The Role of Salvage Second Autologous Hematopoietic Cell Transplantation in Relapsed Multiple Myeloma

Multiple myeloma (MM), a malignant disorder of plasma cells affecting primarily elderly patients, is the second most commonly diagnosed hematologic neoplasm. With the recent influx of effective new agents available, including proteasome inhibitors, immunomodulators, targeted monoclonal antibodies, and now chimeric antigen receptor T cell (CAR-T) therapy, the treatment landscape is evolving rapidly. Although the role of consolidative autologous stem cell transplantation (ASCT) in first remission is well established, in the relapsed setting after upfront ASCT, the role of a second ASCT (SAT) following reinduction is less clear and understudied. Practice patterns vary significantly across institutions, and most of the literature available to guide clinical decisions consists of single-institution experiences, with only 1 randomized study evaluating the role of SAT compared with a nontransplantation approach. SAT is likely underused, because it has not been included in clinical trials examining novel regimens for relapsed disease. Furthermore, outcomes likely can be improved with approaches to intensify the preparative regimen and the use of standard post-transplantation maintenance. In this review, we examine the role of SAT in the current MM treatment landscape in the context of recent data on the efficacy of CAR-T therapy in this disease. We caution the abandonment of SAT, given that CAR-T therapy is in its infancy in MM treatment, and that real-world data in the relapsed setting are consistently inferior to clinical trial outcomes.     

Lenalidomide Maintenance for High-Risk Multiple Myeloma after Allogeneic Hematopoietic Cell Transplantation

Allogeneic hematopoietic cell transplantation (alloHCT) with reduced-intensity conditioning is an appealing option for patients with high-risk multiple myeloma (MM). However, progression after alloHCT remains a challenge. Maintenance therapy after alloHCT may offer additional disease control and allow time for a graft-versus-myeloma effect. The primary objective of this clinical trial was to determine the tolerability and safety profile of maintenance lenalidomide (LEN) given on days 1 to 21 of 28 days cycles, with intrapatient dose escalation during 12 months/cycles after alloHCT. Thirty alloHCT recipients (median age, 54 years) with high-risk MM were enrolled at 8 centers between 2009 and 2012. The median time from alloHCT to LEN initiation was 96 days (range, 66 to 171 days). Eleven patients (37%) completed maintenance and 10 mg daily was the most commonly delivered dose (44%). Most common reasons for discontinuation were acute graft-versus-host disease (GVHD) (37%) and disease progression (37%). Cumulative incidence of grades III to IV acute GVHD from time of initiation of LEN was 17%. Outcomes at 18 months after initiation of maintenance were MM progression, 28%; transplantation-related mortality, 11%; and progression-free and overall survival, 63% and 78%, respectively. The use of LEN after alloHCT is feasible at lower doses, although it is associated with a 38% incidence of acute GVHD. Survival outcomes observed in this high-risk MM population warrant further study of this approach.     

A Randomized Phase II Trial of Fludarabine/Melphalan 100 versus Fludarabine/Melphalan 140 Followed by Allogeneic Hematopoietic Stem Cell Transplantation for Patients with Multiple Myeloma

Allogeneic hematopoietic stem cell transplantation (allo-HCT) is a potentially curative treatment for multiple myeloma (MM); however, because of high treatment-related mortality (TRM), its role is not well defined. Patients with newly diagnosed, relapsed, or primary refractory myeloma were enrolled in a randomized phase II trial of 2 reduced-intensity conditioning regimens: fludarabine 120 mg/m² + melphalan 100 mg/m² (FM100) versus fludarabine 120 mg/m² + melphalan 140 mg/m² (FM140) before allo-HCT from related or unrelated donors. Fifty patients underwent allo-HCT using FM100 (n = 23) or FM140 (n = 27) conditioning between April 2002 and 2011. There were no significant differences between FM100 and FM140 in time to neutrophil engraftment (P = .21), acute grade II to IV graft-versus-host disease (GVHD) (P = 1.0), chronic GVHD (P = .24), response rate (P = 1.0), TRM (13% versus 15%, P = 1.0), median progression-free survival (PFS), 11.7 versus 8.4 months, P = .12, and median overall survival (OS), 35.1 versus 19.7 months, P = .38. Cumulative incidence of disease progression in FM100 and FM140 was 43% and 70%, respectively (P = .08). Recurrent disease was the most common cause of death for both FM100 (26%) and FM140 (44%), P = .24. On multivariate analysis, disease status at allo-HCT, complete response or very good partial response (VGPR) was significantly associated with longer PFS (15.6 versus 9.6 months in patients with <VGPR, P = .05). OS was similar across all variables. We conclude that FM100 and FM140 may result in similar patient outcomes after allo-HCT for MM.     

Hematopoietic Cell Transplant Comorbidity Index Is Predictive of Survival after Autologous Hematopoietic Cell Transplantation in Multiple Myeloma

Autologous hematopoietic stem cell transplantation (AHCT) improves survival in patients with multiple myeloma (MM) but is associated with morbidity and nonrelapse mortality (NRM). Hematopoietic cell transplant comorbidity index (HCT-CI) was shown to predict risk of NRM and survival after allogeneic transplantation. We tested the utility of HCT-CI as a predictor of NRM and survival in patients with MM undergoing AHCT. We analyzed outcomes of 1156 patients of AHCT after high-dose melphalan reported to the Center for International Blood and Marrow Transplant Research. Individual comorbidities were prospectively collected at the time of AHCT. The impact of HCT-CI and other potential prognostic factors, including Karnofsky performance score (KPS), on NRM and survival were studied in multivariate Cox regression models. HCT-CI score was 0, 1, 2, 3, and >3 in 42%, 18%, 13%, 13%, and 14% of the study cohort, respectively. Subjects were stratified into 3 risk groups: HCT-CI score of 0 (42%) versus HCT-CI score of 1 to 2 (32%) versus HCT-CI score > 2 (26%). Higher HCT-CI was associated with lower KPS < 90 (33% of subjects score of 0 versus 50% in HCT-CI score > 2). HCT-CI score > 2 was associated with melphalan dose reduction (22% versus 10% in score 0 cohort). One-year NRM was low at 2% (95% confidence interval, 1% to 4%) and did not correlate with HCT-CI score (P = .9). On multivariate analysis, overall survival was inferior in groups with HCT-CI score of 1 to 2 (relative risk, 1.37, [95% confidence interval, 1.01 to 1.87], P = .04) and HCT-CI score > 2 (relative risk, 1.5 [95% confidence interval, 1.09 to 2.08], P = .01). Overall survival was also inferior with KPS < 90 (P < .001), IgA subtype (P ≤ .001), those receiving >1 pretransplant induction regimen (P = .007), and those with resistant disease at the time of AHCT (P < .001). AHCT for MM is associated with low NRM, and death is predominantly related to disease progression. Although a higher HCT-CI score did not predict NRM, it was associated with inferior survival.     

Autologous Is Superior to Allogeneic Hematopoietic Cell Transplantation for Acute Promyelocytic Leukemia in Second Complete Remission

To identify favored choice of transplantation in patients with acute promyelocytic leukemia (APL) in second complete remission, we studied 294 patients with APL in second complete remission (CR2) receiving allogeneic (n = 232) or autologous (n = 62) hematopoietic cell transplantation (HCT) reported to the Center for International Blood and Marrow Transplantation Research (CIBMTR) from 1995 to 2006, including 155 with pre-HCT PML/RAR∝ status (49% of allogeneic and 66% of autologous). Patient characteristics and transplantation characteristics, including treatment-related mortality, overall survival (OS), and disease-free survival, were collected and analyzed for both univariate and multivariate outcomes. With median follow-up of 115 (allogeneic) and 72 months (autologous), 5-year disease-free survival (DFS) favored autologous with 63% (49% to 75%), compared with allogeneic at 50% (44% to 57%) (P = .10). OS was 75% (63% to 85%) versus 54% (48% to 61%) (P = .002), for autologous and allogeneic transplantation, respectively. Multivariate analysis showed significantly worse DFS after allogeneic HCT (hazard ratio [HR], 1.88; 95% confidence interval [CI], 1.16 to 3.06; P = .011) and age > 40 years (HR, 2.30; 95% CI, 1.44 to 3.67; P = .0005). OS was significantly worse after allogeneic HCT (HR, 2.66; 95% CI, 1.52 to 4.65; P = .0006); age > 40 (HR, 3.29; 95% CI, 1.95 to 5.54; P < .001), and first complete remission < 12 months (HR, 1.56; 95% CI, 1.07 to 2.26; P = .021). Positive pre-HCT PML-RAR∝ status in 17 of 114 allogeneic and 6 of 41 receiving autologous transplantation did not influence relapse, treatment failure, or survival in either group. The survival advantage for autografting was attributable to increased treatment-related mortality (TRM) in the allogeneic group of 30% compared to 2% in the autologous group, in addition to the added mortality associated with GVHD. We conclude that autologous HCT yields superior OS for APL in CR2. Long-term DFS in autologous recipients, even with minimal residual disease–positive grafts, remains an important subject for further study.     

Long-Term Follow-Up of a Donor versus No-Donor Comparison in Patients with Multiple Myeloma in First Relapse after Failing Autologous Transplantation

We report the long-term clinical outcomes of a retrospective multicenter study that enrolled 169 patients with multiple myeloma (MM) in first relapse after failing autologous stem cell transplantation (SCT). After HLA typing at relapse, 79 patients with a suitable donor, 72 (91%) of whom eventually underwent salvage allogeneic SCT (allo-SCT), were compared with 90 patients without a donor who were treated with multiple lines of salvage treatment with bortezomib and/or immunomodulatory agents. At a median follow-up of 30 months (range, 2-180 months) for all patients and 110 months (range, 38-180 months) for surviving patients, 7-year progression-free survival (PFS) was 18% in the donor group and 0% in the no-donor group (hazard ratio [HR], 2.495; 95% confidence interval [CI], 1.770-3.517; P?<?.0001). Seven-year overall survival (OS) was 31% in the donor group and 9% in the no-donor group (HR, 1.835; 95% CI, 1.306-2.577; P?<?.0001). By multivariate analysis, chemosensitivity to salvage treatments and presence of a suitable donor were significantly associated with better PFS and OS. The long-term follow-up of this study confirms the significant PFS benefit and provides new evidence of an OS advantage for patients with MM who have a suitable donor and undergo allo-SCT. Allo-SCT should be considered as a treatment option in young relapsed patients with high-risk disease features after first-line treatment.     

Outcome of a Salvage Third Autologous Stem Cell Transplantation in Multiple Myeloma

To evaluate the outcomes of salvage third autologous stem cell transplantation (ASCT) in patients with relapsed multiple myeloma. We analyzed 570 patients who had undergone a third ASCT between 1997 and 2010 (European Society for Blood and Marrow Transplantation data), of whom 482 patients underwent tandem ASCT and a third ASCT at first relapse (AARA group) and 88 patients underwent an upfront ASCT with second and third transplantations after subsequent relapses (ARARA group). With a median follow-up after salvage third ASCT of 61 months in the AARA group and 48 months in the ARARA group, the day +100 nonrelapse mortality in the 2 groups was 4% and 7%, the incidence of second primary malignancy was 6% and 7%, the median progression-free survival was 13 and 8 months, and median overall survival (OS) was 33 and 15 months. In the AARA group, according to the relapse-free interval (RFI) from the second ASCT, the median OS after the third ASCT was 17 months if the RFI was <18 months, 37 months if the RFI was between 18 and 36 months, and 64 months if the RFI was ≥36 months (P?<?.001). In the ARARA group, the median OS after the third ASCT was 7 months if the RFI was <6 months, 13 months if the RFI was between 6 and 18 months, and 27 months if the RFI was ≥18 months (P?<?.001). In a multivariate analysis of the AARA group, the favorable prognostic factor was an RFI after second ASCT of ≥18 months. Progressive disease and a Karnofsky Performance Status score of <70 at third ASCT were unfavorable factors. A salvage third ASCT is of value for patients with relapsed myeloma, particularly for those with a long duration of response and chemosensitive disease at the time of transplantation.     

Improved Survival with Ursodeoxycholic Acid Prophylaxis in Allogeneic Stem Cell Transplantation: Long-Term Follow-Up of a Randomized Study

We report the long-term results of a prospective randomized study on the use of ursodeoxycholic acid (UDCA) for prevention of hepatic complications after allogeneic stem cell transplantation. Two hundred forty-two patients, 232 with malignant disease, were randomized to receive (n = 123) or not to receive (n = 119) UDCA from the beginning of the conditioning until 90 days post-transplantation. The results were reported after 1-year follow-up. UDCA administration reduced significantly the proportion of patients developing high serum bilirubin levels as well as the incidence of severe acute graft-versus-host disease (GVHD), liver GVHD, and intestinal GVHD. In the UDCA prophylaxis group, nonrelapse mortality (NRM) was lower and overall survival better than in the control group. After a 10-year follow-up, the difference in the survival and NRM in favor of the UDCA-treated group, seen at 1 year, was maintained (survival 48% versus 38%, P = .037; NRM 28% versus 41%, P = .01). A landmark analysis in patients surviving at 1 year post-transplantation showed no significant differences between the study groups in the long-term follow-up in chronic GVHD, relapse rate, NRM, disease-free survival, or overall survival. These long-term results continue to support the useful role of UDCA in the prevention of transplant-related complications in allogeneic transplantation.     

Outcome and Prognostic Factors for Patients Who Relapse after Allogeneic Hematopoietic Stem Cell Transplantation

Disease relapse remains a major obstacle to the success of allogeneic hematopoietic stem cell transplantation (HSCT), yet little is known about the relevant prognostic factors after relapse. We studied 1080 patients transplanted between 2004 and 2008, among whom 351 relapsed. The 3-year postrelapse overall survival (prOS) rate was 19%. Risk factors for mortality after relapse included shorter time to relapse, higher disease risk index at HSCT, myeloablative conditioning, high pretransplantation comorbidity index, and graft-versus-host disease (GVHD) occurring before relapse. Important prognostic factors did not vary by disease type. Based on this, we could stratify patients into 3 groups, with 3-year prOS rates of 36%, 14%, and 3% (P < .0001). This score was validated in an historical cohort of 276 patients. Postrelapse donor lymphocyte infusion or repeat HSCT was associated with improved prOS, as was the development of GVHD after relapse. These differences remained significant in models that accounted for other prognostic factors and in landmark analyses of patients who survived at least 2 months from relapse. The results of this study may aid with prognostication and management of patients who relapse after HSCT and motivate the design of clinical trials aimed at relapse prevention or treatment in higher-risk patients.     

Long-Term Results of Prophylactic Donor Lymphocyte Infusions for Patients with Multiple Myeloma after Allogeneic Stem Cell Transplantation

The major reason for treatment failure after allografting in multiple myeloma (MM) is relapse. Donor lymphocyte infusions (DLIs) are considered a valuable post-transplant strategy mainly for relapsed patients but using them to prevent relapse in MM has been reported rarely. In the present study, we examined the efficacy of prophylactic DLIs after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in myeloma patients with a long-term follow-up of more than 5 years. A total of 61 patients with MM who did not relapse or develop disease progression after allo-HSCT were treated with prophylactic DLI in an escalating fashion (overall 132 DLI procedures) to deepen remission status and prevent relapse. Overall response rate to DLI was 77%. Thirty-three patients (54%) upgraded their remission status, 41 patients (67%) achieved or maintained complete remission, and 26% achieved a molecular remission. Incidence of acute graft-versus-host disease (GVHD) grade II to IV was 33% and no DLI-related mortality was noted. After a median follow-up of 68.7 months from first DLI the estimated 8-year progression-free survival (PFS), and overall survival (OS) in a landmark analysis was 43% (95% confidence interval [CI], 28% to 57%) and 67% (95% CI, 53% to 82%), respectively, with best outcome for patients who acquired molecular remission (8-year PFS was 62% and 8-year OS was 83%). Prophylactic escalating DLI in a selected cohort of MM patients to prevent relapse after allograft resulted in a low incidence of severe GVHD and encouraging long-term results, especially if molecular remission is achieved.     

Outcomes in Patients Age 70 or Older Undergoing Allogeneic Hematopoietic Stem Cell Transplantation for Hematologic Malignancies

Allogeneic hematopoietic stem cell transplantation (HSCT) can achieve durable remissions in a number of patients with advanced hematologic malignancies. Little is known about the safety of HSCT in patients age 70 or older. Consecutive patients (n = 54) age 70 or older underwent HSCT between 2007 and 2012. Diseases included acute myelogenous leukemia (n = 25), myelodysplastic syndrome (n = 12), chronic lymphocytic leukemia (n = 5), non-Hodgkin lymphoma (n = 4), acute lymphoblastic leukemia (n = 3), myeloproliferative neoplasm (n = 4), and chronic myelogenous leukemia (n = 1). Median follow-up for survivors was 21 months. All patients received reduced-intensity conditioning regimens, primarily busulfan/fludarabine. All patients received unmanipulated peripheral blood stem cell grafts: 44 from 8/8 matched unrelated donors, 8 from matched related donors, and 2 from 7/8 matched unrelated donors. Graft-versus-host disease (GVHD) prophylaxis was calcineurin inhibitor–based in all patients. The median age at transplantation was 71 years (range, 70 to 76); the median HCT comorbidity index score was 1 (range, 0 to 5). Two patients died before hematopoietic recovery (1 with graft failure and 1 with disease progression), and 1 patient relapsed before hematopoietic recovery; otherwise, all engrafted with median donor chimerism of 94% at 1 month. Cumulative incidence of grades II to IV acute GVHD was 13% and of grades III to IV acute GVHD, 9.3%. At 2 years, the cumulative incidence of chronic GVHD was 36%, progression-free survival was 39%, overall survival was 39%, and relapse was 56%. Nonrelapse mortality was 3.7% at day +100 and 5.6% at 2 years. We conclude that allogeneic HSCT is a safe and effective option for carefully selected patients age 70 or older.     

Outcomes of Lung Transplantation after Allogeneic Hematopoietic Stem Cell Transplantation

Other than lung transplantation (LT), no specific therapies exist for end-stage lung disease resulting from hematopoietic stem cell transplantation (HCT)-related complications, such as bronchiolitis obliterans syndrome (BOS). We report the indications and outcomes in patients who underwent LT after HCT for hematologic disease from a retrospective case series at our institution and a review of the medical literature. We identified a total of 70 cases of LT after HCT, including 9 allogeneic HCT recipients from our institution who underwent LT between 1990 and 2010. In our cohort, the median age was 16 years (range, 10 to 35 years) at the time of HCT and 34 years (range, 17 to 44 years) at the time of LT, with a median interval between HCT and LT of 10 years (range, 2.9 to 27 years). Indications for LT-included pulmonary fibrosis (n = 4), BOS (n = 3), interstitial pneumonitis related to graft-versus-host disease (GVHD) (n = 1), and primary pulmonary hypertension (n = 1). Median survival was 49 months (range, 2 weeks to 87 months), and 1 patient remains alive at more than 3 years after LT. Survival at 1 year and 5 years after LT was 89% and 37%, respectively. In the medical literature between 1992 and July 2013, we identified 20 articles describing 61 cases of LT after HCT from various centers in the United States, Europe, and Asia. Twenty-six of the 61 cases (43%) involved patients age <18 years at the time of LT. BOS and GVHD of the lung were cited as the indication for LT in the majority of cases (80%; n = 49), followed by pulmonary fibrosis and interstitial lung disease (20%; n = 12). In publications reporting 3 or more cases with a follow-up interval ranging from the immediate postoperative period to 16 years, the survival rate was 71% (39 of 55). Most deaths were attributed to long-term complications of the lung allograft, including infections and BOS. Two deaths were related to recurrent or relapsed hematologic malignancy. LT can prolong survival in some patients who suffer from end-stage pulmonary complications after HCT. Patient factors that likely improve the chances of a good long-term outcome include young age, at least 2 years post-HCT free of relapse from the original hematologic malignancy, and lack of other end-organ dysfunction or manifestations of chronic GVHD that require treatment with immunosuppressive agents.     

Allogeneic Stem Cell Transplantation for Patients with Natural Killer/T Cell Lymphoid Malignancy: A Multicenter Analysis Comparing Upfront and Salvage Transplantation

Natural killer (NK)/T cell lymphoid malignancy comprises extranodal NK/T cell lymphoma (ENKTL) and aggressive NK cell leukemia (ANKL), and the outcomes for advanced or relapsed/refractory ENKTL and ANKL remain poor. Allogeneic stem cell transplantation (SCT) can be used as a frontline consolidation treatment to prevent the relapse of advanced disease or as salvage treatment after chemotherapy for relapsed sensitive disease.We retrospectively analyzed 36 patients (ENKTL, n?=?26; ANKL, n?=?10) who underwent upfront (n?=?19) and salvage allogeneic SCT (n?=?17) at 6 hospitals. Patients received myeloablative (n?=?25) or reduced-intensity (n =11) conditioning regimens depending on the institute's policy.The median age at the time of allogeneic SCT was 37 years (range, 17 to 62), and more patients with ANKL (8/10) received upfront allogeneic SCT than ENKTL patients (11/26). Disease status before allogeneic SCT, conditioning regimen, and donor source did not differ between upfront and salvage allogeneic SCT groups. Febrile neutropenia (n?=?20) and acute graft-versus-host disease (n?=?16) were common adverse events. The median overall survival (OS) and progression-free survival (PFS) after allogeneic SCT were 11.8 months and 10.0 months, respectively. Twelve patients died from disease relapse and 12 from nondisease-related causes. Ten deaths occurred within 100 days after allogeneic SCT (10/24); these were mostly related to disease relapse (n?=?8). The OS after allogeneic SCT did not differ between ENKTL and ANKL (P?=?.550) or between upfront and salvage SCT (P?=?.862). Complete chimerism was significantly associated with better PFS (P < .001). No significant differences in PFS were observed based on the conditioning regimen or source of stem cells (P > .05).Allogeneic SCT may be beneficial for patients with ENKTL and ANKL given that some patients were able to maintain their remission after allogeneic SCT. However, allogeneic SCT should only be performed in highly selected patients because the risks of disease relapse and nondisease-related mortality remain high.     

Comparison of Outcomes of Allogeneic Hematopoietic Cell Transplantation for Multiple Myeloma Using Three Different Conditioning Regimens

Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative therapy for patients with multiple myeloma, as it provides a graft-versus-myeloma effect alongside a myeloma-free graft. Although reduced-intensity conditioning regimens decrease nonrelapse mortality (NRM), there is a paucity of data with regard to the ideal conditioning regimen in myeloma. We conducted a retrospective comparison of 3 different preparative regimens used for allo-HCT for multiple myeloma at our institution in recent clinical trials: busulfan/fludarabine (BuFlu), fludarabine/melphalan 100 mg/m² (FM100), and fludarabine/melphalan 140 mg/m² (FM140). NRM, progression-free survival (PFS) at 3 years, and overall survival (OS) at 3 years were the primary endpoints. Secondary endpoints included time to engraftment, and the incidence of grades II through IV acute graft-versus-host disease and chronic graft-versus-host disease. A total of 73 patients received allo-HCT with these regimens. NRM at 3 years was seen in 3 (21%), 5 (28%), and 6 (24%) patients in the BuFlu, FM100, and FM140 groups, respectively. Three-year PFS in the BuFlu, FM100, and FM140 groups was 16% (hazard ratio [HR], 1.2; 95% confidence interval [CI], 0.6 to 2.1), 26% (HR, 0.6; 95% CI, 0.3 to 1.2), and 11% (reference), respectively. Three-year OS in the BuFlu, FM100, and FM140 groups was 39% (HR, 1.1; 95% CI, 0.5 to 2.2), 43% (HR, 0.7; 95% CI, 0.3 to 1.4), and 32% (reference), respectively. High-risk cytogenetics and relapsed disease prior to allo-HCT were found to be independent predictors of inferior OS on multivariate analysis, with a HR of 2.1 (P = .02) and 2.6 (P = .004), respectively. In contrast, the preparative regimen did not emerge as a predictor of PFS or OS. Durable clinical remission can be achieved in 11% to 25% of patients with multiple myeloma with the use of allo-HCT without any significant difference in the safety or efficacy of the conditioning regimen. High-risk cytogenetics and relapsed disease prior to transplant were associated with inferior PFS and OS.     

Long-Term Outcome of Fludarabine-Based Reduced-Intensity Allogeneic Hematopoietic Cell Transplantation for Debilitating Paroxysmal Nocturnal Hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by intravascular hemolysis, venous thrombosis, and bone marrow failure. Seventeen patients with debilitating PNH, including 8 who were HLA-alloimmunized, underwent a reduced-intensity allogeneic hematopoietic cell transplantation (HCT). All received cyclophosphamide/fludarabine +/− antithymocyte globulin followed by a granulocyte colony-stimulating factor–mobilized HCT from an HLA-matched relative. Glycosylphosphatidylinositol-negative neutrophils were detectable after engraftment but disappeared completely at a median 100 days after transplantation. With a median follow-up of nearly 6 years, 15 patients (87.8%) survived, all without any evidence of PNH, transfusion independent, and off anticoagulation. Allogeneic reduced-intensity HCT remains a curative therapeutic option for PNH patients who are not candidates for eculizumab treatment.     

Biology-Driven Approaches to Prevent and Treat Relapse of Myeloid Neoplasia after Allogeneic Hematopoietic Stem Cell Transplantation

The curative potential of allogeneic hematopoietic cell transplantation (allo-HCT) in the treatment of acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS) relies mainly on the graft-versus-leukemia effect. Relapse after allo-HCT occurs in a considerable proportion of patients and has a dismal prognosis, with still very limited curative potential. This review provides an overview of the established and evolving approaches to preventing or treating relapse of AML and MDS after allo-HCT, in the context of novel insight into the biology of relapse. Established prophylactic measures to prevent relapse include optimized conditioning and graft-versus-host disease (GVHD) prophylaxis, as well as donor lymphocyte infusion (DLI) for high-risk patients; novel immunomodulatory interventions and maintenance approaches are still experimental. Improved diagnostics can detect persistent or recurring disease at a molecular level, enabling early preemptive interventions. Established options include hypomethylating agents and DLI. Standard treatments for hematologic relapse include chemotherapy, cessation of immunosuppressive treatment, and DLI. Experimental approaches include molecular targeted therapies, novel immunomodulatory treatments, and second allo-HCT. For all interventions, the potential risks, including occurrence of GVHD, must be weighed against the benefits individually in each patient. Concurrently, prevention and treatment of relapse after allo-HCT remain challenging and unmet medical needs.     

Survival of Lymphoma Patients Experiencing Relapse or Progression after an Allogeneic Hematopoietic Cell Transplantation

Outcome and management of patients who relapse after allogeneic hematopoietic cell transplantation (allo-HCT) has evolved in the recent decade. Using a multi-institutional retrospective database we report the predictive factors and survival of lymphoma patients who relapse after allo-HCT. We evaluated 495 allo-HCT recipients transplanted between 2000 and 2015 at 3 academic US medical centers. Landmark analysis evaluating predictive factors was performed at 1 month after allo-HCT relapse with a primary endpoint of postrelapse overall survival (PR-OS). A total of 175 lymphoma patients (35%) experienced relapse after allo-HCT. Of these, 126 patients, median age 46 years (range, 19 to 71), were assessable. Most patients (86%) received subsequent therapy; 80 patients received targeted agents and 19 donor lymphocyte infusion. On univariate analysis median PR-OS for patients with Hodgkin lymphoma was 47.9 months compared with 11.3 months in patients with indolent and 10.1 months in aggressive non-Hodgkin lymphoma (P?=?.04). On multivariate analysis postrelapse therapy administration (no therapy versus targeted therapy: hazard ratio, .21 [95% confidence interval, .10 to .45]; no therapy versus nontargeted therapy: hazard ratio, .26 [95% confidence interval, .11 to .57]), late relapse 130 days after allo-HCT (relative to early relapse: hazard ratio, .25; P?<?.001), and Eastern Cooperative Oncology Group performance status of 0 to 1 (versus Eastern Cooperative Oncology Group performance status ≥?2: hazard ratio, .49; P?=?.003) were associated with a significantly reduced risk of mortality. Patients relapsing ≥ 130 days from the time of allo-HCT yielded PR-OS of 48.8 months compared with 6.5 months in patients with early relapse (P?<?.001). Our data suggest that in the modern era, therapies used for patients experiencing lymphoma relapse after allo-HCT can extend survival.     

Mononuclear Cell Telomere Attrition Is Associated with Overall Survival after Nonmyeloablative Allogeneic Hematopoietic Cell Transplantation for Hematologic Malignancies

After allogeneic hematopoietic cell transplantation (allo-HCT), transplanted cells rapidly undergo multiple rounds of division. This may cause extensive telomere attrition, which could potentially prohibit further cell division and lead to increased mortality. We therefore characterized the development in telomere length after nonmyeloablative allo-HCT in 240 consecutive patients transplanted because of hematologic malignancies and tested the hypothesis that extensive telomere attrition post-transplant is associated with low overall survival. Telomere length was measured using quantitative PCR in mononuclear cells obtained from donors and recipients pretransplant and in follow-up samples from recipients post-transplant. Telomere attrition at 9 to 15 months post-transplant was calculated as the difference between recipient telomere length at 9 to 15 months post-transplant and donor pretransplant telomere length, divided by donor pretransplant telomere length. Although allo-HCT led to shorter mean telomere length in recipients when compared with donors, recipients had longer mean telomere length 9 to 15 months post-transplant than they had pretransplant. When compared with donor telomeres, recipients with extensive telomere attrition at 9 to 15 months post-transplant had low overall survival (10-year survival from 9 to 15 months post-transplant and onward: 68% in the tertile with least telomere attrition, 57% in the middle tertile, and 39% in the tertile with most attrition; log-rank P?=?.01). Similarly, after adjusting for potential confounders, recipients with extensive telomere attrition had high all-cause mortality (multivariable adjusted hazard ratio, 1.84 per standard deviation of telomere attrition at 9 to 15 months post-transplant; 95% confidence interval, 1.25 to 2.72; P?=?.002) and high relapse-related mortality (subhazard ratio, 2.07; 95% confidence interval, 1.14 to 3.76; P?=?.02). Taken together, telomere attrition may be a clinically relevant marker for identifying patients at high risk of mortality.