Real-world effectiveness of intensive chemotherapy with 7&3 versus venetoclax and hypomethylating agent in acute myeloid leukemia.

Intensive chemotherapy with cytarabine and anthracycline (7&3) remains the standard therapy for patients medically fit for induction, but the assessment of fitness remains controversial. Venetoclax and hypomethylating agent (ven/HMA) combination therapy has improved outcomes in unfit patients but no prospective study has assessed ven/HMA versus 7&3 as initial therapy in older, fit patients. Given no studies and expectation of ven/HMA use in patients outside of trial criteria, we evaluated retrospective outcomes among newly diagnosed patients. A nationwide electronic health record (EHR)-derived database and the University of Pennsylvania EHR identified 312 patients receiving 7&3 and 488 receiving ven/HMA who were 60-75 years old without history of organ failure. Ven/HMA patients were older and more likely to have secondary AML, adverse cytogenetics, and adverse mutations. Median overall survival (OS) for patients receiving intensive chemotherapy was 22 versus 10 months for ven/HMA (HR 0.53, 95% CI 0.40-0.60). Controlling for measured baseline characteristic imbalances reduced survival advantage by half (HR 0.71, 95% CI 0.53-0.94). A sub-group of patients with equipoise, likelihood at least 30%-70% of receiving either treatment, had similar OS outcomes (HR 1.10, 95% CI 0.75-1.6). Regarding safety outcomes, 60-day mortality was higher for ven/HMA (15% vs. 6% at 60 days) despite higher documented infections and febrile neutropenia for 7&3. In this multicenter real-word dataset, patients selected for intensive chemotherapy had superior OS but a large group had similar outcomes with ven/HMA. Prospective randomized studies, controlling for both measured and unmeasured confounders, must confirm this outcome.

Central line-associated Rhizobium radiobacter bloodstream infection in two allogeneic hematopoietic cell transplant recipients.

INTRODUCTION: Rhizobium radiobacter is a gram-negative, opportunistic phytopathogen that rarely causes human infections. We report two cases of Rhizobium radiobacter central line-associated bloodstream infection (CLABSI) in allogeneic hematopoietic cell transplantation (alloHCT) recipients. We review previous reports and common microbiological characteristics associated with this organism. CASE REPORTS: Two adult males developed R. radiobacter CLABSIs at day +81 and day +77 post-alloHCT. Patient one was asymptomatic on presentation while patient two was febrile. One patient had a polymicrobial infection, which has not been previously described. The presence of high-level ceftazidime resistance in both patients suggests third-generation cephalosporin resistance may be more common than previously recognized. MANAGEMENT AND OUTCOME: For both patients, microbiologic clearance was achieved through peripherally inserted central catheter removal and initiation of intravenous cefepime. Antibiotic therapy was narrowed to oral levofloxacin for a total 14-day course from the time of first negative blood culture. There has been no subsequent recurrence of R. radiobacter infection at 12 and 5 months of follow-up for patients one and two, respectively. DISCUSSION: These two cases add to the scant literature characterizing R. radiobacter infection following alloHCT. Immunosuppressive agents for graft-versus-host disease prophylaxis may have predisposed these patients to R. radiobacter infection. Our reports, and previously reported cases, suggest R. radiobacter exhibits low virulence, mild symptom burden, and does not confer a high mortality risk. In the alloHCT setting, further accumulation of cases is needed to aid in understanding clinical features and characteristics of R. radiobacter infection.

One versus two sets of busulfan therapeutic drug monitoring in myeloablative allogeneic hematopoietic cell transplant.

INTRODUCTION: Busulfan is a common component of allogeneic hematopoietic cell transplant (alloHCT) conditioning, however interpatient pharmacokinetic variability can result in enhanced toxicity or increased relapse risk. Therapeutic drug monitoring (TDM) can minimize variability, yet the optimal frequency of TDM is unknown. We compared outcomes for patients with one versus two sets of busulfan TDM during myeloablative conditioning (MAC) prior to alloHCT. METHODS: We analyzed the impact of busulfan TDM frequency and dose adjustments, with the primary outcome being relapse-free survival (RFS). Other outcomes included the incidence of acute and chronic graft versus host disease (GVHD), oral mucositis, pulmonary toxicity, sinusoidal obstruction syndrome (SOS), the cumulative incidence of relapse (CIR), and overall survival (OS). RESULTS: Twenty-two patients underwent one set of sampling while 53 patients underwent two sets. Similar baseline characteristics were observed between the groups. There were no significant differences observed in RFS by day +180 (77.3% vs. 79.2%, p = 1.0), CIR by day +180 (18.2% vs. 17.8%, p = 0.74), or OS (p = 0.73). The incidences of acute GVHD, chronic GVHD, SOS, and severe mucositis were also similar. In each group, 63% received busulfan dose adjustments after one set, with 52.8% receiving further dose adjustments following the second set. CONCLUSION: We observed no significant difference in alloHCT outcomes between patients who underwent one versus two sets of busulfan TDM sampling, suggesting that a single-time TDM and dose adjustment may be adequate to maximize outcomes after MAC alloHCT.

Fluconazole-Induced adrenal insufficiency following allogeneic hematopoietic cell transplant.

INTRODUCTION: Adrenal insufficiency (AI) is a potentially life-threatening endocrine abnormality rarely associated with azole antifungals. Patients undergoing allogeneic hematopoietic cell transplantation (alloHCT) are at high risk of invasive fungal infection and frequently receive azoles. Signs and symptoms of AI, such as gastrointestinal symptoms, lethargy, and electrolyte disturbances frequently overlap with common alloHCT toxicities, such that azole-induced AI may be under-reported in this population. CASE REPORT: We report the first published case of azole-induced AI following alloHCT. The patient presented with orthostasis and nonspecific gastrointestinal and failure to thrive symptoms in the setting of roughly 6 weeks of fluconazole prophylaxis. The patient was found to have primary AI diagnosed via low serum cortisol and inadequate response to cosyntropin. MANAGEMENT & OUTCOME: AI symptoms resolved with hydrocortisone supplementation and recurred upon rechallenge with fluconazole. The patient had fluconazole permanently discontinued with resolution of symptoms. We rate this case as a probable adverse drug reaction on the Naranjo scale. DISCUSSION: AI may be underreported and misdiagnosed in the alloHCT population given the presence of multiple toxicities with overlapping features. Clinicians must be diligent in investigating adrenal function in patients undergoing alloHCT on azole antifungals who present with symptoms of AI.

Pentosan polysulfate for the treatment of hemorrhagic cystitis after allogeneic hematopoietic cell transplant.

INTRODUCTION: Hemorrhagic cystitis can commonly occur following an allogeneic hematopoietic cell transplant and treatment options are currently limited. Pentosan polysulfate, a heparin-like, sulfated polysaccharide, is used to relieve bladder pain and discomfort associated with interstitial cystitis. Initial reports in patients with hemorrhagic cystitis demonstrate that pentosan polysulfate may hasten hemorrhagic cystitis resolution and control symptoms. METHODS AND RESULTS: This report includes a retrospective case series of six patients who received pentosan polysulfate for the treatment of hemorrhagic cystitis following an allogeneic hematopoietic cell transplant. Pentosan polysulfate was initiated at a median of 4.5 days (range: 3-18) following hemorrhagic cystitis onset and continued for a median duration of 17.5 days (range: 7-64). Four patients were tested for BK virus and all were found to have BK viremia and viruria around the time of pentosan polysulfate initiation. The median number of red blood cell transfusions seemed to decrease in the patients initiated on pentosan polysulfate. All patients received a multi-agent treatment regimen, which included pentosan polysulfate, and half the patients had symptom resolution. The median time to symptom resolution from pentosan polysulfate initiation was 9 days (range: 7-10). CONCLUSION: Pentosan polysulfate was well-tolerated and seemed to assist with symptom resolution. Future studies are needed to confirm the impact of pentosan polysulfate on the treatment of hemorrhagic cystitis.

Day 4 vs. day 12 G-CSF administration following reduced intensity peripheral blood allogeneic stem cell transplant.

INTRODUCTION: Granulocyte colony-stimulating factor (G-CSF) hastens neutrophil engraftment and reduces infections after allogeneic hematopoietic cell transplant (alloHCT), yet the optimal start date is unknown. Additionally, concurrent G-CSF and methotrexate for graft-vs-host disease (GVHD) prophylaxis may potentiate myelosuppression, and prolonged G-CSF is costly. Our institution changed from day + 4 to day + 12 G-CSF initiation following reduced intensity (RIC) alloHCT with methotrexate GVHD prophylaxis. METHODS: We retrospectively compared day + 4 and day + 12 G-CSF initiation after RIC alloHCT from 2017-2021. The primary endpoint was the time to neutrophil engraftment. Secondary endpoints included length of stay (LOS) and the time to platelet engraftment as well as the incidence of infectious events, acute GVHD (aGVHD), and mucositis. RESULTS: Thirty-two patients were included in each group with similar baseline characteristics. We observed faster neutrophil engraftment (median 12 vs. 15 days, p = 0.01) and platelet engraftment (median 13 vs. 15 days, p = 0.026) with day + 4 vs. day + 12 G-CSF initiation. Median LOS was 23 days (range, 19-32) with day + 4 initiation vs. 24 days (21-30) with day + 12 (p = 0.046). The incidence of culture-negative febrile neutropenia (p = 0.12), any grade aGVHD (p = 0.58), and grade 2-4 mucositis (p = 0.8) were similar between groups. CONCLUSION: Compared to day + 4, day + 12 G-CSF initiation following RIC alloHCT had a longer time to neutrophil and platelet engraftment. Day + 12 initiation also resulted in longer LOS, which while statistically significant, was potentially of limited clinical significance. These findings are hypothesis generating.

Tacrolimus induced pseudogout following allogeneic hematopoietic cell transplant.

INTRODUCTION: Crystalline arthritis (CA), characterized by acute joint pain and erythema secondary to calcium pyrophosphate deposition (CPPD, or pseudogout) or monosodium urate crystals (gout), is a potentially underreported complication following allogeneic hematopoietic cell transplant (alloHCT). Graft-versus-host disease prophylaxis with calcineurin inhibitors (CNIs) causes hypomagnesemia and hyperuricemia, resulting in CA. CA related to tacrolimus has yet to be characterized following alloHCT. CASE REPORT: We retrospectively reviewed records of 450 consecutive patients undergoing alloHCT and identified 15 (3.3% incidence) who developed CA on tacrolimus. Large joints were involved in 10 (66.7%) patients, all patients had recent hypomagnesemia, and no patient had hyperuricemia, suggesting CPPD was the most likely etiology.Management and outcome: Eleven (73.3%) patients received systemic corticosteroids; 6 as initial therapy and 5 added to or substituted for colchicine in the setting of slow or inadequate response. The median duration of corticosteroid therapy was 6 days, however 2 patients (13.3%) required prolonged maintenance due to recurrence. Eleven (73.3%) patients received colchicine; 9 as initial therapy and 2 added to or substituted for corticosteroids in the setting of slow or inadequate response. The median duration of colchicine therapy was 18 days. The median time to symptom resolution was 21 days. DISCUSSION: Patients on tacrolimus following alloHCT presenting with acute joint pain and erythema should be evaluated for CPPD. Hypomagnesemia secondary to CNIs is likely the precipitating factor for CPPD in this population. Patients can effectively be managed with systemic corticosteroids and/or colchicine, however prolonged duration of treatment and even maintenance may be necessary. Based on the Naranjo Algorithm, CPPD secondary to tacrolimus induced hypomagnesemia is a possible adverse drug event, with a score of 3-4.

Cytokine release syndrome and neurotoxicity following CAR T-cell therapy for hematologic malignancies.

Chimeric antigen receptor T cells are a new and exciting immunotherapeutic approach to managing cancer, with impressive efficacy but potentially life-threatening inflammatory toxicities such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Patients with severe CRS may develop capillary leak syndrome and disseminated intravascular coagulation, with a cytokine signature similar to that of macrophage activation syndrome/hemophagocytic lymphohistiocytosis. Moderate-to-severe CRS is managed with the IL-6 receptor antagonist tocilizumab with or without corticosteroids, with questions remaining regarding the optimal management of nonresponders. ICANS is an inflammatory neurotoxicity typically occurring after CRS and characterized by impaired blood-brain barrier integrity. Symptoms of encephalopathy range from mild confusion and aphasia to somnolence, obtundation, and in some cases seizures and cerebral edema. ICANS is currently managed with corticosteroids; however, the optimal dose and duration remain to be determined. Little information is available to guide the management of patients with steroid-refractory ICANS. Numerous cytokine-targeted therapies have been proposed to manage these inflammatory toxicities, but few clinical data are available. Management of inflammatory toxicities of chimeric antigen receptor T cells often requires multidisciplinary management and intensive care, during which allergists and immunologists may encounter patients with these unique toxicities.

Risk of invasive fungal infections in patients with high-risk MDS and AML receiving hypomethylating agents.

Invasive fungal infections (IFI) are a significant source of morbidity and mortality for patients with acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). Given the heterogeneity of the population receiving hypomethylating agents (HMA), it is difficult for clinicians to accurately assess their patients' risk of infection. Literature on the incidence of IFI following HMA is limited to several studies of azacitidine. The primary objective of this retrospective study was to establish the incidence of IFI in HMA treated AML/MDS patients at a large U.S. comprehensive cancer center. Secondary objectives included comparing incidence of IFI among pre-specified subgroups to identify potential risk factors for IFI. Two hundred three patients with AML, intermediate to very high risk MDS or chronic myelomonocytic leukemia who received at least two cycles of HMA were included. The incidence of IFI, as defined by the European Organization for Research and Treatment of Cancer / Invasive Fungal Infections Cooperative Group criteria, was 9.6%, with 20 IFI diagnosed following HMA (three proven, four probable, 13 possible). Among the proven cases of IFI, molds included Scedosporium and Fusarium spp. Eleven patients who developed IFIs were neutropenic upon initiating HMA. The majority (17/20) of infections occurred during the first four cycles. Given this incidence, mold-active prophylaxis can be considered in patients who are neutropenic at the start of therapy.

Oral Vancomycin Prophylaxis Is Highly Effective in Preventing Clostridium difficile Infection in Allogeneic Hematopoietic Cell Transplant Recipients.

BACKGROUND: Clostridium difficile infection (CDI) is a leading cause of infectious complications in allogeneic hematopoietic cell transplant recipients (alloHCT). We sought to evaluate whether prophylactic oral vancomycin reduces the incidence of CDI in alloHCT recipients. METHODS: We conducted a retrospective cohort study to examine the effectiveness of CDI prophylaxis with oral vancomycin, as compared to no prophylaxis, in 145 consecutive adult alloHCT recipients at the University of Pennsylvania between April 2015 and November 2016. Patients received oral vancomycin 125 mg twice daily, starting on admission and continuing until discharge. The primary outcome of interest was the association between oral vancomycin prophylaxis and CDI diagnosis. Secondary outcomes included graft-versus-host disease (GVHD) and relapse. RESULTS: There were no cases of CDI in patients that received prophylaxis (0/90, 0%), whereas 11/55 (20%) patients who did not receive prophylaxis developed CDI (P < .001). Oral vancomycin prophylaxis was not associated with a higher risk of acute, grades 2-4 GVHD (subhazard ratio [sHR] 1.59; 95% confidence interval [CI] 0.88-2.89; P = .12), acute, grades 3-4 GVHD (sHR 0.65; 95% CI 0.25-1.66; P = .36), or acute, grades 2-4 gastrointestinal GVHD (sHR 1.95; 95% CI 0.93-4.07; P = .08) at day 180 post-transplant. No associations between oral vancomycin and relapse or survival were observed. CONCLUSIONS: Prophylaxis with oral vancomycin is highly effective in preventing CDI in alloHCT recipients without increasing the risk of graft-versus-host disease or disease relapse. Further evaluation via a prospective study is warranted.

Dose-related periorbital edema following sorafenib in a patient with acute myeloid leukemia.

We describe a case of dose-related periorbital edema in a patient with FLT3-mutated acute myeloid leukemia taking sorafenib and voriconazole that resolved following sorafenib dose reduction. We hypothesize that the mechanism of this adverse event may be related to the inhibition of platelet-derived growth factor receptor (PDGFR) by sorafenib. Clinicians should be aware of this possible dose-related adverse event and the potential role of sorafenib dose reduction when on concurrent voriconazole.

Rituximab-refractory thrombotic thrombocytopenic purpura responsive to intravenous but not subcutaneous bortezomib.

BACKGROUND: Thrombotic thrombocytopenic purpura (TTP) is often characterized by formation of antibodies against a disintegrin and metalloprotease with thrombospondin repeat, member 13 (ADAMTS13). Therapeutic plasma exchange (PEX) is the basis of TTP therapy, with additional immunosuppression to eradicate ADAMTS13 antibody-producing B cells. CASE REPORT: We describe a case of a 22-year-old female with TTP refractory to PEX, high-dose corticosteroid therapy, and rituximab. Laboratory blood tests showed a severe ADAMTS13 deficiency and the presence of an inhibitor. Although one cycle of subcutaneous bortezomib resulted in clinical improvement, the patient remained PEX dependent. A second course of intravenous (IV) bortezomib resulted in a complete remission without evidence of relapse after 18 months. CONCLUSION: This case confirms the efficacy of bortezomib for refractory TTP and suggests that the in vivo activity of IV bortezomib may be distinct from subcutaneous drug in this setting.

Revisiting the role of cladribine in acute myeloid leukemia: an improvement on past accomplishments or more old news?

Originally studied in lymphoid diseases, cladribine (CdA) is an adenosine deaminase resistant analog of adenosine that was later discovered to induce myeloid cell apoptosis. The activity of CdA in myeloid malignancies was first reported in relapsed/refractory (RR) pediatric acute myeloid leukemia (AML) with complete response (CR) rates of up to 47%. Consequently, several studies have confirmed the efficacy of single agent CdA or CdA combination regimens in AML. Established CR rates for combination regimens in RR adults are approximately 50%, while CR rates for newly diagnosed (ND) adults are approximately 70% and show similar toxicity profiles to previously used regimens. Despite these promising data, many centers have yet to adopt CdA combination regimens for these difficult to treat populations. We review the pharmacology, pharmacokinetics, clinical data, and safety of CdA monotherapy and combination regimens for the management of pediatric and adult ND and RR-AML.

Drug-Induced Aseptic Meningitis Associated With Intrathecal Trastuzumab.

Objective: To report a case of drug-induced aseptic meningitis (DIAM) in a patient receiving intrathecal trastuzumab (ITT) for leptomeningeal carcinomatosis (LC) secondary to HER-2/neu positive breast cancer. Case Summary: A 43-year-old female with stage IV breast cancer presented with headache, parasthesias, and aphasia. Brain imaging suggested leptomeningeal enhancement. Adenocarcinoma cells were found on cerebrospinal fluid analysis, and infectious etiologies were excluded. The patient received 30 mg of ITT via Ommaya reservoir and suffered sudden neurologic deterioration within 2 hours. Given the sudden onset of clinical deterioration after ITT administration, it was determined that the patient had suffered from DIAM. The patient suffered progressive neurologic decline and was unable to care for herself any further. Discussion: Treatment for LC remains challenging due to limited clinical experience and the challenging location of the disease. ITT has been used in multiple reports without adverse events. A temporal relationship existed between ITT administration and significant neurologic deterioration, possibly related to DIAM. Our patient was not exposed to any more common causative agents of DIAM. Reasons for her lack of recovery are likely multifactorial. Symptoms of DIAM may have in part been exacerbated by progressive LC; however, prior to ITT, symptoms had shown slow but persistent progression rather than significant, acute changes in severity. Retrial of the offending agent was not attempted due to patient risk; thus, a cause-and-effect relationship cannot be established. This event is a "possible" drug-induced adverse event scoring 2 on the Naranjo algorithm. Conclusions: Use of ITT for LC has been frequently reported in recent literature with substantial efficacy and lack of adverse events. This is the first published report of any significant adverse event associated with ITT. Clinicians need to be aware of the possibility of DIAM with ITT and explore options to prevent or manage this severe complication.

Characterization of the calcineurin inhibitor pain syndrome in patients undergoing allogeneic hematopoietic cell transplantation.

Calcineurin inhibitor pain syndrome (CIPS) is a rare complication of graft-vs-host disease prophylaxis following allogeneic hematopoietic cell transplant (alloHCT). CIPS presents as severe bilateral lower extremity pain, and the incidence, risk factors, and management of CIPS are poorly characterized.This is a single center retrospective study of patients who received tacrolimus (TAC) following alloHCT to describe the characteristics and management of CIPS and compare to a cohort who did not develop CIPS.Fifteen of 585 alloHCT patients (2.6%) developed CIPS at a median of 5 days following TAC initiation and a median level of 10.5 ng/mL. Severe bilateral foot, ankle, or leg pain were the primary symptoms. Patients with CIPS were younger and more frequently received myeloablative conditioning and total body irradiation compared to patients without CIPS. Analgesic regimens included dihydropyridine calcium channel blockers, gabapentinoids, topical diclofenac, and opioids.Clinicians should be aware of this uncommon but severe adverse effect.

Pemigatinib for the treatment of myeloid/lymphoid neoplasms with FGFR1 rearrangement.

INTRODUCTION: Myeloid/lymphoid neoplasms with fibroblast growth factor receptor-1 (FGFR1) rearrangements (MLNFGFR1) are rare entities with aggressive features and poor prognosis. Presentation is heterogeneous, ranging from myeloproliferative neoplasms (with or without eosinophilia) to T-cell lymphoma and acute leukemia. Historical treatments have been guided by the presenting phenotype with induction chemotherapy frequently used. Pemigatinib is a FGFR1-3 tyrosine kinase inhibitor that has demonstrated high complete hematologic and cytogenetic response rates in MLNFGFR1. AREAS COVERED: We discuss the pathogenesis, presentation, and historical treatments for MLNFGFR1, in addition to clinical data using pemigatinib and other targeted therapies. Discussion of the mechanism of action and adverse events is also included. EXPERT OPINION: Pemigatinib represents a significant advance in the management of MLNFGFR1. High rates of complete hematologic and cytogenetic response have been observed. While direct comparative data are unavailable, outcomes appear favorable compared to conventional approaches. Long-term efficacy and tolerability are not yet known, and allogeneic hematopoietic stem cell transplant (alloHSCT) continues to be the treatment with the highest chance of long-term disease free survival in responding patients. Combinations of pemigatinib and chemotherapy, particularly for more aggressive phenotypes, warrant future investigation as does the use of pemigatinib maintenance following alloHSCT.

Clofarabine and Busulfan Myeloablative Conditioning in Allogeneic Hematopoietic Cell Transplantation for Patients With Active Myeloid Malignancies.

Patients with refractory or relapsed and refractory myeloid malignancies have a poor prognosis. Allogeneic hematopoietic cell transplantation (HCT) with myeloablative conditioning (MAC) in patients with active, chemotherapy-refractory myeloid disease is historically associated with high rates of relapse and nonrelapse mortality (NRM). A MAC regimen combining clofarabine with busulfan (Clo/Bu4) has been reported to exhibit antileukemic activity with acceptable toxicity in patients age ≤70 years. Here we describe the clinical outcomes of a real-world population of patients with active myeloid malignancies undergoing allogeneic HCT with Clo/Bu4 MAC. In a single-center retrospective descriptive analysis, we identified patients who underwent HCT for myeloid malignancies not in remission using Clo/Bu4 MAC between 2012 and 2020. We report event-free survival (EFS) and overall survival (OS), cumulative incidences of relapse and NRM, and the incidence and severity of acute and chronic graft-versus-host disease (GVHD). We identified 69 patients with a median age of 60 years (range, 22 to 70 years). Most patients had relapsed/refractory or primary refractory acute myelogenous leukemia (AML; n = 55) or refractory myelodysplastic syndrome (MDS; n = 12); 1 patient had chronic myelogenous leukemia, and 1 patient had a blastic plasmacytoid dendritic cell neoplasm. Fifty patients (72.5%) had complete remission at day 100 post-transplantation. Two-year EFS and OS were 30% (95% confidence interval [CI], 20% to 44%) and 40% (95% CI, 29% to 54%), respectively. Patients with AML had a 2-year EFS and OS of 28% (95% CI, 18% to 44%) and 38% (95% CI, 27% to 54%), respectively; those with MDS had a 2-year EFS and OS of 47% (95% CI, 25% to 88%) and 56% (95% CI, 33% to 94%), respectively. The cumulative incidence of relapse at 2 years was 39% (95% CI, 27% to 51%) for all patients, including 45% (95% CI, 31% to 58%) in the patients with AML and 18% (95% CI, 2% to 45%) in those with MDS. NRM at 2 years was 31% (95% CI, 20% to 42%), including 27% (95% CI, 15% to 39%) in patients with AML and 35% (95% CI, 10% to 63%) in those with MDS. The total incidence of acute GVHD (aGVHD) of any severity was 80%, and the incidence of grade III-IV aGVHD was 22%. In patients who achieved remission, those who required systemic immunosuppression for aGVHD (58%) had poorer 2-year EFS (29% versus 54%; P = .05) and 2-year OS (39% versus 70%; P = .04) compared to those who did not. The 2-year cumulative incidence of chronic GVHD was 44% (95% CI, 28% to 58%). Clo/Bu4 MAC followed by allogeneic HCT for patients with active myeloid malignancies is an effective transplantation strategy for patients up to age 70, particularly those with advanced MDS. The high incidence of and poor outcomes associated with aGVHD highlight the importance of optimizing preventative strategies.

Low-Dose Total Body Irradiation Added to Fludarabine and Busulfan Reduced-Intensity Conditioning Reduces Graft Failure in Patients with Myelofibrosis.

Allogeneic hematopoietic cell transplantation (alloHCT) is indicated for patients with intermediate-risk or high-risk myelofibrosis (MF) and remains the sole potential cure. Reduced-intensity conditioning (RIC) is commonly used because of older patient age, comorbidities, and a high incidence of transplantation-related mortality. Patients with MF are at increased risk of graft failure (GF), which is more common with RIC regimens, and is associated with shortened overall survival (OS). Owing to the high rate of GF with conventional fludarabine (Flu) and busulfan (Bu) RIC, we added low-dose total body irradiation (TBI; 200 cGy) for patients with MF. We retrospectively compared alloHCT outcomes in adult patients with MF who received RIC with Flu/Bu/TBI and those who received RIC with Flu/Bu. The primary endpoint was the incidence of GF. Secondary endpoints included time to engraftment, acute and chronic graft-versus-host disease (GVHD), hepatic sinusoidal obstruction syndrome (SOS), nonrelapse mortality, overall response rate, progression-free survival, and OS. Of 33 patients who underwent alloHCT, 8 received Flu/Bu RIC and 25 received Flu/Bu/TBI RIC. GF occurred in 50% of the Flu/Bu recipients (all secondary GF) and in 4% of the Flu/Bu/TBI recipients (1 case of primary GF; relative risk, .08; 95% confidence interval [CI], .01 to .62; P = .0016). GF incidence was similar with related or unrelated donors and in patients who did and did not receive Janus-associated kinase inhibitors prior to alloHCT. Molecular remission and donor chimerism ≥99% were significantly more common with Flu/Bu/TBI. No significant differences in acute GVHD, chronic GVHD, or time to engraftment were observed. SOS occurred in none of the 8 patients who received Flu/Bu and in 6 of the 25 patients who received Flu/Bu/TBI, but this difference did not reach statistical significance. Progression or relapse at 1 year was less common with Flu/Bu/TBI (0% versus 63%; P < .001). The median OS was 49 months for Flu/Bu/TBI recipients and 30.8 months for Flu/Bu recipients (hazard ratio, .98; 95% CI, .33 to 2.88; P = .97). Flu/Bu/TBI resulted in a significant reduction in GF and a significant improvement in the frequency of molecular remission and full donor chimerism compared with Flu/Bu. The addition of low-dose TBI to Flu/Bu successfully mitigates against GF in patients with MF without increased rates of complications.