Javier Pinilla-Ibarz MD, PhD

Patients who adhere to their tyrosine kinase inhibitor (TKI) medication regimen will achieve CML survival goals that would be expected for their age group. Imatinib is a first generation TKI inhibitor.  In a recent post hoc analysis of the ADAGIO study patients, Obeng-Kusi M et al¹ showed that compared with 90% adherence, a 100% adherence to imatinib was associated with a 2-fold increase in achieving or maintaining treatment response in patients with chronic myeloid leukemia (CML), highlighting the urgent need to assess and promote patient adherence. There is virtually no margin for nonadherence, if the objective is to optimize the likelihood of treatment response, and a minimal margin to avoid impaired treatment response.

On the same topic, Davis TC et al.²also recently reported a study of suboptimal adherence to TKI. From the 86 patients with CML studied, almost 17.9% of participants reported nonadherence, i.e., missing at least 1 dose of CML medication in the previous week. The main reason that patients reported nonadherence were side effects, a busy schedule, and the difficulty of complying daily with the TKI regimen.

Cardiovascular adverse events (AE) have been described with TKI treatment at different rates, but cardiovascular risk stratification was not included in the design of many trials. Baggio D et al³  in a retrospective study included 88 patients with CML treated with any TKI and a median follow up of 3.8 months. They described the rates of major cardiovascular AEs by combining age, history of prior cardiovascular diseases, and Framingham risk score, along with additional insights from coronary artery calcium scoring (CACS). The authors found cardiovascular AEs in 0%, 10%, and 19%, of the low-, intermediate-, and high-risk groups respectively. By using CACS score they were able to reclassify patients from intermediate to low risk and none of those patients experienced a major adverse cardiovascular event.

The use of kinase domain mutation analysis at diagnosis is not a recommended practice by the National Comprehensive Cancer Network (NCCN) or the European Leukemia Net (ELN), but is reserved for use in patents who failed first or subsequent lines of therapies. Furthermore, previous publications in the topic have showed discordant results. More recently, the use of ultra-deep sequencing has detected low-frequency genetic mutations with high sensitivity. Park H et al.⁴ recently described the most common mutations found in a population of 50 CML patients treated with nilotinib. V299 L mutation associated with dasatinib resistance and nilotinib sensitivity were observed in 98% of patients. Two uncommon mutations S417Y and the V371A were associated with reduced molecular response.

References

1. Obeng-Kusi M et al. No margin for non-adherence: Probabilistic Kaplan-Meier modeling of imatinib non-adherence and treatment response in CML (ADAGIO study). Leuk Res. 2021;111:106734 (Oct 21).
2. Davis TC et al. Assessment of oral chemotherapy nonadherence in chronic myeloid leukemia patients using brief measures in community cancer clinics: a pilot study. Int J Environ Res Public Health. 2021;18(21):11045 (Oct 21).
3. Baggio D et al. Prediction of cardiovascular events in patients with chronic myeloid leukaemia using baseline risk factors and coronary artery calcium scoring. Intern Med J. 2021;51(10):1736-40 (Oct 18).  
4. Park H et al. Ultra-deep sequencing mutation analysis of the BCR/ABL1 kinase domain in newly diagnosed chronic myeloid leukemia patients. Leuk Res. 2021;111:106728 (Oct 15).

Patients who adhere to their tyrosine kinase inhibitor (TKI) medication regimen will achieve CML survival goals that would be expected for their age group. Imatinib is a first generation TKI inhibitor.  In a recent post hoc analysis of the ADAGIO study patients, Obeng-Kusi M et al¹ showed that compared with 90% adherence, a 100% adherence to imatinib was associated with a 2-fold increase in achieving or maintaining treatment response in patients with chronic myeloid leukemia (CML), highlighting the urgent need to assess and promote patient adherence. There is virtually no margin for nonadherence, if the objective is to optimize the likelihood of treatment response, and a minimal margin to avoid impaired treatment response.

On the same topic, Davis TC et al.²also recently reported a study of suboptimal adherence to TKI. From the 86 patients with CML studied, almost 17.9% of participants reported nonadherence, i.e., missing at least 1 dose of CML medication in the previous week. The main reason that patients reported nonadherence were side effects, a busy schedule, and the difficulty of complying daily with the TKI regimen.

Cardiovascular adverse events (AE) have been described with TKI treatment at different rates, but cardiovascular risk stratification was not included in the design of many trials. Baggio D et al³  in a retrospective study included 88 patients with CML treated with any TKI and a median follow up of 3.8 months. They described the rates of major cardiovascular AEs by combining age, history of prior cardiovascular diseases, and Framingham risk score, along with additional insights from coronary artery calcium scoring (CACS). The authors found cardiovascular AEs in 0%, 10%, and 19%, of the low-, intermediate-, and high-risk groups respectively. By using CACS score they were able to reclassify patients from intermediate to low risk and none of those patients experienced a major adverse cardiovascular event.

The use of kinase domain mutation analysis at diagnosis is not a recommended practice by the National Comprehensive Cancer Network (NCCN) or the European Leukemia Net (ELN), but is reserved for use in patents who failed first or subsequent lines of therapies. Furthermore, previous publications in the topic have showed discordant results. More recently, the use of ultra-deep sequencing has detected low-frequency genetic mutations with high sensitivity. Park H et al.⁴ recently described the most common mutations found in a population of 50 CML patients treated with nilotinib. V299 L mutation associated with dasatinib resistance and nilotinib sensitivity were observed in 98% of patients. Two uncommon mutations S417Y and the V371A were associated with reduced molecular response.

References

1. Obeng-Kusi M et al. No margin for non-adherence: Probabilistic Kaplan-Meier modeling of imatinib non-adherence and treatment response in CML (ADAGIO study). Leuk Res. 2021;111:106734 (Oct 21).
2. Davis TC et al. Assessment of oral chemotherapy nonadherence in chronic myeloid leukemia patients using brief measures in community cancer clinics: a pilot study. Int J Environ Res Public Health. 2021;18(21):11045 (Oct 21).
3. Baggio D et al. Prediction of cardiovascular events in patients with chronic myeloid leukaemia using baseline risk factors and coronary artery calcium scoring. Intern Med J. 2021;51(10):1736-40 (Oct 18).  
4. Park H et al. Ultra-deep sequencing mutation analysis of the BCR/ABL1 kinase domain in newly diagnosed chronic myeloid leukemia patients. Leuk Res. 2021;111:106728 (Oct 15).

Patients who adhere to their tyrosine kinase inhibitor (TKI) medication regimen will achieve CML survival goals that would be expected for their age group. Imatinib is a first generation TKI inhibitor.  In a recent post hoc analysis of the ADAGIO study patients, Obeng-Kusi M et al¹ showed that compared with 90% adherence, a 100% adherence to imatinib was associated with a 2-fold increase in achieving or maintaining treatment response in patients with chronic myeloid leukemia (CML), highlighting the urgent need to assess and promote patient adherence. There is virtually no margin for nonadherence, if the objective is to optimize the likelihood of treatment response, and a minimal margin to avoid impaired treatment response.

On the same topic, Davis TC et al.²also recently reported a study of suboptimal adherence to TKI. From the 86 patients with CML studied, almost 17.9% of participants reported nonadherence, i.e., missing at least 1 dose of CML medication in the previous week. The main reason that patients reported nonadherence were side effects, a busy schedule, and the difficulty of complying daily with the TKI regimen.

Cardiovascular adverse events (AE) have been described with TKI treatment at different rates, but cardiovascular risk stratification was not included in the design of many trials. Baggio D et al³  in a retrospective study included 88 patients with CML treated with any TKI and a median follow up of 3.8 months. They described the rates of major cardiovascular AEs by combining age, history of prior cardiovascular diseases, and Framingham risk score, along with additional insights from coronary artery calcium scoring (CACS). The authors found cardiovascular AEs in 0%, 10%, and 19%, of the low-, intermediate-, and high-risk groups respectively. By using CACS score they were able to reclassify patients from intermediate to low risk and none of those patients experienced a major adverse cardiovascular event.

The use of kinase domain mutation analysis at diagnosis is not a recommended practice by the National Comprehensive Cancer Network (NCCN) or the European Leukemia Net (ELN), but is reserved for use in patents who failed first or subsequent lines of therapies. Furthermore, previous publications in the topic have showed discordant results. More recently, the use of ultra-deep sequencing has detected low-frequency genetic mutations with high sensitivity. Park H et al.⁴ recently described the most common mutations found in a population of 50 CML patients treated with nilotinib. V299 L mutation associated with dasatinib resistance and nilotinib sensitivity were observed in 98% of patients. Two uncommon mutations S417Y and the V371A were associated with reduced molecular response.

References

1. Obeng-Kusi M et al. No margin for non-adherence: Probabilistic Kaplan-Meier modeling of imatinib non-adherence and treatment response in CML (ADAGIO study). Leuk Res. 2021;111:106734 (Oct 21).
2. Davis TC et al. Assessment of oral chemotherapy nonadherence in chronic myeloid leukemia patients using brief measures in community cancer clinics: a pilot study. Int J Environ Res Public Health. 2021;18(21):11045 (Oct 21).
3. Baggio D et al. Prediction of cardiovascular events in patients with chronic myeloid leukaemia using baseline risk factors and coronary artery calcium scoring. Intern Med J. 2021;51(10):1736-40 (Oct 18).  
4. Park H et al. Ultra-deep sequencing mutation analysis of the BCR/ABL1 kinase domain in newly diagnosed chronic myeloid leukemia patients. Leuk Res. 2021;111:106728 (Oct 15).

In the new era of the COVID-19 pandemic, patients and physicians still struggle to see how different hematologic conditions may be affected by this viral infection. Although it has been well reported that COVID-19 may not be as lethal in chronic myeloid leukemia (CML) as other malignancies, patients still may be at risk of bad outcomes. A recent publication by Breccia et al¹collected retrospective information on more than 8000 CML patients followed at different institutions in Italy up to January 2021. The authors recorded 217 patients (2.5%) who were SARS-CO-V2 (COVID-19) positive. More than half of the patients had concomitant comorbidities. Almost 80% were quarantined while the rest required hospitalization, although only 3.6 required intensive care unit care. Twelve patients died, which represents 0.13% of the whole cohort. The main predisposing factors were age > 65 years and cardiovascular disorders, similar to that the general population.  Most of patients continue tyrosine kinase inhibitor (TKI) therapy during the infection.

While the introduction of TKI for the treatment of CML make the number of allogenic transplants decrease significantly due the high mortality in comparison with TKI therapy, it is still an option for certain patients who failed multiple TKI treatments or progressed to more advanced phases of the disease. Although it has already been described that the introduction of imatinib did not affect outcomes for patients that require this therapeutic option, there was not much data about the effect of second generation TKIs. In a publication by Masouridi-Levrat S et al² the authors examine the effect of second generation TKIs in a prospective non-interventional study performed by the European Group for Blood and Marrow Transplantation on 383 consecutive CML patients previously treated with dasatinib or nilotinib undergoing allogeneic hematopoietic stem cell transplantation (allo-HCT) from 2009 to 2013. Less than 40% of patients received the transplant in the chronic phase while the rest were in accelerated or blast phase. With a median follow-up of 37 months, 8% of patients developed either primary or secondary graft failure, 34% acute graft-versus-host disease (GvHD), and 60% chronic GvHD. The non-relapse mortality was 18% and 24% at 12 months and at 5 years, respectively. Relapse incidence was 36%, overall survival 56%, and relapse-free survival 40% at 5 years. All these data showed the feasibility of this procedure in patients treated with second generation TKIs with similar post-transplant complications in TKI naive patients or patients treated with imatinib.

Patients under therapy with TKIs may frequently present with elevations of creatine kinase (CK), thought to be in some cases related with the classical associations with muscle and joint pain that is also a common side effect. However the long run effect on treatment outcomes has not been well studied. Bankar A et al.³ recently reported on the relation between CK elevations and overall survival (OS) and event free survival (EFS). Interestingly CK elevations secondary to first or second generation TKIs were associated with a better OS and EFS. As expected, high Sokal score patients had a worse OS and EFS.

References

1. Breccia M et al. COVID-19 infection in chronic myeloid leukaemia after one year of the pandemic in Italy. A Campus CML report. Br J Haematol. 2021 Oct 11.
2. Masouridi-Levrat S et al. Outcomes and toxicity of allogeneic hematopoietic cell transplantation in chronic myeloid leukemia patients previously treated with second-generation tyrosine kinase inhibitors: a prospective non-interventional study from the Chronic Malignancy Working Party of the EBMT. Bone Marrow Transplant. 2021 Oct 1.
3. Bankar A, Lipton JH. Association of creatine kinase elevation with clinical outcomes in chronic myeloid leukemia: a retrospective cohort study Leuk Lymphoma. 2021 Sep 8.

In the new era of the COVID-19 pandemic, patients and physicians still struggle to see how different hematologic conditions may be affected by this viral infection. Although it has been well reported that COVID-19 may not be as lethal in chronic myeloid leukemia (CML) as other malignancies, patients still may be at risk of bad outcomes. A recent publication by Breccia et al¹collected retrospective information on more than 8000 CML patients followed at different institutions in Italy up to January 2021. The authors recorded 217 patients (2.5%) who were SARS-CO-V2 (COVID-19) positive. More than half of the patients had concomitant comorbidities. Almost 80% were quarantined while the rest required hospitalization, although only 3.6 required intensive care unit care. Twelve patients died, which represents 0.13% of the whole cohort. The main predisposing factors were age > 65 years and cardiovascular disorders, similar to that the general population.  Most of patients continue tyrosine kinase inhibitor (TKI) therapy during the infection.

While the introduction of TKI for the treatment of CML make the number of allogenic transplants decrease significantly due the high mortality in comparison with TKI therapy, it is still an option for certain patients who failed multiple TKI treatments or progressed to more advanced phases of the disease. Although it has already been described that the introduction of imatinib did not affect outcomes for patients that require this therapeutic option, there was not much data about the effect of second generation TKIs. In a publication by Masouridi-Levrat S et al² the authors examine the effect of second generation TKIs in a prospective non-interventional study performed by the European Group for Blood and Marrow Transplantation on 383 consecutive CML patients previously treated with dasatinib or nilotinib undergoing allogeneic hematopoietic stem cell transplantation (allo-HCT) from 2009 to 2013. Less than 40% of patients received the transplant in the chronic phase while the rest were in accelerated or blast phase. With a median follow-up of 37 months, 8% of patients developed either primary or secondary graft failure, 34% acute graft-versus-host disease (GvHD), and 60% chronic GvHD. The non-relapse mortality was 18% and 24% at 12 months and at 5 years, respectively. Relapse incidence was 36%, overall survival 56%, and relapse-free survival 40% at 5 years. All these data showed the feasibility of this procedure in patients treated with second generation TKIs with similar post-transplant complications in TKI naive patients or patients treated with imatinib.

Patients under therapy with TKIs may frequently present with elevations of creatine kinase (CK), thought to be in some cases related with the classical associations with muscle and joint pain that is also a common side effect. However the long run effect on treatment outcomes has not been well studied. Bankar A et al.³ recently reported on the relation between CK elevations and overall survival (OS) and event free survival (EFS). Interestingly CK elevations secondary to first or second generation TKIs were associated with a better OS and EFS. As expected, high Sokal score patients had a worse OS and EFS.

References

1. Breccia M et al. COVID-19 infection in chronic myeloid leukaemia after one year of the pandemic in Italy. A Campus CML report. Br J Haematol. 2021 Oct 11.
2. Masouridi-Levrat S et al. Outcomes and toxicity of allogeneic hematopoietic cell transplantation in chronic myeloid leukemia patients previously treated with second-generation tyrosine kinase inhibitors: a prospective non-interventional study from the Chronic Malignancy Working Party of the EBMT. Bone Marrow Transplant. 2021 Oct 1.
3. Bankar A, Lipton JH. Association of creatine kinase elevation with clinical outcomes in chronic myeloid leukemia: a retrospective cohort study Leuk Lymphoma. 2021 Sep 8.

In the new era of the COVID-19 pandemic, patients and physicians still struggle to see how different hematologic conditions may be affected by this viral infection. Although it has been well reported that COVID-19 may not be as lethal in chronic myeloid leukemia (CML) as other malignancies, patients still may be at risk of bad outcomes. A recent publication by Breccia et al¹collected retrospective information on more than 8000 CML patients followed at different institutions in Italy up to January 2021. The authors recorded 217 patients (2.5%) who were SARS-CO-V2 (COVID-19) positive. More than half of the patients had concomitant comorbidities. Almost 80% were quarantined while the rest required hospitalization, although only 3.6 required intensive care unit care. Twelve patients died, which represents 0.13% of the whole cohort. The main predisposing factors were age > 65 years and cardiovascular disorders, similar to that the general population.  Most of patients continue tyrosine kinase inhibitor (TKI) therapy during the infection.

While the introduction of TKI for the treatment of CML make the number of allogenic transplants decrease significantly due the high mortality in comparison with TKI therapy, it is still an option for certain patients who failed multiple TKI treatments or progressed to more advanced phases of the disease. Although it has already been described that the introduction of imatinib did not affect outcomes for patients that require this therapeutic option, there was not much data about the effect of second generation TKIs. In a publication by Masouridi-Levrat S et al² the authors examine the effect of second generation TKIs in a prospective non-interventional study performed by the European Group for Blood and Marrow Transplantation on 383 consecutive CML patients previously treated with dasatinib or nilotinib undergoing allogeneic hematopoietic stem cell transplantation (allo-HCT) from 2009 to 2013. Less than 40% of patients received the transplant in the chronic phase while the rest were in accelerated or blast phase. With a median follow-up of 37 months, 8% of patients developed either primary or secondary graft failure, 34% acute graft-versus-host disease (GvHD), and 60% chronic GvHD. The non-relapse mortality was 18% and 24% at 12 months and at 5 years, respectively. Relapse incidence was 36%, overall survival 56%, and relapse-free survival 40% at 5 years. All these data showed the feasibility of this procedure in patients treated with second generation TKIs with similar post-transplant complications in TKI naive patients or patients treated with imatinib.

Patients under therapy with TKIs may frequently present with elevations of creatine kinase (CK), thought to be in some cases related with the classical associations with muscle and joint pain that is also a common side effect. However the long run effect on treatment outcomes has not been well studied. Bankar A et al.³ recently reported on the relation between CK elevations and overall survival (OS) and event free survival (EFS). Interestingly CK elevations secondary to first or second generation TKIs were associated with a better OS and EFS. As expected, high Sokal score patients had a worse OS and EFS.

References

1. Breccia M et al. COVID-19 infection in chronic myeloid leukaemia after one year of the pandemic in Italy. A Campus CML report. Br J Haematol. 2021 Oct 11.
2. Masouridi-Levrat S et al. Outcomes and toxicity of allogeneic hematopoietic cell transplantation in chronic myeloid leukemia patients previously treated with second-generation tyrosine kinase inhibitors: a prospective non-interventional study from the Chronic Malignancy Working Party of the EBMT. Bone Marrow Transplant. 2021 Oct 1.
3. Bankar A, Lipton JH. Association of creatine kinase elevation with clinical outcomes in chronic myeloid leukemia: a retrospective cohort study Leuk Lymphoma. 2021 Sep 8.

Ponatinib is most likely the most powerful tyrosine kinase inhibitor (TKI) approved for the relapsed or refractory chronic myeloid leukemia (CML) after two lines of therapy. In the original PACE study, ponatinib showed deep and durable responses, but arterial occlusive events (AOE) emerged as notable adverse events. Post hoc analyses indicated that AOEs were dose dependent and recommendations to lower the dose from 45 mg to 30 mg after achieving complete cytogenic response (CCR) and to 15 mg after achieving major molecular response (MMR) were used in an attempt to minimize the cardiovascular toxicities. The question remained regarding the optimal dose of ponatinib in terms of efficacy and toxicity. Cortes et al (Blood 2021 Aug 18.) reported the results of the OPTIC trial where patients with chronic phase CML (CP-CML), resistant/intolerant to at least 2 prior BCR-ABL1 TKIs or with a BCR-ABL1T315I mutation, were randomized 1:1:1 to receive 3 different doses of ponatinib daily (45, 30, or 15 mg). Patients who received 45 mg or 30 mg daily reduced their dose to 15 mg upon achievement of response (BCR-ABL1^IS transcript levels ≤1%). The primary endpoint (BCR-ABL1^IS transcript levels ≤1%) was achieved at 12 months in 44.1%, 29.0%, and 23.1% in the 3 cohorts, respectively. Independently confirmed grade 3/4 treatment-emergent AOEs occurred in 5, 5, and 3 patients in the 3 cohorts, respectively. In conclusion, the optimal benefit:risk outcomes occurred with the 45 mg starting dose reduced to 15 mg upon achievement of response.

New drugs with alternative mechanisms of action are always welcome for the treatment of resistant or intolerant CP-CML. Asciminib is a first-in-class STAMP (Specifically Targeting the ABL Myristoyl Pocket) inhibitor with the potential to overcome resistance or intolerance to approved TKIs. Rea et al (Blood 2021 Aug 18) reported the results of the ASCEMBL trial that compare 40 mg twice daily asciminib vs. bosutinib in patients with CP-CML refractory to >2 previous lines of therapy. The rates of MMR at week 24 in patients receiving asciminib and bosutinib were 25.5% and 13.2%, respectively (difference 12.2%; P = .029). The bosutinib arm, compared to the asciminib arm, had a more frequent occurrence of grade 3 or higher adverse events (AE; 60.5% vs. 50.6%) and AEs leading to treatment discontinuation (21.1% vs. 5.8%). This will be another important alternative for CP-CML patients failing 2 lines of therapy; however, it is still unclear if the drug may be superior to ponatinib in the same setting.

In the new era of COVID-19, patients with hematologic malignancies are at an increased risk of SARS-CoV-2 disease (COVID-19) and an adverse outcome. However, is unclear if this can be seen across the board in all type of hematologic malignancies, as a low mortality rate has been described in patients with CP-CML, suggesting that TKIs may have a protective role against severe COVID-19. Bonifacio et al (Cancer Med 2021 Aug 31) conducted a cross-sectional study of 564 consecutive patients with CML who were tested for anti-SARS-CoV-2 IgG/IgM antibodies at their first outpatient visit between May and early November 2020 in 5 hematologic centers representative of 3 Italian regions. Interestingly, the serological prevalence of SARS-CoV-2 infection in patients with CML after the first pandemic wave was similar to that in the general population. The data confirm mild SARS-CoV-2 infection in patients with CML and suggest that patients with CML succeed to mount an antibody response after exposure to SARS-CoV-2 similar to the general population.

Ponatinib is most likely the most powerful tyrosine kinase inhibitor (TKI) approved for the relapsed or refractory chronic myeloid leukemia (CML) after two lines of therapy. In the original PACE study, ponatinib showed deep and durable responses, but arterial occlusive events (AOE) emerged as notable adverse events. Post hoc analyses indicated that AOEs were dose dependent and recommendations to lower the dose from 45 mg to 30 mg after achieving complete cytogenic response (CCR) and to 15 mg after achieving major molecular response (MMR) were used in an attempt to minimize the cardiovascular toxicities. The question remained regarding the optimal dose of ponatinib in terms of efficacy and toxicity. Cortes et al (Blood 2021 Aug 18.) reported the results of the OPTIC trial where patients with chronic phase CML (CP-CML), resistant/intolerant to at least 2 prior BCR-ABL1 TKIs or with a BCR-ABL1T315I mutation, were randomized 1:1:1 to receive 3 different doses of ponatinib daily (45, 30, or 15 mg). Patients who received 45 mg or 30 mg daily reduced their dose to 15 mg upon achievement of response (BCR-ABL1^IS transcript levels ≤1%). The primary endpoint (BCR-ABL1^IS transcript levels ≤1%) was achieved at 12 months in 44.1%, 29.0%, and 23.1% in the 3 cohorts, respectively. Independently confirmed grade 3/4 treatment-emergent AOEs occurred in 5, 5, and 3 patients in the 3 cohorts, respectively. In conclusion, the optimal benefit:risk outcomes occurred with the 45 mg starting dose reduced to 15 mg upon achievement of response.

New drugs with alternative mechanisms of action are always welcome for the treatment of resistant or intolerant CP-CML. Asciminib is a first-in-class STAMP (Specifically Targeting the ABL Myristoyl Pocket) inhibitor with the potential to overcome resistance or intolerance to approved TKIs. Rea et al (Blood 2021 Aug 18) reported the results of the ASCEMBL trial that compare 40 mg twice daily asciminib vs. bosutinib in patients with CP-CML refractory to >2 previous lines of therapy. The rates of MMR at week 24 in patients receiving asciminib and bosutinib were 25.5% and 13.2%, respectively (difference 12.2%; P = .029). The bosutinib arm, compared to the asciminib arm, had a more frequent occurrence of grade 3 or higher adverse events (AE; 60.5% vs. 50.6%) and AEs leading to treatment discontinuation (21.1% vs. 5.8%). This will be another important alternative for CP-CML patients failing 2 lines of therapy; however, it is still unclear if the drug may be superior to ponatinib in the same setting.

In the new era of COVID-19, patients with hematologic malignancies are at an increased risk of SARS-CoV-2 disease (COVID-19) and an adverse outcome. However, is unclear if this can be seen across the board in all type of hematologic malignancies, as a low mortality rate has been described in patients with CP-CML, suggesting that TKIs may have a protective role against severe COVID-19. Bonifacio et al (Cancer Med 2021 Aug 31) conducted a cross-sectional study of 564 consecutive patients with CML who were tested for anti-SARS-CoV-2 IgG/IgM antibodies at their first outpatient visit between May and early November 2020 in 5 hematologic centers representative of 3 Italian regions. Interestingly, the serological prevalence of SARS-CoV-2 infection in patients with CML after the first pandemic wave was similar to that in the general population. The data confirm mild SARS-CoV-2 infection in patients with CML and suggest that patients with CML succeed to mount an antibody response after exposure to SARS-CoV-2 similar to the general population.

Ponatinib is most likely the most powerful tyrosine kinase inhibitor (TKI) approved for the relapsed or refractory chronic myeloid leukemia (CML) after two lines of therapy. In the original PACE study, ponatinib showed deep and durable responses, but arterial occlusive events (AOE) emerged as notable adverse events. Post hoc analyses indicated that AOEs were dose dependent and recommendations to lower the dose from 45 mg to 30 mg after achieving complete cytogenic response (CCR) and to 15 mg after achieving major molecular response (MMR) were used in an attempt to minimize the cardiovascular toxicities. The question remained regarding the optimal dose of ponatinib in terms of efficacy and toxicity. Cortes et al (Blood 2021 Aug 18.) reported the results of the OPTIC trial where patients with chronic phase CML (CP-CML), resistant/intolerant to at least 2 prior BCR-ABL1 TKIs or with a BCR-ABL1T315I mutation, were randomized 1:1:1 to receive 3 different doses of ponatinib daily (45, 30, or 15 mg). Patients who received 45 mg or 30 mg daily reduced their dose to 15 mg upon achievement of response (BCR-ABL1^IS transcript levels ≤1%). The primary endpoint (BCR-ABL1^IS transcript levels ≤1%) was achieved at 12 months in 44.1%, 29.0%, and 23.1% in the 3 cohorts, respectively. Independently confirmed grade 3/4 treatment-emergent AOEs occurred in 5, 5, and 3 patients in the 3 cohorts, respectively. In conclusion, the optimal benefit:risk outcomes occurred with the 45 mg starting dose reduced to 15 mg upon achievement of response.

New drugs with alternative mechanisms of action are always welcome for the treatment of resistant or intolerant CP-CML. Asciminib is a first-in-class STAMP (Specifically Targeting the ABL Myristoyl Pocket) inhibitor with the potential to overcome resistance or intolerance to approved TKIs. Rea et al (Blood 2021 Aug 18) reported the results of the ASCEMBL trial that compare 40 mg twice daily asciminib vs. bosutinib in patients with CP-CML refractory to >2 previous lines of therapy. The rates of MMR at week 24 in patients receiving asciminib and bosutinib were 25.5% and 13.2%, respectively (difference 12.2%; P = .029). The bosutinib arm, compared to the asciminib arm, had a more frequent occurrence of grade 3 or higher adverse events (AE; 60.5% vs. 50.6%) and AEs leading to treatment discontinuation (21.1% vs. 5.8%). This will be another important alternative for CP-CML patients failing 2 lines of therapy; however, it is still unclear if the drug may be superior to ponatinib in the same setting.

In the new era of COVID-19, patients with hematologic malignancies are at an increased risk of SARS-CoV-2 disease (COVID-19) and an adverse outcome. However, is unclear if this can be seen across the board in all type of hematologic malignancies, as a low mortality rate has been described in patients with CP-CML, suggesting that TKIs may have a protective role against severe COVID-19. Bonifacio et al (Cancer Med 2021 Aug 31) conducted a cross-sectional study of 564 consecutive patients with CML who were tested for anti-SARS-CoV-2 IgG/IgM antibodies at their first outpatient visit between May and early November 2020 in 5 hematologic centers representative of 3 Italian regions. Interestingly, the serological prevalence of SARS-CoV-2 infection in patients with CML after the first pandemic wave was similar to that in the general population. The data confirm mild SARS-CoV-2 infection in patients with CML and suggest that patients with CML succeed to mount an antibody response after exposure to SARS-CoV-2 similar to the general population.

Latin American countries have a high rate of SARS-CoV-2 infection and some of the highest COVID-19 deaths worldwide. Brazil, Colombia, Argentina, and Mexico have reported the highest number of confirmed cases. More recently has been reported that in series form US and Europe the mortality of COVID-19 has not been as high as reported in other hematological conditions and the response to vaccination also has bene described as high. In a recent report, Pagnano et al. (Leuk Lymphoma. 2021) has recently reported the clinical evolution and outcome of COVID-19 in patients with chronic myeloid leukemia in Latin America. In an observational multicenter study with a total of 92 patients with COVID-19 between March and December 2020 with 26% of whom were severe or critical. Eighty-one patients recovered (88%), and 11 (11.9%) died from COVID-19. Almost half of them had at least one comorbidity. Patients with a major molecular response presented superior overall survival compared to patients with no major molecular response (91 vs. 61%, respectively; P = 0.004). Patients in treatment-free remission and receiving tyrosine kinase inhibitors showed higher survival rates (100 and 89%) than patients who underwent hematopoietic stem cell transplantation and those who did not receive tyrosine kinase inhibitors (50 and 33%).

Currently the most common reason for TKI discontinuation is intolerance. Ma et al (Leuk Res. 2021) reports the long-term outcomes associated with switch to an alternative TKI after first-line therapy with a 2GTKI. Of 232 patients who initiated a 2GTKI during the study period, 76 (33 %) switched to an alternative TKI. Reasons for switching included intolerance (79 %) and resistance (21 %). Among the 60 patients who switched due to intolerance, 53 (88 %) were able to achieve or maintain a major molecular response (MMR) with 5-year progression-free survival (PFS) 90.5 % (95 % CI 90.4–90.6 %). However, amongst the 16 patients who switched due to resistance, 8 patients (50 %) were able to achieve MMR with 5-year PFS 80.4 % (95 % CI 80.2–80.6 %). Most patients who switched due to intolerance remained on their second-line TKI. Patients who switch for intolerance continue to enjoy excellent long term clinical outcomes.

Latin American countries have a high rate of SARS-CoV-2 infection and some of the highest COVID-19 deaths worldwide. Brazil, Colombia, Argentina, and Mexico have reported the highest number of confirmed cases. More recently has been reported that in series form US and Europe the mortality of COVID-19 has not been as high as reported in other hematological conditions and the response to vaccination also has bene described as high. In a recent report, Pagnano et al. (Leuk Lymphoma. 2021) has recently reported the clinical evolution and outcome of COVID-19 in patients with chronic myeloid leukemia in Latin America. In an observational multicenter study with a total of 92 patients with COVID-19 between March and December 2020 with 26% of whom were severe or critical. Eighty-one patients recovered (88%), and 11 (11.9%) died from COVID-19. Almost half of them had at least one comorbidity. Patients with a major molecular response presented superior overall survival compared to patients with no major molecular response (91 vs. 61%, respectively; P = 0.004). Patients in treatment-free remission and receiving tyrosine kinase inhibitors showed higher survival rates (100 and 89%) than patients who underwent hematopoietic stem cell transplantation and those who did not receive tyrosine kinase inhibitors (50 and 33%).

Currently the most common reason for TKI discontinuation is intolerance. Ma et al (Leuk Res. 2021) reports the long-term outcomes associated with switch to an alternative TKI after first-line therapy with a 2GTKI. Of 232 patients who initiated a 2GTKI during the study period, 76 (33 %) switched to an alternative TKI. Reasons for switching included intolerance (79 %) and resistance (21 %). Among the 60 patients who switched due to intolerance, 53 (88 %) were able to achieve or maintain a major molecular response (MMR) with 5-year progression-free survival (PFS) 90.5 % (95 % CI 90.4–90.6 %). However, amongst the 16 patients who switched due to resistance, 8 patients (50 %) were able to achieve MMR with 5-year PFS 80.4 % (95 % CI 80.2–80.6 %). Most patients who switched due to intolerance remained on their second-line TKI. Patients who switch for intolerance continue to enjoy excellent long term clinical outcomes.

Latin American countries have a high rate of SARS-CoV-2 infection and some of the highest COVID-19 deaths worldwide. Brazil, Colombia, Argentina, and Mexico have reported the highest number of confirmed cases. More recently has been reported that in series form US and Europe the mortality of COVID-19 has not been as high as reported in other hematological conditions and the response to vaccination also has bene described as high. In a recent report, Pagnano et al. (Leuk Lymphoma. 2021) has recently reported the clinical evolution and outcome of COVID-19 in patients with chronic myeloid leukemia in Latin America. In an observational multicenter study with a total of 92 patients with COVID-19 between March and December 2020 with 26% of whom were severe or critical. Eighty-one patients recovered (88%), and 11 (11.9%) died from COVID-19. Almost half of them had at least one comorbidity. Patients with a major molecular response presented superior overall survival compared to patients with no major molecular response (91 vs. 61%, respectively; P = 0.004). Patients in treatment-free remission and receiving tyrosine kinase inhibitors showed higher survival rates (100 and 89%) than patients who underwent hematopoietic stem cell transplantation and those who did not receive tyrosine kinase inhibitors (50 and 33%).

Currently the most common reason for TKI discontinuation is intolerance. Ma et al (Leuk Res. 2021) reports the long-term outcomes associated with switch to an alternative TKI after first-line therapy with a 2GTKI. Of 232 patients who initiated a 2GTKI during the study period, 76 (33 %) switched to an alternative TKI. Reasons for switching included intolerance (79 %) and resistance (21 %). Among the 60 patients who switched due to intolerance, 53 (88 %) were able to achieve or maintain a major molecular response (MMR) with 5-year progression-free survival (PFS) 90.5 % (95 % CI 90.4–90.6 %). However, amongst the 16 patients who switched due to resistance, 8 patients (50 %) were able to achieve MMR with 5-year PFS 80.4 % (95 % CI 80.2–80.6 %). Most patients who switched due to intolerance remained on their second-line TKI. Patients who switch for intolerance continue to enjoy excellent long term clinical outcomes.

The seroconversion was highest in patients with CML with 75% and observed in 5/6 (83%) of CML patients receiving imatinib that compare favorably to the total group with 58% of seroconversions. Interestingly patients treated with pegylated interferon also had a a high response with 88% (7/8).

Another recent publication by Harrington et al Br J Hem 2021, Jun 3 ahead or print, confirmed and extending the previous data by evaluating humoral and cellular immune responses after a first injection of BNT162b2 vaccine in 16 patients with CML. 87.5% patients have a seroconversion and 93.3% developed a T cell response. These responses are seen in contrast to patients with lymphoid hematological malignancies where the responses have been significantly lower.

The main goal of the treatment for chronic phase CML is to stop the progression to more advanced phased of the disease such as blast phase, where treatments are limited and there are no consensus in the treatment approach. In a recent publication by Saxena et al. J Hematol Oncol. 2021 Jun 15 the authors reported the outcomes of patients with BP-CML treated with different regimens that include a combination therapy of tyrosine kinase inhibitor (TKI) with intensive chemotherapy (IC) or hypomethylating agent (HMA) as well as  TKI or IC alone. Response rates were similar between patients treated with IC + TKI and HMA + TKI. When compared to treatment with TKI alone, treatment with IC/HMA + TKI was superior (CRi 57.5% vs 33.9%), as well as higher complete cytogenetic response rate (45% vs 10.7%) and more patients proceeding to ASCT (32.5% vs 10.7%). The results were even better when using a second generation TKI in combination with IC or HMA with a favorable EFS and OS compared to TKI alone.

The seroconversion was highest in patients with CML with 75% and observed in 5/6 (83%) of CML patients receiving imatinib that compare favorably to the total group with 58% of seroconversions. Interestingly patients treated with pegylated interferon also had a a high response with 88% (7/8).

Another recent publication by Harrington et al Br J Hem 2021, Jun 3 ahead or print, confirmed and extending the previous data by evaluating humoral and cellular immune responses after a first injection of BNT162b2 vaccine in 16 patients with CML. 87.5% patients have a seroconversion and 93.3% developed a T cell response. These responses are seen in contrast to patients with lymphoid hematological malignancies where the responses have been significantly lower.

The main goal of the treatment for chronic phase CML is to stop the progression to more advanced phased of the disease such as blast phase, where treatments are limited and there are no consensus in the treatment approach. In a recent publication by Saxena et al. J Hematol Oncol. 2021 Jun 15 the authors reported the outcomes of patients with BP-CML treated with different regimens that include a combination therapy of tyrosine kinase inhibitor (TKI) with intensive chemotherapy (IC) or hypomethylating agent (HMA) as well as  TKI or IC alone. Response rates were similar between patients treated with IC + TKI and HMA + TKI. When compared to treatment with TKI alone, treatment with IC/HMA + TKI was superior (CRi 57.5% vs 33.9%), as well as higher complete cytogenetic response rate (45% vs 10.7%) and more patients proceeding to ASCT (32.5% vs 10.7%). The results were even better when using a second generation TKI in combination with IC or HMA with a favorable EFS and OS compared to TKI alone.

The seroconversion was highest in patients with CML with 75% and observed in 5/6 (83%) of CML patients receiving imatinib that compare favorably to the total group with 58% of seroconversions. Interestingly patients treated with pegylated interferon also had a a high response with 88% (7/8).

Another recent publication by Harrington et al Br J Hem 2021, Jun 3 ahead or print, confirmed and extending the previous data by evaluating humoral and cellular immune responses after a first injection of BNT162b2 vaccine in 16 patients with CML. 87.5% patients have a seroconversion and 93.3% developed a T cell response. These responses are seen in contrast to patients with lymphoid hematological malignancies where the responses have been significantly lower.

The main goal of the treatment for chronic phase CML is to stop the progression to more advanced phased of the disease such as blast phase, where treatments are limited and there are no consensus in the treatment approach. In a recent publication by Saxena et al. J Hematol Oncol. 2021 Jun 15 the authors reported the outcomes of patients with BP-CML treated with different regimens that include a combination therapy of tyrosine kinase inhibitor (TKI) with intensive chemotherapy (IC) or hypomethylating agent (HMA) as well as  TKI or IC alone. Response rates were similar between patients treated with IC + TKI and HMA + TKI. When compared to treatment with TKI alone, treatment with IC/HMA + TKI was superior (CRi 57.5% vs 33.9%), as well as higher complete cytogenetic response rate (45% vs 10.7%) and more patients proceeding to ASCT (32.5% vs 10.7%). The results were even better when using a second generation TKI in combination with IC or HMA with a favorable EFS and OS compared to TKI alone.

In a comprehensive and detailed analysis, Ochi et al evaluated the genetic alterations in 136 blast crisis (BC) and 148 chronic phase (CP) samples from 216 patients with chronic myeloid leukemia (CML) by exome and targeted sequencing. The number of genetic alterations increased during CP to BC progression with a mean of 5.3 nonsynonymous single-nucleotide variants acquired. One or more genetic abnormalities are found in 126 (92.6%) out of the 136 BC patients. As expected, the lineage of the BC and prior use of tyrosine kinase inhibitors (TKIs) correlate with distinct molecular profiles. TKIs markedly suppressed the number of genetic alterations increase during the transition from CP to BC. Notably, genetic alterations such AXL1 mutations complex CNAs, i(17q), and +21, rather than clinical variables, contribute to a better prediction of BC prognosis in early therapy with TKI in CP.

Switching to a second generation TKI with the goal of obtaining a deeper response and therefore a chance for treatment-free remission (TFR), is an option for certain patients and has been investigated in a few trials. ENEStop may be the most popular and Hughes et al had updated the 5 years follow up in a recent publication. The study includes patients with chronic-phase chronic myeloid leukemia (CML-CP)  who achieved sustained deep molecular response only after switching from imatinib to nilotinib and TFR was attempted by 126 patients following 1 year of nilotinib consolidation phase. At 5 years, the rate of successful TFR and overall survival was 42.9% and 95.9%, respectively. Of 59 patients reinitiating nilotinib, 98.3% of patients regained major molecular response. Overall, AEs increased in nilotinib reinitiation vs. consolidation phase including cardiovascular (CV) adverse events (AEs) as patients had a long duration of exposure for nilotinib.

After several publications and recommendations by NCCN and ELN, the optimal cut-off values of the duration of MR4 and deeper responses remain unresolved. Kim et al reported a large study of 131 patients enrolled into the Canadian TKI discontinuation study and evaluated the molecular relapse-free survival (mRFS) at 12 months after imatinib discontinuation. Based on this analysis they propose 6 years with imatinib treatment duration as the shortest imatinib duration- a superior success versus less than 6 years (61.8% vs. 36.0%; P = .01). Also a MR4 duration of 4.5 years or longer vs. less than 4.5 years (64.2% vs. 41.9%; P = .003) was associated with a superior molecular relapse-free survival at 12 months after imatinib discontinuation.

Fatigue is a common complain of patients taking TKI and has been well reported as adverse effects in most of the CML trials. However, when evaluating fatigue, it is always difficult to understand if there are additional factors that can contribute to it. Hyland et al investigated if the use of cognitive behavioral therapy for targeted-therapy related fatigue (CBT-TTF) targeting fatigue perpetuating factors change over time. By delivering CBT via FaceTime or wait list control in CML patients with moderate or severe fatigue, they were able to see an improvement in TKI-related fatigue in CML patients through changes in behavior (sleep, activity patterns) and cognitions about fatigue and cancer.

In a comprehensive and detailed analysis, Ochi et al evaluated the genetic alterations in 136 blast crisis (BC) and 148 chronic phase (CP) samples from 216 patients with chronic myeloid leukemia (CML) by exome and targeted sequencing. The number of genetic alterations increased during CP to BC progression with a mean of 5.3 nonsynonymous single-nucleotide variants acquired. One or more genetic abnormalities are found in 126 (92.6%) out of the 136 BC patients. As expected, the lineage of the BC and prior use of tyrosine kinase inhibitors (TKIs) correlate with distinct molecular profiles. TKIs markedly suppressed the number of genetic alterations increase during the transition from CP to BC. Notably, genetic alterations such AXL1 mutations complex CNAs, i(17q), and +21, rather than clinical variables, contribute to a better prediction of BC prognosis in early therapy with TKI in CP.

Switching to a second generation TKI with the goal of obtaining a deeper response and therefore a chance for treatment-free remission (TFR), is an option for certain patients and has been investigated in a few trials. ENEStop may be the most popular and Hughes et al had updated the 5 years follow up in a recent publication. The study includes patients with chronic-phase chronic myeloid leukemia (CML-CP)  who achieved sustained deep molecular response only after switching from imatinib to nilotinib and TFR was attempted by 126 patients following 1 year of nilotinib consolidation phase. At 5 years, the rate of successful TFR and overall survival was 42.9% and 95.9%, respectively. Of 59 patients reinitiating nilotinib, 98.3% of patients regained major molecular response. Overall, AEs increased in nilotinib reinitiation vs. consolidation phase including cardiovascular (CV) adverse events (AEs) as patients had a long duration of exposure for nilotinib.

After several publications and recommendations by NCCN and ELN, the optimal cut-off values of the duration of MR4 and deeper responses remain unresolved. Kim et al reported a large study of 131 patients enrolled into the Canadian TKI discontinuation study and evaluated the molecular relapse-free survival (mRFS) at 12 months after imatinib discontinuation. Based on this analysis they propose 6 years with imatinib treatment duration as the shortest imatinib duration- a superior success versus less than 6 years (61.8% vs. 36.0%; P = .01). Also a MR4 duration of 4.5 years or longer vs. less than 4.5 years (64.2% vs. 41.9%; P = .003) was associated with a superior molecular relapse-free survival at 12 months after imatinib discontinuation.

Fatigue is a common complain of patients taking TKI and has been well reported as adverse effects in most of the CML trials. However, when evaluating fatigue, it is always difficult to understand if there are additional factors that can contribute to it. Hyland et al investigated if the use of cognitive behavioral therapy for targeted-therapy related fatigue (CBT-TTF) targeting fatigue perpetuating factors change over time. By delivering CBT via FaceTime or wait list control in CML patients with moderate or severe fatigue, they were able to see an improvement in TKI-related fatigue in CML patients through changes in behavior (sleep, activity patterns) and cognitions about fatigue and cancer.

In a comprehensive and detailed analysis, Ochi et al evaluated the genetic alterations in 136 blast crisis (BC) and 148 chronic phase (CP) samples from 216 patients with chronic myeloid leukemia (CML) by exome and targeted sequencing. The number of genetic alterations increased during CP to BC progression with a mean of 5.3 nonsynonymous single-nucleotide variants acquired. One or more genetic abnormalities are found in 126 (92.6%) out of the 136 BC patients. As expected, the lineage of the BC and prior use of tyrosine kinase inhibitors (TKIs) correlate with distinct molecular profiles. TKIs markedly suppressed the number of genetic alterations increase during the transition from CP to BC. Notably, genetic alterations such AXL1 mutations complex CNAs, i(17q), and +21, rather than clinical variables, contribute to a better prediction of BC prognosis in early therapy with TKI in CP.

Switching to a second generation TKI with the goal of obtaining a deeper response and therefore a chance for treatment-free remission (TFR), is an option for certain patients and has been investigated in a few trials. ENEStop may be the most popular and Hughes et al had updated the 5 years follow up in a recent publication. The study includes patients with chronic-phase chronic myeloid leukemia (CML-CP)  who achieved sustained deep molecular response only after switching from imatinib to nilotinib and TFR was attempted by 126 patients following 1 year of nilotinib consolidation phase. At 5 years, the rate of successful TFR and overall survival was 42.9% and 95.9%, respectively. Of 59 patients reinitiating nilotinib, 98.3% of patients regained major molecular response. Overall, AEs increased in nilotinib reinitiation vs. consolidation phase including cardiovascular (CV) adverse events (AEs) as patients had a long duration of exposure for nilotinib.

After several publications and recommendations by NCCN and ELN, the optimal cut-off values of the duration of MR4 and deeper responses remain unresolved. Kim et al reported a large study of 131 patients enrolled into the Canadian TKI discontinuation study and evaluated the molecular relapse-free survival (mRFS) at 12 months after imatinib discontinuation. Based on this analysis they propose 6 years with imatinib treatment duration as the shortest imatinib duration- a superior success versus less than 6 years (61.8% vs. 36.0%; P = .01). Also a MR4 duration of 4.5 years or longer vs. less than 4.5 years (64.2% vs. 41.9%; P = .003) was associated with a superior molecular relapse-free survival at 12 months after imatinib discontinuation.

Fatigue is a common complain of patients taking TKI and has been well reported as adverse effects in most of the CML trials. However, when evaluating fatigue, it is always difficult to understand if there are additional factors that can contribute to it. Hyland et al investigated if the use of cognitive behavioral therapy for targeted-therapy related fatigue (CBT-TTF) targeting fatigue perpetuating factors change over time. By delivering CBT via FaceTime or wait list control in CML patients with moderate or severe fatigue, they were able to see an improvement in TKI-related fatigue in CML patients through changes in behavior (sleep, activity patterns) and cognitions about fatigue and cancer.