Holtan, Shernan G.

Background Most patients with advanced melanomas relapse after checkpoint blockade therapy. Thus, immunotherapies are needed that can be applied safely early, in the adjuvant setting. Seviprotimut-L is a vaccine containing human melanoma antigens, plus alum. To assess the efficacy of seviprotimut-L, the Melanoma Antigen Vaccine Immunotherapy Study (MAVIS) was initiated as a three-part multicenter, double-blind, placebo-controlled phase III trial. Results from part B1 are reported here. Methods Patients with AJCC V.7 stage IIB-III cutaneous melanoma after resection were randomized 2:1, with stage stratification (IIB/C, IIIA, IIIB/C), to seviprotimut-L 40 mcg or placebo. Recurrence-free survival (RFS) was the primary endpoint. For an hypothesized HR of 0.625, one-sided alpha of 0.10, and power 80%, target enrollment was 325 patients. Results For randomized patients (n=347), arms were well-balanced, and treatment-emergent adverse events were similar for seviprotimut-L and placebo. For the primary intent-to-treat endpoint of RFS, the estimated HR was 0.881 (95% CI: 0.629 to 1.233), with stratified logrank p=0.46. However, estimated HRs were not uniform over the stage randomized strata, with HRs (95% CIs) for stages IIB/IIC, IIIA, IIIB/IIIC of 0.67 (95% CI: 0.37 to 1.19), 0.72 (95% CI: 0.35 to 1.50), and 1.19 (95% CI: 0.72 to 1.97), respectively. In the stage IIB/IIC stratum, the effect on RFS was greatest for patients <60 years old (HR=0.324 (95% CI: 0.121 to 0.864)) and those with ulcerated primary melanomas (HR=0.493 (95% CI: 0.255 to 0.952)). Conclusions Seviprotimut-L is very well tolerated. Exploratory efficacy model estimation supports further study in stage IIB/IIC patients, especially younger patients and those with ulcerated melanomas. Trial registration number NCT01546571.

AbstractBackgroundColony‐stimulating factor‐1 receptor (CSF1R)‐related leukoencephalopathy is a rapidly progressive neurodegenerative disease for which there is currently no cure. Hematopoietic stem cell transplantation (HSCT) has been proposed as a disease‐modifying treatment.ObjectiveThe objective of this study was to determine the effect of HSCT on disease progression.MethodsWe collected all available clinical data from a cohort of 7 patients with CSF1R‐related leukoencephalopathy who underwent HSCT at our institutions. Clinical data included detailed neurological examination by a board‐certified neurologist, serial cognitive screens, formal neuropsychological evaluations, and serial brain magnetic resonance imaging (MRI).ResultsOur patients had an average disease duration of 27.6 months at the time of transplant, and we have 87 months of total posttransplant follow‐up time (median, 11; range, 2–27). One patient died in the periprocedural period. The remaining patients showed a variable response to treatment, with 6 of 7 patients trending toward stabilization on motor examination, cognitive scores, and/or MRI abnormalities, especially with white matter lesion burden.ConclusionsThis is the largest series of patients with CSF1R‐related leukoencephalopathy receiving HSCT. We conclude that HSCT can stabilize the disease in some patients. Variability in patient responsiveness suggests that measures of disease heterogeneity and severity need to be considered when evaluating a patient's candidacy for transplant. HSCT appears to be the first disease‐modifying therapy for CSF1R‐related leukoencephalopathy. This milestone may serve as a foothold toward better understanding the disease's pathomechanism, thus providing new opportunities for better disease‐specific therapies. © 2021 International Parkinson and Movement Disorder Society

SummaryRuxolitinib for steroid‐refractory acute graft‐versus‐host disease (SR‐aGVHD) results in resistance or intolerance in 1/5 of patients. Outcomes of such patients are undefined. We identified these patients in a multicentre review and reported outcomes. Ruxolitinib‐resistant aGVHD was identified in 48/307 patients. Among patients receiving additional therapy, the overall response rate to next therapy was 36%. Median survival was 21 days. Ruxolitinib intolerance led to treatment discontinuation in 16/307 patients. Ten intolerant patients received additional therapy with 50% experiencing continued improvement of aGVHD. Median survival was 50 days in these patients. These data serve as a baseline for future SR‐aGVHD studies.

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&lt;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&lt;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&lt;0.01). High AREG was associated with worse OS and NRM in both Minnesota SR (hazard ratios 2-year OS 2.3, p&lt;0.01 and 6 month NRM 2.95, p=0.01, respectively) and HR patients (hazard ratios 2-year OS 3.35, p&lt;0.01 and 6-month NRM 9.38, p&lt;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.

PURPOSE There is no consensus on the best choice of an alternative donor (umbilical cord blood [UCB], haploidentical, one-antigen mismatched [7/8]–bone marrow [BM], or 7/8-peripheral blood [PB]) for hematopoietic cell transplantation (HCT) for patients lacking an HLA-matched related or unrelated donor. METHODS We report composite end points of graft-versus-host disease (GVHD)–free relapse-free survival (GRFS) and chronic GVHD (cGVHD)–free relapse-free survival (CRFS) in 2,198 patients who underwent UCB (n = 838), haploidentical (n = 159), 7/8-BM (n = 241), or 7/8-PB (n = 960) HCT. All groups were divided by myeloablative conditioning (MAC) intensity or reduced intensity conditioning (RIC), except haploidentical group in which most received RIC. To account for multiple testing, P < .0071 in multivariable analysis and P < .00025 in direct pairwise comparisons were considered statistically significant. RESULTS In multivariable analysis, haploidentical group had the best GRFS, CRFS, and overall survival (OS). In the direct pairwise comparison of other groups, among those who received MAC, there was no difference in GRFS or CRFS among UCB, 7/8-BM, and 7/8-PB with serotherapy (alemtuzumab or antithymocyte globulin) groups. In contrast, the 7/8-PB without serotherapy group had significantly inferior GRFS, higher cGVHD, and a trend toward worse CRFS (hazard ratio [HR], 1.38; 95% CI, 1.13 to 1.69; P = .002) than the 7/8-BM group and higher cGVHD and trend toward inferior CRFS (HR, 1.36; 95% CI, 1.14 to 1.63; P = .0006) than the UCB group. Among patients with RIC, all groups had significantly inferior GRFS and CRFS compared with the haploidentical group. CONCLUSION Recognizing the limitations of a registry retrospective analysis and the possibility of center selection bias in choosing donors, our data support the use of UCB, 7/8-BM, or 7/8-PB (with serotherapy) grafts for patients undergoing MAC HCT and haploidentical grafts for patients undergoing RIC HCT. The haploidentical group had the best GRFS, CRFS, and OS of all groups.

Abstract AMD3100, a CXCR4 receptor antagonist, has been studied as a stem cell mobilization agent for the purpose of autologous stem cell transplantation (ASCT) in hematologic malignancies. Lymphocyte subset analysis of peripheral blood in patients treated with AMD3100 has been studied in healthy volunteers. To date, no reports exist describing the lymphocyte subsets of the autograft in patients undergoing AMD3100 stem cell mobilization for the purposes of ASCT in non-Hodgkin lymphoma (NHL). Considering our prior work demonstrating the significant impact of autograft lymphocyte content on clinical outcomes of patients undergoing ASCT for NHL we set out to profile autograft lymphocyte subsets of patients undergoing mobilization with AMD3100. Using flow cytometry, we analyzed aliquots of apheresis products in 7 patients with NHL undergoing AHSCT who received AMD3100 in addition to G-CSF as a part of their mobilization regimen. These results were compared to 29 patients with NHL who had undergone stem cell mobilization with G-CSF alone. There were no significant differences between these two groups of patients in terms of sex, age, performance status, histology, LDH, and number of pretransplant chemotherapeutic regimens. CD34+ cells collected at apheresis did not differ significantly between the groups. However, compared with G-CSF alone, patients that received AMD3100 had an approximate 5-fold increase in CD4+ cells (0.62 x 109 cells/kg vs. 0.12 x 109 cells/kg, p = 0.0004), a 3.5-fold increase in the absolute number of autograft CD3+ cells (1.21 x 109 cells/kg vs. 0.33 x 109 cells/kg, p = 0.0017), and a 2.5-fold increase in CD8+ cells (0.48 x 109 cells/kg vs 0.19 x 109 cells/kg, p = 0.215). A significant increase was also noted in CD4+25+ cell compartment (0.17 x 109 cells/kg vs. 0.006 x 109 cells/kg, p = 0.0001). No significant difference was noted in the absolute number of autograft CD16+56+ NK cells. Finally, an increase in the autograft total absolute lymphocyte count (41.6 x 109 cells/kg vs. 2.88 x 109 cells/kg, p &lt; 0.001) as well as peripheral blood absolute lymphocyte count at day 15 after AHSCT was observed in those patients who had received AMD3100 (0.79 x 109 cells/kg vs. 0.58 x 109 cells/kg, p = 0.04). The increased lymphocyte content of the autograft (total and subset) would suggest the potential of positive impact on clinical outcomes in patients mobilized with AMD3100. Indeed, none of the patients who received AMD3100 had relapsed disease at one year post-transplant (although two of these patients are currently 9 months and 11 months post-transplant respectively), whereas 10 of the 29 control patients had relapsed disease at one year. Further studies are necessary to confirm these observations and ascertain their clinical significance.

Abstract Deletion 5q in Acute Myeloid Leukemia (AML): a Clinicopathological Description of 79 Cases From a Single Institution Rafael Santana-Davila, Shernan G. Holtan, Rhett P. Ketterling, Ryan A. Knudson, David P. Steensma, Dong Chen, James D. Hoyer, Curtis A. Hanson, Ayalew Tefferi. Background: Deletion 5q (del(5q)) is a lenalidomide-sensitive cytogenetic abnormality commonly seen in patients with myeloid disorders. In this study we analyze the clinicopathological characteristics of patients with AML and del(5q). Methods: Patients with del(5q) and AML were identified through a database query of our institutional cytogenetic database from May, 1992 through December, 2005. Both peripheral blood and bone marrow specimens from each patient were morphologically examined by a hematopathologist (DC, JDH and/or CAH). A morphologic diagnosis was given based on current WHO criteria. A critical review of the patient history was performed for each patient. Results: A total 79 patients were identified. Median age was 71 (range 39–87) years, 56% (n=43)were female. The most common subtype according to the FAB classification was M2 (n=23, 29%). In 35 (44%) patients AML developed a median of 9.4 (range 1–294) months since the diagnosis of a pre-existing myeloid malignancy, of which myelodysplastic syndrome accounted for 24 (9 cases of MDS NOS, 6 of RA, 6 of RAEB1, 2 of RAEB-2, and a single RARS), a myeloproliferative neoplasm in 10 (4 cases of a CMPD NOS, 4 cases of PV and a single case of ET and PMF each) and 1 case of a prior history of AML with a t(8;21). The del(5q) was documented in 7 of this 24 patients in the antecedent hematologic disorder. Neither a history of prior exposure to cytotoxic agents nor a prior myeloid disorder was found in 44% (n=35) of the patients. Del(5q) was commonly associated with a complex karyotype (n=67), however in 9 patients it was found to be the sole abnormality. The most frequent breakpoint was q13q33 (n=47) followed by q15q33 (n=12). Initial pathological description did not identify any morphological abnormalities in 6 cases, in contrast myelodysplasia involving at least two cell lines was appreciated in 58% (n=46) of the patients. The median survival was 2.8 months. The majority of the subjects (n=51, 65%) received palliative treatment, 7 patients were lost to follow up and no treatment information was available for review and the remaining 21 received induction chemotherapy with a curative intent, in this group median survival was 8.8 months with 52% (n=11) of patients achieving a complete response. Surprisingly the only factor that appeared to alter survival in the whole group was the presence of the breakpoint in chromosome 5 being distal to q15 (median 2.8 vs 4.1 months, p=0.025) Conclusions: This study constitutes the largest review of del(5q) in AML, its presence is currently associated with advanced age and a poor survival. Close to half of the patients in our series were classified as de novo AML. Although more commonly encountered as part of a complex karyotype it can also be present as a single abnormality. The different cytogenetic characteristics of the del(5q) may impact survival and this deserves further investigation. Figure. Survival of patients with AML and del(5q) in which the breakpoint was found to be distal to q15 (straight line) compared with patients in which the breakpoint was proximal to q13 (dotted line). Figure. Survival of patients with AML and del(5q) in which the breakpoint was found to be distal to q15 (straight line) compared with patients in which the breakpoint was proximal to q13 (dotted line).

Abstract Background: Deletion 5q is a lenalidomide-sensitive cytogenetic abnormality seen usually in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). In the current study, we looked into the occurrence and clinicopathologic correlates of del(5q) in myeloproliferative neoplasms (MPNs) defined according to the World Health Organization (WHO) criteria. Methods: Patients with del(5q)-positive MPN were identified through database query involving over 2000 patients with myeloproliferative neoplasms (MPD) including no less than 500 patients with primary myelofibrosis (PMF), 600 patients with essential thrombocytosis (ET), 500 patients with polycythemia vera (PV), and the remaining comprised of patients with molecularly-undefined chronic eosinophilic leukemia, hypereosinophilic syndrome, systemic mastocytosis (SM), chronic neutrophilic leukemia, and “MPN, unclassifiable”. Results: A total of 23 patients with del(5q) were identified (12 at time of initial diagnosis), suggesting an overall prevalence rate of 1%. A central pathological review was conducted to confirm the diagnosis in each instance. Specific diagnoses included PMF (n=14; estimated prevalence of 3%), MPN, unclassifiable (n=4), PV (n=2), ET (n=1), post ET-myelofibrosis (n=1) and SM (n=1). Del(5q) was a sole abnormality in 5 patients, accompanied by one other abnormality in 6 patients, and part of a complex karyotype in 12 patients. The most common breakpoint was q13q33 (n=10) followed by q15q33 (n=6). Based on sample size adequacy, we focused on del(5q)-positive PMF patients and compared their bone marrow histological and clinical features with their del(5q)-negative counterparts seen at the Mayo Clinic during the same period of time (n=311). There was no difference in gender or age distributions. Histopathological review did not show the typical tight clusters of megakaryocytes seen in classic PMF. The megakaryocytes were not the predominate feature of the biopsy, in general were less lobulated and smaller in size, and had a higher grade of fibrosis (med = 3+) than classic PMF. Furthermore, del(5q)-positive PMF patients presented with significantly lower hemoglobin level (p=0.0009) and platelet count (p=0.0003). The percentage of patients presenting with a hemoglobin level of &lt; 10 g/dL or a platelet count of &lt; 100 × 109/L were 70% and 92% in del(5q)-positive patients as opposed to 43% and 18% in del(5q)-negative patients. However, the presence of del(5q) did not significantly affect either overall survival (Figure) or leukemic transformation in PMF (14% vs 9%). Conclusions: Del(5q) is generally rare in MPNs but might occur in as much as 3% of patients with PMF. The presence of del(5q) does not appear to affect overall survival in PMF despite its clustering with adverse prognostic features for the disease including anemia and thrombocytopenia. Finally, megakaryocyte morphology and distribution in del(5q)-associated PMF are characteristically different from classic PMF. Figure Figure

Abstract The infused autograft absolute lymphocyte count (A-ALC) is an independent prognostic factor for survival after autologous hematopoietic stem cell transplant (AHSCT) in non-Hodgkin’s lymphoma (NHL). Previous studies have shown that A-ALC directly correlates with the peripheral blood absolute lymphocyte count (PC-ALC) at the time of apheresis collection. However, factors affecting the PC-ALC at apheresis remain undefined. We hypothesized that one possible factor impacting PC-ALC may be the time interval from last chemotherapy to stem cell collection (TILC). Data from 160 patients who underwent AHSCT for treatment of relapsed NHL at Mayo Clinic between 1993 and 2001 were collected and analyzed. The primary end point of this study was correlation between TILC and PC-ALC, and our analysis revealed a strong correlation (r = 0.67, p &lt; 0.0001). Further analysis revealed higher PC-ALC numbers in patients with TILC ≥ 60 days versus TILC &lt; 60 days (median of 7.44 x 109/L in the ≥ 60 day group versus 3.87 x 109/L in the &lt; 60 day group, p &lt; 0.0001). Both the median overall survival (figure below) and the progression-free survival were longer in the TILC ≥ 60 days group versus the TILC &lt; 60 days group (76 versus 21 months, p &lt; 0.0037; 76 versus 11 months, p &lt; 0.018, respectively). These findings were independent of other prognostic indicators for relapsed NHL patients undergoing APHSCT. The data supports our hypothesis that TILC affects PC-ALC and survival post-AHSCT in NHL. Figure Figure

8599 Background: Chemotherapy resistance is a common, difficult problem for melanoma patients needing long term care and those suffering from recurrence. Neural growth factor receptor (NGFR), also known as CD271, is commonly expressed on mesenchymal stem cells and is important for development, survival and differentiation of cells. This has previously shown to be expressed on melanoma stem cells. We hypothesized that treatment with carboplatin enriches the population of tumor cells for cancer stem cells (CSC) as a mechanism of chemotherapy resistance. Methods: Core tumor samples from 118 patients with metastatic melanoma were obtained from formalin-fixed paraffin embedded specimens. Slides were stained using an anti-CD271 antibody for IHC. A375 melanoma cells were treated with increasing concentrations of carboplatin for approximately 1 year. WT, 6 mg/mL and 10 mg/mL resistant cells were tagged with CD271-PE antibody and run on a flow cytometer. These cells were then tested for gene expression by microarray using an Affymetrix human 133 plus 2.0 chip, and analyzed on Partek software. Pathway analysis of these carboplatin resistant cells was preformed using Ingenuity. Results: Virtually all melanoma tumor samples stained positively for CD271 by IHC, with a median of 50% cells within tumor samples expressing the cytoplasmic marker. Flow cytometry demonstrated an increase in the percentage of cells expressing CD271 as resistance to carboplatin increased. Wild type A375 cells contained 30% positive CD271, A375 6mg/mL resistant contained 42% positive and A375 10mg/mL resistant showed 66% positive. Microarray also exhibited a direct correlation between CD271 gene expression with increasing carboplatin resistance. Functional ontology enrichment revealed development and regulation of the EMT pathway as an important process impacted by our resistant cell line. Conclusions: The data suggests that as melanoma cells become resistant to certain chemotherapy drugs they essentially loose their differentiated phenotype and become more stem cell-like. Monitoring melanoma expression of CD271 could help individualize therapy and anticipate chemotherapeutic resistance in this high-risk group of patients.