Predictors and outcomes of flares in chronic graft-versus-host disease.

Chronic graft-versus-host disease (cGVHD) after allogeneic hematopoietic cell transplantation (HCT) requires prolonged immunosuppressive therapy (IST), often requiring slow tapering with patients experiencing cGVHD flares and treatment failure. In 145 adult recipients developing cGVHD after matched sibling or umbilical cord blood donor HCT from 2010 to 2018, 2-year cumulative incidence of flares after cGVHD diagnosis was estimated at 60% (95% CI, 51-70%), with median time-to-first flare of 188 days (range, 16-751). Of 88 patients experiencing a flare, 32 (36%) had multiple flares (range, 2-4). First flare treatment consisted of an increase in prednisone dose in 77 patients (88%), plus topical therapy in 8 (9%) or another systemic IST in 43 patients (49%). Higher flare risk was associated with quiescent type of cGVHD at onset (HR 1.8; 95% CI: 1.1-2.7; p = 0.04). Patients without a flare required a shorter duration of IST and were more likely to achieve a durable discontinuation of systemic IST (86% vs. 31% for ≥6 consecutive months). Flares were associated with protective effect on relapse (HR 0.2, 95% CI: 0.1-0.3), however not with worsened 2-year NRM or OS. Flares of cGVHD identify a group needing better approaches to limit the duration of IST and thus the morbidity of cGVHD.

Late-Onset Acute and Chronic Graft-versus-Host Disease in Children: Clinical Features and Response to Therapy.

Although acute graft-versus-host disease (aGVHD) and chronic GVHD (cGVHD) are known causes of morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT), the syndrome of late aGVHD is less well understood, particularly in children. We aimed to characterize the clinical features and response to therapy of late aGVHD and cGVHD by retrospectively reviewing 573 consecutive patients age <18 years who underwent their first allogeneic HCT at the University of Minnesota. We included patients with de novo late aGVHD (ie, first occurrence of aGVHD after day +100 post-HCT) and cGVHD. We retrospectively scored cGVHD cases based on the 2014 National Institutes of Health guidelines. At 3 years, 9 patients (2%) had developed late aGVHD, 16 (3%) had overlap cGVHD, and 7 had (1%) classic cGVHD. No cases of joint or genital cGVHD were observed. The overall response to therapy at 6 months was 78% (95% confidence interval [CI], 40% to 97%) after late aGVHD and 43% (95% CI, 23% to 66%) after cGVHD. Higher nonrelapse mortality from day +100 was seen in patients with cGVHD but not in those with late aGVHD compared with patients without GVHD (hazard ratio, 3.6 [95% CI, 1.3 to 10.0] and 1.6 [95% CI, 0.2 to 11.7], respectively). We found variable organ involvement and treatment responses between patients with late aGVHD and those with cGVHD in a single-center pediatric cohort. Further research is needed to investigate the risks and clinical features of late aGVHD and cGVHD in larger cohorts to better understand how to tailor even more effective GVHD preventive and therapeutic approaches in children.

High incidence of thromboembolism in patients with chronic GVHD: association with severity of GVHD and donor-recipient ABO blood group.

Chronic graft-versus-host disease (cGVHD) after allogeneic hematopoietic cell transplantation (HCT) is associated with systemic inflammation and endothelial dysfunction, increasing risk for thromboembolic events (TEE). In 145 adult recipients who developed cGVHD after a matched sibling or umbilical cord blood donor HCT from 2010 to 2018, 32(22%) developed at least 1 TEE event, and 14(10%) developed 2 TEE events. The 5-year cumulative incidence of TEE was 22% (95% CI, 15-29%) with a median time from cGVHD to TEE of 234 days (range, 12-2050). Median time to the development of LE DVT or PE was 107 (range, 12-1925) compared to 450 days (range, 158-1300) for UE DVT. Cumulative incidence of TEE was 9% (95% CI, 0-20%), 17% (95% CI, 9-25%), and 38% (95% CI, 22-55%) in those with mild, moderate, and severe GVHD, respectively. Higher risk for TEE was associated with cGVHD severity (hazard ratio [HR] 4.9, [95% CI, 1.1-22.0]; p = 0.03), non-O-donor to recipient ABO match compared to O-donor to O-recipient match (HR 2.7, [95% CI, 1.0-7.5]; p = 0.053), and personal history of coronary artery disease (HR 2.4, [95% CI, 1.1-5.3]; p = 0.03). TEE was not associated with 2-year non-relapse mortality or 5-year overall survival.

Outcomes of chronic graft-versus-host disease following matched sibling donor versus umbilical cord blood transplant.

We compared chronic graft-versus-host disease (cGvHD) following umbilical cord blood (UCBT) and matched sibling donor peripheral blood transplant (MSD). 145 patients (2010-2017) with cGvHD after MSD (n = 104) and UCBT (n = 41) were included. Prior acute GvHD was less frequent in MSD (55% vs. 85%; p = 0.01). Severe cGvHD (32% vs. 15%, p = 0.01) and de-novo onset (45% vs. 15%, p < 0.01) were more frequent following MSD. Liver was more frequently involved in MSD recipients (38% vs. 6%); and GI in UCBT (33% vs. 63%), both p < 0.01. Overall response (CR + PR) was similar between both cohorts. 2-year CR was higher in UCBT (14% vs 33%, p = 0.02). Karnofsky score (KPS) ≥ 90 at cGvHD diagnosis was associated with higher odds of response (95%CI: 1.42-10, p < 0.01). The cumulative incidence of durable discontinuation of immune-suppressive therapy, failure-free survival (FFS) and NRM at 2-years were similar between cohorts. KPS < 90 (95%CI: 3.1-24.9, p < 0.01) and platelets <100 × 10e9/L (95%CI: 1.25-10, p = 0.01) were associated with higher risk of NRM. UCBT patients were more likely to have a prior acute GvHD, less severe cGvHD and more likely to attain CR. Despite differences, both cohorts had similar NRM and FFS. High-risk groups, including those with platelets <100 × 10e9/L and KPS < 90, need careful monitoring and intensified therapy.

Antigen-Specific Antitumor Responses Induced by OX40 Agonist Are Enhanced by the IDO Inhibitor Indoximod.

Although an immune response to tumors may be generated using vaccines, so far, this approach has only shown minimal clinical success. This is attributed to the tendency of cancer to escape immune surveillance via multiple immune suppressive mechanisms. Successful cancer immunotherapy requires targeting these inhibitory mechanisms along with enhancement of antigen-specific immune responses to promote sustained tumor-specific immunity. Here, we evaluated the effect of indoximod, an inhibitor of the immunosuppressive indoleamine-(2,3)-dioxygenase (IDO) pathway, on antitumor efficacy of anti-OX40 agonist in the context of vaccine in the IDO- TC-1 tumor model. We demonstrate that although the addition of anti-OX40 to the vaccine moderately enhances therapeutic efficacy, incorporation of indoximod into this treatment leads to enhanced tumor regression and cure of established tumors in 60% of treated mice. We show that the mechanisms by which the IDO inhibitor leads to this therapeutic potency include (i) an increment of vaccine-induced tumor-infiltrating effector T cells that is facilitated by anti-OX40 and (ii) a decrease of IDO enzyme activity produced by nontumor cells within the tumor microenvironment that results in enhancement of the specificity and the functionality of vaccine-induced effector T cells. Our findings suggest a translatable strategy to enhance the overall efficacy of cancer immunotherapy. Cancer Immunol Res; 6(2); 201-8. ©2018 AACR.

Agonist anti-GITR antibody significantly enhances the therapeutic efficacy of Listeria monocytogenes-based immunotherapy.

BACKGROUND: We previously demonstrated that in addition to generating an antigen-specific immune response, Listeria monocytogenes (Lm)-based immunotherapy significantly reduces the ratio of regulatory T cells (Tregs)/CD4+ and myeloid-derived suppressor cells (MDSCs) in the tumor microenvironment. Since Lm-based immunotherapy is able to inhibit the immune suppressive environment, we hypothesized that combining this treatment with agonist antibody to a co-stimulatory receptor that would further boost the effector arm of immunity will result in significant improvement of anti-tumor efficacy of treatment. METHODS: Here we tested the immune and therapeutic efficacy of Listeria-based immunotherapy combination with agonist antibody to glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR) in TC-1 mouse tumor model. We evaluated the potency of combination on tumor growth and survival of treated animals and profiled tumor microenvironment for effector and suppressor cell populations. RESULTS: We demonstrate that combination of Listeria-based immunotherapy with agonist antibody to GITR synergizes to improve immune and therapeutic efficacy of treatment in a mouse tumor model. We show that this combinational treatment leads to significant inhibition of tumor-growth, prolongs survival and leads to complete regression of established tumors in 60% of treated animals. We determined that this therapeutic benefit of combinational treatment is due to a significant increase in tumor infiltrating effector CD4+ and CD8+ T cells along with a decrease of inhibitory cells. CONCLUSION: To our knowledge, this is the first study that exploits Lm-based immunotherapy combined with agonist anti-GITR antibody as a potent treatment strategy that simultaneously targets both the effector and suppressor arms of the immune system, leading to significantly improved anti-tumor efficacy. We believe that our findings depicted in this manuscript provide a promising and translatable strategy that can enhance the overall efficacy of cancer immunotherapy.