Blinatumomab for MRD-Negative Acute Lymphoblastic Leukemia in Adults.

BACKGROUND: Many older adults with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) have a relapse despite having a measurable residual disease (MRD)-negative complete remission with combination chemotherapy. The addition of blinatumomab, a bispecific T-cell engager molecule that is approved for the treatment of relapsed, refractory, and MRD-positive BCP-ALL, may have efficacy in patients with MRD-negative remission. METHODS: In a phase 3 trial, we randomly assigned patients 30 to 70 years of age with BCR::ABL1-negative BCP-ALL (with :: indicating fusion) who had MRD-negative remission (defined as <0.01% leukemic cells in bone marrow as assessed on flow cytometry) after induction and intensification chemotherapy to receive four cycles of blinatumomab in addition to four cycles of consolidation chemotherapy or to receive four cycles of consolidation chemotherapy alone. The primary end point was overall survival, and relapse-free survival was a secondary end point. RESULTS: The data and safety monitoring committee reviewed the results from the third efficacy interim analysis and recommended that they be reported. Complete remission with or without full count recovery was observed in 395 of 488 enrolled patients (81%). Of the 224 patients with MRD-negative status, 112 were assigned to each group. The characteristics of the patients were balanced between the groups. At a median follow-up of 43 months, an advantage was observed in the blinatumomab group as compared with the chemotherapy-only group with regard to overall survival (at 3 years: 85% vs. 68%; hazard ratio for death, 0.41; 95% confidence interval [CI], 0.23 to 0.73; P = 0.002), and the 3-year relapse-free survival was 80% with blinatumomab and 64% with chemotherapy alone (hazard ratio for relapse or death, 0.53; 95% CI, 0.32 to 0.87). A higher incidence of neuropsychiatric events was reported in the blinatumomab group than in the chemotherapy-only group. CONCLUSIONS: The addition of blinatumomab to consolidation chemotherapy in adult patients in MRD-negative remission from BCP-ALL significantly improved overall survival. (Funded by the National Institutes of Health and others; E1910 ClinicalTrials.gov number, NCT02003222.).

Patient-reported outcomes in ZUMA-7, a phase 3 study of axicabtagene ciloleucel in second-line large B-cell lymphoma.

Here, we report the first comparative analysis of patient-reported outcomes (PROs) with chimeric antigen receptor T-cell therapy vs standard-of-care (SOC) therapy in second-line relapsed/refractory large B-cell lymphoma (R/R LBCL) from the pivotal randomized phase 3 ZUMA-7 study of axicabtagene ciloleucel (axi-cel) vs SOC. PRO instruments were administered at baseline, day 50, day 100, day 150, month 9, and every 3 months from randomization until 24 months or an event-free survival event. The quality of life (QoL) analysis set comprised patients with a baseline and ≥1 follow-up PRO completion. Prespecified hypotheses for Quality of Life Questionnaire-Core 30 (QLQ-C30) physical functioning, global health status/QoL, and EQ-5D-5L visual analog scale (VAS) were tested using mixed-effects models with repeated measures. Clinically meaningful changes were defined as 10 points for QLQ-C30 and 7 for EQ-5D-5L VAS. Among 359 patients, 296 (165 axi-cel, 131 SOC) met inclusion criteria for QoL analysis. At day 100, statistically significant and clinically meaningful differences in mean change of scores from baseline were observed favoring axi-cel over SOC for QLQ-C30 global health status/QoL (estimated difference 18.1 [95% confidence interval (CI), 12.3-23.9]), physical functioning (13.1 [95% CI, 8.0-18.2]), and EQ-5D-5L VAS (13.7 [95% CI, 8.5-18.8]; P < .0001 for all). At day 150, scores significantly favored axi-cel vs SOC for global health status/QoL (9.8 [95% CI, 2.6-17.0]; P = .0124) and EQ-5D-5L VAS (11.3 [95% CI, 5.4-17.1]; P = .0004). Axi-cel showed clinically meaningful improvements in QoL over SOC. Superior clinical outcomes and favorable patient experience with axi-cel should help inform treatment choices in second-line R/R LBCL. This trial was registered at www.clinicaltrials.gov as #NCT03391466.

NCCN Guidelines® Insights: Hematopoietic Cell Transplantation, Version 3.2022.

The NCCN Guidelines for Hematopoietic Cell Transplantation (HCT) provide an evidence- and consensus-based approach for the use of autologous and allogeneic HCT in the management of malignant diseases in adult patients. HCT is a potentially curative treatment option for patients with certain types of malignancies; however, recurrent malignancy and transplant-related complications often limit the long-term survival of HCT recipients. The purpose of these guidelines is to provide guidance regarding aspects of HCT, including pretransplant recipient evaluation, hematopoietic cell mobilization, and treatment of graft-versus-host disease-a major complication of allogeneic HCT-to enable the patient and clinician to assess management options in the context of an individual patient's condition. These NCCN Guidelines Insights provide a summary of the important recent updates to the NCCN Guidelines for HCT, including the incorporation of a newly developed section on the Principles of Conditioning for HCT.

Estimation of Kidney Function in Patients With Multiple Myeloma: Implications for Lenalidomide Dosing.

BACKGROUND: Lenalidomide is an immunomodulatory drug used to treat multiple myeloma that requires renal dosing adjustment based on Cockcroft-Gault (CG). Various equations to estimate kidney function exist and pose a potential issue with lenalidomide dosing. OBJECTIVE: The objective of this analysis was to evaluate the impact of estimating kidney function in newly diagnosed multiple myeloma patients with CG, Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and their potential impact on lenalidomide dosing. METHODS: Data from 1121 multiple myeloma patients at the time of diagnosis acquired from the Mayo Clinic were used to calculate creatinine clearance (CrCl) using Cockcroft-Gault with actual body weight (CGABW), ideal body weight (CGIBW), or adjusted body weight (CGAdjBW); MDRD; and CKD-EPI for each subject. Discordances in dosing were then analyzed, and lenalidomide exposure was calculated for each subject to assess impact on pharmacokinetics of lenalidomide for patients who received discordant doses. RESULTS: Overall, approximately 16% of patients received a discordant dose when using MDRD or CKD-EPI instead of CGABW. The most common dose discordance was the decrease of a full dose of lenalidomide 25 mg when using CGABW down to 10 mg and when using MDRD or CKD-EPI with 53.8% to 55.6% of all discordances in this category. When assessing different body weights, the most common discordance was a decrease from 25 to 10 mg when using CGIBW instead of CGABW; the same trend was observed when using CGAdjBW instead as well. Patients were also at risk of over- or underexposure based on area under the concentration versus time curve (AUC) for discordant dosing. CONCLUSION AND RELEVANCE: A significant proportion of patients are at risk of under- or overdose of lenalidomide if CKD-EPI or MDRD are used instead of CGABW. Physicians should use CGABW when estimating renal function to dose lenalidomide.

KTE-X19 for relapsed or refractory adult B-cell acute lymphoblastic leukaemia: phase 2 results of the single-arm, open-label, multicentre ZUMA-3 study.

BACKGROUND: Despite treatment with novel therapies and allogeneic stem-cell transplant (allo-SCT) consolidation, outcomes in adult patients with relapsed or refractory B-precursor acute lymphoblastic leukaemia remain poor, underlining the need for more effective therapies. METHODS: We report the pivotal phase 2 results of ZUMA-3, an international, multicentre, single-arm, open-label study evaluating the efficacy and safety of the autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy KTE-X19 in adult patients with relapsed or refractory B-precursor acute lymphoblastic leukaemia. Patients were enrolled at 25 sites in the USA, Canada, and Europe. Eligible patients were aged 18 years or older, with Eastern Cooperative Oncology Group performance status of 0-1, and morphological disease in the bone marrow (>5% blasts). After leukapheresis and conditioning chemotherapy, patients received a single KTE-X19 infusion (1 × 106 CAR T cells per kg bodyweight). The primary endpoint was the rate of overall complete remission or complete remission with incomplete haematological recovery by central assessment. Duration of remission and relapse-free survival, overall survival, minimal residual disease (MRD) negativity rate, and allo-SCT rate were assessed as secondary endpoints. Efficacy and safety analyses were done in the treated population (all patients who received a dose of KTE-X19). This study is registered with ClinicalTrials.gov, NCT02614066. FINDINGS: Between Oct 1, 2018, and Oct 9, 2019, 71 patients were enrolled and underwent leukapheresis. KTE-X19 was successfully manufactured for 65 (92%) patients and administered to 55 (77%). The median age of treated patients was 40 years (IQR 28-52). At the median follow-up of 16·4 months (13·8-19·6), 39 patients (71%; 95% CI 57-82, p<0·0001) had complete remission or complete remission with incomplete haematological recovery, with 31 (56%) patients reaching complete remission. Median duration of remission was 12·8 months (95% CI 8·7-not estimable), median relapse-free survival was 11·6 months (2·7-15·5), and median overall survival was 18·2 months (15·9-not estimable). Among responders, the median overall survival was not reached, and 38 (97%) patients had MRD negativity. Ten (18%) patients received allo-SCT consolidation after KTE-X19 infusion. The most common adverse events of grade 3 or higher were anaemia (27 [49%] patients) and pyrexia (20 [36%] patients). 14 (25%) patients had infections of grade 3 or higher. Two grade 5 KTE-X19-related events occurred (brain herniation and septic shock). Cytokine release syndrome of grade 3 or higher occurred in 13 (24%) patients and neurological events of grade 3 or higher occurred in 14 (25%) patients. INTERPRETATION: KTE-X19 showed a high rate of complete remission or complete remission with incomplete haematological recovery in adult patients with relapsed or refractory B-precursor acute lymphoblastic leukaemia, with the median overall survival not reached in responding patients, and a manageable safety profile. These findings indicate that KTE-X19 has the potential to confer long-term clinical benefit to these patients. FUNDING: Kite, a Gilead Company.

Prophylactic corticosteroid use in patients receiving axicabtagene ciloleucel for large B-cell lymphoma.

ZUMA-1 (NCT02348216) examined the safety and efficacy of axicabtagene ciloleucel (axi-cel), an autologous CD19-directed chimaeric antigen receptor (CAR)-T cell therapy, in refractory large B-cell lymphoma. To reduce treatment-related toxicity, several exploratory safety management cohorts were added to ZUMA-1. Specifically, cohort 6 investigated management of cytokine release syndrome (CRS) and neurologic events (NEs) with prophylactic corticosteroids and earlier corticosteroid and tocilizumab intervention. CRS and NE incidence and severity were primary end-points. Following leukapheresis, patients could receive optional bridging therapy per investigator discretion. All patients received conditioning chemotherapy (days -5 through -3), 2 × 106  CAR-T cells/kg (day 0) and once-daily oral dexamethasone [10 mg, day 0 (before axi-cel) through day 2]. Forty patients received axi-cel. CRS occurred in 80% of patients (all grade ≤2). Any grade and grade 3 or higher NEs occurred in 58% and 13% of patients respectively. Sixty-eight per cent of patients did not experience CRS or NEs within 72 h of axi-cel. With a median follow-up of 8·9 months, objective and complete response rates were 95% and 80% respectively. Overall, prophylactic corticosteroids and earlier corticosteroid and/or tocilizumab intervention resulted in no grade 3 or higher CRS, a low rate of grade 3 or higher NEs and high response rates in this study population.

In vitro induction of neoantigen-specific T cells in myelodysplastic syndrome, a disease with low mutational burden.

Therapies that utilize immune checkpoint inhibition work by leveraging mutation-derived neoantigens and have shown greater clinical efficacy in tumors with higher mutational burden. Whether tumors with a low mutational burden are susceptible to neoantigen-targeted therapy has not been fully addressed. To examine the feasibility of neoantigen-specific adoptive T-cell therapy, the authors studied the T-cell response against somatic variants in five patients with myelodysplastic syndrome (MDS), a malignancy with a very low tumor mutational burden. DNA and RNA from tumor (CD34+) and normal (CD3+) cells isolated from the patients' blood were sequenced to predict patient-specific MDS neopeptides. Neopeptides representing the somatic variants were used to induce and expand autologous T cells ex vivo, and these were systematically tested in killing assays to determine the proportion of neopeptides yielding neoantigen-specific T cells. The authors identified a total of 32 somatic variants (four to eight per patient) and found that 21 (66%) induced a peptide-specific T-cell response and 19 (59%) induced a T-cell response capable of killing autologous tumor cells. Of the 32 somatic variants, 11 (34%) induced a CD4+ response and 11 (34%) induced a CD8+ response that killed the tumor. These results indicate that in vitro induction of neoantigen-specific T cells is feasible for tumors with very low mutational burden and that this approach warrants investigation as a therapeutic option for such patients.

Chronic oral graft-versus-host disease: induction and maintenance therapy with photobiomodulation therapy.

This study presents follow-up of a prior study of patients with chronic symptomatic oral chronic graft-versus-host-disease (cGVHD) managed with photobiomodulation therapy (PBM therapy for 1 month. Here, we report long-term follow-up of a series of patients where PBM therapy in patients with oral cGVHD for maintenance follows the initial period of PBM therapy for continuing management. PATIENTS AND METHODS: We report continuing follow-up of 7 cases of oral cGVHD that were treated with PBM therapy. PBM therapy was continued in these patients with the goal of determining the best management schedule of PBM to maintain or improve control of each patient's symptoms and signs of oral cGVHD. RESULTS: Oral sensitivity and mucosal changes of cGVHD were controlled with a continuing schedule of PBM therapy of up to 6-8-week treatment intervals in patients with continuing GVHD. These findings suggest that PBM therapy represents an additional approach for continuing management of oral cGVHD and that the frequency of treatment should be individualized for each patient to provide best control of oral findings. In one case weekly PBM treatment was continued, while in others, management on a monthly or bimonthly basis was associated with control of the oral condition. PBM may be individualized and provided based upon best control of the symptoms and signs of oral GVHD.

Phase 1 clinical trial evaluating abatacept in patients with steroid-refractory chronic graft-versus-host disease.

Steroid-refractory chronic graft-versus-host disease (SR-cGVHD) remains a major cause of morbidity and mortality after allogeneic stem cell transplantation. Innovative immunotherapeutic strategies are urgently needed for the treatment of SR-cGVHD. We conducted a phase 1 clinical trial to evaluate the safety, efficacy, and immune effects of abatacept, a novel immunomodulatory drug that acts as an inhibitor of T-cell activation via costimulatory blockade, in the treatment of SR-cGVHD. The study followed a 3+3 design with 2 escalating abatacept doses: 3 mg/kg and 10 mg/kg, with an expansion cohort treated at 10 mg/kg. Abatacept was well-tolerated with no dose-limiting toxicities. Of the 16 evaluable patients, 44% achieved a clinical partial response per 2005 National Institutes of Health Consensus Criteria. Importantly, abatacept resulted in a 51.3% reduction in prednisone usage in clinical responders (mean baseline, 27 vs 14 mg; P = .01). Increased PD-1 expression on circulating CD4 (P = .009) and CD8 (P = .007) T cells was observed in clinical responders. In summary, abatacept was safe and led to a marked improvement in National Institutes of Health cGVHD scores and a significant reduction in prednisone use. In this cohort of heavily pretreated patients, the results suggest abatacept may be a promising therapeutic agent for SR-cGVHD, and a phase 2 trial has been initiated. This trial was registered at www.clinicaltrials.gov as #NCT01954979.

Hematopoietic Cell Transplantation, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology

Hematopoietic cell transplantation (HCT) involves the infusion of hematopoietic progenitor cells into patients with hematologic disorders with the goal of re-establishing normal hematopoietic and immune function. HCT is classified as autologous or allogeneic based on the origin of hematopoietic cells. Autologous HCT uses the patient's own cells while allogeneic HCT uses hematopoietic cells from a human leukocyte antigen-compatible donor. Allogeneic HCT is a potentially curative treatment option for patients with certain types of hematologic malignancies, and autologous HCT is primarily used to support patients undergoing high-dose chemotherapy. Advances in HCT methods and supportive care in recent decades have led to improved survival after HCT; however, disease relapse and posttransplant complications still commonly occur in both autologous and allogeneic HCT recipients. Allogeneic HCT recipients may also develop acute and/or chronic graft-versus-host disease (GVHD), which results in immune-mediated cellular injury of several organs. The NCCN Guidelines for Hematopoietic Cell Transplantation focus on recommendations for pretransplant recipient evaluation and the management of GVHD in adult patients with malignant disease.

CHAMPION-1: a phase 1/2 study of once-weekly carfilzomib and dexamethasone for relapsed or refractory multiple myeloma.

Carfilzomib, a proteasome inhibitor, is approved in the United States as a single agent, and in combination with dexamethasone or lenalidomide/dexamethasone (KRd) for relapsed or refractory multiple myeloma (MM). Under the single-agent and KRd approvals, carfilzomib is administered as a 10-minute IV infusion on days 1, 2, 8, 9, 15, and 16 of 28-day cycles (20 mg/m(2) [cycle 1, days 1-2]; 27 mg/m(2) thereafter). This multicenter, single-arm, phase 1/2 study, Community Harmonized Assessment of Myeloma Patients via an Integrated Oncology Network-1 (CHAMPION-1), evaluated once-weekly carfilzomib with dexamethasone in relapsed, or relapsed and refractory MM (1-3 prior therapies). Patients received carfilzomib (30-minute IV infusion) on days 1, 8, and 15 of 28-day cycles. The phase 1 portion used a 3 + 3 dose-escalation scheme to determine the maximum tolerated dose (MTD) of carfilzomib. During phase 2, patients received carfilzomib on the same schedule at the MTD. Patients received dexamethasone (40 mg) on days 1, 8, 15, and 22; dexamethasone was omitted on day 22 for cycles 9+. A total of 116 patients were enrolled. The MTD was 70 mg/m(2), and 104 patients (phase 1/2) received carfilzomib 70 mg/m(2) At 70 mg/m(2), the median number of prior regimens was 1; and 52% were bortezomib-refractory. At 70 mg/m(2), the most common grade ≥3 adverse events were fatigue (11%) and hypertension (7%). Overall response rate at 70 mg/m(2) was 77%. Median progression-free survival was 12.6 months. These findings merit additional evaluation of the once-weekly dosing regimen. This trial was registered at www.clinicaltrials.gov as #NCT01677858.

A Case of Subacute Encephalopathy Developing After Treatment With Clofarabine and Methotrexate That Resolved With Corticosteroids.

This is the case of a 24-year-old woman with relapsed acute undifferentiated leukemia who developed subacute encephalopathy with hemiparesis and dysarthria after treatment with high dose and intrathecal methotrexate, clofarabine, and cytarabine that resolved rapidly and completely after the administration of corticosteroids. We hypothesize that clofarabine might predispose to methotrexate-induced central nervous system toxicity by increasing endothelial permeability (capillary leak syndrome) and suggest that corticosteroids are effective in the treatment of this type of encephalopathy.

Early diagnosis and successful management of oral mucormycosis in a hematopoietic stem cell transplant recipient: case report and literature review.

PURPOSE: Oral mucormycosis is a rare and high risk of infection in patients following hematopoietic cell transplantation few cases in the literature. We review the literature and present an additional case to emphasize the subtle changes that resulted in positive outcome when diagnosed and managed in a comprehensive transplant team. RESULTS: A patient was diagnosed with gingival mucormycosis on day +25 following a hematopoietic stem cell transplant for lymphoblastic transformation of chronic myeloid leukemia. The patient was diagnosed with minor and nonspecific symptoms and was successfully treated with local dental extraction, a short course of liposomal amphotericin B and 4 months of oral posaconazole. CONCLUSIONS: The good outcome of this case highlights the subtle clinical changes that present early in mucormycosis and the importance of early detection and treatment of post-transplant oral infections by an experienced multidisciplinary team.

Complex management of resistant oral herpes simplex virus infection following hematopoietic stem cell transplantation: potential role of topical cidofovir.

PURPOSE: Herpes simplex virus (HSV) infection commonly occurs during the immunosuppression associated with hematopoietic stem cell transplantation (HSCT). Prophylaxis of recurrent infection and management of clinical infection have relied upon acyclovir and congeners. More recently, resistant HSV infection is seen in HSCT and presents new challenges in management. We present a case of HSV following HSCT that provided effective symptomatic management. RESULTS: Oral symptoms and lesions were repeatedly reduced when topical cidofovir was used, strongly supporting the effect of cidofovir used in a host who could not tolerate systemic antiviral medications. CONCLUSIONS: Topical cidofovir can provide effective management of symptomatic oropharyngeal HSV while reducing risk of systemic toxicity and drug interaction and represents an additional approach to management for management in medically compromised patients.

Yttrium-90 ibritumomab tiuxetan followed by rituximab maintenance as treatment for patients with diffuse large B-cell lymphoma are not candidates for autologous stem cell transplant.

BACKGROUND: Not all patients with diffuse large B-cell lymphoma (DLBCL) are candidates for aggressive regimens. (90)Y ibritumomab tiuxetan ((90)Y-IT), an anti-CD20 radionuclide-conjugated antibody, has demonstrated clinical efficacy in DLBCL with a favorable toxicity profile. METHODS: This phase II trial investigated the overall response rate (ORR), event-free survival (EFS), overall survival (OS) and toxicity of treatment with (90)Y-IT (0.4 or 0.3 mCi (90)Y/kg based on platelets) followed by rituximab maintenance therapy in patients with DLBCL not candidates for transplant. RESULTS: 25 patients were enrolled. At best response 8 patients obtained a complete response (CR) and 1 a partial response (ORR 36%). Median EFS was 2.5 months and OS 8.1 months. No patient who obtained CR later relapsed systemically. Two patients were free of disease at the 61- and 100-month follow-ups; 65% had grade 3/4 thrombocytopenia, but no significant bleeding was observed. Grade 3 nonhematologic toxicity occurred in 36%. Patients who had progressed through a rituximab-containing regimen responded poorly. CONCLUSION: The ORR of 36% with (90)Y-IT as salvage therapy for DLBCL while inferior to more aggressive regimens is significant with acceptable toxicity. For a subset of patients not candidates for salvage with autologous transplant, this treatment strategy can produce a durable, long-lasting remission.

Successful treatment of refractory Guillain-Barré syndrome with alemtuzumab in a patient with chronic lymphocytic leukemia.

This is the case of a 79-year-old man with chronic lymphocytic leukemia who presented with Guillain-Barré syndrome with features overlapping with the Miller Fisher syndrome and Bickerstaff brainstem encephalitis and positive antiganglioside GQ1b antibody about 6 months after treatment with bendamustine and rituximab. His clinical and neurologic condition continued to deteriorate despite sequential treatment with corticosteroids, intravenous immunoglobulin and plasmapheresis, but in the end, he had a complete and durable response to treatment with alemtuzumab.

Pregabalin's abuse potential: a mini review focusing on the pharmacological profile.

Pregabalin, an analogue of the gamma-aminobutyric acid mammalian neurotransmitter and its structurally related compound gabapentin are known as α2δ ligands. They might act as inhibitory modulators of neuronal excitability that reduce ectopic neuronal activation of hyperexcited neurons while normal activation remains unchanged. However, the interaction with Ca²âº channel α2δ subunit is not sufficient to account for the broad clinical spectrum of pregabalin effects including the abuse potential. Pregabalin is approved for the treatment of partial epilepsy; generalized anxiety disorder; peripheral and central neuropathic pain and fibromyalgia. Its prescribing is rapidly increasing and total sales of the drug worldwide reached 4.6 billion US$ in 2012. Since entering widespread clinical use, reports of pregabalin abuse appeared more often, usually involving individuals with a history of abuse of other medications. The purpose of this mini review is to present available published data signaling pregabalin's abuse liability reflecting on the pharmacological characteristics that might enable this agent to trigger addictive behaviors.

A Difficult Case of Calcineurin Inhibitor Neurotoxicity Post-Haploidentical HCT With a Successful Novel Solution: Cytotoxic T-Lymphocyte-Associated Protein 4-Immunoglobulin Blockade for GVHD Prophylaxis.

Post-allogeneic hematopoietic cell transplant (HCT) immunosuppression regimens are given as graft-versus-host disease (GVHD) prophylaxis. Most GVHD prophylaxis regimens are based on calcineurin inhibitors (CNIs). Unfortunately, CNIs are associated with significant associated morbidity, frequently cannot be tolerated, and often need to be discontinued. There is no consensus as to which alternative immunosuppression should be used in cases where CNIs have to be permanently discontinued. Cytotoxic T-lymphocyte-associated protein 4-immunoglobulin (CTLA4-Ig) blocking agents are well tolerated and have been used extensively in patients with autoimmune disease and as post-transplant immunosuppression. There are two CTLA4-Ig agents: belatacept and abatacept. Belatacept is routinely used in adult kidney transplantation to prevent rejection and abatacept has been approved by the Food and Drug Administration (FDA) for GVHD prophylaxis in patients undergoing a matched or one allele-mismatched unrelated allogenic HCT. Herein, we describe a case in which abatacept was given off-label to replace tacrolimus GVHD prophylaxis in a patient with neurotoxicity undergoing haploidentical HCT. This case suggests that CTLA4-Ig blockade may be a good alternative to a CNI in cases where the CNI needs to be discontinued and warrants further investigation.