No abstract

Background: Mexico and Central America have a high incidence of acute lymphoblastic leukemia (ALL) in adolescents and young adults (AYA). Chemotherapy with Hyper-CVAD has been widely used with poor outcomes, with a 3-year overall survival (OS) of 25.7% in this group of age. In low-and middle-income countries (LMIC), limitations in supportive care such as low access to neutrophil stimulant agents, antifungal prophylaxis and limited intensive care access, may increase treatment-related mortality. On the other hand, reports suggest that specific high-risk subgroups may be more frequent in Hispanic patients from Mexico and Central America. We hypothesize that the use of a less-myeloablative regimen, based on L-asparaginase could overcome the bad outcomes previously reported. Methods We modified the original CALGB 10403 based on local drug-access. We include patients with newly diagnosed Philadelphia-negative B- or T-cell ALL between 14-49 years from 4 centers in Mexico and one in Guatemala. We modified the regimen as following: replaced pegaspargase by E. Coli asparaginase, thioguanine by 6-mercapatopurine and incorporate rituximab 375mg/m2 for 6 doses in CD20 positive patients. After the first interim analysis (October 2019), we replaced the prednisone by dexamethasone during induction. Minimal residual disease (MRD) was assessed by flow cytometry after induction and after first consolidation. We considered high-risk karyotype if MLL-rearrangements, complex or hypodiploid and high-white blood cell count (WBC) if >30 x10 3/mcL for B-ALL or >100 x10 3/mcL for T-ALL. The main objective was to evaluate OS and as secondary objectives to evaluate complete response (CR) rate, relapse-free survival (RFS) and to assess the safety of this regimen. Results From January 2017 to December 2020, 95 patients have been enrolled with a median age of 23 years (range 14-49). One third (34.6%) had overweight and 11.7% were obese. The majority (92.6%) had a B-cell ALL and a normal karyotype (81.2%). The median WBC was 18.4 x10 3/mcL (0.2-427.7) and 40.9% had a high-WBC. During induction, adverse events (AE) included grade 3/4 elevated bilirubin (21.1%), transaminases (14.7%), hyperglycemia (14.7%), hypofibrinogenemia (44.2%), thrombosis (10.5%), hypersensitivity (2.2%) and pancreatitis (2.1%). During consolidation, AE included grade 3/4 hepatic toxicity (18.9%), hypertriglyceridemia (14.8%), thrombosis (5.3%) and pancreatitis (2.1%). Neutropenic fever occurred in 55.8% during induction (grade 4: 31.5%), and in 32.9% during consolidation (grade 4/5: 5.3%). A dose adjustment due to AE was required in 22.1% during induction and in 23.2% during consolidation. The induction related-mortality (IRM) rate was 7.4% The CR rate was 87.8%. After-induction, MRD was <0.01% in 39.1%, 0.01-0.1% in 39.1% and > 0.1% in 24.6%. Post-consolidation MRD was only measured in 43 patients and was <0.01% in 37.2%. During follow-up, 26.7% relapsed: 62.5% bone marrow (BM) relapses, 25.0% central nervous system (CNS) relapses and 12.5% CNS + BM relapses. Eight patients (8.4%) received an allogeneic-stem cell transplant (HSCT) as consolidation. The 2-year OS was 72.1%. The post-induction MRD <0.1% was associated with a better OS (figure 1A) (HR: 0.17 (95%CI: 0.06-0.55), p=0.003) and a high-WBC with an inferior OS (figure 1B) (HR: 4.13 (95%CI: 1.68-10.14), p=0.002). The 2-year RFS was 65.2%. The post-induction MRD <0.1% was associate with a better RFS (figure 1C) (HR: 0.19 (95%CI: 0.07-0.50), p=0.001) and a high-WBC and overweight / obesity with an inferior RFS (HR: 4.08 (95%CI: 1.71-9.73), p=0.001 and 2.50 (95%CI: 1.06-5.86), p=0.036 respectively) (figure 1D). Conclusions: The adoption of modified CALGB10403 regimen in Central America based on local resources is feasible. It is associated with a significant improvement in the OS and decrease in IRM when compared with previous reports. Despite a very high-rate of hepatic and metabolic toxicities, these were manageable. As reported by other groups, MRD, high-WBC and overweight/obesity are associated with poor outcomes. Despite being encouraging results, a significant number of patients persist with positive MRD and the main cause of dead is disease progression. Access to cellular therapies, and BiTes is cost restricted in LMIC. Hence, we should generate strategies to intensify treatment in MRD positive patients and expand transplant access to overcome outcomes. Figure 1 Figure 1. Disclosures Rangel-Patiño: Bristol: Consultancy; Abbvie: Speakers Bureau. Ceniceros: Amgen: Speakers Bureau. Espinosa: Amgen: Speakers Bureau; Janssen: Consultancy; Pfizer: Consultancy. Amador: Abbvie: Consultancy, Speakers Bureau; Bristol: Consultancy. Cabrero Garcia: Takeda: Speakers Bureau; Abbvie: Speakers Bureau; Roche: Speakers Bureau; Janssen: Speakers Bureau; Astellas: Consultancy; BD: Speakers Bureau. Inclan-Alarcon: Janssen: Speakers Bureau; Boehringer: Speakers Bureau. Neme Yunes: Janssen: Consultancy, Speakers Bureau; Bristol: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Bristol: Consultancy, Speakers Bureau; Abbvie: Consultancy, Speakers Bureau; Abbvie: Speakers Bureau. Meillon-García: Amgen: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Roche: Speakers Bureau; Astellas: Consultancy. Apodaca: Sanofi: Consultancy; Asofarma: Consultancy, Speakers Bureau; Abbvie: Speakers Bureau. Demichelis: Bristol/Celgene: Consultancy, Speakers Bureau; Astellas: Consultancy; Gilead: Consultancy; ASH: Research Funding; Abbvie: Consultancy, Speakers Bureau; AMGEN: Consultancy, Speakers Bureau; Novartis: Consultancy, Research Funding, Speakers Bureau; Jazz: Consultancy.

Background: SB12 has been developed as a biosimilar of the reference product (RP) eculizumab. Eculizumab is a humanized monoclonal antibody (IgG2/4 kappa immunoglobulin) that binds to the human C5 complement protein with high affinity. Binding to this protein blocks its cleavage into C5a and C5b, thereby inhibiting terminal complement-mediated intravascular haemolysis. It is currently indicated for the treatment of patients with paroxysmal nocturnal haemoglobinuria, atypical haemolytic uremic syndrome (aHUS), refractory generalized Myasthenia Gravis (gMG) and Neuromyelitis Optica Spectrum Disorder (NMOSD). Objectives: To demonstrate pharmacokinetic (PK) equivalence and evaluate pharmacodynamic (PD), safety, tolerability, and immunogenicity profiles between SB12 and the RP eculizumab. Methods: This was a double-blind, three-arm, parallel group, and single-dose study in healthy subjects, between 18-55 years of age, randomized in a ratio of 1:1:1 to receive a single 300 mg dose of either SB12, European Union (EU) sourced eculizumab, or United States of America (US) sourced eculizumab via intravenous (IV) infusion for 35 minutes. Blood samples for PK and PD analysis were collected over 64 days. The primary objective of this study was to demonstrate PK similarity between the investigational products (IPs), as assessed by area under the concentration-time curve from time zero to infinity (AUC inf). Secondary PK endpoints included area under the concentration-time curve from time zero to the last quantifiable concentration (AUC last) and maximum observed concentration (C max). Equivalence for the primary endpoint (AUC inf) was determined if 90% confidence intervals (CIs) for the ratio of geometric least squared means (LSMeans) of SB12 to EU sourced eculizumab, SB12 to US sourced eculizumab, and EU sourced eculizumab to US sourced eculizumab was within the equivalence margin of 80.00% to 125.00%, respectively. Other objectives for the study were to evaluate safety, tolerability, immunogenicity, and PD profiles for the IPs. Results: A total of 240 subjects (80 in each treatment group) were enrolled. Back transformation provided the geometric LSMean ratio for the comparison of SB12/EU sourced eculizumab, SB12/US sourced eculizumab and EU sourced eculizumab/US sourced eculizumab for AUC inf were 99.1 % (95.41,102.85), 95.1 % (91.40, 99.04), and 96.0 % (92.16, 100.10), respectively. The corresponding 90% CI was within the pre-defined equivalence margin of 80.00-125.00%, indicating that the each of two treatments are bioequivalent. The profiles of mean terminal complement activity and mean change from baseline of complement activity were superimposable following administration of SB12, EU sourced eculizumab, and US sourced eculizumab. There was a rapid decrease in the complement activity at the end of infusion and then a slow restoration. There was no non-responder in the aspect of the measured complement activity after treatment. There were no deaths or discontinuation of IP due to treatment-emergent adverse events (TEAEs) during the study. Two serious adverse events (SAEs) (renal colic in the SB12 treatment group and back pain in the US eculizumab treatment group) were reported, in 2 subjects. Both events were considered not related to the IP. The proportion of subjects who experienced TEAEs were similar between the SB12, EU sourced eculizumab, and US sourced eculizumab treatment groups (70.0%, 65.0%, and 71.3% of subjects, respectively). The overall incidence of subjects with post-dose anti-drug antibodies (ADA) to eculizumab was 2 (2.5%), 1 (1.3%), and 0 (0.0%) subjects in the SB12, EU sourced eculizumab, and US sourced eculizumab treatment groups, respectively. There was no significant difference between treatment groups. None of the subjects with post-dose ADA to eculizumab had a positive result for neutralizing antibodies. Conclusion: The Phase I study demonstrated PK bioequivalence and showed comparable PD, safety, immunogenicity between SB12 and the RP eculizumab. Disclosures Lee: Samsung Bioepis, Co., Ltd.: Current Employment. Jang: Samsung Bioepis, Co., Ltd.: Current Employment. Kim: Samsung Bioepis, Co., Ltd.: Current Employment. Jeong: Samsung Bioepis, Co., Ltd.: Current Employment. Lee: Samsung Bioepis, Co., Ltd.: Current Employment. Jung: Samsung Bioepis, Co., Ltd.: Current Employment. Demichelis: Novartis: Consultancy, Research Funding, Speakers Bureau; Bristol/Celgene: Consultancy, Speakers Bureau; AMGEN: Consultancy, Speakers Bureau; ASH: Research Funding; Jazz: Consultancy; Gilead: Consultancy; Astellas: Consultancy; Abbvie: Consultancy, Speakers Bureau.

No abstract

Background: Splenectomy is an effective second line therapy for patients with immune cytopenias. Fifteen percent of patients are going to relapse after splenectomy. These patients are categorized as refractory and their treatment is challenging. The incidence of an accessory spleen diagnosed by gammagraphy is estimated to be 8-20% in this scenario. Current treatment guidelines do not address the issue of searching for an accessory spleen or performing accessory splenectomy as a treatment strategy for these patients. The aim of this study was to identify risk factors for the presence of accessory spleen diagnosed by gammagraphy in patients with refractory immune cytopenias and analyze the response rate of its removal. Methods: It is a case control, single center, retrospective study. We included adult patients with refractory immune cytopenias who underwent gammagraphy to search for an accessory spleen, from 1996 to 2016. Cases were patients with a positive gammagraphy, controls were those with a negative gammagraphy. Patients who failed to have at least one year of follow-up after splenectomy or accessory splenectomy, were excluded. A logistic regression was performed to determine factors associated with the presence of an accessory spleen. Results: We analyzed 71 refractory patients with a gammagraphy performed searching for an accessory spleen, 87.3% with a diagnosis of immune thrombocytopenia (IT), 7% autoimmune hemolytic anemia (AHA) and 5.6% Evans Syndrome. Fourteen percent of the patients had secondary immune cytopenias all of them due to autoimmune diseases. There was a predominance of women with 74.6% of the subjects studied. Patients received a median of 2 (0-4) lines of treatment before the splenectomy. The majority of patients (98.6%) had received, as first line of treatment corticosteroids, with an overall response rate (ORR) of 84% and a complete response (CR) rate of 38.6%. Of the 71 patients, splenectomy achieved an ORR of 83.1% with CR in 80.3%. The incidence of accessory spleen diagnosed by gammagraphy at their relapse was 15.5% (11 patients). In the multivariate analysis, we found two factors associated with positivity of the gammagraphy: CR to corticosteroids pre-splenectomy with an OR of 5.2 (CI 95% 1.24-21.78; p=0.021) and the presence of Howell Jolly bodies (HJb) with an OR of 0.088 (CI95% 0.02-0.37; p=0.001) as a protective factor. We developed a risk score consisting of: 0 risk factors, 1 risk factor (CR to corticosterois pre-splenectomy or abscense of HJb) and 2 risk factors. The percentage of patients who were positive by gammagraphy using this score was 83.3%, 25.6% and 3% for 2, 1 and no risk factors respectively (p<0.001) (Figure1). Eight patients underwent accesory splenectomy, all of them achieved responses with CR of 87.5%, and none experienced complications associated with the procedure. Seven patients acquired the presence of HJb after accesory splenectomy (Table 1). With a median follow-up of 60.2 months (1.54-194.56), 62.5% mantained the response obtained with the accesory splenectomy. One patient didn´t acquire HJb post accesory splenectomy, he relapsed and was diagnosed with a new accesory spleen. He underwent a second accesory splenectomy and is now in CR with the presence of HJb in the blood smear. Conclusions: The search for an accesory spleen in patients with refractory immune cytopenias with risk factors (absence of Howell Jolly bodies and or complete response to steroids as first line therapy) is usefull. Accesory splenectomy is a safe and effective therapeutic strategy in the treatment of these patients. Disclosures No relevant conflicts of interest to declare.