Flowers, Mary E.D.

Abstract Introduction: Amphiregulin (AREG) is an epidermal growth factor receptor (EGFR) ligand that can restore integrity to damaged intestinal mucosa in murine models of acute graft-versus-host disease (aGVHD). We previously described AREG as a circulating biomarker of late-onset aGVHD, but its relevance combined with clinical risk factors has not yet been tested in a large cohort of patients with aGVHD occurring prior to day 100 post-transplant. We therefore tested samples from two aGVHD first-line treatment trials, Blood and Marrow Transplant Clinical Trials Network (BMT CTN) 0302 and 0802, and identified a clinically relevant threshold level of circulating AREG at aGVHD onset. We then investigated whether incorporating AREG into the refined Minnesota Risk Score could further risk-stratify patients. Patients and Methods: Blood samples were obtained at the onset of systemic aGVHD treatment within BMT CTN 0302 (serum) and BMT CTN 0802 (plasma). All patients with response data and samples for analysis from both trials were included (N=251). We determined the association of AREG with clinical outcomes, including risk stratification by the refined Minnesota criteria, day 28 complete/partial response (CR/PR) to first-line therapy, 2-year overall survival (OS) and 6-month and 2-year non-relapse mortality (NRM). We investigated the effect of AREG on clinical endpoints per a doubling in the value of AREG, defined a clinically relevant threshold level in the AREG values using two-fold cross-validation, and confirmed the clinical relevance of this cut-point in independent samples (N=92) from pooled from drawn from the Chronic GVHD Consortium and the Mount Sinai Acute GVHD International Consortium (MAGIC). Results: In patients enrolled in BMT CTN 0302/0802, AREG levels were 1.7-fold higher in patients with Minnesota high-risk (HR) compared to standard-risk (SR) aGVHD (HR median 53.4 vs SR 31 pg/ml, p<0.01). Every 2-fold increase in AREG was associated with a 33% decrease in the likelihood of day 28 CR/PR (odds ratio [OR] 0.67, p<0.01, table). Clinical factors alone, as determined by the refined Minnesota Risk Score, were associated with day 28 CR/PR (p=0.02, table). Adding AREG to the Minnesota Risk Score could further risk-stratify patients. Minnesota SR patients with elevated AREG ≥ 33 pg/mL showed a 59% lower odds of day 28 CR/PR than SR patients with low AREG (OR 0.41, p=0.02). Patients with Minnesota HR aGVHD with AREG ≥ 33 pg/mL had the worst outcomes, with an 82% lower odds of day 28 CR/PR in comparison to HR with low AREG (OR 0.18, p<0.01). High AREG was associated with worse OS and NRM in both Minnesota SR (hazard ratios 2-year OS 2.3, p<0.01 and 6 month NRM 2.95, p=0.01, respectively) and HR patients (hazard ratios 2-year OS 3.35, p<0.01 and 6-month NRM 9.38, p<0.01 respectively, figure). Finally, in independent samples from the Chronic GVHD Consortium/MAGIC we confirmed that high AREG was associated with worse day 28 CR/PR (55.2% vs. 79.4%, p=0.02) and significantly worse 6-month survival after the onset of aGVHD (57.1% vs. 82.5%, p=0.01). Conclusion: AREG is elevated in patients with poor aGVHD outcomes and adds to the accuracy of risk stratification when combined with the refined Minnesota Risk Score. AREG ≥33 pg/mL at aGVHD onset is associated with lower day 28 CR/PR and higher mortality in samples from 4 multicenter cohorts. The mechanism of elevated circulating AREG in severe aGVHD is not yet known, although we hypothesize the degree of AREG elevation reflects the intensity of immune-mediated tissue injury resulting in AREG release. With accumulating evidence of altered EGFR ligands in aGVHD, further investigation into epithelial repair pathways involving AREG may lead to new adjunctive therapies to overcome poor steroid response in high-risk aGVHD. Disclosures Holtan: Incyte: Other: One-time advisory board member. Khera: Novartis: Consultancy. Lee: Mallinckrodt: Honoraria; Amgen: Other: One-time advisory board member; Bristol-Myers-Squibb: Other: One-time advisory board member; Kadmon: Other: One-time advisory board member. Chen: Immudex: Research Funding. Arora: Takeda Oncology: Consultancy. Flowers: Pharmacyclics: Consultancy. Cutler: Pfizer: Consultancy; Kite: Consultancy; Incyte: Consultancy; Bristol-Myers Squibb: Consultancy; Pharmacyclics: Consultancy; Astellas: Consultancy. Jagasia: Janssen: Consultancy, Research Funding; Therakos: Consultancy, Research Funding; Mallinckrodt: Consultancy. Hexner: Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding. Levine: Novartis Pharmaceuticals Corporation: Membership on an entity's Board of Directors or advisory committees. MacMillan: Magenta Therapeutics: Research Funding.

Abstract We examined the risk of subsequent neoplasms (SNs) and late mortality in children and adolescents undergoing allogeneic hematopoietic cell transplantation (HCT) for nonmalignant diseases (NMDs). We included 6028 patients (median age, 6 years; interquartile range, 1-11; range, <1 to 20) from the Center for International Blood and Marrow Transplant Research (1995-2012) registry. Standardized mortality ratios (SMRs) in 2-year survivors and standardized incidence ratios (SIRs) were calculated to compare mortality and SN rates with expected rates in the general population. Median follow-up of survivors was 7.8 years. Diagnoses included severe aplastic anemia (SAA; 24%), Fanconi anemia (FA; 10%), other marrow failure (6%), hemoglobinopathy (15%), immunodeficiency (23%), and metabolic/leukodystrophy syndrome (22%). Ten-year survival was 93% (95% confidence interval [95% CI], 92% to 94%; SMR, 4.2; 95% CI, 3.7-4.8). Seventy-one patients developed SNs (1.2%). Incidence was highest in FA (5.5%), SAA (1.1%), and other marrow failure syndromes (1.7%); for other NMDs, incidence was <1%. Hematologic (27%), oropharyngeal (25%), and skin cancers (13%) were most common. Leukemia risk was highest in the first 5 years posttransplantation; oropharyngeal, skin, liver, and thyroid tumors primarily occurred after 5 years. Despite a low number of SNs, patients had an 11-fold increased SN risk (SIR, 11; 95% CI, 8.9-13.9) compared with the general population. We report excellent long-term survival and low SN incidence in an international cohort of children undergoing HCT for NMDs. The risk of SN development was highest in patients with FA and marrow failure syndromes, highlighting the need for long-term posttransplantation surveillance in this population.

Abstract Abstract 3094 The HLA class II DRB1 antigen DR15 is an important immunobiologic marker in immune mediated marrow failure states. DR15 has also been reported in small studies to be associated with favorable outcomes (reduction in acute GVHD and reduced relapse resulting in improved overall survival) after allogeneic hematopoietic cell transplant. To elucidate the impact of DR15 on major transplant outcomes, we conducted a retrospective study of 2, 891 recipients of first marrow or mobilized peripheral blood stem cell transplantation for the treatment of acute myeloid leukemia (n=1038), acute lymphoblastic leukemia (n=700), chronic myeloid leukemia (n=948), or myelodysplastic syndrome (n=205) between 1990–2008 and reported to the CIBMTR registry. Selection was confined to HLA-identical sibling transplantation to avoid HLA-disparity as a driving force for observed differences. All patients received conventional myeloablative conditioning, T-replete grafts and cyclosporine plus methotrexate- based GVHD prophylaxis. DNA-based HLA typing allowed categorization of 732 (25.3%) patients as positive and 2159 (74.7%) patients as negative for DRB1*15 :01 or *15 :02 (DR15). There were no significant differences in baseline characteristics between the HLA DR15-positive and -negative groups. In univariate analysis, HLA-DR15 status had no impact on neutrophil engraftment, acute graft-versus-host disease (GvHD) II-IV or III-IV, chronic GVHD, treatment related mortality, relapse, disease-free survival or overall survival. Confining the univariate analysis to myeloid malignancies did not alter these findings. Multivariate analysis models were constructed with DR15 status forced into the models in all steps of model building and the final model regardless of its statistical significance. Other variables tested included: donor/recipient age, CMV status, disease, disease stage, graft source, Karnofsky score, race and year of transplant. Variables that attained a p-value ≤0.05 were held in the final multivariate models. In multivariate analysis, DR15 status showed no significant difference in the primary outcomes of acute GVHD II-IV or III-IV, chronic GVHD, overall survival, or relapse. In conclusion, DR15 status had no impact on major HLA-matched sibling donor hematopoietic cell transplantation outcomes in this large and homogenous cohort of leukemia and MDS patients. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 897 Recent changes in allogeneic hematopoietic cell transplantation (HCT) including increased use of reduced-intensity conditioning, peripheral blood cells as the graft source (PB) and unrelated donors (URD) warrant re-evaluation of risk factors for acute graft-versus-host disease (aGVHD) and its impact on overall survival (OS). Risk factors for these outcomes were analyzed using more recent data from CIBMTR observational database. Methods: The cohort included adult patients ≥ 20 y transplanted from an HLA-identical sibling (SD) (n=3191) or URD (N=2370) for acute myelogenous leukemia (AML), acute lymphoid leukemia (ALL), chronic myeloid leukemia (CML), or myelodsyplastic syndrome (MDS) using a T-cell replete graft from 1999–2005. Six groups were created to evaluate the impact of conditioning [(myeloablative (MA) and reduced-intensity or non-myeloablative (RIC)], total-body irradiation (TBI) and graft source [(bone marrow (BM) or PB] as follows: MA+TBI+PB (group 1), MA+TBI+BM (group 2) MA+ no TBI+PB (group 3), MA+ no-TBI+BM (group 4), RIC+PB (group 5) and RIC+BM (group 6). Separate analyses were performed for SD and URD. IBMTR grade was used to classify aGVHD. A p-value of ≤ 0.01 was considered significant. Results: Among the SD cohort, the probability of aGVHD grade B-D and grade C-D at 100 days was 39% (95% CI, 37–41%) and 16% (95% CI, 14–17%). In multivariate analyses, non-TBI based MA regimens with a BM graft (group 4), RIC conditioning with PB (group 5) and tacrolimus plus methotrexate aGVHD prophylaxis were associated with lower odds ratio of grade B-D aGVHD (Table 1). The probability of OS was 51% (95% CI: 49–53%) at 3 y and 46% (95% CI: 44–49%) at 5 y. In multivariate analyses, grade B-D aGVHD was associated with a higher risk of death. Other independent risk factors for OS are shown in Table 2. Among the URD cohort, the probability of aGVHD grade B-D and C-D at 100 days was 59% (95%, CI 57–61%) and 32% (30-34%). In multivariate analysis, BM with MA (TBI and no TBI) or RIC conditioning (groups 2, 4 and 6) were significantly associated with lower odds ratio of grade B-D aGVHD (Table 1). Other independent risk factors included a diagnosis of CML. HCT from a 7/8 HLA-mismatched URD showed a trend for higher incidence of aGVHD (p=0.02). The probability of OS was 38% (95% CI: 35–40%) at 3 y and 33% (95% CI: 31–35%) at 5 y. In multivariate analysis, grade B-D aGVHD was associated with a higher mortality. Table 2 shows other independent risk factors for OS. Conclusion: Intensity of the conditioning regimen, TBI and the graft source has a combined effect on the risk of aGVHD. In both SD and URD cohorts, BM with MA, non-TBI regimens were associated with lower risk of aGVHD. In URD cohort, BM after a RIC also was associated with a reduced risk of aGVHD. Modulation of these risk factors is needed to reduce acute GVHD incidence and death after allogeneic transplantation. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 1940 Background: Chronic graft-versus-host disease (GVHD) is a significant source of morbidity, mortality, impaired patient-reported quality of life (QOL), greater symptom burden, and prolonged duration of immune suppressive therapy following allogeneic hematopoietic cell transplantation (HCT). While available data support the adverse prognosis of overlap subtype of chronic GVHD, the relative importance of site of gastrointestinal (GI) and type of hepatic involvement is not known. Methods: We analyzed prospectively acquired observational cohort data to examine whether the site of GI involvement (esophageal, upper GI, lower GI) and type of hepatic laboratory test abnormality (bilirubin, alkaline phosphatase (AP), alanine aminotransferase (ALT) elevation over the upper limit of normal based on study site-specific laboratory reference ranges) among chronic GVHD-affected patients are associated with overall survival (OS) and non-relapse mortality (NRM), symptoms (Lee Symptom Scale), and quality of life (QOL) per SF-36 and FACT-BMT instruments. Results: This analysis included 567 individual subjects with baseline and 1548 follow up visits. The majority were incident cases (59%), adults (98%), and predominantly White/Non-Hispanic. Median time from HCT to cohort enrollment was 11.9 months (range 3–294 months). Overall NIH chronic GVHD severity was mild in 10%, moderate in 52%, and severe in 38% at enrollment. Prior acute GVHD was noted in 66%, KPS < 80% in 17%, and platelet count at chronic GVHD onset of < 100 K/uL in 23%. At enrollment, GI involvement was seen in 40% (upper GI 20%, esophagus 16%, lower GI 13%), and liver involvement was seen in 52% (AP 38%, ALT 38%, bilirubin 10%). Time from transplant to cGVHD onset was not different for patients with or without GI involvement or hepatic involvement. In multivariate analysis utilizing data from enrollment visits only and adjusting for patient and transplant variables, lower GI involvement (HR 1.7, p=0.03) and elevated bilirubin (HR 2.36, p=0.001) were associated with OS; both were also associated with NRM. In multivariable analysis using all visits (time-dependent covariates), GI score greater than zero (HR 1.7, p=0.01) and elevated bilirubin (HR 3.7, p<0.001) were associated with OS; results were similar for NRM. Separate models were constructed to examine the relationship of severity of GI and hepatic involvement (0–3 severity score per NIH consensus) and mortality: Increasing lower GI severity at enrollment was significantly associated with non-relapse mortality, with progressively increasing HR for greater severity levels (lower GI score 2/3 vs. 0: HR 5.5, 95% CI 2.3–13.1, p = 0.0001). Increasing bilirubin was also associated with NRM (bilirubin score 2/3 vs. 0: HR 3.3, 95% CI 1.3–8.4, p=0.01). A similar association was observed for bilirubin elevation and NRM in the time-dependent model (bilirubin 2/3 vs. 0: HR 8.9, 95% CI 3.3–24, p < 0.0001). When analyzing all visits, any esophageal involvement and GI score greater than zero were associated with both symptoms and QOL while elevated bilirubin was associated with QOL. We found no consistent evidence that upper GI involvement, AP, ALT, or NIH liver score add prognostic value for survival, overall symptom burden, or quality of life. Conclusion: These data support important differences in patient-reported outcomes according to GI and hepatic involvement among chronic GVHD affected patients, and identify those with elevated bilirubin or higher GI score at any time, or lower GI involvement at cohort enrollment, as patients at greater risk for mortality under current treatment approaches. Disclosures: No relevant conflicts of interest to declare.

Key PointsHigh-circulating AREG (≥33 pg/mL) reclassifies additional patients into HR categories and further refines the Minnesota aGVHD risk score. Patients with aGVHD and AREG ≥33 pg/mL have lower rates of steroid response, higher NRM, and poorer OS.

Key Points Complete or partial response at 1 year without secondary systemic treatment provides clinical benefit in patients with chronic GVHD. Success defined by this endpoint is currently observed in fewer than 20% of patients after initial systemic treatment of chronic GVHD.

Key Points Under current treatment approaches, patients with LA GVHD have poor overall and failure-free survival. Levels of AREG are elevated in LA GVHD, and the AREG/EGF ratio is predictive of overall survival and nonrelapse mortality in LA GVHD.

Key Points Survival of chronic GVHD patients was predicted by clinician-assessed response and changes in patient-reported outcomes. FFS was predicted by clinician-assessed response, changes in patient-reported outcomes, and the 2014 NIH response criteria.

Abstract Purpose: Cutaneous sclerosis occurs in 20% of patients with chronic graft-versus-host disease (GVHD) and can compromise mobility and quality of life. Experimental design: We conducted a prospective, multicenter, randomized, two-arm phase II crossover trial of imatinib (200 mg daily) or rituximab (375 mg/m2 i.v. weekly × 4 doses, repeatable after 3 months) for treatment of cutaneous sclerosis diagnosed within 18 months (NCT01309997). The primary endpoint was significant clinical response (SCR) at 6 months, defined as quantitative improvement in skin sclerosis or joint range of motion. Treatment success was defined as SCR at 6 months without crossover, recurrent malignancy or death. Secondary endpoints included changes of B-cell profiles in blood (BAFF levels and cellular subsets), patient-reported outcomes, and histopathology between responders and nonresponders with each therapy. Results: SCR was observed in 9 of 35 [26%; 95% confidence interval (CI); 13%–43%] participants randomized to imatinib and 10 of 37 (27%; 95% CI, 14%–44%) randomized to rituximab. Six (17%; 95% CI, 7%–34%) patients in the imatinib arm and 5 (14%; 95% CI, 5%–29%) in the rituximab arm had treatment success. Higher percentages of activated B cells (CD27+) were seen at enrollment in rituximab-treated patients who had treatment success (P = 0.01), but not in imatinib-treated patients. Conclusions: These results support the need for more effective therapies for cutaneous sclerosis and suggest that activated B cells define a subgroup of patients with cutaneous sclerosis who are more likely to respond to rituximab. Clin Cancer Res; 22(2); 319–27. ©2015 AACR.