Current Status and Perspectives of Irradiation-Based Conditioning Regimens for Patients with Acute Leukemia Undergoing Hematopoietic Stem Cell Transplantation

Women's Sexual Dysfunctions Following Stem Cell Transplant and the Impact on Couple Relationship

Stem cell transplant proved its efficacy in increasing the survival rate among young patients diagnosed with hematological malignancies. A transplant conditioning regimen is particularly destructive on the genital system, often determining premature ovarian failure, accompanied by vulvovaginal atrophy and sexual dysfunctions. The aims of the present study were, first, to evaluate sexual dysfunctions among transplanted women, using clinical examination and the female sexual function index (FSFI), and second, to determine their impact on a couple's relationship. A prospective observational comparative study was performed and included 38 patients who underwent allogenic stem cell transplant (SCT) procedures for different hematological malignancies and 38 healthy patients (control group). This study included baseline evaluation, one-year, and three-year follow-up visits. In addition to anamnesis and medically obtained information, FSFI was evaluated to determine the impact of gynecological damage in a subjective manner. In the study group, vulvovaginal atrophy was diagnosed in 76.32%, with subsequent sexual dysfunctions in 92.10% of patients, based on FSFI scoring. Even though the results improved throughout the study, at the last visit, mild vulvovaginal atrophy was diagnosed in 81.58% of patients, and the FSFI score was abnormal for 21.05%. When compared to the control group, both sexual dysfunctions and FSFI results were considerably impaired, with statistical significance. There is a confirmed negative impact of sexual dysfunctions and self-declared FSFI on couple/marital status and couple relationships, with statistical significance, at the last visit. In conclusion, anatomical, functional, and psychological difficulties are a reality of long-term survivors after a stem cell transplant. They should be addressed and assessed equally to other medical conditions, as they may determine serious consequences and impact the sexual quality of life and the couple's relationship.

Fludarabine versus cyclophospamide in combination with myeloablative total body irradiation as conditioning for patients with acute myeloid leukemia treated with allogeneic hematopoietic cell transplantation. A study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Total body irradiation (TBI) at a dose of 12 Gy combined with cyclophosphamide (CyTBI12Gy) is one of the standard myeloablative regimens for patients with acute myeloid leukemia (AML) treated with allogeneic hematopoietic cell transplantation (allo-HCT). In clinical practice, cyclophosphamide may be substituted with fludarabine (FluTBI12Gy) to reduce toxicity. We retrospectively compared outcomes of CyTBI12Gy with FluTBI12Gy for patients with AML treated in complete remission (CR) with allo-HCT from either a matched sibling or unrelated donor. Of 1684 adults who met inclusion criteria, 109 patients in each group were included in a matched-pair analysis. The cumulative incidence of relapse at 2 years was 25% in the FluTBI12Gy compared to 28% in the CyTBI12Gy group (p = .44) while non-relapse mortality (NRM) was 17% versus 19%, (p = .89) respectively. The rates of leukemia-free survival and overall survival were 65% versus 54% (p = .28) and 70% versus 60.5% (p = .17). Cumulative incidence of grade 2-4 acute graft-versus-host disease (GVHD) was significantly lower for FluTBI12Gy than CyTBI12Gy (16% vs. 34%, p = .005), while the incidences of grade 3-4 acute GVHD and chronic GVHD did not differ significantly. The probability of GVHD and relapse-free survival was 49% in the FluTBI12Gy and 41% in the CyTBI12Gy group (p = .17). We conclude that for patients with AML treated with allo-HCT in CR, cyclophosphamide may be substituted with fludarabine in a regimen based on TBI at a dose of 12 Gy without negative impact on the efficacy. FluTBI12Gy is associated with reduced risk of grade 2-4 acute GVHD and encouraging survival rates.

Comparison of fludarabine-melphalan and fludarabine-treosulfan as conditioning prior to allogeneic hematopoietic cell transplantation-a registry study on behalf of the EBMT Acute Leukemia Working Party

In recent years considerable variations in conditioning protocols for allogeneic hematopoietic cell transplantation (allo-HCT) protocols have been introduced for higher efficacy, lower toxicity, and better outcomes. To overcome the limitations of the classical definition of reduced intensity and myeloablative conditioning, a transplantation conditioning intensity (TCI) score had been developed. In this study, we compared outcome after two frequently used single alkylator-based conditioning protocols from the intermediate TCI score category, fludarabine/melphalan 140 mg/m2 (FluMel) and fludarabine/treosulfan 42 g/m2 (FluTreo) for patients with acute myeloid leukemia (AML) in complete remission (CR). This retrospective analysis from the registry of the Acute Leukemia Working Party (ALWP) of the European Society of Bone Marrow Transplantation (EBMT) database included 1427 adult patients (median age 58.2 years) receiving either Flu/Mel (n = 1005) or Flu/Treo (n = 422). Both groups showed similar 3-year overall survival (OS) (54% vs 51.2%, p value 0.49) for patients conditioned with FluMel and FluTreo, respectively. However, patients treated with FluMel showed a reduced 3-year relapse incidence (32.4% vs. 40.4%, p value < 0.001) and slightly increased non-relapse mortality (NRM) (25.7% vs. 20.2%, p value = 0.06) compared to patients treated with FluTreo. Our data may serve as a basis for further studies examining the role of additional agents/ intensifications in conditioning prior to allo-HCT.

Impact of conditioning regimen intensity on outcomes of second allogeneic hematopoietic cell transplantation for secondary acute myelogenous leukemia

Limited data is available on factors impacting the outcomes of second hematopoietic cell transplantation (HCT2) in patients with secondary acute myeloid leukemia (sAML). This study aimed to assess HCT2 outcome for sAML comparing reduced-intensity (RIC) to myeloablative (MAC) conditioning. Two hundred and fifteen patients were included: RIC (n = 134), MAC (n = 81). The median follow-up was 41.1 (95% CI: 26.7-69.3) and 28.5 (95% CI: 23.9-75.4) months, respectively. At two years, the relapse incidence (RI) was 58.3% versus 51.1% in RIC and MAC, respectively. The 2-year leukemia free survival (LFS) was 26.6% versus 26%, and the graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS) was 16.4% versus 12.1%, while OS was 31.4% and 39.7%, for RIC and MAC respectively. MVA showed a significantly lower RI [hazard ratio (HR) = 0.46 (95% CI, 0.26-0.8, p = 0.006)] and improved LFS [HR = 0.62 (95% CI, 0.39-0.98, p = 0.042)] with MAC versus RIC. The choice of conditioning regimen did not impact non-relapse mortality [HR = 1.14 (95% CI, 0.52-2.5, p = 0.74)], overall survival (OS) [HR = 0.72 (95% CI, 0.44-1.17, p = 0.18)] or GRFS [HR = 0.89 (95% CI, 0.59-1.36, p = 0.6)]. In conclusion, MAC was associated with a lower RI and superior LFS. These results support the use of MAC for eligible patients with sAML who are being considered for HCT2.

Two compound techniques for total body irradiation

INTRODUCTION

Total body irradiation (TBI) is an important treatment modality that is used in combination with chemotherapy in many stem cell transplantation protocols. Therefore, the quality of the irradiation is important. Two techniques for planning and delivering TBI are presented and compared.

METHODS AND MATERIALS

The technique named ExIMRT is a combination of manually shaped conventional fields from an extended SSD and isocentric IMRT fields. The technique named ExVMAT is a combination of conventional and IMRT fields from an extended SSD and isocentric VMAT fields. Dosimetric data from 32 patients who were planned and treated according to one of the two techniques were compared.

RESULTS

When comparing the two techniques, it is determined that the ExVMAT technique is able to significantly reduce the mean total volume overdosed by 120% from 408 to 12 cm³. The dose covering 98% of the total lung volume is significantly increased by this technique from a mean of 9.7 Gy to 10.3 Gy. Additionally, the dose covering 2% of the total kidney volume is significantly decreased from a mean of 12.8 to 12.5 Gy. Furthermore, the population-based variance of the median dose to the total lung volume, the heart and the volume of the body prescribed to 12.5 Gy is significantly reduced. The results are obtained without compromising overall treatment quality as treatment time or dose rate to the lungs.

CONCLUSION

Using the ExVMAT technique, a superior dose distribution can be delivered both from a patient and a population perspective compared to the ExIMRT technique.

Neurological complications in Chinese children undergoing hematopoietic stem cell transplantation

BACKGROUND

Hematopoietic stem cell transplantation, despite being a curative treatment for various pediatric disorders, is associated with significant acute and chronic complications.

METHODS

This retrospective review of 196 hematopoietic stem cell transplantation episodes (144 allogeneic, 52 autologous) performed in a tertiary pediatric unit focused on neurological symptoms and complications occurred from the start of conditioning to within 3 years of transplantation. Indications for transplantation included both benign and malignant diseases. For episodes involving allogeneic transplantation, 42% of donors were matched-unrelated, 19% were matched-sibling, and 12% were haploidentical.  RESULTS: Neurological complications developed in 17% of all hematopoietic stem cell transplantation episodes. Tumors of central nervous system and leukemia or lymphoma were two indications reported to have higher incidence of 42% and 21%, respectively. The occurrence of neurological complications was significantly associated with primary diagnosis (p = 0.01), central nervous system involvement by underlying disease (p = 0.001), and radiation-based conditioning (p = 0.018). Upon multivariate analysis, central nervous system involvement by underlying disease remained to be the only significant factor (p = 0.019), while radiation-based containing conditioning (p = 0.029) is revealed to be associated when considering allogeneic transplantation alone. Pre-transplant central nervous system-directed treatment, allogeneic versus autologous donor, stem cell source, donor type, busulfan use, and cyclosporin use were not significantly associated with neurological complications. Patients with neurological complications were also found to have an inferior 2-year overall survival (53.9% ± 8.8% versus 63.8% ± 4.2%; p = 0.016).

CONCLUSION

Neurological complications were common in pediatric hematopoietic stem cell transplantation and were associated with adverse outcome; non-radiation containing conditioning regimens might be beneficial in mitigating the risk of such complications.

Post-transplant cyclophosphamide versus anti-thymocyte globulin for graft-versus-host disease prevention in haploidentical transplantation for adult acute lymphoblastic leukemia

Graft-versus-host disease (GVHD) prophylaxis for unmanipulated haploidentical hematopoietic cell transplantation (haplo-HCT) include post-transplant cyclophosphamide (PTCy) and anti-thymocyte globulin (ATG). Utilizing EBMT registry, we compared ATG versus PTCy based GVHD prophylaxis in adult acute lymphoblastic leukemia (ALL) patients undergoing haplo-HCT. Included were 434 patients; ATG (n=98) and PTCy (n=336). Median follow-up was ~2 years. Baseline characteristics were similar between the groups except that the ATG-group was more likely to have relapsed/refractory ALL (P=0.008), non-TBI conditioning (P<0.001), peripheral blood graft source (P=<0.001) and transplanted at an earlier time-period (median year of HCT 2011 vs. 2015). The 100-day grade II-IV and III-IV acute-GVHD was similar between ATG and PTCy, as was 2-year chronic-GVHD. On multivariate analysis (MVA), leukemia-free survival (LFS) and overall survival (OS) was better with PTCy compared to ATG prophylaxis. Relapse incidence (RI) was lower in the PTCy group (P=0.03), while non-relapse mortality (NRM) was not different. Advanced disease and lower performance score were associated with poorer LFS and OS and advanced disease with inferior GVHD-free/relapse-free survival (GRFS). Peripheral grafts were associated with higher GVHD compared to bone marrow grafts. In ALL patients undergoing unmanipulated haplo-HCT, PTCy for GVHD prevention resulted in lower RI and improved LFS and OS compared to ATG.

Hematopoietic Cell Transplantation in the Treatment of Newly Diagnosed Adult Acute Myeloid Leukemia: An Evidence-Based Review from the American Society of Transplantation and Cellular Therapy

The role of hematopoietic cell transplantation (HCT) in the management of newly diagnosed adult acute myeloid leukemia (AML) is reviewed and critically evaluated in this evidence-based review. An AML expert panel, consisting of both transplant and nontransplant experts, was invited to develop clinically relevant frequently asked questions covering disease- and HCT-related topics. A systematic literature review was conducted to generate core recommendations that were graded based on the quality and strength of underlying evidence based on the standardized criteria established by the American Society of Transplantation and Cellular Therapy Steering Committee for evidence-based reviews. Allogeneic HCT offers a survival benefit in patients with intermediate- and high-risk AML and is currently a part of standard clinical care. We recommend the preferential use of myeloablative conditioning in eligible patients. A haploidentical related donor marrow graft is preferred over a cord blood unit in the absence of a fully HLA-matched donor. The evolving role of allogeneic HCT in the context of measurable residual disease monitoring and recent therapeutic advances in AML with regards to maintenance therapy after HCT are also discussed.

Improved Outcomes of Haploidentical Hematopoietic Cell Transplantation with Total Body Irradiation-Based Myeloablative Conditioning in Acute Lymphoblastic Leukemia

The optimal myeloablative conditioning (MAC) for patients undergoing haploidentical hematopoietic cell transplantation (haplo-HCT) is unknown. We studied the outcomes of total body irradiation (TBI)-based versus chemotherapy (CT)-based MAC regimens in patients with acute lymphoblastic leukemia (ALL). The study included 427 patients who underwent first haplo-HCT with post-transplantation cyclophosphamide (PTCy), following TBI-based (n = 188; 44%) or CT-based (n = 239; 56%) MAC. The median patient age was 32 years. Fludarabine-TBI (72%) and thiotepa-busulfan-fludarabine (65%) were the most frequently used TBI- and CT-based regimens, respectively. In the TBI and CT cohorts, 2-year leukemia-free survival (LFS) was 45% versus 37% (P = .05), overall survival (OS) was 51% versus 47% (P = .18), relapse incidence (RI) was 34% versus 32% (P = .44), and nonrelapse mortality (NRM) was 21% versus 31% (P < .01). In the multivariate analysis, TBI was associated with lower NRM (hazard ratio [HR], 0.53; 95% confidence interval [CI], 0.33 to 0.86; P = .01), better LFS (HR, 0.71; 95% CI, 0.52 to 0.98; P =.04), and increased risk for grade II-IV acute graft-versus-host disease (GVHD) (HR, 1.59; 95% CI, 1.08 to 2.34; P = .02) compared with CT-based MAC. The type of conditioning regimen did not impact RI, chronic GVHD, OS, or GVHD-free, relapse-free survival after adjusting for transplantation-related variables. TBI-based MAC was associated with lower NRM and better LFS compared with CT-based MAC in patients with ALL after haplo-HCT/PTCy.

Underdiagnosed veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) as a major cause of multi-organ failure in acute leukemia transplant patients: an analysis from the EBMT Acute Leukemia Working Party

Allogeneic hematopoietic cell transplantation (alloHCT) is a complex, potentially fatal therapy featuring a myriad of complications. Triggering event(s) of such complications vary significantly, but often a so-called "multi-organ failure" (MOF) is reported as the leading cause of death. The identification of the exact trigger of MOF is critical towards early and disease-specific intervention to improve outcome. We examined data from 202 alloHCT patients reported to have died of MOF from the EBMT registry aiming to determine their exact cause of death focusing on veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) due to its life-threatening, often difficult to capture yet preventable nature. We identified a total of 70 patients (35%) for whom VOD/SOS could be considered as trigger for MOF and leading cause of death, among which 48 (69%) were previously undiagnosed. Multivariate analysis highlighted history of hepatic comorbidity or gentuzumab use and disease status beyond CR1 as the only significant factors predictive of VOD/SOS incidence (OR = 6.6; p = 0.001 and OR = 3.3; p = 0.004 respectively). VOD/SOS-related MOF was widely under-reported, accounting for 27% of deaths attributed to MOF of unknown origin without a previous VOD/SOS diagnosis. Our results suggest most missed cases developed late VOD/SOS beyond 21 days post-alloHCT, highlighting the importance of the newly revised EBMT criteria.

Total body irradiation + fludarabine compared to busulfan + fludarabine as "reduced-toxicity conditioning" for patients with acute myeloid leukemia treated with allogeneic hematopoietic cell transplantation in first complete remission: a study by the Acute Leukemia Working Party of the EBMT

The optimal conditioning for patients with acute myeloid leukemia in first complete remission treated with allogeneic hematopoietic cell transplantation (allo-HCT) has not been defined so far. In this retrospective study, we compared two "reduced-toxicity" regimens: intravenous busulfan at a total dose of 9.6 mg/kg (3 days) + fludarabine (Bu3/Flu) and total body irradiation at a dose of 8 Gy + fludarabine (TBI8Gy/Flu). In the entire study cohort (n = 518), the probabilities of overall survival (OS), leukemia-free survival (LFS), relapse and non-relapse mortality (NRM) at 2 years for Bu3/Flu and TBI8Gy/Flu were 62% vs. 72.5% (p = 0.051), 59.5% vs. 65% (p = 0.15), 30% vs. 20% (p = 0.01), and 10% vs. 14% (p = 0.18), respectively. In multivariate model for patients <50 years old, TBI8Gy/Flu was associated with improved LFS (hazard ratio (HR) = 0.5, p = 0.04), OS (HR = 0.31, p = 0.004), and survival free from both graft-versus-host disease and relapse (HR = 0.55, p = 0.03), as well as tendency to reduced risk of relapse (HR = 0.53, p = 0.08). Among patients aged 50 years or older the use of TBI8Gy/Flu was associated with increased incidence of NRM (HR = 3.9, p = 0.0009), with no significant impact on other outcome measures. We conclude that the use of TBI8Gy/Flu as "reduced-toxicity" regimen may be advised in younger patients with AML referred for allo-HCT.

Allogeneic stem-cell transplantation with sequential conditioning in adult patients with refractory or relapsed acute lymphoblastic leukemia: a report from the EBMT Acute Leukemia Working Party

Treatment of relapsed/refractory acute lymphoblastic leukemia (RR-ALL) remains a clinical challenge with generally dismal prognosis. Allogeneic stem-cell transplantation using sequential conditioning ("FLAMSA"-like) has shown promising results in relapsed/refractory acute myeloid leukemia, but little is known about its efficacy in RR-ALL. We identified 115 patients (19-66 years) with relapsed (74%) or primary-refractory (26%) ALL allografted from matched related (31%), matched unrelated (58%), or haploidentical donor (11%). Median follow-up was 37 (13-111) months. At day 100, cumulative incidences of grade II-IV/III-IV acute graft-versus-host-disease (GVHD) were 30% and 17%, respectively. Two-year cumulative incidence of chronic GVHD was 25% with 11% extensive cases. Two-year relapse incidence (RI) was 45%, non-relapse mortality was 41%. Two-year leukemia free survival (LFS) was 14%, overall survival (OS) 17%, and GVHD relapse-free survival (GRFS) was 14%. In multivariable analysis, Karnofsky score <90 negatively affected RI, LFS, OS, and GRFS. Conditioning with chemotherapy alone, compared with total body irradiation (TBI) negatively affected RI (HR = 3.3; p = 0.008), LFS (HR = 1.94; p = 0.03), and OS (HR = 2.0; p = 0.03). These patients still face extremely poor outcomes, highlighting the importance of incorporating novel therapies (e.g., BITE antibodies, inotuzumab, CAR-T cells). Nevertheless, patients with RR-T-cell ALL remain with an unmet treatment need, for which TBI-based sequential conditioning could be one of few available options.

Fractionated gemtuzumab ozogamicin in association with high dose chemotherapy: a bridge to allogeneic stem cell transplantation in refractory and relapsed acute myeloid leukemia

Optimization of the salvage regimen is required to improve prognosis in primary refractory or relapsed acute myeloid leukemia (AML). In fit patients, a bridge to allogeneic transplant is the primary purpose of salvage. We tested the combination of fractionated gemtuzumab ozogamicin with cytarabine and mitoxantrone (MYLODAM schema) with primary endpoint of efficacy and safety. We also attempted to define predictive factors for survival and response after salvage. We included 58 patients with a median age at salvage of 56 years. The overall response rate was 67%. Leukemia-free survival (LFS) and overall survival (OS) at 2 years was 36% (95% CI: 23-49) and 54% (95% CI: 39-68), respectively. Treatment-related mortality was 7%. Three veno-occlusive diseases (SOS/VOD) occurred during salvage. In the allogeneic group of 28 patients (48%), LFS and OS at 2 years was 57 % (95% CI: 36.3-77.5) and 69 % (95% CI: 49.3-88.7), respectively. Incidences of nonrelapse mortality, grade II-IV acute graft-versus-host disease (GVHD) and chronic GVHD were 16%, 40%, and 45%, respectively. A GO-based intensive regimen is a viable option for salvage therapy and a feasible schedule as a bridge to allogeneic transplant.