Understanding health outcome preferences of older adults diagnosed with multiple myeloma.

INTRODUCTION: Health outcome preferences of older adults with cancer vary based on burden/intensity of treatment and its impact on health outcomes such as survival, quality of life, and functional and cognitive well-being. We studied the association between age and health outcome preferences of adults with multiple myeloma (MM). MATERIALS AND METHODS: Using a single center prospective cohort study, we identified adults ≥50y with MM who underwent geriatric assessment (GA) within 30 days of initiating a new line of therapy. We assessed health outcome preferences using a nine-item health outcome preference scale where patients were asked to prioritize varying treatment outcomes in a Likert scale. We compared the response patterns for each item by age group (50-69y vs ≥70y) using Mantel-Haenszel chi-squared test. For items significant in bi-variable analysis, we built proportional odds models to study the association between age and health outcome preferences adjusting for sex, race, frailty, and high risk cytogenetics. RESULTS: We included 119 patients with a median age of 65y. Of these, 58% were male, 56% were non-Hispanic White, and 28% were frail. Older adults (≥70y) versus younger adults (50-69y) were more likely to prioritize health outcomes such as quality of life (53% vs. 34%), functional independence (74% vs. 33%), maintaining cognitive ability (79% vs. 54%), and living free from pain (50% vs 18%) over longer survival (all p values <0.05). In multivariable models, each one interquartile range (IQR) increase in age was associated with increased odds of prioritization of functional independence [adjusted odds ratio (aOR) 2.55, 95% confidence interval (CI) (1.44-4.53)], maintaining cognitive ability [aOR 1.75, 95% CI (1.01-3.02)], and willingness to take milder/ fewer treatments [aOR 2.40, 95% CI (1.36-4.26)] over longer survival. Similarly, each IQR increase in age was associated with decreased odds of prioritization of survival over quality of life [aOR 0.45, 95% CI (0.26-0.78)] and survival over being free from pain [aOR 0.39, 95% CI (0.22-0.69)]. DISCUSSION: Three out of four older adults (age ≥ 70y) with MM rated other outcomes, particularly functional and cognitive well-being, above survival. Determining the most significant treatment outcomes for older adults with MM can aid in establishing treatment goals and enhance shared decision-making.

Daratumumab-based quadruplet therapy for transplant-eligible newly diagnosed multiple myeloma with high cytogenetic risk.

In the MASTER study (NCT03224507), daratumumab+carfilzomib/lenalidomide/dexamethasone (D-KRd) demonstrated promising efficacy in transplant-eligible newly diagnosed multiple myeloma (NDMM). In GRIFFIN (NCT02874742), daratumumab+lenalidomide/bortezomib/dexamethasone (D-RVd) improved outcomes for transplant-eligible NDMM. Here, we present a post hoc analysis of patients with high-risk cytogenetic abnormalities (HRCAs; del[17p], t[4;14], t[14;16], t[14;20], or gain/amp[1q21]). Among 123 D-KRd patients, 43.1%, 37.4%, and 19.5% had 0, 1, or ≥2 HRCAs. Among 120 D-RVd patients, 55.8%, 28.3%, and 10.8% had 0, 1, or ≥2 HRCAs. Rates of complete response or better (best on study) for 0, 1, or ≥2 HRCAs were 90.6%, 89.1%, and 70.8% for D-KRd, and 90.9%, 78.8%, and 61.5% for D-RVd. At median follow-up (MASTER, 31.1 months; GRIFFIN, 49.6 months for randomized patients/59.5 months for safety run-in patients), MRD-negativity rates as assessed by next-generation sequencing (10-5) were 80.0%, 86.4%, and 83.3% for 0, 1, or ≥2 HRCAs for D-KRd, and 76.1%, 55.9%, and 61.5% for D-RVd. PFS was similar between studies and superior for 0 or 1 versus ≥2 HRCAs: 36-month PFS rates for D-KRd were 89.9%, 86.2%, and 52.4%, and 96.7%, 90.5%, and 53.5% for D-RVd. These data support the use of daratumumab-containing regimens for transplant-eligible NDMM with HCRAs; however, additional strategies are needed for ultra-high-risk disease (≥2 HRCAs). Video Abstract.

Low skeletal muscle mass and treatment outcomes among adults with haematologic malignancies: A systematic review and meta-analysis.

BACKGROUND: Low skeletal muscle mass (LSMM) and/or, function associated with an increased risk of treatment-related toxicities and inferior overall survival (OS) among adults with solid malignancies. However, the association between LSMM and treatment-related toxicities among adults with haematologic malignancies remains unclear. METHODS: Using a pre-published protocol (CRD42020197814), we searched seven bibliographic databases from inception to 08/2021 for studies reporting the impact of LSMM among adults ≥18 years with a known haematologic malignancy. The primary outcome of interest was OS, and secondary outcomes included progression free survival (PFS) and non-relapse mortality (NRM). These effect sizes were quantified in terms of hazards ratio (HR) along with 95% confidence interval (CI) and pooled across studies using a DerSimonian-Laird random-effects model. Heterogeneity was assessed using the Cochran's Q and the I2 statistic. All hypothesis testing was two-sided with an alpha of 0.05. RESULTS: Of 3791 studies screened, we identified 20 studies involving 3468 patients with a mean age of 60 years; 44% were female and the most common malignancy was diffuse large B-cell lymphoma (42%). Most studies measured muscle mass using single slice computed tomography imaging at the L3 level. The presence of LSMM was associated with worse OS (pooled HR = 1.81, 95% CI = 1.48-2.22, P < 0.001) with moderate heterogeneity (Cochran's Q, I2 = 60.4%), PFS (pooled HR = 1.61, 95% CI = 1.28-2.02, P < 0.001) with moderate heterogeneity (Cochran's Q, I2 = 66.0%). Similarly, LSMM was associated with worse NRM (HR = 1.72, 95% CI = 1.34-2.22, P < 0.001) with little evidence of heterogeneity (Cochran's Q, I2 = 0.0%). CONCLUSIONS: LSMM is associated with worse survival outcomes among adults with haematologic malignancies. Further research into understanding the underlying mechanism of this association and mitigating the negative effects of LSMM among adults with haematologic malignancies is needed.

Subsequent therapy and outcomes in patients with newly diagnosed multiple myeloma experiencing disease progression after quadruplet combinations.

The combination of anti-CD38 monoclonal antibodies to a proteasome inhibitor, an immunomodulatory agent and dexamethasone (quadruplet-QUAD) in sequence with autologous stem cell transplantation (ASCT) leads to deep and durable responses in newly diagnosed multiple myeloma (NDMM). Disease progression in the first year post-QUADs is uncommon. We analysed 274 consecutive NDMM patients treated with QUADs + ASCT. After a median follow-up of 21.3 months, 20 patients had disease progression <18 months and 21 had progression ≥18 months after the onset of a QUAD regimen. All patients received subsequent anti-MM therapy, and 38 were evaluated for response. Nine (22.0%) received T-cell redirecting therapy as the next treatment, and 21 (51.2%) at some point in the treatment course. Response to next therapy was 26.3% for patients with progression <18 months and 52.6% for those with progression ≥18 months after the onset of a QUAD regimen. Median PFS on the next therapy was 2.5 months (95% CI 1.5-3.4) for those with progression <18 months and 7.0 months (95% CI 3.6-10.5) for those with progression ≥18 months. Efforts should focus on the early deployment of therapies with new mechanism of action for patients experiencing treatment failure after QUADs.

Bridging treatment prior to chimeric antigen receptor T-cell therapy in multiple myeloma.

Autologous patient-derived adoptive T-cell therapies have revolutionized the management of relapsed multiple myeloma (MM). However, the current manufacturing and quality control processes result in lengthy vein-to-vein time, making bridging therapy necessary for most patients. Yet the decision and choice of optimal bridging therapy are complex in the heavily pretreated relapsed MM patient. In this perspective piece, the authors provide their approach and considerations while selecting an optimal bridging regimen before autologous chimeric antigen receptor T-cell therapy.

Minimal residual disease response-adapted therapy in newly diagnosed multiple myeloma (MASTER): final report of the multicentre, single-arm, phase 2 trial.

BACKGROUND: For patients with newly diagnosed multiple myeloma, reaching minimal residual disease (MRD) negativity after treatment is associated with improved outcomes; however, the use of MRD to modulate therapy remains elusive. We present the final analysis of the MASTER trial of daratumumab, carfilzomib, lenalidomide, and dexamethasone (Dara-KRd) therapy in patients with newly diagnosed multiple myeloma, in which MRD status is used to modulate treatment duration and cessation. METHODS: MASTER was a multicentre, single-arm, phase 2 trial conducted in five academic medical centres in the USA. Eligible participants were 18 years or older with newly diagnosed multiple myeloma (measurable by serum or urine protein electrophoresis or serum free light chains), a life expectancy of at least 12 months, and an Eastern Cooperative Oncology Group performance status of 0-2, and had received no previous treatment for multiple myeloma except up to one cycle of therapy containing bortezomib, cyclophosphamide, and dexamethasone. The study was enriched for participants with high-risk chromosome abnormalities (HRCAs). During the induction phase, participants received four 28-day cycles of Dara-KRd, each comprising daratumumab (16 mg/kg intravenously on days 1, 8, 15, and 22), carfilzomib (56 mg/m2 intravenously on days 1, 8, and 15), lenalidomide (25 mg orally on days 1-21), and dexamethasone (40 mg orally or intravenously on days 1, 8, 15, and 22); induction was followed by autologous haematopoietic stem-cell transplantation and up to two phases of consolidation with Dara-KRd. We assessed MRD by next-generation sequencing after or during each phase. The primary endpoint was reaching MRD negativity (<10-5). Participants who reached MRD negativity after or during two consecutive phases stopped treatment and began observation with MRD surveillance (MRD-SURE); participants who did not reach two consecutive MRD-negative results received maintenance lenalidomide. Secondary endpoints included progression-free survival and cumulative incidence of progression. All analyses were conducted in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT03224507, and is complete. FINDINGS: Between Mar 21, 2018, and Oct 23, 2020, 123 participants were recruited to the study, of whom 70 (57%) were men, 53 (43%) were women, 94 (76%) were non-Hispanic White, 25 (20%) were non-Hispanic Black, and four (3%) were of another race or ethnicity. The median age of participants was 61 years (IQR 55-68), and 24 (20%) were aged 70 years or older. The median duration of follow up was 42·2 months (IQR 34·5-46·0). Of the 123 participants, 53 (43%) had no HRCAs, 46 (37%) had one HRCA, and 24 (20%) had two or more HRCAs. For 118 (96%) of 123 participants, MRD was evaluable by next-generation sequencing; the remaining five had an absence of sufficiently unique clonogenic sequences to enable tracking by the assay. Of these 118 participants, 96 (81%, 95% CI 73-88) reached MRD of less than 10-5 (comprising 39 [78%, 64-88] of 50 participants with no HRCAs, 38 [86%, 73-95] of 44 participants with one HRCA, and 19 [79%, 58-93] of 24 participants with two or more HRCAs) and 84 (71%, 62-79) reached MRD-SURE and treatment cessation. 36-month progression-free survival among all 123 participants was 88% (95% CI 78-95) for participants with no HRCAs, 79% (67-88) for those with one HRCA, and 50% (30-70) for those with two or more HRCAs. For the 84 participants reaching MRD-SURE, the 24-month cumulative incidence of progression from cessation of therapy was 9% (95% CI 1-19) for participants with no HRCAs, 9% (1-18) for those with one HRCA, and 47% (23-72) for those with two or more HRCAs. 61 participants (comprising 52% of 118 MRD-evaluable participants and 73% of 84 participants who reached MRD-SURE) remain free of therapy and MRD-negative as of Feb 7, 2023. The most common grade 3-4 adverse events were neutropenia (43 patients, 35%), lymphopenia (28 patients, 23%), and hypertension (13 patients, 11%). Three treatment-emergent deaths were recorded: two sudden deaths and one due to viral infection, none of which were judged to be treatment-related. INTERPRETATION: This approach provided positive outcomes and a pathway for treatment cessation in most patients with newly diagnosed multiple myeloma. Outcomes for patients with ultra-high-risk multiple myeloma, defined as those with two or more HRCAs, remain unsatisfactory, and these patients should be prioritised for trials with early introduction of therapies with novel mechanisms of action. FUNDING: Amgen and Janssen Pharmaceuticals.

Humoral immune reconstitution following therapy with daratumumab, carfilzomib, lenalidomide, and dexamethasone (Dara-KRd), autologous hematopoietic cell transplantation, and measurable residual disease-response-adapted treatment cessation.

Quadruplet induction, autologous hematopoietic cell transplant (AHCT), and measurable residual disease (MRD) response-adapted consolidation yield an unprecedented depth of response in newly diagnosed multiple myeloma. Patients treated on MASTER (NCT03224507) ceased therapy and entered active surveillance (MRD-SURE) after achieving MRD negativity. This study characterizes quantitative changes in the immunoglobulin (Ig) gene repertoire by next-generation sequencing and serum gamma globulin levels. Quadruplet therapy leads to profound hypogammaglobulinemia and reduction in the Ig gene repertoire. Immune reconstitution (IR) is delayed in patients who received post-AHCT consolidation compared to those who do not. Eighteen months after treatment cessation, there was no statistically significant difference between the groups.

Teclistamab in patients with multiple myeloma and impaired renal function.

Robust anti-myeloma activity with teclistamab in patients with severe renal impairment.

Recommendations on prevention of infections during chimeric antigen receptor T-cell and bispecific antibody therapy in multiple myeloma.

Chimeric antigen receptor T (CAR T) cell and bispecific antibody therapies have shown unprecedented efficacy in heavily pretreated patients with multiple myeloma (MM). However, their use is associated with a significant risk of severe infections, which can be attributed to various factors such as hypogammaglobulinemia, neutropenia, lymphopenia, T-cell exhaustion, cytokine-release syndrome and immune-effector cell-associated neurotoxicity syndrome. As these therapies have been recently approved by regulatory agencies, it is crucial to establish practical guidelines for infection monitoring and prevention until robust data from prospective clinical trials become available. To address this issue, a panel of experienced investigators from the Academic Consortium to Overcome Multiple Myeloma through Innovative Trials (COMMIT) developed consensus recommendations for mitigating infections associated with CAR T-cell and bispecific antibody therapies in MM patients.

Stem Cell Mobilization Yields with Daratumumab- and Lenalidomide-Containing Quadruplet Induction Therapy in Newly Diagnosed Multiple Myeloma: Findings from the MASTER and GRIFFIN Trials.

For eligible patients with newly diagnosed multiple myeloma (NDMM), standard of care includes induction therapy followed by autologous stem cell transplantation (ASCT). Daratumumab as monotherapy and in combination treatment is approved across multiple lines of therapy for multiple myeloma (MM), and lenalidomide is an effective and commonly used agent for induction and maintenance therapy in MM. However, there is concern that lenalidomide and daratumumab given as induction therapy might impair mobilization of stem cells for ASCT. Therefore, we assessed stem cell mobilization in patients following frontline induction therapy in the MASTER and GRIFFIN phase 2 clinical studies by examining stem cell mobilization yields, apheresis attempts, and engraftment outcomes for patients from each study. Adult transplantation-eligible patients with NDMM received induction therapy consisting of daratumumab plus carfilzomib/lenalidomide/dexamethasone (D-KRd) for four 28-day cycles in the single-arm MASTER trial or lenalidomide/bortezomib/dexamethasone (RVd) with or without daratumumab (D) for four 21-day cycles in the randomized GRIFFIN trial, followed by stem cell mobilization and ASCT in both studies. Institutional practice differed regarding plerixafor use for stem cell mobilization; the strategies were upfront (ie, planned plerixafor use) or rescue (ie, plerixafor use only after mobilization parameters indicated failure with granulocyte colony-stimulating factor [G-CSF] alone). Descriptive analyses were used to summarize patient characteristics, stem cell mobilization yields, and engraftment outcomes. In MASTER, 116 D-KRd recipients underwent stem cell mobilization and collection at a median of 24 days after completing induction therapy. In GRIFFIN, 175 patients (D-RVd, n = 95; RVd, n = 80) underwent mobilization at a median of 27 days after completing D-RVd induction therapy and 24 days after completing RVd induction therapy. Among those who underwent mobilization and collection, 7% (8 of 116) of D-KRd recipients, 2% (2 of 95) of D-RVd recipients, and 6% (5 of 80) of RVd recipients did not meet the center-specific minimally required CD34+ cell yield in the first mobilization attempt; however, nearly all collected sufficient stem cells for ASCT on remobilization. Among patients who underwent mobilization, plerixafor use, either upfront or as a rescue strategy, was higher in patients receiving D-KRd (97%; 112 of 116) and D-RVd (72%; 68 of 95) compared with those receiving RVd (55%; 44 of 80). The median total CD34+ cell collection was 6.0 × 106/kg (range, 2.2 to 13.9 × 106/kg) after D-KRd induction, 8.3 × 106/kg (range, 2.6 to 33.0 × 106/kg) after D-RVd induction, and 9.4 × 106/kg (range, 4.1 to 28.7 × 106/kg) after RVd induction; the median days for collection were 2, 2, and 1, respectively. Among patients who underwent mobilization, 98% (114 of 116) of D-KRd patients, 99% (94 of 95) of D-RVd patients, and 98% (78 of 80) of RVd patients underwent ASCT using median CD34+ cell doses of 3.2 × 106/kg, 4.2 × 106/kg, and 4.8 × 106/kg, respectively. The median time to neutrophil recovery was 12 days in all 3 treatment groups across the 2 trials. Because both trials used different criteria to define platelet recovery, data on platelet engraftment using the same criteria are not available. Four cycles of daratumumab- and lenalidomide-based quadruplet induction therapy had a minimal impact on stem cell mobilization and allowed predictable stem cell harvesting and engraftment in all patients who underwent ASCT. Upfront plerixafor strategy may be considered, but many patients were successfully collected with the use of G-CSF alone or rescue plerixafor.

Clinical implications of measurable residual disease assessment in multiple myeloma in the era of quadruplet therapy.

Multiple myeloma is a complex hematological malignancy with substantial heterogeneity in its clinical manifestations, biological processes, and patient outcomes. Although many biomarkers with have been identified to assist with disease monitoring and prognostication, predictive markers that inform treatment decisions remain elusive. As treatments become more effective, assays for measurable residual disease (MRD) below the level of detection of traditional assays have emerged as an essential component of disease assessment with powerful prognostic value for dynamic risk assessment. As its role as a potentially predictive biomarker continues to evolve, it is increasingly clear that MRD assessment has substantial clinical utility in the evaluation of patients with myeloma. In this review, we will summarize the evidence supporting the role of MRD as a prognostic biomarker and highlight the current clinical implications and future applications of MRD assessment in multiple myeloma.

Multiple myeloma with t(11;14): unique biology and evolving landscape.

Multiple myeloma is characterized by heterogeneity in clinical presentation, response to treatment, and importantly, patient outcomes. The translocation of chromosomes 11 and 14 [t(11;14)(q13;32)], hereafter referred to as t(11;14), is the most common primary translocation event in multiple myeloma, occurring in approximately 16%-24% of patients. Multiple myeloma harboring t(11;14) represents a unique disease subset as t(11;14)-positive myeloma cells exhibit biological features that are distinct from t(11;14)-negative myeloma cells, including overexpression of cyclin D1, higher levels of the antiapoptotic protein BCL-2, and the frequent expression of the B-cell lineage protein CD20. Additionally, t(11;14) is associated with less common clinical features, such as immunoglobulin M and light chain disease. With the evolution of the treatment landscape, the prognostic significance of t(11;14) multiple myeloma remains debatable. However, it is clear that t(11;14) multiple myeloma represents a distinct subset and a rare opportunity for targeted therapy with BCL-2 inhibition. In this review, we first describe the underlying biology of t(11;14) multiple myeloma cells, then summarize the body of literature evaluating the prognosis of patients with t(11;14) multiple myeloma, and finally discuss therapeutic implications.

Patterns of Utilization and Outcomes of Autologous Stem Cell Transplantation and Chimeric Antigen Receptor T-Cell Therapy in Relapsed or Refractory Diffuse Large B-cell Lymphomas with MYC and BCL2 and/or BCL6 Rearrangements.

BACKGROUND: Patients with Diffuse Large Bcell Lymphoma (DLBCL) with MYC and BCL2 and/or BCL6 gene rearrangements [double-hit lymphoma/triple-hit lymphoma (DHL/THL)] have poor prognosis in the relapsed/refractory setting. METHODS: We utilized a real-world deidentified database of DLBCL patients and report patterns of therapy utilization in relapsed/refractory DLBCL. We used log-rank test to compare real-world overall survival (rwOS) among DHL and non-DHL subgroups for CAR Tcell therapy or ASCT respectively, stratified for prior lines of therapy. RESULTS: Of all 7,877 patients with DLBCL, 367 patients had DHL while 6113 had non-DHL. Second line chemotherapy was administered to 147 DHL patients and 1517 non-DHL. 1393 were excluded, including 934 with unknown DHL/THL status. Approximately 47% received salvage intent chemotherapy in the DHL subgroup, of which 19% patients eventually received ASCT, while 34% received salvage intent chemotherapy in the non-DHL/THL group with 32% receiving ASCT. DHL/THL status negatively influenced median rwOS for patients who underwent ASCT in the second-line while it was associated with numerically inferior but without statistically significant rwOS among patients that underwent CAR Tcell therapy on multivariable analysis. CONCLUSION: rwOS of relapsed DHL/THL is inferior to non-DHL/THL. Fewer patients with DHL/THL were able to proceed with ASCT after salvage chemotherapy compared to non-DHL/THL. ASCT as second-line therapy for relapsed DHL/THL had worse rwOS than for non-DHL/THL, consistent with the natural history of DHL/THL. This difference was not seen for CAR Tcell therapy, which combined with promising results from clinical trials, suggests a greater role for CAR T-cell therapy in relapsed/refractory DHL.

Impact of autologous hematopoietic cell transplantation on disease burden quantified by next-generation sequencing in multiple myeloma treated with quadruplet therapy.

The incremental impact of autologous hematopoietic cell transplantation (AHCT) on disease burden with quadruplet induction in newly diagnosed multiple myeloma (NDDM) can be reappraised with the serial assessment of minimal residual disease (MRD). We describe the impact of AHCT on MM burden assessed by next-generation sequencing (NGS) for patients enrolled in a clinical trial utilizing quadruplet induction, AHCT, followed by MRD-adapted consolidation. We describe quantitative changes in MRD burden with AHCT and explore patient and disease features influencing the magnitude of MRD reduction with AHCT. Among 123 included patients, 109 underwent AHCT and had MRD assessment pre and post AHCT. Forty percent achieved MRD < 10-5 post-induction, increasing to 70% after AHCT. Of the 65 patients (60%) who remained MRD positive post-induction, 54 (83%) had a reduction in MRD burden with AHCT. The median reduction in MRD with AHCT was 1.10 log10 (range, -1.26 to 3.41). Patients with high-risk cytogenetic abnormalities (HRCA) had greater reduction in MRD burden (p = .02) after AHCT. Median relative reduction was 0.91 log10 (range, -0.75 to 2.14), 1.26 log10 (range, -0.21 to 3.26) and 1.34 log10 (range, -1.28 to 3.41) for patients with 0, 1 and 2+ HRCA, respectively. The presence of HRCA was the only factor associated with greater than 1 log10 reduction in MRD burden with AHCT. Serial NGS MRD demonstrates the incremental effect of AHCT in MM marrow burden in the context of quadruplet induction, particularly in high-risk MM.

Revisiting the impact of immunoglobulin isotypes in multiple myeloma.

Association of immunoglobulin isotypes with survival in the context of modern prognostic factors has not been determined. We utilized the Flatiron Health Electronic Health Record database and identified 8468 MM patients. Compared to IgG MM, patients with IgA MM were more likely to have ISS-III, anemia, and t(4;14), and light chain (LC) MM had higher renal dysfunction and t(11;14). IgA and LC MM patients have an inferior OS. The adverse prognostic impact of IgA and LC isotypes on OS persisted even after adjustment for variables impacting outcomes and likely suggests their unique biology beyond the presence of adverse prognostic factors.

Outcomes of Allogeneic Hematopoietic Cell Transplantation in T Cell Prolymphocytic Leukemia: A Contemporary Analysis from the Center for International Blood and Marrow Transplant Research.

T cell prolymphocytic leukemia (T-PLL) is a rare, aggressive malignancy with limited treatment options and poor long-term survival. Previous studies of allogeneic hematopoietic cell transplantation (alloHCT) for T-PLL are limited by small numbers, and descriptions of patient and transplantation characteristics and outcomes after alloHCT are sparse. In this study, we evaluated outcomes of alloHCT in patients with T-PLL and attempted to identify predictors of post-transplantation relapse and survival. We conducted an analysis of data using the Center for International Blood and Marrow Transplant Research database on 266 patients with T-PLL who underwent alloHCT between 2008 and 2018. The 4-year rates of overall survival (OS), disease-free survival (DFS), relapse, and treatment-related mortality (TRM) were 30.0% (95% confidence interval [CI], 23.8% to 36.5%), 25.7% (95% CI, 20% to 32%), 41.9% (95% CI, 35.5% to 48.4%), and 32.4% (95% CI, 26.4% to 38.6%), respectively. In multivariable analyses, 3 variables were associated with inferior OS: receipt of a myeloablative conditioning (MAC) regimen (hazard ratio [HR], 2.18; P < .0001), age >60 years (HR, 1.61; P = .0053), and suboptimal performance status, defined by Karnofsky Performance Status (KPS) <90 (HR, 1.53; P = .0073). Receipt of an MAC regimen also was associated with increased TRM (HR, 3.31; P < .0001), an elevated cumulative incidence of grade II-IV acute graft-versus-host disease (HR, 2.94; P = .0011), and inferior DFS (HR, 1.86; P = .0004). Conditioning intensity was not associated with relapse; however, stable disease/progression was correlated with increased risk of relapse (HR, 2.13; P = .0072). Both in vivo T cell depletion (TCD) as part of conditioning and KPS <90 were associated with worse TRM and inferior DFS. Receipt of total body irradiation had no significant effect on OS, DFS, or TRM. Our data show that reduced-intensity conditioning without in vivo TCD (ie, without antithymocyte globulin or alemtuzumab) before alloHCT was associated with long-term DFS in patients with T-PLL who were age ≤60 years or who had a KPS >90 or chemosensitive disease.