Abstract: Introduction: asciminib is a first-in-class STAMP (Specifically Targeting the ABL Myristoyl Pocket) inhibitor that potently inhibits aberrant kinase activity of the BCR-ABL1 oncoprotein via allosteric binding. asciminib has shown high efficacy profile in heavily pretreated Chronic Myeloid Leukemia (CML) patients with an adequate safety profile in phase I and III clinical trials. However, data from the use of asciminib in real life setting are still scarce. Methods: We gathered real-life retrospective data from 49 patients with BCR-ABL1 positive CML treated with asciminib (mean dose: 40 mg twice daily) between October 2018 and July 2021 at 33 institutions. The indication of asciminib was made according to the criterion of the attending physician and the drug was granted by Novartis under a controlled access program. Molecular biology tests were performed according to ELN guidelines and BCR-ABL/ABL ratios were expressed as % IS in all centers. Treatment responses were calculated with the patients at risk at each specific time points. For the event free survival (EFS), the events were treatment discontinuation due to any reason, progression or death. Data collection followed the local regulations for observational studies. Results: Median time on asciminib was 11,69 months for the entire cohort. Patients' characteristics are displayed on Table 1. Most patients were heavily pretreated with at least 3 prior TKI lines in 45 patients (91,83%), 18 of them receiving prior Ponatinib. Switch to asciminib occurred due to intolerance in 32 patients and due to resistance in the remaining 17. Fifteen patients (30,61%) harbored mutations in BCR-ABL1 (3 with a T315 mutation). Regarding efficacy (Table 2), probability of reaching or maintaining previous responses were 94%, 45% and 21% for complete hematological response (CHR), complete cytogenetic response (CCyR) and major molecular response (MMR), respectively. Considering probabilities of improving previous response, rates were 40%, 42% and 33% for the same parameters. Probabilities to obtain CCyR and MMR in resistant and intolerant patients were 29% (4/14) vs 55% (6/11) and 27% (4/15) vs 52% (11/21), respectively. Amid the patients previously treated with Ponatinib, probabilities of reaching or maintaining previous response were 53% (9/17) and 35% (6/17) for CCyR and MMR respectively, and 30% (3/10), 23% (3/13) displayed improvement of response. Regarding responses in patients with mutations, 39% (5/13) achieved or maintained CCyR and 31% (4/13) MMR; whereas 20% (2/10) and 18% (2/11) improved such responses. Of the three patients with T315I mutation, one discontinued due to progression to advanced stages, and the rest maintained the previous response. With a median follow-up of 11,69 months, the estimated EFS was 80% (figure 1). In terms of safety (Table 3), the most frequent extra-hematological adverse events (AE) were: fatigue (16,2%), joint pain (13,5%) and nausea (8,1%), most of them grade 1-2. Grade 3-4 AE were observed in 10% of patient (fatigue (2), cholestasis enzyme elevation (1), hypertension (1), pancreatitis (1) and pericardial effusion (1)). Thrombocytopenia was shown as the most frequent AE (16,3%), with 6% of patients suffering from grade 3-4. Dose reduction was required in 15 patients (30,6%). After a median follow up of 51 weeks, 73,5% of the patients remained on treatment. Only fourteen patients discontinued treatment due to progression or loss of efficacy, whereas 6% of patients discontinuing treatment due to intolerance. Conclusions: The results presented are in line with the data obtained in clinical trials, positioning asciminib as a potential safe and efficacious treatment for CML patients with failure to several TKI lines. Figure 1 Figure 1. Disclosures Sanchez-Guijo: Novartis: Consultancy, Honoraria, Research Funding; Celgene/Bristol-Myers-Squibb,: Consultancy, Honoraria; Incyte: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Takeda: Honoraria, Research Funding; Roche: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Garcia Gutierrez: BMS: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Incyte: Consultancy, Honoraria, Research Funding.

Abstract: Introduction Chronic lymphocytic leukemia (CLL) is a lymphoid neoplasm which represents the most frequent hematologic malignancy in Caucasians. Every year, there are15,000 new diagnoses and 5000 CLL deaths in the United States. Its prevalence in México and other non-Caucasian populations is substantially lower and the clinical course of CLL patients has been described to be less aggressive Methods All consecutive patients seeking medical care after 1983 in our institution as a result of CLL and followed for at least 3 months were entered in the study. The study was approved by the institutional review board. The treatment of patients was withheld in: (a) Persons with CLL Rai stage 0 or 1, until progression; (b) Persons with CLL Rai stage 2-4, with a negative expression of ZAP-70 until progression. Progression was defined by: Anemia, thrombocytopenia, massive symptomatic or progressive splenomegaly and or adenopathy, progressive lymphocytosis ( & gt;50% increase in two months or lymphocyte doubling timeless than 6 months), autoimmune hemolytic anemia not responding to standard therapies, or constitutional symptoms: Weight loss greater than 10% in 6 months, unexplained night sweats or unexplained fever for 2 or more weeks. Refractoriness of the disease was defined as progression despite treatment for a minimum of 3 months. Results Among 98 patients with CLL who were accrued in the study between 1983 and 2019, 49 (50%) were followed for three or more months and accordingly, entered in the study. Median follow up time of the patients is 61 months (95% CI 46.1-75.8). There were 15 females and 34 males, the median age was 65 years (range 23-86). According to the Rai staging system, there were 24 stage 0, 7 stage I, 8 stageII, 0 stage III and 10 stage IV; 80% of patients were identified in stages 0-II. In 28 patients a complete immune phenotype of the malignant cells was analyzed: 89% of patients were ZAP-70 negative (ZAP expression in less than 20% of malignant cells), 79% expressed CD5, 100% CD19 and 86% CD23. Three patients were born in European countries, whereas 6 had an immediate European ancestor, indicating that a Caucasian background was identified in 9/49patients (18%). There were no instances of T-cell CLL. Median OS for all the patients has not been reached, being above 247 months (20 years). The OS of patients given or not any treatment was not statistically different (p= 0.09). It is clear that patients who needed treatment did worse than those not needing treatment but the differences were not significant. Patients with advanced stages (III and IV) had a worse outcome than those in early stages. Median OS for patients given no treatment at all has not been reached and is above 247 months; median OS for patients given CP was 115 months, median OS for those given FC has not been reached and is above 132 months, whereas median OS for persons given FCR has not been reached, being above 136 months; all these differences are not statistically significant. Eight of 49 patients were found to be refractory to treatment; they were receiving CP (5 cases); FC (2 cases) and FCR (one case); these refractory patients were given, FCR (7 cases) and rituximab/ifosfamide/carboplatin/etoposide (one case). No patient had to be given cladribine, pentostatin, alemtuzumab (anti-CD52), bendamustine, ofatumumab (anti-CD20), obinutuzumab (anti-CD20), lenalidomide, ibrutinib nor idelalisib. Conclusion In the era of novel anti-CLL drugs, we have found that the clinical course of these patients in México seems to be less aggressive than in Caucasian populations and that, in consequence, circa 50% of them do not need any treatment at all. In those needing treatment, the use of a simplified approach and taking advantage of improved supportive care measures, acceptable results are obtained even if all of the new CLL drugs are not employed. These observations may be critical in developing countries, where the cost of the drugs will continue to be a major factor in choosing therapies. Disclosures No relevant conflicts of interest to declare.

Abstract: Introduction The COVID-19 pandemic has affected the entire world. Health systems have been affected in such a way that patients with diseases other than COVID-19 have suffered serious consequences. In Latin America, the disease has emerged in a fragile system with more disparities, making our patients more vulnerable. Acute leukemia patients have a high risk of severe COVID-19 disease. Various expert recommendations have emerged with the aim of minimizing the risk of COVID-19 without affecting leukemia-related outcomes. However, multiple logistical issues tangentially associated with the pandemic have also appeared, potentially limiting the quality of management of these patients. The objective of this study was to register treatment modifications associated with the COVID-19 pandemic and its short-term consequences in Latin American countries. Methods We included patients older than 14 years, from 14 centers of 4 Latin American countries (Mexico, Peru, Guatemala and Panama), with the diagnosis of acute leukemia, who were on active treatment since the first case of COVID-19 was documented in each country. We documented their baseline characteristics and followed the patients prospectively until July 15, were data-cutoff for this pre-planned analysis was performed. The primary outcome was the incidence of COVID-19 disease and its complications. Secondary outcomes included treatment and consult modifications, and cause of death during the study period. Logistic regression was performed to determine factors associated with COVID-19 and all-cause mortality. Results We recorded the information of 635 patients: 58.1% Ph-negative ALL, 25.7% AML, 9% APL and 7.2% Ph+ALL. The median age was 35 years (14-90 years); 58.8% were consideredf high-risk patients. The majority were on CR (68.3%) receiving consolidation or maintenance therapy, while 14.5% were newly diagnosed and 17.2% with relapsed/refractory disease. The majority (91.8%) were treated in centers that were also receiving COVID-19 patients, 40.2% in centers were patients could not be electively hospitalized for leukemia treatment because of the COVID-19 pandemic. The COVID-pandemic led to treatment-modifications in 40.8% of the cases. Reasons for modifications were associated with logistical issues (22.4%), medical decisions (15.1%) or patient choice (3.3%). The most frequent modification was chemotherapy delay (17.3%) followed by regimen modification (13.4%) and dose-reductions (10.1%). (Figure 1) 83 patients (13.1%) developed COVID-19 disease, the majority mild-moderate disease (54.2%), 27.7% severe disease and 18.1% critically ill; 27.7% required mechanical ventilation and 37.7% died from COVID-19 disease, representing 4.9% of the entire cohort. We identify as risk factors for COVID-19 disease the presence of active leukemia (newly diagnosed or relapsed) (OR 3.46 [95% CI: 2.16-5.5], p & lt;0.001), high-risk leukemia (OR 1.63 [95% CI: 1.54-4.52], p & lt;0.001) and being treated in a center were elective hospitalization was possible (OR 2.17 [95% CI 1.29-3.67], p=0.004). Treatment modifications, appointment prolongations or the use of virtual consultation were not associated with a reduction in the risk of COVID-19. On the other hand, 16.7% of patients died during period analyzed due to leukemia (57.5%), COVID-19 (29.2%) or treatment related-mortality (13.2%). Independent factors associated with mortality were AML vs. ALL (OR 1.89 [95% CI: 1.12-3.18], p= 0.016), relapsed-refractory disease (OR 8.34 [95% CI: 4.83-14.41], p & lt;0.001), induction/consolidation vs. maintenance therapy (OR 2.20 [95% CI: 1.25-3.18], p & lt;0.001) and the use of virtual consultation (OR 0.35 [95% CI: 0.13-0.94] p=0.037). (Table 1) Discussion/Conclusions The COVID-19 pandemic led to significant modifications in the standard of care treatment of patients with acute leukemia. The incidence of COVID-19 disease in acute leukemia patients was considerable and more than a third of the patients with acute leukemia and COVID-19 disease died. Despite a short-follow up, 16.7% of the patients died and leukemia-related deaths were the most frequent. In low- and middle-income countries with fragile health systems, the collateral damage for patients with acute leukemia may be just as important as the direct consequences of COVID-19. Disclosures Alvarado: Roche: Speakers Bureau; Novartis: Speakers Bureau; Amgen: Speakers Bureau; Celgene: Speakers Bureau; Alexion: Speakers Bureau. De la Peña-Celaya:Amgen: Speakers Bureau; Janssen: Speakers Bureau; Novartis: Speakers Bureau. Perez:Roche: Speakers Bureau; Celgene: Speakers Bureau; Novartis: Speakers Bureau. Gomez-Almaguer:Amgen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene/BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Abstract: Introduction One important aspect of quality assurance in transplantation relates to the maintenance of central venous access (CVA), especially in outpatient conditions in which patients have a higher degree of activity and manipulation of CVA tends to be more frequent. A comprehensive program oriented to prevent and control complications related to CVA insertion, maintenance and removal is thought to be a highly effective strategy to improve safety outcomes. Methods A retrospective study evaluating complications related to central venous access (CVA) in patients undergoing hematopoietic stem cell transplantation (HSCT) was conducted using electronic medical records (EMR) at our center. Laboratory and radiology reports were collected in order to identify complications related to CVA. Patients from May 2015 to July 2021 were included in the study. As per local protocol, insertion of Mahurkar catheter for cell collection is conducted by an experienced surgeon under general anesthesia on day -3 and after a short-stay (6 hours) in hospital patients are discharged. On day -2, cell collection is accomplished following all cautionary measures and removal of catheter is done on day -1. Maintenance and care of CVA is guided by standardized protocols related to cleaning, manipulation, blood sample collection and removal. All patients signed a consent to participate in the study and the study protocol was approved by Clínica Ruiz IRB. To be considered as statistically significant, results had to display a two-sided p value & lt;0.05. Results A total of 1088 patients recruited since May 2015 were included in the study. Main indication for auto-HSCT was multiple sclerosis with 1066 (98%), followed by chronic inflammatory demyelinating polyneuropathy with 16 (1.5%) and 5 (0.5%) patients with other autoimmune disorders. Median age of donors was 46 (40 - 54) years. Median dose of CD34 + cells x10 6/kg infused per patient was 7.0 (3.7 - 11.3) and the median of collection events per patient was 1 (1 - 2). Cell collection was accomplished via apheresis in (99.5%) of patients, of those CVA was used as collection site in 998 (92%) patients, while a change for peripheral venous access occurred in 85 (8%) patients, due to different reasons, most frequent being any type of CVA obstruction in 62 (83%) of donors. Pneumothorax occurred in 11 (1.1%) patients in whom CVA was used for collection. All cases were successful managed with pleural drainage and hospital admission longer than 24 hours was required for 3 (27%). Furthermore, catheter-related bloodstream infections were identified in 3 (0.3%) patients whom were admitted and treated with broad-spectrum antibiotics and discharged with no further events. There were no misplacement, thrombotic- nor hemorrhagic-related events in patients with CVA. A multifactorial analysis revealed that relevant factors such as, age, sex and type of disease were not correlated with any type of CVA-related complications. Conclusions We have shown that prevention and control of complications related to CVA at our campuses are highly effective. The proportion of patients experiencing a CVA-related complication was minimal in comparison with other experiences. Disclosures Gomez-Almaguer: Roche: Honoraria, Speakers Bureau; Takeda: Honoraria, Speakers Bureau; Bristol-Myers-Squibb: Honoraria, Speakers Bureau; Janssen: Honoraria, Speakers Bureau.

Abstract: We studied lineage-specific chimerism and minimal residual disease (MRD) in sequential posttransplant samples from 55 patients who underwent unmanipulated (n = 44) or partially T-cell–depleted (n = 11) allogeneic bone marrow transplantation (BMT) for chronic myeloid leukemia (CML). Chimerism was assessed by polymerase chain reaction (VNTR [variable number of tandem repeats]-PCR) analysis in highly purified CD19+, CD3+, CD15+, and CD56+ cell fractions, whereas MRD was investigated in whole blood by reverse transcriptase–PCR (RT-PCR) of both p210BCR-ABL and p190BCR-ABL hybrid transcripts. Of 55 patients, 14 (including 6 T-cell–depleted patients) had cytogenetic relapse at 5-80 months and progressed to hematologic relapse, while 41 patients remained in prolonged cytogenetic remission 12-107 months post-BMT. Before leukemia recurrence, patients in the relapse group showed a consistent evolution pattern sequentially featured by persistent p210BCR-ABL positivity, increasing mixed chimerism (MC) in myeloid cells, p190BCR-ABL positivity, and, finally, cytogenetic relapse. Myeloid MC preceded cytogenetic relapse by 2-12 months, whereas p190BCR/ABL was detected 1-6 months prior to cytogenetic relapse in 11 patients and concomitant with cytogenetic relapse in 3 patients. In the remission group, all patients invariably tested negative for p190BCR-ABL; 10 patients tested positive for p210BCR-ABL at variable time-points but showed persistent full donor chimerism (DC), whereas 31 patients tested p210BCR-ABL negative and displayed full DC or transient MC due to the persistence of recipient T cells. Two patients in the relapse group were successfully reinduced into molecular remission with donor lymphocyte infusion. Sequential molecular analysis after such treatment showed the inverse pattern to that observed prior to relapse, ie, progressive disappearance of p190BCR-ABL transcripts, conversion of myeloid chimerism to donor type, and, finally, p210BCR-ABL negativity. We conclude that lineage-specific chimerism and p190BCR-ABL messenger RNA (mRNA) analyses contribute a better characterization of CML evolution after BMT and enable early identification of patients at the highest risk of relapse.

Abstract: Introduction: Around 30% of Hodgkin Lymphoma (HL) patients are refractory or relapse (RR) after first line therapy. Salvage chemotherapy followed by high-dose chemotherapy and with Autologous Peripheral Blood Stem Cell Transplantation (APBSCT) can cure many patients, but those who are transplanted with active disease detectable by PET-CT have a very poor prognosis. Therefore, the current challenge in HL is to improve the results of the pre-transplant chemotherapy. Phase 2 single agent trials with Brentuximab Vedotin (BV) in highly RRHL patients have demonstrated overall and complete response rates of 75% and 34%, respectively (Younes, JCO 2012; 30:2183); as 2nd line, BV has provided very promising results in combination with chemotherapy (LaCasce, Blood 2014; 124(21):3099) Objectives: We conducted a phase I/II trial to determine the dose limiting toxicity (DLT), maximum tolerated dose (MTD), and response rate with combined Brentuximab vedotin with ESHAP chemotherapy [BRESHAP] as 2nd line therapy for RRHL prior to APBSCT (ClinicalTrials.gov #NCT02243436). Methods: The primary efficacy endpoint was the proportion of complete responses (CR) pre-APBSCT. It is a phase I-II trial with dose escalation followed by expansion. Treatment consisted of Etoposide (40 mg/m2/day IV, D1-4), Solumedrol (250 mg/day IV, D1-4), High dose AraC (2 g/m2 IV, D5) and cisPlatin (25 mg/m2/day IV, D1-4). BV was administered at three dose levels: 0.9, 1.2 or 1.8 mg/kg IV on day 1 to each cohort of patients, following the scheme of cohorts of 3 patients each, to assess the maximum tolerable dose (MTD). The dose limiting toxicity (DLT) was defined as Grade 4 hematologic toxicity extended over 3 weeks or non-hematologic toxicity grade ≥3 during the first treatment cycle. Patients were evaluated weekly. Results: Patients with relapsed or refractory classical HL (cHL) after one prior line of therapy were eligible. To date, 27 patients have been included in the trial. The first 9 have completed the three courses as scheduled, without TLD doses. Fifteen patients have received the first full cycle, presenting 4 episodes of severe adverse reactions: non-neutropenic fever due to IV AraC and to complicated catheter insertion; one pneumothorax after catheter insertion; and one febrile neutropenia recovered with antibiotic treatment. Grade 4 hematologic toxicity presented in three of these nine patients: 2 neutropenia and thrombocytopenia 1. All nine patients underwent stem cell mobilization after the 1st or the 2nd treatment cycle with subcutaneous G-CSF 5 mcg/Kg days +7 to +14, collecting 〉 2·10e6/Kg peripheral blood CD34+ cells in all cases, with no grade 3-4 toxicity. The number of harvesting procedures was one & two in seven & two patients, respectively. The transplant has been done in 6 patients, with a median of 9 days and 10 days for neutrophil and platelet recovery, respectively. All nine patients had no evidence of disease before the transplant by PET-CT, although one patient had residual FGD uptaking areas without underlying anatomical lesions on CT (metabolic complete response: 89%). Six patients have been evaluated after the APBSCT and they are all in metabolic CR. The phase II of the trial was open on April the 12th 2015, with BV at the recommended dose of 1.8 mg/kg per course. At the submission of this report, there were 28 patients recruited, and 17 evaluated pre-transplant, achieving 16 CR. The complete results will be presented during the meeting; the projected recruitment by the meeting is 45 (65% of the total planned recruitment). Conclusions: BRESHAP is a tolerable treatment scheme as remission induction prior to transplant in patients with refractory or relapsed Hodgkin lymphoma, and it offers very promising results. Disclosures Off Label Use: Brentuximab Vedotin in Resistant or Relapsed Hodgkin Lymphoma patients who are candidates to Autologous Stem Cell Transplant. Sureda:Seattle Genetics Inc.: Research Funding; Takeda: Consultancy, Honoraria, Speakers Bureau. Caballero:Takeda: Honoraria, Research Funding.

Abstract: We studied lineage-specific chimerism and minimal residual disease (MRD) in sequential posttransplant samples from 55 patients who underwent unmanipulated (n = 44) or partially T-cell–depleted (n = 11) allogeneic bone marrow transplantation (BMT) for chronic myeloid leukemia (CML). Chimerism was assessed by polymerase chain reaction (VNTR [variable number of tandem repeats]-PCR) analysis in highly purified CD19+, CD3+, CD15+, and CD56+ cell fractions, whereas MRD was investigated in whole blood by reverse transcriptase–PCR (RT-PCR) of both p210BCR-ABL and p190BCR-ABL hybrid transcripts. Of 55 patients, 14 (including 6 T-cell–depleted patients) had cytogenetic relapse at 5-80 months and progressed to hematologic relapse, while 41 patients remained in prolonged cytogenetic remission 12-107 months post-BMT. Before leukemia recurrence, patients in the relapse group showed a consistent evolution pattern sequentially featured by persistent p210BCR-ABL positivity, increasing mixed chimerism (MC) in myeloid cells, p190BCR-ABL positivity, and, finally, cytogenetic relapse. Myeloid MC preceded cytogenetic relapse by 2-12 months, whereas p190BCR/ABL was detected 1-6 months prior to cytogenetic relapse in 11 patients and concomitant with cytogenetic relapse in 3 patients. In the remission group, all patients invariably tested negative for p190BCR-ABL; 10 patients tested positive for p210BCR-ABL at variable time-points but showed persistent full donor chimerism (DC), whereas 31 patients tested p210BCR-ABL negative and displayed full DC or transient MC due to the persistence of recipient T cells. Two patients in the relapse group were successfully reinduced into molecular remission with donor lymphocyte infusion. Sequential molecular analysis after such treatment showed the inverse pattern to that observed prior to relapse, ie, progressive disappearance of p190BCR-ABL transcripts, conversion of myeloid chimerism to donor type, and, finally, p210BCR-ABL negativity. We conclude that lineage-specific chimerism and p190BCR-ABL messenger RNA (mRNA) analyses contribute a better characterization of CML evolution after BMT and enable early identification of patients at the highest risk of relapse.

Abstract: Introduction: Asciminib is a new BCR-ABL1 inhibitor that differs from previous tyrosine kinase inhibitors (TKIs) in that it does not bind to the ATP-binding site of the kinase. Data from different clinical trials has shown an adequate safety and efficacy profile in chronic myeloid leukemia (CML) patients failing previous TKIs. However, no findings have been communicated in real life experience. The aim of our study is to present first results of asciminib in CML patients failing previous TKIs under the current compassionate use program. Methods: We retrospectively collected data from 31 patients treated with asciminib in 25 centers under compassionate use program. Data collecting was performed between October 2018 and June 2020. Patients baseline characteristics are shown in table 1. Most patients were heavily pretreated with 28 patients receiving 3 or more TKIs previous to asciminib. Eleven patients (35.5%) had been treated with ponatinib at some point throughout the disease. Twelve patients showed BCR-ABL1 mutations (only 1 case with T315I mutation). Switch to asciminib was due to intolerance in 22 patients and due to resistance in the remaining 9. Median dose of asciminib was 80mg per day (40mg every 12 hours). Treatment responses were evaluated according to European Leukemia Net recommendations. Data compilation and analysis were performed with REDCap Software and IBM SPSS (Version 25.0). Results: Median time on asciminib for the entire cohort was 35 weeks. Regarding toxicities, 13 patients (42%) experienced mild extra-hematological side effects (grade 1-2) being the most frequent fatigue (19%), joint pain (16%) and nausea (9%). Four patients (12,9%) showed severe (grade 3-4) extra-hematological events: fatigue, hepatotoxicity, hypertension and pericardial effusion (1 patient each). Three patients (9,7%) suffered from grade 4 thrombocytopenia, 2 of them associating grade 4 neutropenia. All toxicities according to previous TKIs adverse effects as well as cross-intolerance data is shown in table 2. Dose reduction had to be carried out in 9 patients (29%), 7 of those with temporary treatment interruptions; most owing to hematological adverse effects. In terms of efficacy (Graph 1), probability of reaching or at least maintaining previous response was 100%, 61.3% and 35.5% for complete hematological response (CHR), complete cytogenetic response (CCyR) and major molecular response (MMR), respectively. Regarding probabilities to improve previous responses, rates of CCyR and MMR were, respectively, 22,2% (2/9) and 22,2% (2/9) for resistant patients and 44% (4/9) and 62,5%. (10/16) for intolerant group. Amid the 11 patients previously treated with ponatinib, 3 patients (27,3%) showed improvement of response achieving at least MMR, 2 of them from the TKI-intolerant group and 1 from the TKI-resistant group. The median follow-up time was 40 weeks, after which 27 patients (87.1%) continued with asciminib. Treatment cessation happened in 2 patients due to progression to blastic phase and in 2 patients due to lack of efficacy. No patients discontinued due to side effects. Conclusion: The data presented, similar to that known from clinical trials, supports the use of asciminib in routine clinical practice in CML patients failing to previous TKIs. Disclosures Garcia-Gutiérrez: Novartis: Consultancy, Other: Travel, Accommodation, Expenses, Research Funding; Bristol-Myers Squibb: Consultancy, Other: Travel, Accommodation, Expenses, Research Funding; Pfizer: Consultancy, Other: Travel, Accommodation, Expenses, Research Funding; Incyte: Consultancy, Other: Travel, Accommodation, Expenses, Research Funding.