Carfilzomib for Treatment of Refractory Chronic Graft-versus-Host Disease: A Chronic GVHD Consortium Pilot Phase II Trial

A personalized, organ-based approach to the treatment of chronic steroid-refractory graft-versus-host disease

Chronic graft-versus-host-disease (cGvHD) remains the leading cause of morbidity among transplant recipients. The efficacy of second-line treatments varies widely based on many factors, including wide differences in the organ overall response-rate response and in the current era where multiple agents are approved, and optimal sequencing of drugs based on organ ORR is unknown. We aimed to evaluate outcomes based on ORRs to the most common agents for the treatment of steroid-refractory/steroid-dependent cGvHD by conducting a systematic literature review. A total of 387 studies were evaluated for the ORRs of 12 cGvHD treatments. The highest skin ORR was observed to be 77% though some agents had an acceptable ORR. Most agents had an ocular response ranging from 17 to 50% Some agents resulted in a GI ORR of ≥88%. Rituximab showed the best response for musculoskeletal-GvHD. In the case of lung-GvHD (bronchiolitis obliterans syndrome [BOS]), negligible response was observed in patients treated with various agents. No clinically meaningful responses to treatments were reported for genital-GvHD. Most GvHD trials are focused on the ORR and partial response rates (PRR). The evidence for optimal agents for each organ is limited, and therefore, our study results are striking for differences in organ-ORR yields for a clinically meaningful difference. Thus, a personalized organ-based approach to the selection of therapeutic agents in cGvHD could result in favorable outcomes.

The clinical landscape of chronic graft-versus-host disease management in 2021

Chronic graft-versus-host disease (cGVHD) is an important systemic complication of allogeneic haematopoietic stem cell transplantation with heterogeneous, multi-organ involvement that can lead to increased morbidity and mortality. Despite significant advances in understanding the complex pathophysiology driving the disease, curative treatment options remain suboptimal. The past decade, however, has seen much growth in collaborative research efforts and standardization of criteria for clinical trials that have led to discovery of several new second-line therapies in cGVHD. The key to successful cGVHD control and management includes a comprehensive and sustained multidisciplinary effort with emphasis on ancillary and supportive care for these patients. The focus of this review is to summarize the new developments in systemic, organ-specific, and topical treatments in the management of cGVHD that emerged since the 2014 NIH consensus conference.

Ibrutinib in Steroid-Refractory Chronic Graft-versus-Host Disease, a Single-Center Experience

Chronic graft-versus-host disease (cGVHD) is a leading cause of late morbidity and mortality after allogenic hematopoietic stem cell transplantation. Corticosteroid-based therapies are a mainstay of its initial treatment but there is no consensus in how to treat steroid-refractory cGVHD. Ibrutinib is a Bruton tyrosine kinase and IL-2-inducible kinase inhibitor thought to affect pathways driving cGVHD, and it was approved for the treatment of refractory cGVHD by the Food and Drug Administration (FDA) in August 2017 after a landmark phase 1b/2 study. It was the first medication approved for this indication, but how to best treat refractory cGVHD remains an open question, and there has been limited literature on ibrutinib after the FDA approval. This study sought to characterize the utilization and outcomes associated with ibrutinib use in cGVHD via a retrospective single-center study. Fifty-three patients were identified as having been treated with ibrutinib for cGVHD following FDA approval between September 1, 2017, and December 31, 2020, using an institutional data repository. Their records were reviewed for demographics, cGVHD characteristics, and outcomes. For the entire cohort, two-year overall survival was 76% (95% confidence interval [CI], 60% to 86%), with a median follow-up among survivors of 26 months (range, 1.3 to 39.5 months). However, the 2-year failure-free survival (FFS) after initiation of ibrutinib was 9% (95% CI, 2.6% to 20%), and the median FFS was 4.5 months (95% CI, 2.8 to 7.1 months). Events of FFS included treatment change due to lack of response or toxicity, malignant relapse, or non-treatment related mortality. At the time of this report, 11 patients (21%) remained on ibrutinib. At the time of the FFS event or last follow-up, 6 patients (12%) had a complete or partial response, 34 (64%) had stable disease, and 13 (25%) had progressive disease. Ibrutinib use was associated with no reduction in corticosteroid dose between ibrutinib initiation and FFS event or last follow-up (mean difference, 0.00; P = .98). The most frequently used noncorticosteroid cGVHD therapy after ibrutinib was ruxolitinib (n = 14; 33%). The most common adverse events associated with treatment discontinuation were infection (lung, skin, enterocolitis; n = 6), bleeding and bruising (hematoma, epistaxis, gastrointestinal bleed; n = 5), and muscle aches (n = 2). In a real-world setting, ibrutinib is associated with a modest response rate and FFS and its use in a narrower, more targeted patient population may be indicated.

Hydrogen in Patients With Corticosteroid-Refractory/Dependent Chronic Graft-Versus-Host-Disease: A Single-Arm, Multicenter, Open-Label, Phase 2 Trial

Chronic graft-versus-host-disease (cGVHD) is the leading cause of late non-relapse mortality after allogeneic hematopoietic stem cell transplantation(HSCT). There is no standard therapy for patients refractory or dependent to corticosteroid treatment. We hypothesized that hydrogen may exert therapeutic effects on cGVHD patients with few side effects. A prospective open-label phase 2 study of hydrogen was conducted. Patients received hydrogen-rich water 4ml/kg orally three times a day. Responses were graded in the skin, mouth, Gastrointestinal(GI), liver, eyes, lungs and joints and fascia every 3 months. A total of 24 patients (median age 27) were enrolled. Of the 24 patients, 18 (75%; 95% CI, 55.1% to 88%) had an objective response. No significant toxicity was observed. The estimated 4-year overall survival rate was 74.7%(95% CI, 54.9%-94.5%). The survival time was significantly prolonged in the response group. The survival rate at 4 years in the response group is significantly higher than the nonresponse group (86.6% vs 0%; p= 0.000132). Hydrogen showed great efficacy on cGVHD patients and long-term administration of hydrogen was not associated with significant toxic effects. The trial was registered at www.ClinicalTrials.Gov, NCT02918188.

New Approaches for the Treatment of Chronic Graft-Versus-Host Disease: Current Status and Future Directions

Chronic graft-versus-host disease (cGvHD) is a severe complication of allogeneic hematopoietic stem cell transplantation that affects various organs leading to a reduced quality of life. The condition often requires enduring immunosuppressive therapy, which can also lead to the development of severe side effects. Several approaches including small molecule inhibitors, antibodies, cytokines, and cellular therapies are now being developed for the treatment of cGvHD, and some of these therapies have been or are currently tested in clinical trials. In this review, we discuss these emerging therapies with particular emphasis on tyrosine kinase inhibitors (TKIs). TKIs are a class of compounds that inhibits tyrosine kinases, thereby preventing the dissemination of growth signals and activation of key cellular proteins that are involved in cell growth and division. Because they have been shown to inhibit key kinases in both B cells and T cells that are involved in the pathophysiology of cGvHD, TKIs present new promising therapeutic approaches. Ibrutinib, a Bruton tyrosine kinase (Btk) inhibitor, has recently been approved by the Food and Drug Administration (FDA) in the United States for the treatment of adult patients with cGvHD after failure of first-line of systemic therapy. Also, Janus Associated Kinases (JAK1 and JAK2) inhibitors, such as itacitinib (JAK1) and ruxolitinib (JAK1 and 2), are promising in the treatment of cGvHD. Herein, we present the current status and future directions of the use of these new drugs with particular spotlight on their targeting of specific intracellular signal transduction cascades important for cGvHD, in order to shed some light on their possible mode of actions.

Ixazomib for Chronic Graft-versus-Host Disease Prophylaxis following Allogeneic Hematopoietic Cell Transplantation

Chronic graft-versus-host disease (cGVHD) is major cause of morbidity and mortality following allogeneic hematopoietic cell transplantation (HCT). Ixazomib is an oral, second-generation, proteasome inhibitor that has been shown in preclinical models to prevent GVHD. We conducted a phase I/II trial in 57 patients to evaluate the safety and efficacy of ixazomib administration for cGVHD prophylaxis in patients undergoing allogeneic HCT. Oral ixazomib was administered on a weekly basis for a total of 4 doses, beginning days +60 through +90, to recipients of matched related donor (MRD, n = 25) or matched unrelated donor (MUD, n = 26) allogeneic HCT in phase II portion of the study, once the recommended phase II dose of 4 mg was identified in phase I (n = 6). All patients received peripheral blood graft and standard GVHD prophylaxis of tacrolimus and methotrexate. Ixazomib administration was safe and well tolerated, with thrombocytopenia, leukopenia, gastrointestinal complaints, and fatigue the most common adverse events (>10%). In phase II (n = 51), the cumulative incidence of cGVHD at 1 year was 36% (95% confidence interval [CI], 19% to 54%) in the MRD cohort and 39% (95% CI, 21% to 56%) in the MUD cohort. One-year cumulative incidence of nonrelapse mortality (NRM) and relapse was 0% and 20% (95% CI, 8% to 36%) in the MRD cohort, respectively. In the MUD cohort, the respective NRM and relapse rates were 4% (0% to 16%) and 34% (17% to 52%). The outcomes on the study were compared post hoc with contemporaneous matched Center for International Blood and Marrow Transplant Research (CIBMTR) controls. This post hoc analysis showed no significant improvement in cGVHD rates in both the MRD (hazard ratio [HR] = 0.85, P = .64) or MUD cohorts (HR = 0.68, P = .26) on the study compared with CIBMTR controls. B cell activating factor plasma levels were significantly higher after ixazomib dosing in those who remained cGVHD free compared with those developed cGVHD. This study shows that the novel strategy of short-course oral ixazomib following allogeneic HCT is safe but did not demonstrate significant improvement in cGVHD incidence in recipients of MRD and MUD transplantation compared with matched CIBMTR controls. This study is registered at www.clinicaltrials.gov as NCT02250300.

Carfilzomib combined with cyclosporine and methotrexate for the prevention of graft-versus-host disease after allogeneic stem-cell transplantation from unrelated donors

Acute graft-versus-host disease (aGVHD) is the major treatment-related complication after stem-cell transplantation (SCT) from unrelated donors. The proteasome-inhibitor bortezomib was added to GVHD prevention regimens with initial promise. However, two randomized studies failed to show efficacy. We explored the addition of carfilzomib, s second-generation proteasome inhibitor (20 mg/m², intravenously on days +1 and +2) to cyclosporine/methotrexate backbone in 26 patients after SCT from unrelated donors. We compared outcomes to historical group of 100 patients given cyclosporine/methotrexate alone. Median follow-up was 34 months. There was no difference between the groups in engraftment or toxicities. The cumulative incidence of aGVHD grade II-IV, 6 months post transplant was 11% (95% CI, 4-32) and 39% (95% CI, 30-50), respectively (P = 0.01). The cumulative incidence of chronic GVHD, 2 years post transplant, was 49% (95% CI, 32-75) and 41% (95% CI, 33-52), respectively (P = 0.98). Three-year non-relapse mortality was 11% (95% CI, 4-33) and 18% (95% CI, 12-27, P = 0.45) while 3-year relapse rates were 8% (95% CI, 2-29) and 26% (95% CI, 18-36), respectively (P = 0.06). Three-year survival was 81% (95%CI, 66-96) and 56% (95% CI, 46-66), respectively (P = 0.05). In conclusion, carfilzomib with cyclosporine/methotrexate is safe, may reduce aGVHD, and possibly improve survival after unrelated donor SCT. These initial observations merit further study in larger comparative studies. ClinicalTrial.gov NCT01991301.

Therapeutic options for steroid-refractory acute and chronic GVHD: an evolving landscape

Introduction: The traditional therapeutic modalities to manage SR-acute GVHD have focused on the inhibition of the alloreactive T-cell response, while in the setting of SR-chronic GVHD the focus has been on a combination of T-cell and B-cell targeting strategies. However, new therapeutic modalities have shown promise. The purpose of this review is to summarize the current treatment landscape of SR-acute and chronic GVHD.Areas covered: A systematic search of MEDLINE, EMBASE, and clinicaltrials.gov databases for published articles, abstracts, and clinical trials pertaining to available therapeutic modalities for SR-acute and SR-chronic GVHD was conducted. Also highlighted is a number of ongoing clinical trials in both SR-acute and SR-chronic GVHD with strategies targeting the JAK-1/2 pathway, the Treg:Tcon ratio, the immunomodulation mediated by mesenchymal stem cells, and the gut microbiome, among others. Expert opinion: Ruxolitinib has emerged as the preferred therapeutic modality for SR-acute GVHD, with alpha-1-antitrypsin and extracorporeal photophoresis (ECP) being reasonable alternatives. Ruxolitinib and Ibrutinib are among the preferred options for SR-chronic GVHD, with ECP being a viable alternative particularly if the skin is involved. A number of novel therapeutic modalities, including those enhancing the activity of regulatory T-cells have shown great promise in early phase trials of SR-chronic GVHD.