.2%) patient had received 3rd-line chemotherapy. The median age was 63 years (range 43-78) and 9 (37.5%) patients were female. Fifteen (62.5%) patients had B symptoms, including weight loss in 3 (12.5%) cases, night sweat in 1 (4.2%) case and fever in 11 (45.8%) cases. Sixteen (66.7%) patients had elevated serum lactate dehydrogenase (LDH), and 21 (87.5%) patients had IPI score≥2. All patients had completed RLC treatment for at least 1 cycle and underwent imaging assessment. The ORR was 75% (18/24) with a complete remission (CR) rate of 20.8% (5/24), and 13 (54.2%) patients achieved partial remission (PR). While 1 (4.2%) patient achieved stable disease (SD) and 5 (20.8%) patients achieved progressive disease (PD). Two patients received autologous hematopoietic stem cell transplantation as consolidation treatment after achieving CR from RLC chemotherapy. With a median follow-up of 9.7 months, 9 patients had died. The median PFS was 10.8 months (95% confidence interval <CI>, 9.0 to 12.6 months), but the median OS was not reached. No patient presented with Grade 5 AE. The most frequent all-grade hematological toxicity included leucopenia (35.7%, 5/14), followed by anemia (21.4%, 3/14) and thrombocytopenia (41.7%, 10/24). Other common toxicities included infusion reaction (16.7%, 4/24), skin rash (20.8%, 5/24), pulmonary pneumonia (41.7%, 10/24), and nausea (12.5%, 3/24). Dose reduction was performed in 8 patients. The exploratory analysis of possible prognostic factors by mass spectrum flow are undergoing. Conclusions The updated results of this prospective study confirmed the good response rate and manageable toxicity of rituximab and lenalidomide plus chidamide (RLC) regimen. This combination may be a promising regimen in patients with relapsed/refractory AITL.

Prognostic Significance of CD30 Expression and Response to Brentuximab Vedotin in Patients with Angioimmunoblastic T Cell Lymphoma

Background Angioimmunoblastic T-cell lymphoma (AITL) is a subtype of peripheral T-cell lymphoma (PTCL) characterized by a follicular helper T-cell phenotype. The standard frontline treatment for AITL typically involves CHOP or CHOP-like regimens, with consideration for autologous stem cell transplant. A promising treatment option for CD30-positive (CD30+) PTCLs, including AITL, is the anti-CD30 antibody drug conjugate, brentuximab vedotin (BV). The ECHELON-2 study demonstrated equivocal outcomes in CD30+ PTCL patients (pts) who received BV-CHP instead of CHOP. However, response of BV in CD30+ AITL pts is still uncertain. This study aims to evaluate the relationship between CD30 expression and the clinical response to BV in pts diagnosed with AITL. Methods This retrospective IRB approved study conducted at MD Anderson Cancer Center, where we analyzed pts with AITL diagnosed between 1997- 2023. Patient demographics, laboratory data at diagnosis, pathology review, treatment, and treatment response were collected and analyzed. Expression of CD30 expression in neoplastic cells was evaluated by immunohistochemistry and scored in 5% increments. Kaplan- Meier method was used to assess overall survival (OS) and log-rank used to compare different groups. Results This study included a cohort of 339 pts with AITL. Among them, 55 (23%, n=237) had no detectable CD30 expression (CD30=0%),182 (77%, n=237) patients had detectable CD30 expression (CD30>1%), and 102 pts had unknown CD30 expression. Table 1 shows patient characteristics by CD30 expression and response to first-, second-, and third- line BV treatment. There were 113 (48%, n=237) females and 124 (52%, n=237) males with a median age of 66 years. Most patients were Whites (88%, n=196) followed by Black (4%, n=196), and Asian (5%, n=196). Fifty-two (n=122) of pts who were CD30+ had stage III, 43% (n=122) had stage IV (p-value= <0.001), and 38% had BM involvement (p- value= 0.3). For pts with disease showing no CD30 expression (CD30neg) 16% (n=43) of pts had stage III, 70% (n=43) had stage IV, and 48% (n=42) had BM involvement. Auto-Stem cell transplant (ASCT) was performed in 48% of those with CD30+ and 43% of CD30neg. The most common first-line treatment was chemotherapy combination of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) followed by other CHOP like regimens. In total, 35 pts received BV treatment as first-line, 32 patients received BV in combination with chemotherapy and 3 received BV only. For second-line treatment, 11 received BV treatment and for third- line only 6 received BV. First- line treatment with BV showed better clinical response rates, with 82% achieving complete response (CR, n= 34), followed by second line CR with 56% (n= 9) and third- line with 0% (n= 6). The median OS were similar between those with CD30+ who did or did not receive first line BV (20 months vs. 19 months, p>0.05). The median OS for CD30neg pts who did not receive BV was 25 months (p=0.42). Furthermore, there was no statistically significant difference in OS between pts who underwent a ASCT (CD30+ 24.5 months and CD30neg 32.5 months, respectively) and those who did not (CD30+ 18.5 months and CD30neg 24.5 months, respectively, p- value = 0.29). Conclusion While this study did not find CD30 expression to be a predictor of response to BV treatment or ASCT in AITL pts, it provides valuable insights into the prevalence of CD30 expression and BV response as first- line treatment. Notably, 77% of pts had CD30 expression and pts who received BV as first- line had a higher proportion of CRs compared to pts who received BV as second- and third- line treatments. Further investigations with larger patient cohorts are necessary to determine the prognostic and predictive role of CD30 in AITL. Additional studies analyzing CD30 expression levels in malignant cells, immunoblasts, and macrophages are planned for presentation at the upcoming annual meeting.

A Retrospective Study on the Efficacy and Safety of Chidamide As a Maintenance Therapy for Peripheral T-Cell Lymphoma

Background: Peripheral T-cell lymphomas (PTCLs) are a set of rare and highly heterogeneous tumors of non-Hodgkin's lymphoma (NHL) with inferior outcomes. Chidamide is a novel benzamide class of histone deacetylase (HDAC) inhibitor (HDACi) that was approved by the Chinese Food and Drug Administration in 2014 for the treatment of relapsed or refractory (R/R) PTCL patients. This study aimed to assess the efficacy and safety of chidamide as a maintenance therapy after induction or salvage treatment in patients with PTCLs. Methods: The clinical data of 58 patients with different PTCL subtypes who received chidamide as a maintenance therapy after first-line or salvage treatment were collected. Progression-free survival (PFS), overall survival (OS), and safety were analyzed. Results: Fifty-eight patients enrolled in our study between January 2015 and July 2022, of whom 39 patients received chidamide as a maintenance therapy after first-line treatment and 19 patients after salvage treatment. All patients started chidamide maintenance after reaching at least partial response (PR). The median age was 66 (29-83) years. Patients with angioimmunoblastic T-cell lymphoma (AITL) represented the largest subgroup (34, 58.6%), followed by PTCL, not otherwise specified (PTCL-NOS) (10, 17.2%), anaplastic large cell lymphoma (ALCL) (8, 13.8%), NK/T cell lymphoma (NKTCL) (5, 8.6%) and monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) (1, 1.7%). Thirty-four (58.6%) patients were stage III-IV, and 38 (65.5%) patients had intermediate or high risk (prognostic index for T-cell lymphoma (PIT) 2-4). Among the 39 patients who underwent chidamide maintenance after first-line treatment, 30/39 (76.9%) patients began maintenance after reaching complete response (CR) and 9/39 (23.1%) after achieving PR. Notably, 8/9 (88.9%) patients achieved CR from PR during maintenance treatment, with a median time of 6 (3-12) months. A total of 11/39 (28.2%) patients experienced disease progression during the maintenance treatment, and their median duration of remission was 6 (3-13) months. Among them, 2 patients experienced disease progression 2 to 3 months after drug withdrawal due to COVID-19 infection. A total of 19 patients who received maintenance treatment after salvage therapy, 9 (47.4%) received maintenance therapy after CR and 10 (52.6%) received maintenance therapy after PR. Among them, 9/19 (47.4%)had disease progression and their median duration of remission was 16 (2-25) months. The remaining 10 patients (8 CR and 2 PR) were still undergoing maintenance treatment and follow-up. The median maintenance treatment time for all patients was 16 (1-72) months, and the median maintenance dose was 20 (15-30) mg twice weekly. The median follow-up time was 39 (2-79) months, the median PFS was 33 months, and the median OS had not been reached (Figure 1 a, b) for all patients. The median PFS and OS of the patients who received first-line maintenance therapy were not reached, which were significantly better compared to patients who received chidamide as salvage treatment maintenance (the median PFS and OS were 7 and 67 months, P < 0.001, P = 0.009, respectively) (Figure 1 c, d). There was no statistical difference in PFS and OS among the different pathological subtypes, but AITL seemed to achieve better PFS (Figure 1 e, f). The most common toxicities were hematologic toxicities, including neutropenia (42, 72.4%), anemia (23, 39.7%), and thrombocytopenia (29, 50.0%), followed by fatigue (35, 60.3%), anorexia (31, 53.4%), liver dysfunction (10, 17.2%), and pneumonia (4, 6.9%). Most adverse events were grade 1 or 2, and the grade 3‒4 adverse events were neutropenia (15/42), thrombocytopenia (7/29), fatigue (1/35), and pneumonia (2/4). Twelve (20.7%) patients underwent a dose reduction and three patients discontinued treatment (two patients with severe pulmonary infections, and one patient had intolerable fatigue) due to adverse events. One patient stopped maintenance treatment after taking chidamide for 10 months for financial reasons and he is still in follow-up. Conclusion: The findings of this study showed that patients with chidamide maintenance therapy had a better PFS and OS with a manageable safety profile, especially as the first-line maintenance therapy. We conclude that chidamide can be used as a maintenance treatment to improve the survival of patients with PTCLs.

C17ORF58 Is Upregulated in Peripheral T-Cell Lymphomas and Encodes a Protein Critical for Survival of PTCL Cells

Peripheral T-cell lymphomas (PTCL) constitute a group of heterogeneous T- and NK-cell malignancies, accounting for about 15% of Non-Hodgkin lymphomas (NHL). Most PTCL subtypes exhibit an aggressive disease presentation, carrying a worse prognosis than B-cell lymphomas. PTCL - Not Otherwise Specified (PTCL-NOS), the largest subgroup, is categorized by exclusion, with a diagnosis given if the patient does not meet the diagnostic criteria of other PTCL subtypes. PTCL-NOS is a heterogeneous group with diverse cells of origin, varied cytogenic, molecular, and morphological phenotypes, and antigen variability. Despite the increase in specific T-cell lymphoma treatment options, such as belinostat, romidepsin, pralatrexate, and brentuximab vedotin, alongside conventional non-targeted chemotherapy like CHOP and R-CHOP, the overall 5 year survival remains only at 20-30%. A deeper understanding of the pathways and genes critical for PTCL-NOS survival is urgently needed. In our quest to better understand the molecular landscape, we performed a gene expression analysis of ten PTCL-NOS lymphomas and five normal samples using RNAseq analysis. Our study identified ~400 genes consistently upregulated in lymphoma samples, indicating potential involvement in tumor maintenance. Following the exclusion of common essential genes, we performed a shRNA-mediated knockdown screen of the remaining candidates in the human PTCL-NOS cell line T8ML-1. This approach unveiled several lethal genes, including MYBL2, TRIP13, KIF18B, C17ORF58, and others. Cell cycle analysis demonstrated that while knockdown of MYBL2, TRIP13, and KIF18B induced G2-M arrest, downregulation of C17ORF58 primarily induced apoptosis. Notably, downregulation of C17ORF58 did not impact the proliferation of human embryonic kidney fibroblasts HEK 293T, suggesting that normal cells might not require this protein for growth. However, its downregulation in additional hematologic cell lines, such as Cutaneous T-cell lymphoma cell lines (HH, Hut78) and T-cell lymphoblastic leukemia (Jurkat), also induced apoptosis, which suggests a key role for C17ORF58 in T-cell malignancies. Analysis of publicly available RNAseq data revealed overexpression of C17ORF58 in the majority of PTCL-NOS, Anaplastic Large Cell, Hepatosplenic T-cell, and malignant NK/T-cell lymphomas, relative to normal T-cells, thus highlighting its possible role in tumor development and maintenance. C17ORF58 encodes a predicted protein of 339 amino acids, with an estimated molecular weight of 37 kDa. This protein features two putative domains: the PRK07764 domain, which is homologous to DNA polymerase III subunits gamma and tau, and the netrin module, a 130 amino acid residue domain found within the C-terminal sections of various proteins, including netrins, complement proteins C3-C5, secreted frizzled-related proteins, and type I procollagen C-proteinase enhancer proteins. The predicted promoter has binding sites for Oct-B1-3, Pax-2, POU2F1-2, 2B, and 2C, suggesting that the C17ORF58-encoded protein may participate in normal development. In conclusion, our data indicate that upregulation of C17ORF58 may contribute to the progression and maintenance of PTCL and could serve as a potential target for treating T-cell malignancies. Investigations into its physiological role in normal T-cells and pathways deregulated upon its inactivation are ongoing.

DNA Methylation Landscape of Peripheral T-Cell Lymphomas Not Otherwise Specified

DNA methylation is an epigenetic modification catalyzed by DNA methyltransferases that regulate gene transcription in mammalian cells. DNA methylation in gene promoters is associated with repressive histone marks and contributes to gene repression. This process is involved in various physiological processes, including development, X chromosome inactivation, genomic imprinting, differentiation, and hematopoiesis. The global, genome-wide deregulation of methylation patterns contributes to the pathogenesis of immune disorders, hematologic malignancies, and cancer. Because aberrations in DNA methylation can deregulate spatiotemporal gene expression in a cell type-specific manner, genome-wide changes in this epigenetic modification may contribute to tumor development. Specifically, the downregulation of tumor suppressors through promoter hypermethylation is a widely accepted mechanism in cancer progression. Due to its distinct patterns in cancer, DNA methylation can be used as a diagnostic and predictive biomarker. Peripheral T-cell lymphomas, Not Otherwise Specified (PTCL-NOS), are a group of heterogeneous T-cell malignancies with diverse cytogenic, molecular, and morphological phenotypes. Despite large-scale gene expression profiling, the molecular features-and DNA methylation in particular-of these rare but aggressive malignancies remain poorly understood. To better understand the molecular landscape of PTCL-NOS, we performed global methylation profiling via Whole Genome Bisulfite Sequencing on 10 lymphomas and compared those to patterns seen in normal T-cells and Anaplastic Large Cell Lymphoma (ALCL). Our analysis revealed large-scale deregulation of methylation in all tumors at levels of both differentially methylated cytosines and regions. The dominant molecular change was hypomethylation, which was, on average, 7 times more frequent than hypermethylation. Hypomethylation was not limited to repetitive elements but was also seen in all genomic elements, including promoters, enhancers, gene bodies, and exons. Out of 1,286 genes whose promoters were consistently hypomethylated in Peripheral T-cell lymphomas (PTCL), 39 genes were associated with an increase in expression, suggesting that the loss of methylation may have contributed to their deregulation. This hypomethylated and overexpressed signature contained genes that might be involved in tumor progression or maintenance, such as Rac GTPase activating protein 1 ( RACGAP1), regulator of chromosome condensation 1 ( RCC1), anillin actin-binding protein ( ANLN), and others. Out of 578 genes whose promoters were consistently hypermethylated in PTCL, the expression of 56 genes was decreased. These included genes with tumor suppressor function, such as splicing factor 3b subunit 1 ( SF3B1) and lymphoid enhancer-binding factor 1 ( LEF1). Our analysis also identified differential methylation between PTCL-NOS and ALCL in various genomic features. For example, 71 hypo- and 59 hypermethylated promoters were found only in ALCL but not PTCL-NOS. Conversely, 326 hypo- and 254 hypermethylated promoters were observed only in PTCL-NOS. Analysis of gene expression also revealed specific changes in both PTCL subtypes, manifested by the activation of different signaling pathways as identified by Ingenuity Pathway Analysis. PTCL-NOS was characterized by the suppression of the SUMOylation pathway, PTEN, and EIF2 Signaling, and the activation of NF-κB and Notch signaling. ALCLs were characterized by the suppression of the Role of CHK Proteins in Cell Cycle Control, Erythropoietin, ERBB signaling, the Coronavirus Pathogenesis pathway, IGF-1 signaling, and the activation of Glutathione-mediated Detoxification and Triacylglycerol Biosynthesis. Altogether, we identified recurrent specific methylation and expression changes that could serve as the basis for the development of tools facilitating the diagnosis and prognosis of PTCL-NOS. In addition, our data may contribute to the identification of epigenetically-regulated drivers of tumor initiation, progression, and maintenance.

AFM13 in Combination with Allogeneic Natural Killer Cells (AB-101) in Relapsed or Refractory Hodgkin Lymphoma and CD30 + Peripheral T-Cell Lymphoma: A Phase 2 Study (LuminICE)

Background and Significance Limited treatment options are available for patients with relapsed or refractory (R/R) Hodgkin lymphoma (HL) and no standard-of-care therapy is established for R/R peripheral T-cell lymphoma (PTCL); novel therapies to improve outcomes in these patients are required. AFM13 is a tetravalent, bispecific innate cell engager that binds CD16A on natural killer (NK) cells and CD30 expressed (CD30 +) on HL and PTCL cells, enhancing NK cell-mediated antibody-dependent cellular cytotoxicity (ADCC). AFM13 monotherapy trials in patients with R/R HL and PTCL have shown promising clinical activity and a tolerable safety profile (Sasse et al. Blood 2020; Kim et al. Cancer Res 2023). Recently, a Phase 1/2 study of AFM13 in combination with cord blood (cb)-derived NK cells in patients with R/R CD30 + lymphomas treated at the recommended phase 2 dose (n=35) achieved an objective response rate (ORR) of 94% and a complete response (CR) rate of 71% (Nieto et al. Blood 2022, oral presentation). AB-101 is a non-genetically modified, allogeneic, cryopreserved, off-the-shelf, cb-derived NK cell product optimized for enhanced ADCC through selection for the KIR-B haplotype and the CD16 F158V polymorphism. AB-101 has demonstrated potent killing of tumor cell lines in vitro and in vivo and preliminary results of a Phase 1/2 trial of AB-101 alone and in combination with rituximab in patients with R/R B cell non-Hodgkin lymphoma demonstrated AB-101 is well tolerated (Khanal et al. J Clin Oncol 2023). Combining AFM13 with AB-101 has the potential to synergistically enhance and redirect antitumor immune responses to target HL and CD30 + PTCL cells. Study Design and Methods This Phase 2, open-label, multi-center, multi-cohort study (NCT05883449) aims to evaluate the efficacy and safety of AFM13 in combination with AB-101 in patients with R/R HL and certain R/R CD30 + PTCL subtypes. PTCL subtypes permitted are PTCL not-otherwise specified, angioimmunoblastic T-cell lymphoma, and ALK-positive and -negative anaplastic large cell lymphoma (ALCL). Patients aged ≥18 years are planned for enrolment and patients with R/R HL must have received at least two prior lines of therapy including prior combination chemotherapy, brentuximab vedotin (BV) and a checkpoint inhibitor. Patients with R/R PTCL must have confirmed CD30 expression of ≥1% by immunohistochemistry and have received at least one prior line of combination chemotherapy; patients with ALCL must have received or been intolerant to BV. Prior autologous or allogeneic hematopoietic stem cell transplant is permitted. Exclusion criteria include treatment with any anti-cancer agent ≤21 days prior to enrolment, continuing toxicity from a prior therapy, central nervous system involvement, or previous treatment with AFM13 or NK cells. The primary objective is to determine the ORR (complete and partial responses) by Independent Radiology Committee (IRC) based on PET-CT per Lugano classification. Secondary objectives include safety and immunogenicity, complete response rate, duration of response and progression free survival. Treatment will be given intravenously (IV) over 48-day cycles for up to 3 cycles. A run-in phase will assess two dose levels of AFM13 and AB-101 in 4 cohorts (Figure). A standard lymphodepletion regimen of fludarabine (30 mg/m 2/day) and cyclophosphamide (300 mg/m 2/day) will be administered IV from Day −5 to Day −3 at the start of each treatment cycle. Following this, AFM13 (200 mg or 300 mg once weekly) will be given, with AB-101 (dose level 1 or 2, see Figure) given 1 hour later per cycle. Patients will also receive 6 ×10 6 IU of IL-2 subcutaneously at least 1 hour after each AB-101 dose. Cohorts 1 and 2 will enrol in parallel; cohorts 3 and 4 will start only if cohorts 1 and 2 are cleared per protocol safety criteria. After cycle 1 has completed for each subject enrolled in all 4 cohorts, an analysis of the safety and clinical responses will be performed to determine the two dose levels to be evaluated in the main study. In addition, an exploratory cohort (cohort 5) will begin enrolment of patients with CD30 + PTCL. Disease and efficacy assessments will be conducted at screening and on Day 43 (± 3 days) of each cycle.

Valemetostat for Relapsed or Refractory Peripheral T-Cell Lymphomas: Primary Results from a Phase 1 Trial

Introduction: Treatment (Tx) options for T-cell non-Hodgkin lymphomas (T-NHLs) are limited and prognosis is too often poor for patients (pts) with relapsed or refractory (R/R) disease. Enhancer of zeste homolog (EZH)2 and EZH1 are methyltransferases that catalyze trimethylation of histone H3 at lysine 27 (H3K27me3); this repressive transcriptional profile is broadly associated with gene silencing. Valemetostat tosylate (valemetostat) is a novel, potent, and selective dual inhibitor of EZH2 and EZH1 that prevents H3K27me3 and increases expression of genes involved in immune function ( SLA, PAG1) that can be silenced by H3K27me3. Valemetostat was approved in Japan for the Tx of R/R adult T-cell leukemia/lymphoma (ATLL) in 2022. The clinical activity of valemetostat in pts with R/R NHLs was investigated in the phase 1 DS3201-A-J101 (“J101”; NCT02732275) trial. Interim data were reported previously. Here we report primary outcomes for pts in J101 with R/R T-NHLs treated with valemetostat. Methods: This open-label, multicenter study was conducted in Japan and the United States (US). Eligible pts were ≥ 18 (US) or ≥ 20 (Japan) years (y) of age and relapsed from, refractory to, or ineligible for standard therapies. The trial included a dose-escalation phase (Japan only) followed by a dose-expansion phase (Japan & US). Enrollment in the expansion phase was limited to pts with R/R peripheral T-cell lymphoma (PTCL) or ATLL. Pts received valemetostat once daily in continuous 28-day (d) Tx cycles at 150-300 mg/d in the escalation phase and 200 mg/d in the expansion phase until disease progression or intolerance. Key endpoints for the dose-escalation and dose-expansion cohorts were safety and PK parameters. Preliminary efficacy assessment included objective response rate (ORR), complete response (CR) rate, duration of response (DOR), and progression-free survival (PFS). DOR and PFS were estimated using Kaplan-Meier methods. Results for PTCL and ATLL are reported separately. Results: At the primary data cutoff (Dec 31, 2022), 71 pts were included in the efficacy and safety analyses; 57 with PTCL and 14 with ATLL. Median age at baseline was 68.0 (range 26-83) y in the PTCL group and 66.5 (37-78) y in the ATLL group, and median prior therapies were 2.0 (1-8) and 2.5 (1-8), respectively; 16 (28%; 14 autologous, 2 allogeneic) pts with PTCL and 2 (14%, both allogeneic) with ATLL had previously undergone transplant. The most common PTCL subtypes were PTCL, not otherwise specified (PTCL, NOS; n = 26, 46%) and angioimmunoblastic T-cell lymphoma (AITL; n = 23, 40%). Tx was ongoing for 8 (11%) pts at data cutoff. All 71 pts included at data cutoff experienced ≥ 1 Tx-emergent adverse event; 59 (83%) pts had a Tx-related adverse event (TRAE). The most common all-grade TRAEs were cytopenias, dysgeusia, and alopecia; the most frequent grade ≥ 3 TRAEs were decreased neutrophil (17%), lymphocyte (11%), and platelet (14%) counts ( Table 1). TRAEs led to Tx discontinuation for 4 (6%) pts (1 each: acute myeloid leukemia, myelodysplastic syndrome, colitis, and acute kidney injury), dose reduction for 5 (7%) pts, and Tx interruption for 18 (25%) pts. The ORR was 55% (30/55) in the PTCL group and 64% (9/14) in the ATLL group, with CR rates of 31% (17/55) and 29% (4/14), respectively; within the PTCL group, the ORR among evaluable pts was 50% (13/26) for PTCL, NOS and 64% (14/22) for AITL ( Table 2). Median times to response were 1.8 (range 1.0-5.6) months (mo) in the PTCL group and 1.9 (1.7-19.4) mo in the ATLL group. Median DOR was 21.9 mo (95% confidence interval [CI], 10.2 mo to not reached [NR]) in the PTCL group (median follow-up 16.4 mo) and 21.2 (95% CI, 1.4 to 38.7) mo in the ATLL group (median follow-up 23.0 mo). Median PFS was 7.7 and 4.1 mo, respectively (median follow-up 18.2 mo and NR). Conclusions: Valemetostat was well tolerated and showed encouraging clinical activity in pts with R/R T-NHLs. Cytopenias were common but could usually be managed without Tx discontinuation. Valemetostat induced durable responses, with median DOR of > 1.5 y in both the PTCL and ATLL groups. Results for pts in this trial with R/R B-NHLs (Izutsu et al) and from a phase 2 trial in R/R T-NHLs (Horwitz et al) are reported separately.

Strategies to Develop Anti-KIR Mab Lacutamab in Patients with Peripheral T-Cell Lymphoma: Preliminary Monotherapy Clinical Data and Pre-Clinical Combinability Data

Peripheral T-cell Lymphoma (PTCL) is a heterogeneous group of aggressive T-cell lymphomas associated with poor prognosis. Many patients with PTCL do not respond or relapse despite responding to first line systemic therapy. Despite the common use of chemotherapies, there is no universally accepted standard of care. This highlights an urgent and significant need for innovative treatment strategies that incorporate novel mechanisms of action, particularly for patients with relapsed or refractory (R/R) PTCL. One such novel target is KIR3DL2, a killer immunoglobulin-like receptor that is expressed across different subtypes of T-cell lymphomas including approximately 50% of PTCL patients. Lacutamab is a first-in-class monoclonal antibody designed to specifically deplete KIR3DL2-expressing cells through antibody-dependent cell-cytotoxicity (ADCC) and antibody-dependent cell-phagocytosis (ADCP). It is being developed as a novel treatment for patients with R/R PTCL as a single agent or in combination. In previous trials in patients with R/R cutaneous T-cell lymphoma (CTCL), lacutamab showed acceptable safety profile with no dose limiting toxicities and promising activity. Here we provide preclinical combination data supporting anti-tumor activity and rationale for the exploration of lacutamab in combination with approved and novel therapies in patients with PTCL and we present preliminary monotherapy data from an ongoing Phase 1b study in PTCL. To further develop novel-lacutamab combinations, the combinability of lacutamab with therapies used in R/R or frontline PTCL e.g., pralatrexate or CHOP, respectively, was tested. Pralatrexate is an antineoplastic folate analog approved for the treatment of R/R PTCL. In vitro, pralatrexate was shown to induce KIR3DL2 upregulation on several tumor cell lines with endogenous or forced KIR3DL2 expression and to enhance lacutamab-induced ADCC by NK cells. Importantly, the combination of lacutamab with pralatrexate in vivo delayed tumor growth (Figure 1A) and improved survival (Figure 1B) compared to each monotherapy. CHOP-based chemotherapy is a standard of care in the frontline treatment of PTCL subtypes. In a preclinical in vivo human tumor model, lacutamab in combination with CHOP was shown to reduce tumor growth compared with CHOP or lacutamab alone. An ongoing multi-center, open-label, Phase Ib trial (NCT05321147) evaluate the safety and efficacy of lacutamab monotherapy in patients with KIR3DL2-expressing R/R PTCL who have received at least one prior line of systemic therapy. Lacutamab 750 mg is administered as an intravenous infusion weekly x 5 weeks, every 2 weeks x 10 then every 4 weeks until disease progression or unacceptable toxicity. The primary objective was to assess the safety and tolerability of lacutamab in R/R PTCL. Secondary objectives were to assess clinical activity and to characterize the pharmacokinetics and immunogenicity of lacutamab. At the data cut-off, 10 patients were treated with lacutamab. Median age was 71.0 years (range: 61-77), median prior lines of therapies was 3 (range: 1-5), and median follow-up was 1.9 months (m) (range: 0.5-8.8 m). The majority (90%) of treatment-emergent adverse events (TEAEs) were of grade 1-2 severity, grade ≥3 related TEAEs were observed in 2 (20%) patients: 1 with serum sickness, and 1 with aspartate aminotransferase elevation. No serious TEAEs were observed and none of the patients discontinued study drug due to TEAE. Overall, preliminary Phase 1b data in patients with R/R PTCL confirm the acceptable safety profile of lacutamab monotherapy. The preclinical activity profile improves when assessed in combination. These data inform the future development of lacutamab to provide additional therapeutic options that may improve outcomes for PTCL patients, including those who relapse or are refractory to available therapies. A Phase 2 study evaluating the combination of lacutamab with GemOx is ongoing (NCT04984837) based on pre-clinical observations that GemOx improves lacutamab-induced ADCC by NK cells.

Outcomes of Contemporary Novel Agent and Stem Cell Transplantation in Relapsed/Refractory PTCL

Background Outcomes in relapsed/refractory (R/R) peripheral T-cell lymphoma (PTCL) continue to be suboptimal. In the last decade, several novel agents have been approved; however, their impact on survival remains to be defined. In this multi-center retrospective analysis, we assessed survival following initial progression with respect to novel agent exposure with and without the use of stem cell transplant (SCT). Methods Patients with PTCL diagnosed between 1998-2021 at New York Presbyterian Hospitals, Columbia and Cornell, were included after IRB approval. Medical records were reviewed for baseline characteristics and treatment parameters. In the second line setting, each patient fell into one of four categories: 1. novel agent containing regimen only ( novel-containing only), 2. novel agent containing regimen with SCT at end of second line ( novel + SCT), 3. chemotherapy alone ( chemo-only), and 4. chemotherapy with SCT at end of second line ( chemo + SCT). Event-free survival (EFS) was calculated as time from 1 st progression to 2 nd progression, re-treatment, or death. Subsequent OS (sOS) was calculated from date of first progression to death or last follow-up. Kaplan-Meier method was used to estimate survival probability. Survival difference was tested by log-rank and Cox regression analysis. Results A total of 348 patients with PTCL were identified, of which 189 had R/R disease and 184 had sufficient data for analysis. The median follow-up was 62.5m. Baseline characteristics are shown in Table 1. Most common PTCL subtypes were AITL (N=52, 28.3%), PTCL-NOS (N=39, 21.2%), ATLL (N=34, 18.5%), and ALCL (ALK- = 13, ALK+ = 11, n=24, 13%). Median age at diagnosis was 58 years. Median EFS and sOS from date of initial progression for the entire cohort was 5.0m and 25.1m, respectively. In the second-line setting, 92 (50%) received a novel-containing only, 62 (34%) patients received chemo-only, 17 (9%) received chemo + SCT, and 13 (7%) received novel + SCT. Median EFS from first progression among patients who received second-line novel + SCT was 16.0m (95% CI 6.0 - NR), chemo + SCT 15.0m (95% CI 6.2 - 24.5), novel-containing only 3.9m (95% CI 3.5 - 5.3), and chemo-only 4.1m (95% CI 2.9 - 5.1) as shown in Figure 1. Two-year EFS favored novel + SCT at 38.5m (95% CI 12.0 - 64.9) and chemo + SCT 34.0m (95% CI 10.8 - 57.1), compared to novel-containing only at 18.3m (95% CI 10.1 - 26.6) and chemo-only 11.3m (95% CI 3.0 - 19.6), with p < 0.001 across all groups. Median sOS among patients who received second-line novel + SCT was 70.7m (95% CI 16.0 - NR), chemo + SCT not reached (95% CI 15.0 - NR), novel-containing only 23.3m (95% CI 10.5 - NR), and chemo-only 16.7m (95% CI 11.7 - 27.0). Two-year sOS favored novel + SCT at 74.6m (95% CI 49.7 - 99.5) and chemo + SCT 70.4m (95% CI 48.5 - 92.2) compared to novel-containing only at 49.4m (95% CI 37.9 -61.0) and chemo-only 43.4m (95% CI 30.0 - 56.9), with p =0.014 across all groups. Conclusion This multi-center study represents one of the largest retrospective R/R PTCL cohorts in the modern era with sOS of 25.1m, which compares favorably to historical data collected a decade ago reporting a sOS of 5.5m in R/R patients receiving chemo-only (Mak 2013), however, compares similarly to more recent data from the COMPLETE study (Lansigan 2019). This improvement in sOS may reflect availability of more effective therapies for sequencing in the novel agent era. Our data suggests that SCT in second-line setting is associated with improved EFS and sOS for both those treated with novel agent containing regimens and chemotherapy. Differences are more prominent for two-year EFS and sOS, favoring SCT arms and novel agents. However, the retrospective nature of our data limits definitive conclusion of benefit derived from SCT in the second-line setting, which underscores the need for prospective studies in this area. *This work has been funded ASH RTAF

Biological insights into the role of TET2 in T cell lymphomas.

Peripheral T cell lymphomas (PTCL) are a heterogenous group of mature T cell lymphomas with an overall poor prognosis. Understanding the molecular heterogeneity in PTCL subtypes may lead to improved understanding of the underlying biological mechanisms driving these diseases. Mutations in the epigenetic regulator TET2 are among the most frequent mutations identified in PTCL, with the highest frequency in angioimmunoblastic T cell lymphomas and other nodal T follicular helper (TFH) lymphomas. This review dissects the role of TET2 in nodal TFH cell lymphomas with a focus on emerging biological insights into the molecular mechanism promoting lymphomagenesis and the potential for epigenetic therapies to improve clinical outcomes.

Advances in the pathogenesis and therapeutic strategies of angioimmunoblastic T-cell lymphoma.

Angioimmunoblastic T-cell lymphoma (AITL) is an aggressive subtype of peripheral T-cell lymphomas with its cell origin determined to be follicular helper T-cells. AITL is characterized by a prominent tumor microenvironment involving dysregulation of immune cells, signaling pathways, and extracellular matrix. Significant progress has been made in the molecular pathophysiology of AITL, including genetic mutations, immune metabolism, hematopoietic-derived microenvironment, and non-hematopoietic microenvironment cells. Early diagnosis, detection of severe complications, and timely effective treatment are crucial for managing AITL. Treatment typically involves various combination chemotherapies, but the prognosis is often poor, and relapsed and refractory AITL remains challenging, necessitating improved treatment strategies. Therefore, this article provides an overview of the pathogenesis and latest advances in the treatment of AITL, with a focus on potential therapeutic targets, novel treatment strategies, and emerging immunotherapeutic approaches.

Influence of treatment intensity and medical comorbidities in older adults with peripheral T cell lymphoma

We conducted a population-based study of patients >65 years, diagnosed 2008-2017, with peripheral T-cell lymphoma (PTCL) using SEER-Medicare. Associations between PTCL subtype, treatment regimen, comorbidity, and mortality were assessed using the Kaplan-Meier method and multivariable Cox regression. Amongst the 2,546 patients, the median age was 77 years (interquartile range, 71–83). 5-year overall survival (OS) ranged from 22.2% to 37.3% depending on PTCL subtype. The most common frontline regimen was cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP). 5-year OS rate was 47.0% for patients treated with etoposide + CHOP (N = 67; CHOEP), 33.7% for those treated with CHOP (N = 732), and 23.8% for patients treated with non-anthracycline-containing regimens (N = 105; p < 0.001). In patients without comorbidities, CHOEP remained independently associated with improved OS (HR 0.52, 95% CI,0.30-0.91). Median OS was 1.2 years from initiation of second-line therapy (N = 228) independent of treatment regimen. Frontline but not second-line treatment regimen is associated with OS in older patients with PTCL.

Autologous, allogeneic hematopoietic cell transplantation and CAR-T/NK therapy: what is their real importance in PTCL?

Peripheral T cell lymphoma (PTCL) is a rare and aggressive type of non-Hodgkin's lymphoma that affects mature T cells. This type of cancer is characterized by the abnormal growth of T cells, which can accumulate in the lymph nodes, spleen, bone marrow, and other organs, leading to a variety of symptoms. PTCLs are often difficult to diagnose and treat, and they have a poorer prognosis than other types of lymphoma. However, recent advancements in treatment options, such as targeted therapies have shown promise in improving outcomes for patients with PTCL. Here, we discuss the use of autologous and allogeneic hematopoietic cell transplantation (HCT) as a treatment strategy for patients with PTCL, as well as the recent treatment approaches based on advanced cellular therapy. The current evidence for the use of HCT in PTCL is mainly derived from registry data, retrospective studies, and expert opinion, as randomized trials are limited due to the low incidence and histological heterogeneity of PTCL subtypes.

The SALENTO prognostic model for limited-stage peripheral T-cell lymphoma from the International T-Cell Project Network.

The natural history of limited-stage peripheral T-cell lymphomas (PTCLs) remains poorly defined. We investigated outcomes and prognostic variables in patients registered in the T-Cell Project (TCP) (#NCT01142674) to develop a model to predict overall survival (OS) for the common nodal PTCL subtypes (PTCL-NOS, AITL, ALCL). The model was validated in an independent data set from Australian and Brazilian registries. 211 patients registered in the TCP between 2006-2018 were studied. The median age was 59 years (range 18-88) and median follow-up was 49 months. One hundred twenty-seven patients (78%) received anthracycline-based regimens, 5 patients (3%) radiotherapy alone (RT), 24 patients (15%) chemotherapy+RT. 5-year OS and PFS were 47% and 37%, respectively. Age >60 years, elevated LDH and low serum albumin were independent prognostic factors. The model identified 3 groups with low- (26%, score 0), intermediate- (41%, score 1), and high-risk (33%, score 2-3) with 5-year OS of 78% (95% confidence interval [95% CI], 29-127), 46% (95% CI, 24-68), and 25% (95% CI, 20-30), respectively (P < 0.001) and 5-year PFS of 66% (95% CI, 33-99), 37% (95% CI, 9-65), and 17% (95% CI, 9-25), respectively (P < 0.001). The model demonstrated greater discriminatory power than established prognostic indices and an analogous distribution and outcomes in the 3 groups in the validation cohort of 103 patients. The SALENTO Model (Limited Stage Peripheral T-Cell Lymphoma Prognostic Model) is an objective, simple and robust prognostic tool. The high-risk group has poor outcomes, comparable to advanced stage disease, and should be considered for innovative first-line approaches.

Spontaneous remission of angioimmunoblastic T-cell lymphoma in a child with ataxia–telangiectasia: a case report

BackgroundAngioimmunoblastic T-cell lymphoma is an uncommon subtype of peripheral T-cell lymphoma in children with fewer than 20 cases reported in literature.Case presentationA 3-year-old Omani boy was diagnosed with ataxia–talengectasia presenting with fever and generalized lymphadenopathy. His biopsy revealed atypical lymphocytic infiltrate consistent with the diagnosis of angioimmunoblastic T-cell lymphoma. Within 3 weeks from the initial presentation and without any neoadjuvant therapy, he showed complete recovery of symptoms with absence of fever and regression of all previously affected lymph nodes. He has remained in remission ever since.ConclusionThis is the first report of spontaneous improvement of angioimmunoblastic T-cell lymphoma in a patient with ataxia–telangiectasia who was 3 years old at presentation. Owing to the paucity of similar cases, this report adds valuable diagnostic, therapeutic, and monitoring data.