Three US Food and Drug Administration-approved therapies for chronic GVHD

An Update on the Nitrogen Heterocycle Compositions and Properties of U.S. FDA-Approved Pharmaceuticals (2013-2023)

This Perspective is a continuation of our analysis of U.S. FDA-approved small-molecule drugs (1938-2012) containing nitrogen heterocycles. In this study we report drug structure and property analyses of 321 unique new small-molecule drugs approved from January 2013 to December 2023 as well as information about frequency of important heteroatoms such as sulfur and fluorine and key small nitrogen substituents (CN and NO2). The most notable change is an incredible increase in drugs containing at least one nitrogen heterocycle─82%, compared to 59% from preceding decades─as well as a significant increase in the number of nitrogen heterocycles per drug. Pyridine has claimed the #1 high-frequency nitrogen heterocycle occurrence spot from piperidine (#2), with pyrimidine (#5), pyrazole (#6), and morpholine (#9) being the big top 10 climbers. Also notable is high number of fused nitrogen heterocycles, apparently driven largely by newly approved cancer drugs.

Understanding Ocular Graft-Versus-Host Disease to Facilitate an Integrated Multidisciplinary Approach

Ocular Graft-versus-Host Disease (oGVHD) remains a challenging and potentially devastating complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT). It significantly impacts the quality of life of affected survivors, however, is often underrecognized particularly during the early stages. Targeting all providers in the HSCT community who see patients regularly and frequently for their post-allo-HSCT care, this review and opinion piece introduces the basic concepts of ocular surface pathophysiology, dissects the different stages of clinical presentation of oGVHD, explains why the current diagnostic criteria tend to capture the late disease stages, highlights the warning signs of early disease development, in hope to facilitate prompt referral of oGVHD suspects for ocular specialist care. In addition to introducing a comprehensive list of treatment options, this review emphasizes basic therapeutic strategy and options that are safe and effective to be initiated by any care provider. We believe in empowering the patients as well as the care providers beyond disciplinary boundaries, in order to provide the most cohesive and integrated care to our patients in a multidisciplinary approach.

Adoptive transfer of donor B lymphocytes: a phase 1/2a study for patients after allogeneic stem cell transplantation

ABSTRACT

Immune reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is slow and patients carry a high and prolonged risk of opportunistic infections. We hypothesized that the adoptive transfer of donor B cells can foster after HSCT immuno-reconstitution. Here, we report, to our knowledge, the results of a first-in-human phase 1/2a study aimed to evaluate the feasibility and safety of adoptively transferred donor B cells and to test their activity upon recall vaccination. Good manufactoring practice (GMP) B-cell products were generated from donor apheresis products using 2-step magnetic cell separation. Fifteen patients who had undergone allo-HSCT were enrolled and treated after taper of immunosuppression (median, day +148; range, 130-160). Patients received 4 different doses of B cells (0.5 × 106 to 4.0 × 106 B cells per kg body weight). To test the activity of infused donor memory B cells in vivo, patients were vaccinated with a pentavalent vaccine 7 days after B-cell transfer. We observed the mobilization of plasmablasts and an increase in serum titers against vaccine antigens, with a stronger response in patients receiving higher B-cell numbers. Analysis of immunoglobulin VH-sequences by next-generation sequencing revealed that plasmablasts responding to vaccination originated from memory B-cell clones from the donor. Donor B-cell transfer was safe, as no Epstein-Barr virus (EBV) reactivation was observed, and only low-grade graft-versus-host disease (GVHD) occurred in 4 out of 15 patients. This pilot trial may pave the way for further studies exploring the adoptive transfer of memory B cells to reduce the frequency of infections after allo-HSCT. This trial was registered at ClinicalTrial.gov as #NCT02007811.

Study protocol: Close Assessment and Testing for Chronic Graft-vs.-Host disease (CATCH)

Chronic graft-versus-host disease (GVHD) is an immune-mediated disorder that causes significant late morbidity and mortality following allogeneic hematopoietic cell transplantation. The "Close Assessment and Testing for Chronic GVHD (CATCH)" study is a multi-center Chronic GVHD Consortium prospective, longitudinal cohort study designed to enroll patients before hematopoietic cell transplantation and follow them closely to capture the development of chronic GVHD and to identify clinical and biologic biomarkers of chronic GVHD onset. Data are collected pre-transplant and every two months through one-year post-transplant with chart review thereafter. Evaluations include clinician assessment of chronic GVHD and its manifestations, patient-reported outcomes, multiple biospecimens (blood, saliva, tears, buccal mucosa and fecal samples, biopsies of skin and mouth), laboratory testing, and medical record abstraction. This report describes the rationale, design, and methods of the CATCH study, and invites collaboration with other investigators to leverage this resource. trial registration: This study is registered at www.clinicaltrials.gov as NCT04188912.

Targeting TGFβ-activated kinase-1 activation in microglia reduces CAR T immune effector cell-associated neurotoxicity syndrome

Cancer immunotherapy with chimeric antigen receptor (CAR) T cells can cause immune effector cell-associated neurotoxicity syndrome (ICANS). However, the molecular mechanisms leading to ICANS are not well understood. Here we examined the role of microglia using mouse models and cohorts of individuals with ICANS. CD19-directed CAR (CAR19) T cell transfer in B cell lymphoma-bearing mice caused microglia activation and neurocognitive deficits. The TGFβ-activated kinase-1 (TAK1)-NF-κB-p38 MAPK pathway was activated in microglia after CAR19 T cell transfer. Pharmacological TAK1 inhibition or genetic Tak1 deletion in microglia using Cx3cr1CreER:Tak1fl/fl mice resulted in reduced microglia activation and improved neurocognitive activity. TAK1 inhibition allowed for potent CAR19-induced antilymphoma effects. Individuals with ICANS exhibited microglia activation in vivo when studied by translocator protein positron emission tomography, and imaging mass cytometry revealed a shift from resting to activated microglia. In summary, we prove a role for microglia in ICANS pathophysiology, identify the TAK1-NF-κB-p38 MAPK axis as a pathogenic signaling pathway and provide a rationale to test TAK1 inhibition in a clinical trial for ICANS prevention after CAR19 T cell-based cancer immunotherapy.

Overlap chronic GVHD is associated with adverse survival outcomes compared to classic chronic GVHD

Chronic graft-versus-host-disease (cGVHD) is divided into two subtypes: classic (absence of acute GVHD features) and overlap cGVHD ('ocGVHD'), in which both chronic and acute GVHD clinical features are present simultaneously. While worse outcomes with ocGVHD have been reported, there are few recent analyses. We performed a secondary analysis of data from the ABA2 trial (N = 185), in which detailed GVHD data were collected prospectively and systematically adjudicated. Analyses included cumulative incidence of classic versus ocGVHD, their specific organ manifestations, global disease severity scores, non-relapse mortality (NRM), disease-free survival (DFS) and overall survival (OS) in these two cGVHD subtypes. Of 92 patients who developed cGVHD, 35 were classified as ocGVHD. The 1-year cumulative incidence, organ involvement, and global severity of classic and ocGVHD were similar between ABA2 patients receiving CNI/MTX+placebo and CNI/MTX+abatacept; thus, cohorts were combined for ocGVHD evaluation. This analysis identified ocGVHD as having significantly higher severity at presentation and at maximum global severity compared to classic cGVHD. OS and DFS were significantly lower for ocGVHD versus classic cGVHD. OcGVHD is associated with increased cGVHD severity scores, and is associated with decreased OS and DFS compared to classic cGVHD, underscoring the high risks with this cGVHD subtype.

Minnelide suppresses GVHD and enhances survival while maintaining GVT responses

Allogeneic hematopoietic stem cell transplantation (aHSCT) can cure patients with otherwise fatal leukemias and lymphomas. However, the benefits of aHSCT are limited by graft-versus-host disease (GVHD). Minnelide, a water-soluble analog of triptolide, has demonstrated potent antiinflammatory and antitumor activity in several preclinical models and has proven both safe and efficacious in clinical trials for advanced gastrointestinal malignancies. Here, we tested the effectiveness of Minnelide in preventing acute GVHD as compared with posttransplant cyclophosphamide (PTCy). Strikingly, we found Minnelide improved survival, weight loss, and clinical scores in an MHC-mismatched model of aHSCT. These benefits were also apparent in minor MHC-matched aHSCT and xenogeneic HSCT models. Minnelide was comparable to PTCy in terms of survival, GVHD clinical score, and colonic length. Notably, in addition to decreased donor T cell infiltration early after aHSCT, several regulatory cell populations, including Tregs, ILC2s, and myeloid-derived stem cells in the colon were increased, which together may account for Minnelide's GVHD suppression after aHSCT. Importantly, Minnelide's GVHD prevention was accompanied by preservation of graft-versus-tumor activity. As Minnelide possesses anti-acute myeloid leukemia (anti-AML) activity and is being applied in clinical trials, together with the present findings, we conclude that this compound might provide a new approach for patients with AML undergoing aHSCT.

Navigating the Complexity of Chronic Graft-vs-Host Disease: Canadian Insights into Real-World Treatment Sequencing

BACKGROUND

Graft-vs-Host Disease (GVHD) is a donor immune-mediated syndrome occurring in patients who undergo an allogeneic hematopoietic cell transplant (HCT). Chronic GVHD (cGVHD) presents with complications of variable severity. Corticosteroids are standard first-line (1L) treatment, but the sequence after 1L is unclear with the availability of new treatments. This research aimed to understand real-world treatment sequencing for cGVHD.

METHODS

This retrospective study investigated adult patients across 7 treatment sites in Canada who had received an allogeneic HCT >18 months prior to the study, experienced cGVHD, and received systemic treatment, including extracorporeal photopheresis (ECP).

RESULTS

A total of 77 cases were reviewed retrospectively (median age = 51 (IQR 41-62), 51% female). 59 patients remained on active systemic treatment, and among this group, the most common treatments in use were corticosteroids (47%) and ruxolitinib (47%). One patient died, and 17 patients were on non-systemic treatment after complications resolved. The median lines of treatment (LOT) received was 2 (IQR 1-3), with 39% of patients having received >2 LOT. Among patients with lung complications (n = 24), 41% had received 3 or more LOT. Among patients with scleroderma (n = 22), 77% had received 3 or more LOT, 23% of which had received 6 or more unique treatments.

CONCLUSIONS

The first treatment given to cGVHD patients was corticosteroids. Ruxolitinib was the most used second-line treatment. About 40% of cGVHD patients received >2 treatments, and scleroderma was associated with more LOT. There is a need for more effective cGVHD treatment options when early treatments fail to resolve complications.

Patient-reported treatment response in chronic graft-versus-host disease

Not available.

Chronic graft-versus-host disease. Part I: Epidemiology, pathogenesis, and clinical manifestations

Chronic graft-versus-host disease is a major complication of allogeneic hematopoietic cell transplantation and a leading cause of long-term morbidity, nonrelapse mortality, and impaired health-related quality of life. The skin is commonly affected and presents heterogeneously, making the role of dermatologists critical in both diagnosis and treatment. In addition, new clinical classification and grading schemes inform treatment algorithms, which now include 3 U.S. Food and Drug Administration-approved therapies, and evolving transplant techniques are changing disease epidemiology. Part I reviews the epidemiology, pathogenesis, clinical manifestations, and diagnosis of chronic graft-versus-host disease. Part II discusses disease grading and therapeutic management.

Chronic graft-versus-host disease. Part II: Disease activity grading and therapeutic management

Chronic graft-versus-host disease (cGVHD) is a major complication of allogeneic hematopoietic cell transplantation and a leading cause of long-term morbidity, nonrelapse mortality, and impaired health-related quality of life. The skin is commonly affected and presents heterogeneously, making the role of dermatologists critical in both diagnosis and treatment. In addition, new clinical classification and grading schemes inform treatment algorithms, which now include 3 Federal Drug Administration-approved therapies, and evolving transplant techniques are changing disease epidemiology. Part I reviews the epidemiology, pathogenesis, clinical manifestations, and diagnosis of cGVHD. Part II discusses disease grading and therapeutic management.

Severity of Chronic Graft-versus-Host Disease and Late Effects Following Allogeneic Hematopoietic Cell Transplantation for Adults with Hematologic Malignancy

The study aimed to determine the association of chronic graft-versus-host disease (cGVHD) diagnosis and severity with the development of subsequent neoplasms (SN) and nonmalignant late effects (NM-LE) in 2-year disease-free adult survivors following hematopoietic cell transplantation (HCT) for a hematologic malignancy. To do so, we conducted a retrospective analysis of 3884 survivors of HCT for hematologic malignancy in the Center of International Blood and Marrow Transplant Research database. We conducted a landmark analysis at the 2-year post-transplantation date, comparing first SN and NM-LE in survivors with and without cGVHD. The cumulative incidence (CuI) of SN and NM-LE were estimated through 10 years post-HCT in both groups, with death or disease relapse as a competing risk. Cox proportional hazards models were used to evaluate the associations of cGVHD and its related characteristics with the development of SN and NM-LE. The estimated 10-year CuI of SN in patients with GVHD (n = 2669) and patients without cGVHD (n = 1215) was 15% (95% confidence interval [CI], 14% to 17%) versus 9% (7.2% to 11%) (P < .001). cGVHD by 2 years post-HCT was independently associated with SN (hazard ratio [HR], 1.94; 95% CI, 1.53 to 2.46; P < .0001) with a standardized incidence ratio of 3.2 (95% CI, 2.9 to 3.5; P < .0001). Increasing severity of cGVHD was associated with an increased risk of SN. The estimated 10-year CuI of first NM-LE in patients with and without cGVHD was 28 (95% CI, 26% to 30%) versus 13% (95% CI, 11% to 15%) (P < .001). cGVHD by 2 years post-HCT was independently associated with NM-LE (HR, 2.23; 95% CI, 1.81 to 2.76; P < .0001). Multivariate analysis of cGVHD-related factors showed that increasing severity of cGVHD, extensive grade, having both mucocutaneous and visceral involvement, and receiving cGVHD treatment for >12 months were associated with the greatest magnitude of risk for NM-LE. cGVHD was closely associated with both SN and NM-LE in adult survivors of HCT for hematologic malignancy. Patients identified as having more severe involvement and both mucocutaneous and visceral organ involvement may warrant enhanced monitoring and screening for SNs and NM-LEs. However, caution is warranted when interpreting these results, as patients with cGVHD may have more vigilant post-transplantation health care and surveillance for late effects.

CSF-1R inhibitor PLX3397 attenuates peripheral and brain chronic GVHD and improves functional outcomes in mice

Graft-versus-host disease (GVHD) is a serious complication of otherwise curative allogeneic haematopoietic stem cell transplants. Chronic GVHD induces pathological changes in peripheral organs as well as the brain and is a frequent cause of late morbidity and death after bone-marrow transplantation. In the periphery, bone-marrow-derived macrophages are key drivers of pathology, but recent evidence suggests that these cells also infiltrate into cGVHD-affected brains. Microglia are also persistently activated in the cGVHD-affected brain. To understand the involvement of these myeloid cell populations in the development and/or progression of cGVHD pathology, we here utilized the blood-brain-barrier permeable colony stimulating factor-1 receptor (CSF-1R) inhibitor PLX3397 (pexidartinib) at varying doses to pharmacologically deplete both cell types. We demonstrate that PLX3397 treatment during the development of cGVHD (i.e., 30 days post-transplant) improves disease symptoms, reducing both the clinical scores and histopathology of multiple cGVHD target organs, including the sequestration of T cells in cGVHD-affected skin tissue. Cognitive impairments associated with cGVHD and neuroinflammation were also attenuated by PLX3397 treatment. PLX3397 treatment prior to the onset of cGVHD (i.e., immediately post-transplant) did not change in clinical scores or histopathology. Overall, our data demonstrate significant benefits of using PLX3397 for the treatment of cGVHD and associated organ pathologies in both the periphery and brain, highlighting the therapeutic potential of pexidartinib for this condition.

Separation of GVL from GVHD -location, location, location

Allogeneic hematopoietic cell transplantation (HCT) is a curative therapy for various hematologic malignancies. However, alloimmune response is a double-edged sword that mediates both beneficial graft-versus-leukemia (GVL) effects and harmful graft-versus-host disease (GVHD). Separation of GVL effects from GVHD has been a topic of intense research to improve transplant outcomes, but reliable clinical strategies have not yet been established. Target tissues of acute GVHD are the skin, liver, and intestine, while leukemic stem cells reside in the bone marrow. Tissue specific effector T-cell migration is determined by a combination of inflammatory and chemotactic signals that interact with specific receptors on T cells. Specific inhibition of donor T cell migration to GVHD target tissues while preserving migration to the bone marrow may represent a novel strategy to separate GVL from GVHD. Furthermore, tissue specific GVHD therapy, promoting tissue tolerance, and targeting of the tumor immune microenvironment may also help to separate GVHD and GVL.

Long-term Use of Ibrutinib in Japanese Patients with Steroid Dependent/Refractory cGVHD: Final Analysis of Multicenter Study

Background

Chronic graft-versus-host disease (cGVHD) is a serious complication after allogeneic stem cell transplantation. Poor prognosis has been shown in patients with cGVHD after the failure of primary steroid-based treatments. A previous report demonstrated the efficacy and safety of ibrutinib in these patients, leading to the approval of ibrutinib for cGVHD in Japan. Here, we report the extended follow-up of patients in this study.

Objectives

To evaluate the safety and efficacy of ibrutinib in Japanese patients with steroid-dependent or refractory cGVHD.

Study Design

An open-label, single-arm, multicenter study of ibrutinib in Japanese patients with steroid-dependent or refractory cGVHD (NCT No.: NCT03474679; Clinical Registry No.: CR108443).

Results

At the time of the final data cutoff, 7/19 (36.8%) patients completed the study treatment, and 12/19 (63.2%) patients discontinued ibrutinib. After a median follow-up of 31.11 months (range:1.9 to 38.6 months), the best overall response rate was 84.2% (16/19 patients; 95% CI:60.4%, 96.6%) in all treated populations, with a median time to response of 2.81 (range:1.0 to 27.6) months. Of 15 responders with ≥2 organs involved at baseline, seven (46.7%) had responses in multiple organs. An improvement in the organ response rate was observed for the skin, eye, mouth, and esophagus compared with that in a previous report. The rate of sustained response for ≥20 weeks, ≥32 weeks, and ≥44 weeks were 68.8%, 62.5%, and 50.0%, respectively for 16 responders. The median daily corticosteroid dose requirement tended to decrease over time for all treated analysis sets. Twelve of 19 patients (63.2%) reached a corticosteroid dose of <0.15 mg/kg/day for at least one week, and four (21.1%) discontinued corticosteroid treatment for at least 28 days during the study. The failure-free and overall survival rates at 30 months were 62.7% and 62.0%, respectively. The safety findings of this updated analysis were consistent with the safety profile observed at the time of the primary analysis and the known ibrutinib safety profile. Common grade ≥3 treatment-emergent adverse events (TEAEs) were pneumonia (6/19 [31.6%] patients), platelet count decreased, and cellulitis (3/19 [15.8%] patients each). After the primary analysis, no new TEAEs leading to death, treatment discontinuation, or dose reduction were reported, and no new patients reported major hemorrhage. Cardiac arrhythmia (Grade 2 atrial flutter) was reported in 1/19 (5.3%) patients. No new safety signs were observed despite prolonged ibrutinib exposure.

Conclusions

The final results support previous conclusions, demonstrating a clinically meaningful response and acceptable safety profile of ibrutinib in Japanese patients with steroid-dependent or refractory cGVHD.

Novel therapies for graft versus host disease with a focus on cell therapies

Graft versus host disease (GVHD) can occur at any period post allogeneic hematopoietic stem cell transplantation as a common clinical complication contributing to significant morbidity and mortality. Acute GVHD develops in approximately 30-50% of patients receiving transplants from matched related donors. High doses of steroids are used as first-line treatment, but are unsuccessful in around 40% of patients, resulting in the diagnosis of steroid-refractory acute GVHD. Consensus has yet to develop for the management of steroid-refractory acute GVHD, and prognosis at six months has been estimated at around 50%. Thus, it is critical to find effective treatments that increase survival of steroid-refractory acute GVHD. This article describes the currently known characteristics, pathophysiology, and treatments for GVHD, with a special focus on recent advances in cell therapies. In particular, a novel cell therapy using decidua stromal cells (DSCs) was recently shown to have promising results for acute GVHD, with improved effectiveness over previous treatments including mesenchymal stromal cells. At the Karolinska Institute, severe acute GVHD patients treated with placenta-derived DSCs supplemented with either 5% albumin or 10% AB plasma displayed a one-year survival rate of 76% and 47% respectively. Furthermore, patients with steroid-refractory acute GVHD, displayed survival rates of 73% with albumin and 31% with AB plasma-supplemented DSCs, compared to the 20% survival rate in the mesenchymal stromal cell control group. Adverse events and deaths were found to be attributed only to complications of hematopoietic stem cell transplant and GVHD, not to the study intervention. ASC Therapeutics, Inc, in collaboration with the Karolinska Institute, will soon initiate a phase 2 multicenter, open-label study to further assess the efficacy and safety of intravenous DSC treatment in sixty patients with Grade II-IV steroid-refractory acute GVHD. This novel cell therapy represents a promising treatment to combat the poor prognosis that steroid-refractory acute GVHD patients currently face.

Treatment of steroid-refractory graft versus host disease in children

Systemic steroids are still the first-line approach in acute graft-versus-host disease (aGvHD), and the backbone of chronic GvHD management. Refractoriness to steroid represent a major cause of morbidity and non-relapse mortality after hematopoietic stem cell transplantation (HSCT). In both backgrounds, several second-line immunosuppressive agents have been tested with variable results in terms of efficacy and toxicity. Solid evidence regarding these approaches is still lacking in the pediatric setting where results are mainly derived from adult experiences. Furthermore, the number of treated patients is limited and the incidence of acute and chronic GvHD is lower, resulting in a very heterogeneous approach to this complication by pediatric hematologists. Some conventional therapies and anti-cytokine monoclonal antibodies used in the adult setting have been evaluated in children. In recent years, the increasing understanding of the biological mechanisms underpinning the pathogenesis of GvHD justified the efforts toward the adoption of targeted therapies and non-pharmacologic approaches, with higher response rates and lower immunosuppressive effects. Moreover, many questions regarding the precise timing and setting in which to integrate these new approaches remain unanswered. This Review aims to critically explore the current evidence regarding novel approaches to treat SR-GvHD in pediatric HSCT recipients.

Chronic GvHD NIH Consensus Project Biology Task Force: evolving path to personalized treatment of chronic GvHD

Chronic graft-versus-host disease (cGvHD) remains a prominent barrier to allogeneic hematopoietic stem cell transplantion as the leading cause of nonrelapse mortality and significant morbidity. Tremendous progress has been achieved in both the understanding of pathophysiology and the development of new therapies for cGvHD. Although our field has historically approached treatment from an empiric position, research performed at the bedside and bench has elucidated some of the complex pathophysiology of cGvHD. From the clinical perspective, there is significant variability of disease manifestations between individual patients, pointing to diverse biological underpinnings. Capitalizing on progress made to date, the field is now focused on establishing personalized approaches to treatment. The intent of this article is to concisely review recent knowledge gained and formulate a path toward patient-specific cGvHD therapy.

Belumosudil Impacts Immunosuppression Pharmacokinetics in Patients with Chronic Graft-versus-Host Disease

Belumosudil (BEL) is a novel Rho-associated coiled-coil containing protein kinase 2 (ROCK2) inhibitor approved for the treatment of chronic graft-versus-host disease (cGVHD) in patients who have failed 2 or more prior lines of systemic therapy. Although the pharmacokinetic effects of BEL on other immunosuppressive (IS) agents have not been clinically evaluated, in vitro data indicate that BEL may have possible interactions with drugs with a narrow therapeutic index used to treat cGVHD, such as tacrolimus, sirolimus, and cyclosporine, through cytochrome P450 (CYP3A) and p-glycoprotein interactions. Further evaluation of these potential interactions is warranted to optimize the safety and effectiveness of these medications when combined with BEL. In this study, we investigated the potential effects of BEL on sirolimus and tacrolimus levels when used concurrently by assessing changes in IS levels after the addition of BEL. This retrospective single-center study of patients who started BEL while on tacrolimus and/or sirolimus between February 1, 2019, to February 1, 2023, included patients who had IS levels measured at baseline prior to starting BEL and at least 1 subsequent IS measurement to assess changes over time. The primary endpoint was the concentration-dose (C/D) ratio analyzed before and after the addition of BEL. Secondary endpoints included the incidence of IS levels outside of the therapeutic range (subtherapeutic or supratherapeutic) and mean dosage changes over time. Thirty-seven patients met our eligibility criteria and were included in this analysis. Patients taking sirolimus (n = 30) or tacrolimus (n = 16) concurrently with BEL had a statistically significant increase in the C/D ratio (sirolimus recipients, 160% [P < .001]; tacrolimus recipients, 113% [P = .013]) between the pre-BEL and final post-BEL assessments. The C/D ratios for both tacrolimus and sirolimus recipients continued to increase at several time points after initiation of BEL, indicating that multiple drug dosage adjustments may be required. After BEL initiation, 19% of tacrolimus levels and 57% of sirolimus levels were supratherapeutic. Despite dosage adjustments, 27% of tacrolimus levels were supratherapeutic at both the second and third assessments after starting BEL, and 28% and 30% of sirolimus levels were supratherapeutic at these 2 time points, respectively. All 12 of the patients who discontinued BEL during the study period (100%) showed a return to their baseline C/D ratio, confirming that the C/D ratio change can be attributed to BEL. The impact of BEL on IS levels is clinically significant, warranting dosage adjustments of concurrent medications. A significant number of patients taking sirolimus with BEL had levels >15 ng/mL during the study period, indicating a potential risk for toxicity if this interaction is unmonitored. We recommend empiric dose reductions of 25% for tacrolimus and 25% to 50% for sirolimus when adding BEL, as well as close monitoring of IS levels during the initial weeks of BEL therapy. Future studies are warranted to better describe the impact of BEL on patients taking CYP3A inhibitors.

Propensity score matching analysis comparing the efficacy of Ruxolitinib to historical controls in second-line or beyond treatment for chronic GvHD after steroid failure

Established first-line therapy for chronic graft-versus-host disease (cGvHD) comprises corticosteroids with/without calcineurin inhibitors, but about half of cGvHD patients are refractory to corticosteroid therapy. The present study retrospectively analyzed treatment outcomes in 426 patients and undertook a propensity-score matching (PSM) analysis between ruxolitinib (RUX) treated group and a historical group of cGvHD patients treated with best available treatment (BAT). PSM process adjusted unbalanced risk factors between the 2 groups, including GvHD severity, HCT-CI score, and treatment line, extracting 88 patients (44 in BAT/RUX groups each) for final analysis. In PSM subgroup, RUX group showed 74.7% 12 months' FFS rate vs 19.1% for BAT group (p < 0.001), whereas 12 months' OS rates were 89.2% and 77.7%, respectively. Multivariate analysis for FFS confirmed RUX superiority over BAT together with HCT-CI score 0-2 vs ≥3. For OS, RUX was superior to BAT, while age ≥60 years and severe grade cGvHD adversely impacted OS. In PSM subgroup, at months 0, 3, and 6, 4.5%, 12.2% and 22.2% more patients in RUX group could discontinue prednisone compared to BAT group, respectively. In conclusion, the current study showed that for FFS, RUX was superior to BAT as second-line therapy or beyond in cGvHD patients after therapy failure.

Graft versus Leukemia in 2023

Allogeneic hematopoietic stem cell transplantation (HSCT) is commonly utilized in the management of leukemia across multiple subtypes. Graft versus leukemia (GVL) is a critical component of successful transplantation and involves donor cells eradicating residual leukemia within the recipient. Graft versus host disease (GVHD) by contrast is a common complication of the transplantation process in which donor cells identify the recipient's various organ systems as foreign, thereby leading to a multitude of organ toxicities that can be described as autoimmune in nature. As both GVL and GVHD are mediated by a similar mechanism, these processes are felt to occur in tandem with one another. Here, we review the allogeneic HCT process in the context of GVL.

Real-world experience with low-dose IL-2 for children and young adults with refractory chronic graft-versus-host disease

The majority of patients with chronic graft-versus-host disease (cGVHD) are steroid refractory (SR), creating a need for safe and effective therapies. Subcutaneous low-dose interleukin-2 (LD IL-2), which preferentially expands CD4+ regulatory T cells (Tregs), has been evaluated in 5 clinical trials at our center with partial responses (PR) in ∼50% of adults and 82% of children by week 8. We now report additional real-world experience with LD IL-2 in 15 children and young adults. We conducted a retrospective chart review of patients with SR-cGVHD at our center who received LD IL-2 from August 2016 to July 2022 not on a research trial. The median age at start of LD IL-2 was 10.4 years (range, 1.2-23.2 years) at a median of 234 days from cGVHD diagnosis (range, 11-542 days). Patients had a median of 2.5 (range, 1-3) active organs at LD IL-2 start and received a median of 3 (range, 1-5) prior therapies. The median duration of LD IL-2 therapy was 462 days (range, 8-1489 days). Most patients received 1 × 106 IU/m2 per day. There were no serious adverse effects. The overall response rate in 13 patients who received >4 weeks of therapy was 85% (complete response, n = 5; PR, n = 6) with responses in diverse organs. Most patients significantly weaned corticosteroids. Tregs preferentially expanded with a median peak fold increase of 2.8 in the ratio of Tregs to CD4+ conventional T cells (range, 2.0-19.8) by 8 weeks on therapy. LD IL-2 is a well-tolerated, steroid-sparing agent with a high response rate in children and young adults with SR-cGVHD.

Synthetic Approaches to the New Drugs Approved During 2021

Each year, new drugs are introduced to the market, representing structures that have affinity for biological targets implicated in human diseases and conditions. These new chemical entities (NCEs), particularly small molecules and antibody-drug conjugates, provide insight into molecular recognition and serve as potential leads for the design of future medicines. This annual review is part of a continuing series highlighting the most likely process-scale synthetic approaches to 35 NCEs that were first approved anywhere in the world during 2021.

Perspectives on oral chronic graft-versus-host disease from immunobiology to morbid diagnoses

Chronic Graft-versus-Host Disease (cGVHD) is a major long-term complication, associated with morbidity and mortality in patients following allogenic hematopoietic cell transplantation (HCT) for immune hematopoietic disorders. The mouth is one of the most frequently affected organs after HCT (45-83%) and oral cGVHD, which may appear as the first visible sign. Manifestations present with mucosal lichenoid lesions, salivary gland dysfunction and limited oral aperture. Diagnosis of oral cGVHD severity is based on mucosal lesions with symptoms of sensitivity and pain and reduced oral intake. However, diagnostic difficulties arise due to subjective definitions and low specificity to cover the spectrum of oral cGVHD. In recent years there have been significant improvements in our understanding of the underlying oral cGVHD disease mechanisms. Drawing upon the current knowledge on the pathophysiology and biological phases of oral cGVHD, we address oral mucosa lichenoid and Sjogren's Syndrome-like sicca syndromes. We consider the response of alloreactive T-cells and macrophages to recipient tissues to drive the pathophysiological reactions and biological phases of acute inflammation (phase 1), chronic inflammation and dysregulated immunity (phase 2), and subsequent aberrant fibrotic healing (phase 3), which in time may be associated with an increased malignant transformation rate. When formulating treatment strategies, the pathophysiological spectrum of cGVHD is patient dependent and not every patient may progress chronologically through the biological stages. As such there remains a need to address and clarify personalized diagnostics and management to improve treatment descriptions. Within this review, we highlight the current state of the art knowledge on oral cGVHD pathophysiology and biological phases. We address knowledge gaps of oral cGVHD, with a view to facilitate clinical management and improve research quality on lichenoid biology and morbid forms of oral cGVHD.

Study protocol: Phase I/II trial of induced HLA-G+ regulatory T cells in patients undergoing allogeneic hematopoietic cell transplantation from an HLA-matched sibling donor

Regulatory T-cell (Treg) immunotherapy has emerged as a promising and highly effective strategy to combat graft-versus-host disease (GvHD) after allogeneic hematopoietic cell transplantation (allo-HCT). Both naturally occurring Treg and induced Treg populations have been successfully evaluated in trials illustrating the feasibility, safety, and efficacy required for clinical translation. Using a non-mobilized leukapheresis, we have developed a good manufacturing practice (GMP)-compatible induced Treg product, termed iG-Tregs, that is enriched in cells expressing the potent immunosuppressive human leucocyte antigen-G molecule (HLA-G⁺). To assess the safety and the maximum tolerable dose (MTD) of iG-Tregs, we conduct a phase I-II, two-center, interventional, dose escalation (3 + 3 design), open-label study in adult patients undergoing allo-HCT from an HLA-matched sibling donor, which serves also as the donor for iG-Treg manufacturing. Herein, we present the clinical protocol with a detailed description of the study rationale and design as well as thoroughly explain every step from patient screening, product manufacturing, infusion, and participant follow-up to data collection, management, and analysis (registered EUDRACT-2021-006367-26).

Day 4 collection of granulocyte colony-stimulating factor-mobilized HLA-matched sibling donor peripheral blood allografts demonstrates no long-term increase in chronic graft-versus-host disease or relapse rates

BACKGROUND AIMS

In a previous pilot study of HLA-matched sibling donor hematopoietic cell transplantation (HCT), the authors determined the feasibility of day 4 versus day 5 granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood stem cell (PBSC) collection compared with a historical cohort. Given identified differences in the PBSC product (day 4 cohort with significantly lower infused total nucleated, mononuclear and CD3 cells compared with other collection cohorts), the authors performed a follow-up study to determine long-term post-HCT outcomes, including detailed characterization of chronic graft-versus-host disease (GVHD).

METHODS

This was a prospective observational study, and the authors collected data on chronic GVHD, staging, sites of involvement and treatments. Performance status, incidence of relapse, overall survival and duration of immunosuppressive therapy (IST) were also evaluated. Data were examined retrospectively. To account for differences in length of follow-up among cohorts, the authors also determined performance status and chronic GVHD staging, sites and treatment at 2 years post-HCT.

RESULTS

At 2 years post-HCT, the overall survival rate was 71.7% in the day 4 cohort compared with 61.5%, 52% and 56% in the day 5, 2-day and historical cohorts, respectively (P = 0.283). The cumulative incidence of chronic GVHD was 65.2% in the day 4 cohort versus 46.4% in the day 5 cohort, 51.1% in the 2-day cohort and 65% in the historical cohort (P = 0.26). There was no significant difference in the maximum overall stage of chronic GVHD (P = 0.513), median number of sites involved (P = 0.401) or cumulative incidence of discontinuation of IST (P = 0.32). Death from chronic GVHD was less common in the day 4 and day 5 cohorts compared with the 2-day and historical cohorts, though this did not reach statistical significance.

CONCLUSIONS

The authors' preliminary results demonstrated that collection of allogeneic matched sibling donor PBSCs on day 4 of G-CSF was feasible, reduced donor exposure to growth factor and was associated with an initial cost savings. Importantly, the authors now demonstrate that transplantation of day 4 mobilized PBSCs is not associated with any adverse outcomes post-HCT, including late effects such as chronic GVHD. Further investigation of donor G-CSF collection algorithms is merited in other HCT settings, including unrelated and mismatched related donors.

Correlation of Patient-Reported Outcomes with Clinical Organ Responses: Data from the Belumosudil Chronic Graft-versus-Host Disease Studies

Chronic graft-versus-host disease (GVHD) is a major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT) owing to both the disease itself and the immunosuppressive agents used for treatment. Response criteria endorsed by the National Institutes of Health (NIH) Consensus Conference on Clinical Trials in chronic GVHD include both clinician-documented measures and patient-reported outcomes (PROs) since both are considered clinical benefits by the Food and Drug Administration. The correlation between clinically assessed responses in organs and PRO improvements in organ-specific symptoms has not been investigated in depth. We used data from 2 published studies of belumosudil, an oral rho-associated coiled-coil-containing protein kinase-2 (ROCK2) inhibitor, for chronic GVHD to test the correlation between clinical and PRO outcomes. Participants completed PROs at enrollment and every 1 to 2 cycles according to the study design. Individual organ responses (complete plus partial response) and clinically meaningful changes in PROs were defined according to published methods. Generalized estimating equation methods were used to correlate changes in PROs associated with clinical responses according to NIH criteria, accounting for missing information and repeated measures. Data from all doses in both trials were included without stratification. The liver and genital tract were not included owing to a lack of site-specific PROs. Our pooled analysis of clinical and PRO data included 170 patients enrolled in 2 belumosudil studies (NCT02841995, n = 54; NCT03640481, n = 132) for whom we had baseline PROs, at least 1 follow-up PRO, and at least 1 response assessment. There was a strong positive correlation between complete and partial organ and overall responses and changes in PRO symptom scores, as well as clinically meaningful improvements. For all organs except joints, esophagus, and lower gastrointestinal tract, there was at least 1 PRO statistically correlated with NIH organ response. These data support the use of PROs for response assessment to document clinically meaningful benefit in chronic GVHD clinical trials.

Durability of clinical and immunologic responses to extended low-dose interleukin-2 therapy in patients with refractory chronic graft-versus-host disease

Chronic graft-versus-host disease (cGVHD) remains a frequent cause of non-relapse morbidity and mortality after allogeneic hematopoietic stem cell transplantation. In our single center trials of low-dose interleukin-2 (LD IL-2), the immunomodulatory properties of regulatory T cells (Tregs) have been harnessed to treat steroid-refractory cGVHD (SR-cGVHD) safely and effectively in adults and children. In these trials, 50-60% of patients showed clinical improvement of their cGVHD manifestations with partial responses at the primary response endpoint of 8-12 weeks. Many patients continued extended duration LD IL-2 therapy and achieved deeper clinical responses, including some complete responses. However, the durability of the clinical and immunologic improvement following IL-2 discontinuation has not been reported previously. We examined 20 adult and 2 pediatric patients who received extended duration LD IL-2 for a median of 103 weeks (range, 21-258) and had stable improvement or resolution of their cGVHD symptoms before discontinuing LD IL-2 therapy. The median follow-up after stopping IL-2 was 203 weeks (range 92-599). During this time, 16 patients (73%) were able to wean off all systemic immunosuppression without disease flare or progression. Among 13 patients with available immune cell data, the median fold change in absolute Treg count was 0.58 between 1 to 10 weeks after stopping IL-2 whereas CD4+ conventional T-cell (Tcon) and CD8+ T-cell numbers remained stable. Despite a decline in Treg numbers after IL-2 discontinuation, Treg numbers remained above the pre-treatment baseline. In addition, many patients had sustained clinical improvement after stopping IL-2, suggesting that extended IL-2 therapy can lead to immune tolerance.