Phase II trial of natalizumab with corticosteroids as initial treatment of gastrointestinal acute graft-versus-host disease.

The α4ß7 integrin is upregulated on naive and memory T cell subsets in patients who subsequently develop gastrointestinal (GI) acute GVHD. Natalizumab (Tysabri®, Biogen Inc.) acts against the α4 subunit that mediates homing of lymphocytes to the GI tract. We initiated a phase II study of natalizumab with corticosteroids for initial treatment of acute GI GVHD. In total, 300 mg IV of natalizumab was given, with steroids initiated up to 3 days prior. Twenty-one subjects were treated, median age was 63 years (range 38-74), and 15 (71%) were male. Eighteen (86%) underwent RIC, 15 (71%) received MUD, and all received PBSCs. Overall GVHD at enrollment was grade II in 4 and grade III in 17. The primary endpoint, day 56 GVHD-free survival rate, was attained in 33.3%. The overall response rate at day 28 and 56 was 57% and 52%, respectively. Six of eight CRs were durable for 1 year. Five experienced toxicity possibly related to natalizumab and ten had infections before day 100. 2-year OS was 43% (95% CI 22-62%) and 2-year NRM was 52% (95% CI 29-71%). Natalizumab with corticosteroids as initial treatment of acute GI GVHD is safe, effective, and durable.

Haematopoietic cell transplantation with and without sorafenib maintenance for patients with FLT3-ITD acute myeloid leukaemia in first complete remission.

We performed a retrospective study analysing the effect of sorafenib, an oral fms-Like Tyrosine Kinase 3 (FLT3)/multikinase inhibitor, as post-transplant maintenance in adult patients with FLT3-internal tandem duplication (ITD) acute myeloid leukaemia (AML). We identified consecutive patients with FLT3-ITD AML diagnosed between 2008 and 2014 who received haematopoietic cell transplantation (HCT) in first complete remission (CR1). Post-HCT initiation of sorafenib (yes/no) was evaluated as a time-varying covariate in the overall survival/progression-free survival (OS/PFS) analysis and we performed a landmark analysis of controls alive without relapse at the median date of sorafenib initiation. We identified 26 sorafenib patients and 55 controls. Median follow-up was 27·2 months post-HCT for sorafenib survivors, and 38·4 months for controls (P = 0·021). The median time to initiating sorafenib was 68 days post-HCT; 43 controls were alive without relapse at this cut-off. Sorafenib patients had improved 2-year OS in the d+68 landmark analysis (81% vs. 62%, P = 0·029). Sorafenib was associated with improved 2-year PFS (82% vs. 53%, P = 0·0081) and lower 2-year cumulative incidence of relapse (8·2% vs. 37·7%, P = 0·0077). In multivariate analysis, sorafenib significantly improved OS [Hazard ratio (HR) 0·26, P = 0·021] and PFS (HR 0·25, P = 0·016). There was no difference in 2-year non-relapse mortality (9·8% vs. 9·3%, P = 0·82) or 1-year chronic graft-versus-host disease (55·5% vs. 37·2%, P = 0·28). These findings suggest potential benefit of post-HCT sorafenib in FLT3-ITD AML, and support further evaluation of post-HCT FLT3 inhibition.

Targeted Rho-associated kinase 2 inhibition suppresses murine and human chronic GVHD through a Stat3-dependent mechanism.

Chronic graft-versus-host disease (cGVHD) remains a major complication following allogeneic bone marrow transplantation (BMT). The discovery of novel therapeutics is dependent on assessment in preclinical murine models of cGVHD. Rho-associated kinase 2 (ROCK2) recently was shown to be implicated in regulation of interleukin-21 (IL-21) and IL-17 secretion in mice and humans. Here, we report that the selective ROCK2 inhibitor KD025 effectively ameliorates cGVHD in multiple models: a full major histocompatibility complex (MHC) mismatch model of multiorgan system cGVHD with bronchiolitis obliterans syndrome and a minor MHC mismatch model of sclerodermatous GVHD. Treatment with KD025 resulted in normalization of pathogenic pulmonary function, which correlates with a marked reduction of antibody and collagen deposition in the lungs of treated mice to levels comparable to non-cGVHD controls. Spleens of mice treated with KD025 had decreased frequency of T follicular helper cells and increased frequency of T follicular regulatory cells, accompanied by a reduction in signal transducer and activator of transcription 3 (STAT3) and concurrent increase in STAT5 phosphorylation. The critical role of STAT3 in this cGVHD model was confirmed by data showing that mice transplanted with inducible STAT3-deficient T cells had pulmonary function comparable to the healthy negative controls. The therapeutic potential of targeted ROCK2 inhibition in the clinic was solidified further by human data demonstrating the KD025 inhibits the secretion of IL-21, IL-17, and interferon γ along with decreasing phosphorylated STAT3 and reduced protein expression of interferon regulatory factor 4 and B-cell lymphoma 6 (BCL6) in human peripheral blood mononuclear cells purified from active cGVHD patients. Together these data highlight the potential of targeted ROCK2 inhibition for clinical cGVHD therapy.

A Bortezomib-Based Regimen Offers Promising Survival and Graft-versus-Host Disease Prophylaxis in Myeloablative HLA-Mismatched and Unrelated Donor Transplantation: A Phase II Trial.

Hematopoietic stem cell transplantation (HSCT) recipients lacking HLA-matched related donors have increased graft-versus-host disease (GVHD) and nonrelapse mortality (NRM). Bortezomib added to reduced-intensity conditioning can offer benefit in T cell-replete HLA-mismatched HSCT and may also benefit myeloablative conditioning (MAC) transplants. We conducted a phase II trial of short-course bortezomib plus standard tacrolimus/methotrexate after busulfan/fludarabine MAC in 34 patients with predominantly myeloid malignancies. Fourteen (41%) received 8/8 HLA-matched unrelated donor (MUD) and 20 (59%) received 7/8 HLA-mismatched related/unrelated donor peripheral blood stem cell grafts. Median age was 49 years (range, 21 to 60), and median follow-up was 25 months (range, 11 to 36). The regimen was well tolerated. No dose modifications were required. Neutrophil and platelet engraftment occurred at a median of 14 (range, 10 to 33) and 17 (range, 10 to 54) days, respectively. Median 30-day donor chimerism was 99% (range, 90 to 100), and 100-day grades II to IV and III to IV acute GVHD incidence was 32% and 12% respectively. One-year chronic GVHD incidence was 50%. Two-year cumulative incidence of both NRM and relapse was 16%. Two-year progression-free and overall survival rates were 70% and 71%, respectively. Outcomes were comparable to an 8/8 MUD MAC cohort (n = 45). Immune reconstitution was robust. Bortezomib-based MAC HSCT is well tolerated, with HLA-mismatched outcomes comparable with 8/8 MUD MAC HSCT, and is suitable for randomized evaluation. (clinicaltrials.gov: NCT01323920.).

Ibrutinib treatment ameliorates murine chronic graft-versus-host disease.

Chronic graft-versus-host disease (cGVHD) is a life-threatening impediment to allogeneic hematopoietic stem cell transplantation, and current therapies do not completely prevent and/or treat cGVHD. CD4+ T cells and B cells mediate cGVHD; therefore, targeting these populations may inhibit cGVHD pathogenesis. Ibrutinib is an FDA-approved irreversible inhibitor of Bruton's tyrosine kinase (BTK) and IL-2 inducible T cell kinase (ITK) that targets Th2 cells and B cells and produces durable remissions in B cell malignancies with minimal toxicity. Here, we evaluated whether ibrutinib could reverse established cGVHD in 2 complementary murine models, a model interrogating T cell-driven sclerodermatous cGVHD and an alloantibody-driven multiorgan system cGVHD model that induces bronchiolar obliterans (BO). In the T cell-mediated sclerodermatous cGVHD model, ibrutinib treatment delayed progression, improved survival, and ameliorated clinical and pathological manifestations. In the alloantibody-driven cGVHD model, ibrutinib treatment restored pulmonary function and reduced germinal center reactions and tissue immunoglobulin deposition. Animals lacking BTK and ITK did not develop cGVHD, indicating that these molecules are critical to cGVHD development. Furthermore, ibrutinib treatment reduced activation of T and B cells from patients with active cGVHD. Our data demonstrate that B cells and T cells drive cGVHD and suggest that ibrutinib has potential as a therapeutic agent, warranting consideration for cGVHD clinical trials.

Decision analysis of peripheral blood versus bone marrow hematopoietic stem cells for allogeneic hematopoietic cell transplantation.

Peripheral blood stem cells (PBSCs) and bone marrow (BM) hematopoietic stem cells represent therapeutic alternatives in allogeneic hematopoietic cell transplantation. Randomized controlled trials and an individual patient data meta-analysis (IPDMA) have demonstrated a decreased risk of disease relapse and an increased risk of acute and chronic graft-versus-host disease (aGVHD, cGVHD) in patients receiving PBSCs compared with those receiving BM stem cells. Decision modeling provides quantitative integration of the risks and benefits associated with these alternative treatments, incorporates survival discounts for lower quality of life in patients with aGVHD or cGVHD and post-transplantation relapse, and allows sensitivity analyses for all model assumptions. We have constructed an externally validated Markov model to represent and analyze the decision to use PBSC or BM, estimating post-transplantation state transition probabilities (eg, GVHD and relapse) and quality-of-life discounts from the IPDMA and relevant literature; importantly, this IPDMA synthesized data from primarily adult patients treated with myeloablative (MA) conditioning regimens with T cell-replete matched sibling donors. In this setting, the model demonstrates the superiority of PBSC over BM in both overall and quality-adjusted life expectancy, with a 7-month advantage for PBSC. Sensitivity analyses support this conclusion through a range of values for each variable supported by the IPDMA and quality-of-life discounts, as supported by the literature. However, BM is the optimal strategy in conditions in which the 1-year relapse probability is < 5%. PBSC is the optimal stem cell source in terms of both overall and quality-adjusted life expectancy, except in conditions with a very low relapse probability, in which BM provides optimal outcomes.

Severe acute gastrointestinal graft-vs-host disease: an emerging surgical dilemma in contemporary cancer care.

OBJECTIVE: To determine the natural history of and guidelines for the surgical management of severe acute gastrointestinal (GI) graft-vs-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HSCT). DESIGN: Case series from a prospective database. SETTING: Tertiary care referral center/National Cancer Institute-designated Comprehensive Cancer Center. PATIENTS: A total of 63 of 2065 patients (3%) undergoing HSCT for hematologic malignancies from February 1997 to March 2005 diagnosed clinically with severe (stage 3 or 4) acute GI GVHD. Main Outcome Measure Percutaneous or surgical intervention. Perforation, obstruction, ischemia, hemorrhage, and abscess were considered surgically correctable problems. RESULTS: Severe acute GI GVHD was diagnosed in 63 patients (median age at HSCT, 47.6 years) at a median of 23 days after HSCT. Clinical diagnosis was confirmed histologically in 84% of patients. On computed tomography and/or magnetic resonance images, 64% had bowel wall thickening, 20% had a normal-appearing bowel, and 16% had nonspecific findings; none had evidence of perforation, obstruction, or abscess. All were initially treated with immunosuppression. Only 1 patient (1.6%) required intervention, undergoing a nontherapeutic laparotomy for worsening abdominal pain. A total of 83% of patients have died (median time to death from HSCT, 119 days; from GI GVHD diagnosis, 85 days). None who underwent an autopsy died of a surgically correctable cause. CONCLUSIONS: This series represents a large single-center experience with GI GVHD reviewed from a surgical perspective. Operative intervention was rarely required. Therefore, mature surgical judgment is necessary to confirm the absence of surgically reversible problems, thus avoiding unnecessary operations in this challenging patient population.

Current and novel therapies in acute GVHD.

Despite improvements in our understanding of transplant immunology and clinical and supportive care, acute graft-versus-host disease (GVHD) remains a clinical challenge and a major cause of morbidity and mortality for patients after allogeneic hematopoietic stem-cell transplantation. While systemic corticosteroid is standard primary therapy for acute GVHD, there is no established standard treatment in the steroid-refractory setting. New generations of monoclonal antibodies, biologics, and chemotherapeutics with immunomodulatory effects have been developed over the past decade, and are being tested as novel therapies in this disease. Many of these agents - including, among others, mycophenolate mofetil, anti-tumor necrosis factor-alpha antibodies, denileukin diftitox, and anti-interleukin-2Ralpha-chain antibodies - have demonstrated promising activity in steroid-refractory acute GVHD. Despite the high response rates, however, long-term survival remains poor due to a high incidence of infections. The key to improving acute GVHD outcomes may, in fact, rest upon successful initial therapy, and timely taper of corticosteroids to promote healthier immune reconstitution. Clinical trials combining these newer agents with systemic corticosteroids as initial treatment are under way, and will determine whether fortifying initial therapy will indeed reduce the development of steroid-refractory GVHD and improve long-term outcomes. In this article, we review current and novel agents available for acute GVHD, and discuss newer investigational approaches - such as phototherapy and cellular therapies - in the management of this common transplant complication.

Prognostic impact of elevated pretransplantation serum ferritin in patients undergoing myeloablative stem cell transplantation.

Iron overload could be a significant contributor to treatment-related mortality (TRM) for patients with hematologic malignancies undergoing hematopoietic stem cell transplantation (HSCT). We studied 590 patients who underwent myeloablative allogeneic HSCT at our institution, and on whom a pretransplantation serum ferritin was available. An elevated pretransplantation serum ferritin level was strongly associated with lower overall and disease-free survival. Subgroup multivariable analyses demonstrated that this association was restricted to patients with acute leukemia or myelodysplastic syndrome (MDS); in the latter group, the inferior survival was attributable to a significant increase in TRM. There was also a trend toward an increased risk of veno-occlusive disease in patients with high ferritin. Our results argue that iron overload plays an important role in transplantation outcome for patients with acute leukemia or MDS, as it does in thalassemia. They also suggest future prospective trials to examine the potential benefit of chelation therapy in this setting.