Incidence Of Major Molecular Response Research Articles

Treatment-Free Remission Era: BCR-ABL1 mRNA Transcript Level

Background: Early acquisition of a deeper molecular response (DMR) and maintenance of a sustained DMR are prerequisites for implementing treatment-free remission (TFR) in CML patients. Earlier identification of patients who have not reached 24-month DMR and timely intervention is particularly important for patients with a strong desire for TFR. Early molecular response (EMR) of BCR-ABL1 mRNA <10% at 3 months after the initiation of TKI therapy is strongly predictive of a 12-month major molecular response (MMR). Whether the EMR <10% is also a good predictor of the 24-month DMR is unknown. Exploring early predictors of 24-month DMR could help guide clinical treatment decisions and advance the implementation of the TFR plan. Aim: Exploring early predictors of 24-month DMR. Methods: We performed a retrospective analysis of all adult patients with newly diagnosed CML-CP in the Department of Hematology at Guangdong Provincial People's Hospital (Guangzhou, China) between Mar 2009 and May 2019. Patients were monitored with BCR-ABL1 mRNA quantitative RT-PCR monthly for the first 3 months of TKI treatment, then every 3 months for a minimum of 2 years, and then every 3 to 6 months. Results: A total of 314 patients with complete medical recorders and routinely monitoring BCR-ABL1 mRNA transcript data of each molecular response milestone were enrolled. Patients' characteristics are summarized in Table 1. The median follow-up time was 54 months (14 to 146 months). The 5-year cumulative rate of MMR, MR 4 and MR 4.5 with TKI treatment were 80%, 48.1%, and 38.4%, respectively. The results of the ROC analysis showed that a 3-month BCR-ABL1 mRNA transcript level of 4.94% correlated well with the 24-month DMR. The sensitivity and specificity of its predictive function were 82.8% (95% CI, 73.6-89.8) and 66.97% (95% CI, 60.3-73.1), respectively. So, we adopted BCR-ABL1 mRNA transcript level ≤4.94% at 3 months as the optimal threshold for predicting 24-month DMR. To reveal the cumulative incidence (CI) of 12-month MMR, 24-month MR 4 and MR 4.5 at different thresholds of BCR-ABL1 mRNA transcript levels at 3 months. Patients were divided into 3 groups according to the BCR-ABL1 mRNA transcript levels, group I <5% (n=150, 47.7%), group II 5% to 10% (n=36, 11.5%), group III >10% (n=128, 40.8%). Patients with BCR-ABL1 mRNA transcript levels <5% at 3 months after TKI initiation are more likely to achieve DMR than the other two groups and take less time to achieve DMR. Patients of Group I with 12-month MMR and 24-month MR 4 were significantly higher than the other two groups, with 66.7% vs 30.6% or 8.6% and 50% vs 16.1% or 7% (P<0.001), respectively. And group II was compared with group III. The cumulative incidence of MMR, MR 4 and MR 4.5 was also significantly higher in Group I than in the other two groups (Fig.1). The survival outcome of patients with BCR-ABL1 transcript levels <5% at 3 months had significantly superior compared with those with BCR-ABL1 transcript levels ≥5%: the 5-year EFS， PFS and OS were 88.6% vs 86.4% (P=0.037), 100% vs 95.7% (P=0.011) and 100% vs 95% (P=0.014)， respectively (Fig. 1). Conclusion: BCR-ABL1 mRNA transcript levels <5% at 3 months is a new landmark EMR (EMR <5%) which can predict 24-month DMR for patients with TKI treatment. EMR <5% may be used to guide the clinical timely switching of TKI or treatment and facilitate the implementation of TFR.

Lower-Initiating Dose of Bosutinib for Resistant or Intolerant to Prior Therapy Chronic Myeloid Leukemia Patients (BOGI trial): A Single-Arm, Multicenter, Phase II Trial

Introduction: The introduction of ABL1 tyrosine kinase inhibitors (TKIs) has markedly improved the survival outcomes in patients with chronic phase chronic myeloid leukemia (CML-CP). Second-generation TKIs are highly active for patients with newly diagnosed and resistant/intolerant CML-CP. Although bosutinib is generally safe, drug-related toxicities (DRTs) such as diarrhea or increased transaminase leading to treatment discontinuation, are often observed. The standard initial daily dosage of bosutinib is 400 mg for newly diagnosed or 500 mg for resistant/intolerant patients with CML-CP, whereas some experts suggest lower dose (200-300 mg) initiation is recommended to reduce adverse events (AEs). However, the safety and efficacy of lower dose initiation of bosutinib are unknown. Hence, we conducted a phase 2 study of BOsutinib Gradual Increase as a second/third-line treatment for CML-CP (BOGI trial, UMIN 000032282) to clarify whether a lower initiating dose of bosutinib (200 mg daily) would reduce discontinuation or interruption of treatment due to DRTs. Patients and methods We included CML patients who developed at least one line of treatment failure (resistant or intolerant), aged >18 years with an ECOG performance status of 0-2 and adequate organ function. After enrollment, the patients initiated 200 mg of bosutinib daily; subsequently, dose escalation was performed by 100 mg daily (up to 500 mg daily) every 2 weeks if no grade 3 or higher AEs occurred. BCR::ABL1 mRNA levels were measured by the standardized international scale at a central laboratory at 3, 6, 9, and 12 month since treatment initiation. The primary endpoint was the treatment discontinuation rate due to DRTs at 12 months. Secondary endpoints included the treatment interruption rate, mean bosutinib dosage, dosing days and relative dose intensity until 12 months, achievement of cytogenetic response (CCyR), cumulative rates of major molecular response (MMR) or deep molecular response (DMR). Sample size calculation was performed by research and biostatistics SWOG statistical tools (at null proportion = 0.32, alternative proportion = 0.14, one-sided α error = 5% and β error = 20%, power 80%) with the discontinuation rate of the previous Japanese phase 1/2 study of bosutinib as a reference (Nakaseko C, et al. Int J Hematol. 2015). Considering protocol deviations, sample size was 35 participants. Results Between Feb 4, 2019, and May 24, 2022, 35 patients enrolled from four Japanese hospitals. The median age was 61 years (range, 26 - 81 years); 19 patients were male and 16 were female and 16, 12, and 7 patients had low,intermediate, and high Sokal scores, respectively. Ten patients had hypertension, five had diabetes millitus, three had chronic heart disease, two had solid tumor, and one had cerebrovascular disease, respectively. Numbers of patients with previous TKIs were one for 19 (54%), two for 12 (34%) and three for 4 (11%), respectively and prior TKIs are imatinib (8, 23%), dasatinib (27, 77%), nilotinib (16, 46%) and bosutinib (1, 3%), respectively. In the intention to treat population, the bosutinib discontinuation rate at 12 months was 25.7% (95% CI, 15.6-39.3%) which is significantly lower than that of the previous report (v.s. 43.0%, p=0.019). Similarly, bosutinib discontinuation rate due to DRTs was 11.4% (95% CI, 5.2 - 23.2%), which is also significantly lower (v.s. 32%, p = 0.005). These results suggest lower initiating dose of bosutinib reduced bosutinib discontinuation rate due to DRTs, thus the primary endpoint was met. A total of 22 patients (62.9%) interrupted bosutinib at least once. Median bosutinib dosage, bosutinib dosing days and relative dose intensity until 12 months were 391.7 (204.9-477.3) mg/day, 351.0 (20-365) days and 78% (41-95), respectively. 28 patients (80.0%) achieved cytogenetic response (CCyR) at 6 months; cumulative incidence of MMR and DMR at 12 months were 23 (65.7%; 95%CI, 49.2-79.2%) and 15 (42.9%; 95%CI, 28.0-59.1%), indicating these secondary endpoints were comparable with the previous report. Grade 3 to 4 transaminase elevation was 20% which is comparable with the previous report (v.s. 29%, p=0.427), while a lower rate of diarrhea (3%; v.s. 25%, p=0.009) was notable. Conclusion The lower initiating dose followed by a gradual dose increase of bosutinib reduced the drug discontinuation rate due to severe DRTs, especially diarrhea, while efficacy was assured.

Flumatinib for Newly Diagnosed Chronic Phase Chronic Myeloid Leukemia: An Open-Label, Multi-Center Study

Background Tyrosine kinase inhibitors (TKIs) ushered in the era of targeted therapy for chronic myeloid leukemia(CML), which greatly improved the prognosis of patients with CML. Flumatinib is a second-generation tyrosine kinase inhibitor (TKI), which is currently approved for patients with Philadelphia chromosome-positive chronic myeloid leukemia (Ph+ CML) in China. And some current clinical trials revealed that flumatinib has been shown to be a more potent inhibitor of BCR::ABL than imatinib. Methods In this open label, single-arm, multicenter study, 127 patients with newly diagnosed chronic-phase chronic myeloid leukemia (CP-CML) treated with flumatinib were enrolled. The primary endpoint of this study was early molecular response (EMR) rates at 3 months. The secondary were the rates of complete cytogenic response (CCyR), major molecular response (MMR) at 3, 6, 12 months and treatment-related adverse events (AEs). The trial is registered with ClinicalTrials.gov NCT04591197. Results From October 2020 to December 2022, a total of 158 patients with CP-CML were assessed for eligibility, of whom 127 were followed up for more than 3 months. 79(62%) patients were men and 48 (38%) were women. The median age was 47 years (range, 19-82 years), The median time from diagnosis to treatment was 6 days (0-176 days) and the median follow-up was 9.7 months (range 3.1-26.6 months). Of evaluable 127 patients, EMR was achieved by 85% (95% confidence interval [CI], 77.6%-90.7%) of patients at 3 months. After the initiation of flumatinib treatment, the incidence of MMR at 3, 6, and 12 months was 24%, 59%, and 73%, respectively. Patients receiving flumatinib had higher rates of CCyR at 6 months and MMR 12 months than the data from DASISION (dasatinib) and ENESTnd (nilotinib) therapy (85% vs 73% vs 67% and 73% vs 46% vs 44%). Progression-free survival (PFS) rate at 1-year was 97.2%. Diarrhea (34%) were the most commonly reported adverse events. Most treatment-related adverse events were grade 1/2. None of the patients discontinued or died due to AEs. Conclusion Flumatinib as first-line therapy in patients with newly diagnosed CP-CML was not inferior to nilotinib and dasatinib and well tolerated.

Canadian real-world experience of asciminib treatment in heavily pre-treated chronic myeloid leukemia (CML) patients who failed multiple lines of tyrosine kinase inhibitor (TKI) therapy

BackgroundAsciminib is a novel drug specifically targeting ABL myristoyl pocket in the ABL1 protein. MethodsForty one patients with chronic myeloid leukemia treated with asciminib from 2018 to 2022 were reviewed and analyzed for the efficacy and tolerability of asciminib using real-world experience data. ResultsThe median age was 60 years (range 17–90) with a past history of a cardiovascular event in 21 patients (51%). Patients were pretreated with a median of 3 previous tyrosine kinase inhibitors (range 1–5). After a median of 12 months of asciminib (range 3–41), major molecular response (MMR) rate was 39% (n = 11/28) and 42% (n = 5/12) at 6 and 12 months, respectively. Molecular response with 2 log reduction (MR2) was noted in 54% (n = 15/28) and 50% (n = 6/12) at 6 and 12 months. The cumulative incidence of MMR and MR2 was 46.3% and 66% at 12 months.Five patients discontinued asciminib due to treatment failure (n = 3) or thrombocytopenia (n = 2). There were no cardiovascular events. Out of 7 patients treated with high dose asciminib for T315I mutation, 5 patients achieved MMR or deeper response. The event-free survival was 63% at 12 months. ConclusionThis study confirmed clinical efficacy and tolerability of asciminib with real-world experience.

Two-Year Updated Results of Asciminib Managed-Access Program (MAP) in Russia

Background: Asciminib is a Specifically Targeting the ABL Myristoyl Pocket (STAMP) ABL. kinase inhibitor that has shown efficacy and a good safety profile in clinical trials in patients with Ph-positive chronic myeloid leukemia (CML) failing prior TKI lines. It was confirmed by real world data in Novartis approved Managed Access Program (MAP) in several countries.Aim: to present two-year updated results of asciminib use in clinical practice in the MAP program in 3 centers of Russia. Methods: In total the data of 50 CML pts who received asciminib for more than 9 months and did not undergo bone marrow transplantation was analyzed. Pts recruitment, dosing regimen, response monitoring, and toxicity control were performed according to the MAP treatment plan. All pts had a chronic phase (CP) CML, 8 pts had a second CP after accelerated phase (n=7) or blast crisis (BC). Complete cytogenetic response (CCyR) corresponding to BCR::ABL1 ≤1%, major molecular response (MMR) and deep molecular response (MR4) achievement was assessed by cumulative incidence function (CIF) with Gray's test for comparison responses in subgroups. Survival analysis was performed by Kaplan-Meier method. Results: All pts were divided into two groups: 20 pts received an initial dose of 200 mg BID (19/20 pts with BCR::ABL1 T315I ), 30 pts received 40 mg BID (1/30 pts with BCR::ABL1 T315I ). Baseline characteristics of the two dose groups are presented in table 1. The median follow-up among all pts was 17 months (range 10-37); 7(14%) pts discontinued asciminib (5 due to resistance, 2 due to progression). Two-year survival rate without treatment discontinuation was 83%. The 2-year OS was 100% and 93% in 400 mg and 80 mg dose groups, respectively, two (4%) pts progressed to BC and died. CIF of CCyR, MMR and MR4 by 24 month was 55%, 29% and 17% for 80 mg dose and 45%, 48% and 45% for 400 mg dose respectively. There was no significant difference in response rates between the two dose groups. In the 400 mg dose group, the cumulative incidence of MMR was significantly higher in ponatinib-naive patients (75% vs. 23% in ponatinib-pretreated patients, p=0.006) (figure 1). Twenty two (44%) pts experienced any adverse events (AEs) and 8 (16%) had AEs of grade 3-4. AEs of grade 3-4 connected with asciminib included neutropenia, thrombocytopenia and irregular menstruation. No pts stopped treatment due to toxicity; no difference in toxicity was found between doses of 80 and 400 mg/day. Conclusion: Asciminib shows promising results for the treatment of highly pre-treated CML pts and should be considered as therapeutic options for pts with failure to previous TKIs. The 400 mg dose was well tolerated and highly effective in ponatinib-naive pts with BCR::ABL1 T315I and should be investigated in clinical trials in patients without T315I as a potentially more effective and well tolerated dose. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Real-world efficacy and safety outcomes of imatinib treatment in patients with chronic myeloid leukemia: An Australian experience.

Tyrosine kinase inhibitors (TKI) have revolutionized the treatment of chronic myeloid leukemia (CML), but patients still experience treatment‐limiting toxicities or therapeutic failure. To investigate the real‐world use and outcomes of imatinib in patients with CML in Australia, a retrospective cohort study of patients with CML commencing imatinib (2001–2018) was conducted across two sites. Prescribing patterns, tolerability outcomes, and survival and molecular response were evaluated. 86 patients received 89 imatinib treatments. Dose modifications were frequently observed (12‐month rate of 58%). At last follow‐up, 62 patients (5‐year rate of 55%) had permanently discontinued imatinib treatment, of which 44 switched to another TKI (5‐year rate of 46%). Within 3 months of starting imatinib, 43% (95% CI, 32%–53%) of patients experienced imatinib‐related grade ≥3 adverse drug reactions (ADRs). Higher comorbidity score, lower body weight, higher imatinib starting dose, and Middle Eastern or North African ancestry were associated with a higher risk of grade ≥3 ADR occurrence on multivariable analysis (MVA). Estimated overall survival and event‐free survival rates at 3 years were 97% (95% CI, 92%–100%) and 81% (95% CI, 72%–92%), respectively. Cumulative incidence of major molecular response (MMR) at 3 years was 63% (95% CI, 50%–73%). On MVA, imatinib starting dose, ELTS score, BCR‐ABL1 transcript type, pre‐existing pulmonary disease, and potential drug–drug interactions were predictive of MMR. In conclusion, imatinib induced deep molecular responses that translated to good survival outcomes in a real‐world setting, but was associated with a higher incidence of ADRs, dose modifications and treatment discontinuations than in clinical trials.

Real-world therapeutic response and tyrosine kinase inhibitor discontinuation in chronic phase-chronic myeloid leukemia: data from the French observatory.

Guidelines for tyrosine kinase inhibitor (TKI)-treated chronic phase-chronic myeloid leukemia (CML) management are essentially based on data from clinical research trials; however, real-world data should be valuable for optimizing such recommendations. Here, we analyzed the data collected in the French CML Observatory database, a multicenter real-world cohort (n = 646), using a first-line "intention-to-treat" analysis strategy. This cohort included patients treated with first-line imatinib (n = 484), nilotinib (n = 103), dasatinib (n = 17), imatinib and interferon (n = 9), or second-generation (2G)-TKIs and interferon (n = 29). The cumulative incidence of major molecular response (MMR), MR4, MR4.5 and MR5 confirmed the faster response kinetics with 2G-TKIs. Multivariate analysis identified being a woman and residual disease at month 6 as the main predictive factors of deep molecular response (DMR). Moreover, 30% of patients met the criteria for treatment discontinuation (5years of treatment and ≥ 2years of DMR), but only 38% of them stopped treatment. Among the 92 patients who actually discontinued treatment due to optimal response, 31.5% relapsed (48% of them after > 6months of TKI discontinuation). Multivariate analysis identified age and TKI duration as factors positively correlated with treatment-free remission maintenance. Late (> 6months) relapses were more frequent in patients with the e14a2 BCR::ABL transcript. Relapse rate was higher in patients who stopped TKI before than after 5years of treatment (52.6% vs 26%; p = 0.040). These results advocate caution concerning early treatment withdrawal, including in patients receiving 2G-TKIs. This still recruiting database is a valuable source of information for the real-world follow-up of patients with CML.

Efficacy and Safety Results from Ascembl, a Multicenter, Open-Label, Phase 3 Study of Asciminib, a First-in-Class STAMP Inhibitor, Vs Bosutinib in Patients with Chronic Myeloid Leukemia in Chronic Phase after ≥2 Prior Tyrosine Kinase Inhibitors: Update after 48 Weeks

Efficacy and Safety Results from Ascembl, a Multicenter, Open-Label, Phase 3 Study of Asciminib, a First-in-Class STAMP Inhibitor, Vs Bosutinib in Patients with Chronic Myeloid Leukemia in Chronic Phase after ≥2 Prior Tyrosine Kinase Inhibitors: Update after 48 Weeks

Long-term outcome of tyrosine kinase inhibitor treatment in children and adolescents with newly diagnosed chronic myeloid leukemia in chronic phase.

Long-term outcome of tyrosine kinase inhibitor treatment in children and adolescents with newly diagnosed chronic myeloid leukemia in chronic phase.

The effect of body mass index on efficacy and safety of bosutinib or imatinib in patients with newly diagnosed chronic myeloid leukemia.

7037 Background: Bosutinib (BOS) is approved for the treatment (Tx) of Philadelphia chromosome–positive (Ph+) chronic myeloid leukemia (CML) resistant/intolerant to prior therapy and newly diagnosed Ph+ chronic phase (CP) CML. Body mass index (BMI) was shown to influence Tx response with front-line dasatinib vs imatinib (IMA). We report the efficacy and safety of BOS and IMA by BMI in patients (pts) with newly diagnosed CP CML. Methods: In the open-label BFORE trial, pts were randomized to receive 400 mg once daily BOS or IMA. Outcomes were assessed according to baseline BMI ≥25 or = 25 kg/m2. This post hoc analysis was based on the final 5-y analysis (database lock: June 12, 2020). Results: In the BOS and IMA arms, respectively, 149 (56.4%) vs 115 (43.6%) pts and 145 (54.3%) vs 122 (45.7%) pts had BMI ≥25 vs = 25. In both the BOS and IMA arms, median Tx duration and time on study was 55 mo for pts with BMI ≥25 or = 25; respective median dose intensity was 394 vs 393 mg/d and 400 vs 400 mg/d. Molecular response (MR) rates are shown in the table. Cumulative incidence of major MR was similar in pts with ≥25 vs = 25 receiving BOS (HR 0.99; 95% CI 0.74−1.31) or IMA (HR 1.09; 95% CI 0.81−1.47). Event-free survival (EFS) and overall survival (OS) rates at 60 mo are shown in the table. Most common reasons for Tx discontinuation were adverse events (AEs) (BOS 28.2 vs 20.0%; IMA 13.3 vs 10.7%) and lack of efficacy (BOS 5.4 vs 5.2%; IMA 16.1 vs 19.8%). In pts with BMI ≥25 vs = 25, dose reductions and interruptions due to Tx-emergent AEs (TEAEs) occurred in 43.6 % vs 46.2% and 66.4% vs 69.7% of pts with BOS and 24.5% vs 24.6% and 40.6% vs 50.8% with IMA. Any grade TEAEs in ≥30% of pts with BMI ≥25 vs = 25 were diarrhea (73.8 vs 73.1%), nausea (40.9 vs 31.9%), thrombocytopenia (30.9 vs 41.2%), increased alanine (37.6 vs 28.6%) and aspartate aminotransferase (30.2 vs 20.2%) with BOS and diarrhea (49.0 vs 29.5%), nausea (46.2 vs 37.7%), muscle spasms (33.6 vs 26.2%), neutropenia (14.7 vs 32.0%) and thrombocytopenia (10.5% vs 30.3%) with IMA. Conclusions: Efficacy of BOS was consistent in pts with BMI ≥25 or = 25; however, with IMA a low (vs high) BMI appeared to be associated with worse survival outcomes. Differences in certain TEAEs were observed between BMI subgroups in both treatment arms. Clinical trial information: NCT02130557. [Table: see text]

CML-393: Incidence of Deep Molecular Response and Its Association with Clinical and Molecular Variables in Patients with Chronic Myeloid Leukemia Treated with Imatinib in a Population with Limited Health Resources

Context Since deep molecular response (DMR) confers a better progression-free survival in chronic myeloid leukemia (CML), it is now a primary goal and also is an absolutely requirement for therapy discontinuation. Objective Here, we investigate the incidence of DMR and its association with clinical and molecular variables. Design Retrospective cohort of patients ≥18 years with chronic-phase CML treated with imatinib for at least 12 months. The primary objective was to explore the accumulate incidence of DMR and analyze the following variables: age, gender, Sokal risk, variant of the BCR/ABL1 transcript, imatinib exposure time, body mass index (BMI) and albumin and its association with the achievement of DMR. Results Ninety-six patients with a mean follow-up of 8 years were analyzed. The cumulative rate of DMR at the last follow-up was 65.62%, and the median time to document DMR was 63.13 months. The clinical and molecular variables were compared among three groups of response: no major molecular response (NO MMR), major molecular response (MMR), and DMR; the median age was 44.36, 35, and 42.87 years (p= 0.25); the median BMI was 27.71, 26.69 and 27.53 kg/m2 (p= 0.91); the median concentration of albumin was 4.18, 3.95, and 3.93 g/dL (p= 0.22); and the median time of exposure to imatinib was 63.82, 101.2, and 114.7 months (p= 0.0001). respectively. Patients with a high Sokal risk were associated with a lower incidence of MMR and DMR compared with a low risk (27.27% vs. 54.54% and 20.63 vs. 50.7%, respectively, p=0.007). The proportion of patients with a known transcript (incidence of e14a2 variant) was higher than e13a2 (31.25% vs 23.95%) but without statistically significant differences between the groups (p=0.99). Conclusions Incidence of DMR to imatinib exposure in our population is similar and even higher than reported in the literature regarding the several available data. The above findings, despite not following strict molecular monitoring, suggests that molecular monitoring by qRT-PCR can be performed in a longer interval. In this study, the prolonged exposure time to imatinib and the low Sokal risk, were significantly associated with a deeper molecular response.

Responses to Dasatinib as a Second- and Third-Line Tyrosine Kinase Inhibitor in Chronic Phase Chronic Myeloid Leukaemia Patients

We retrospectively evaluated the efficacy and safety of dasatinib among 48 Chinese patients with chronic phase chronic myeloid leukaemia. The proportions of patients achieving the optimal molecular responses at 3, 6, and 12 months, a major molecular response (MMR) rate and a complete cytogenetic response (CCyR) rate were 87.0, 87.0, 72.2, 45.8, and 72.7% for patients with dasatinib as second-line therapy, and 34.8, 34.8, 33.3, 20.8, and 46.2% as third-line therapy, respectively. A BCR-ABL1 transcript level on the International Scale (BCR-ABL1^IS) of ≤10% at the initiation of ­dasatinib treatment was found to be associated with a higher probability of achieving MMR. Among patients with a ­BCR-ABL1^IS higher than 10% at initiation of dasatinib treatment, dasatinib showed better performance as a second-line therapy than as a third-line therapy. The patients who achieved an optimal molecular response at 3 months had a superior cumulative incidence of MMR and CCyR compared with patients who failed to achieve such a response. Dasatinib induced considerable responses as a second-line treatment, especially in patients with a BCR-ABL1^IS ≤10% at initiation of treatment, whereas the efficacy was limited in patients receiving third-line therapy with a BCR-ABL1^IS >10% at the initiation of treatment.

Sex and Major Molecular Response to Imatinib Treatment for Patients with Chronic Myeloid Leukemia

Objective: The prognosis for chronic myeloid leukemia (CML) has been significantly improved in the era of tyrosine kinase inhibitors (TKIs) whose leader is Imatinib mesylate (IM). Obtaining a major molecular response (MMR) is a major objective to achieve. However, the difference in response between the two sexes is often controversial. This work aims to evaluate the molecular response according to sex in Algerian patients with chronic phase CML (CML-CP) treated with IM in first intention. Methods: All Novo CML patients benefited from molecular follow-up by quantification of transcripts by real-time quantitative PCR (RQ-PCR). The cumulative incidence of MMR (CIMMR) was estimated by the Kaplan-Meier method. The comparison was made using the parametric Log-Rank test. A value of P ≤ 0.05 is considered significant. Results: Fifty-five patients were included in this study, with a mean age of 45.7 ± 13.9 including 29 men (53%) and 26 women (47%). For women, the incidence of Mb3a2 transcript was higher than that of Mb2a2 (72% vs. 28%, P=0.12). Men, on the other hand, had an almost equal distribution (52% vs. 48%, P = 0.88). The CIMMR for men was lower than that for women (45% vs. 80%, P=0.018). Conclusion: Women seem to respond more favorably to IM than men.

Ponatinib evaluation and safety in real-life chronic myelogenous leukemia patients failing more than two tyrosine kinase inhibitors: the PEARL observational study

Ponatinib represents a remarkable progress in the treatment of heavily pretreated chronic myelogenous leukemia (CML) and de novo Philadelphia chromosome-positive ALL patients despite significant toxicity in clinical trials. To date, "real-life" data remain few and the use of ponatinib in this setting and its consequences remain mostly unknown. We report, within a national observational study, the use of ponatinib in unselected CML patients who had previously failed ≥2 lines of tyrosine kinase inhibitor (TKI) therapy (or one line if an Abelson (ABL)T315I mutation was identified), in real-life conditions (2013-2014) in a compassionate program. Our analysis has been focused on 48 chronic phase CML patients recorded. With a median follow-up of 26.5 months since ponatinib initiation, the overall survival (OS) rates (80.5% at 3 years) and cumulative incidence of major molecular response (81.8% at 18 months) were similar to those of the phase II study, with no influence of BCR-ABL mutations nor the reason of ponatinib prescription. A specific subanalysis of the preexisting cardiovascular risk factors and events occurring on ponatinib is described. These events occurred after a median time on ponatinib of 5.8 months (excluding hypertension) and were observed in 29/48 patients (47%), even in those already on anti-aggregants/coagulants. The majority were not severe and resolved, but two cases were fatal. Other hematological or nonhematological nonvascular adverse events were similar to those previously described in trials. This observational study reports similar rates of survival, molecular responses, and a slight increase in the cardiovascular toxicity of ponatinib in real-life conditions, prompting improved control of cardiovascular risk factors and selection of patients.

Comparative analyses of nilotinib versus high-dose imatinib versus sustained standard-dose imatinib in patients with chronic phase chronic myeloid leukemia following suboptimal molecular response to first-line imatinib

The aim of this study was to investigate the efficacy of nilotinib (NIL) versus high-dose imatinib (IM) versus sustained standard-dose IM for patients with chronic myeloid leukemia (CML) with suboptimal molecular response to first-line IM therapy. Patients with CML who achieved complete cytogenetic response (CCyR) but not major molecular response (MMR) after 18–24 months on first-line IM therapy were enrolled and divided into three treatment cohorts: NIL 800 mg/day (Cohort 1, n = 28) and IM 800 mg/day (Cohort 2, n = 28) in the RE-NICE study, and sustained IM 400 mg/day (Cohort 3, n = 52) in clinical practice. The primary efficacy variable of cumulative rate of MMR by 12 months was not different among the three cohorts. However, the cumulative incidence of MMR by 36 months was significantly higher in Cohort 1 than Cohort 3 (83.1% vs. 57.1%, P = 0.021), but there were no significant differences in Cohort 1 vs. 2 (P = 0.195) and Cohort 2 vs. 3 (P = 0.297). Different profile for adverse events was observed between NIL and high-dose IM therapy. In conclusion, our data suggested that switching to NIL may provide more effective long-term response than sustaining standard-dose IM for patients with suboptimal molecular response to first-line IM.

Results of following up patients with chronic myeloid leukemia and a deep molecular response without tyrosine kinase inhibitor therapy

To assess the results of following up patients with chronic myeloid leukemia (CML) and a deep molecular response (MR) without tyrosine kinase inhibitor (TKI) therapy. The reasons for TKI discontinuation in 70 patients with CML and a deep MR of more than 1 year's duration were adverse events, pregnancy, and patients' decision. Information was collected retrospectively and prospectively in 2008-2016. The median follow-up after TKI therapy discontinuation was 23 months (2 to 100 months). At 6, 12 and 24 months after TKI therapy discontinuation, the cumulative incidence of major MR (MMR) loss was 28, 41 and 48%, respectively; the survival rates without TKI therapy were 69, 50, and 39%, respectively. MMR loss was noted in 28 (88%) patients at 12 months; it was not seen without TKI therapy at 2-year follow-up. Deaths due to CML progression were absent. The Sokal risk group was a reliable factor influencing MMR loss (p ≤ 0.05). The cumulative recovery rate for deep MR after resumption of TKI use was 73 and 100% at 12 and 24 months, respectively, with a median follow-up of 24 months (1 to 116 months). Deep MR recovered at a later time when the therapy was resumed more than 30 days after MMR loss. Safe follow-up is possible in about 50% of the patients with CML and stable deep MRs without TKI therapy. The introduction of this approach into clinical practice requires regular molecular genetic monitoring and organizational activities. Biological factors in maintaining remission after TKI discontinuation need to be separately studied.

Impact of Body Weight Adjusted Dose on Efficacy and Safety of Radotinib in Chronic Myeloid Leukemia

▪Background: Radotinib is a BCR-ABL tyrosine kinase inhibitor (TKI) approved for the treatment of chronic myeloid leukemia in chronic phase (CP-CML). It is typically administered as a fixed dose; however, a subanalysis of the Phase 2 study (Leuk Lymphoma. DOI 10.3109/10428194.2015.1113278) demonstrated that as the dose adjusted for body weight (Dose/BW) increased the risk of dose-limiting toxicity (DLT) significantly.Aims: To assess the impact of Dose/BW of radotinib on the occurrence of DLT as well as on the achievement of major molecular response (MMR) using the clinical data obtained from the Phase 3 studyMethods: The Phase 3 study involved 160 CP-CML patients who were randomly assigned to a fixed dose of radotinib 300 mg BID or 400 mg BID regardless of BW. The authors performed a logistic regression analysis to evaluate the relationship between daily Dose/BW and the probability of achieving MMR at 12 months as well as experiencing DLT by 12 months. Chi-square test and Kaplan-Meier analysis (log-rank test) were utilized to compare the incidence of MMR and DLT, respectively, according to specific Dose/BW cut-offs.Results:Efficacy. Dose/BW of radotinib was negatively associated with the rate of MMR when controlled for gender (p = 0.033). That is, increasing Dose/BW rather decreased the likelihood of achieving MMR. More specifically, patients who received ≥13 mg/kg/d showed a significantly lower rate of MMR at 12 months (35%) than those who received <13 mg/kg/d (56%) (p = 0.045). Safety. Dose/BW of radotinib was positively associated with the rate of DLT (p = 0.003). A Dose/BW cut-off 13 mg/kg/d yielded the largest difference in the rate of DLT, such that the patients who received ≥13 mg/kg/d had a substantially higher rate of DLT (91%) than those who received <13 mg/kg/d (57%) (p <0.001). The time at which 50% of patients experienced their first DLT was also much earlier in the ≥13 mg/kg/d group (83 days) than in the <13 mg/kg/d group (194 days) (p <0.001).Conclusion: Dose adjustment of radotinib based on BW is warranted so as not to exceed 13 mg/kg/d. Therefore, a two-tier weight-based dosing regimen was developed: radotinib 300 mg BID for patients who weigh 60 kg or less, and 400 mg BID for patients who weigh more than 60 kg. A prospective clinical trial would be needed to confirm the efficacy and safety of this new dosing regimen. DisclosuresNoh:Il-Yang Pharmaceutical: Research Funding. Jung:Il-Yang Pharmaceutical: Research Funding. Park:Il-Yang Pharmaceutical: Employment. Jo:Il-Yang Pharmaceutical: Employment. Shin:Il-Yang Pharmaceutical: Employment. Kim:BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; ILYANG: Consultancy, Honoraria, Research Funding. Lee:Il-Yang Pharmaceutical: Research Funding.

Clinical Application of Artificial Intelligence in Patients with Chronic Myeloid Leukemia in Chronic Phase

▪IntroductionArtificial intelligence (AI) has been applied to a wide range of daily activities to assist in decision-making. Randomized clinical trials can compare the efficacy of treatment between patient groups. However, the best treatment decision for each individual patient, with their own clinical and biological features, and in the context of comparable treatment options, is more difficult to predict. The integrated consideration of various prognostic features can reach the point beyond human recognition. An AI-assisted approach may help with decision-making in complex clinical situations. The aim of this study is to introduce a prototype of AI to predict outcome such as achievement of major molecular response (MMR) within 1 year of the start of tyrosine kinase inhibitor (TKI).MethodsResponse data for 630 patients with newly diagnosed CML-CP in consecutive prospective clinical trials of frontline imatinib (n=73; NCT00048672), high-dose imatinib (n=208; NCT00038469 and NCT00050531), nilotinib (n=148; NCT00129740), dasatinib (n=150; NCT00254423), and ponatinib (n=51; NCT01570868) were analyzed. After multiple imputation for missing variables, neural network analysis with a multilayer perceptron model using the statistically significant variables by stepwise multivariate analysis was performed to predict the cumulative incidence of MMR within 1 year. The hyperbolic tangent and softmax activation function were used to create the architecture of hidden layers and output layers, respectively. Batch training with scaled conjugate gradient optimization algorithm with learning parameters (initial Lambda of 0.0000005, initial Sigma of 0.00005, interval center of 0, and interval offset of ±0.5) was used to train the neural network. To evaluate the accuracy of prediction, the entire cohort was randomly divided into training dataset (70%) and test dataset (30%). The correct prediction in the test dataset was repeatedly assessed 1,000 times to validate this approach. The whole cohort was subsequently used to create the AI model for MMR prediction, and was divided into two cohorts based on the prediction by the AI; AI-predicted response, and AI-predicted nonresponse. Hypothetical choice of TKI was assumed to rank the selection of TKI among imatinib 400 mg/day, imatinib 800 mg/day, dasatinib, nilotinib, and ponatinib to calculate the estimated percentage of MMR within 1 year for each patient. The Kaplan-Meier method with a log-rank test was used for failure-free survival (FFS), transformation-free survival (TFS), event-free survival (EFS), and overall survival (OS). To balance baseline patient characteristics between cohorts, propensity score matching after propensity score calculation by logistic regression was performed with nearest neighbor matching method with a caliper of 0.20. Exact matching was used for the type of cytogenetic, transcript, and TKI.ResultsOf 630 patients treated, 464 (74%) achieved MMR within 1 year. The stepwise multivariate analysis identified the selection of TKI, type of transcript, white blood cell count, albumin, and spleen size at diagnosis were the predictors for MMR within 1 year. Neural network analysis with a multilayer perceptron model is shown in figure 1. Through repeated random selection for training set (70%) and test set (30%), the mean correct prediction for MMR within 1 year was 77.4% (95% confidence interval [CI], 74.2-80.5), and 76.9% (95% CI, 71.4-82.3), respectively. Of 630 patients, the neural network model predicted 539 patients (86%) as responders, and 91 patients (14%) as nonresponders (table 1). Before propensity score matching, the AI-response cohort had higher rates of CCyR, MMR, MR4, MR4.5, and CMR as well as FFS, TFS, EFS, and OS compared to those of the AI-nonresponse cohort (figure 2). After propensity score matching, 25 patients in each cohort were identified, and the baseline differences were minimized (table 1). The AI-response cohort had higher rates of MMR, MR4, and FFS than those of AI-non-response cohort (figure 2).ConclusionAI with a multilayer perceptron model can predict target outcome. Incorporation of additional clinical and biological variables may improve the prediction rates to suggest the best treatment option in each patient with CML-CP. Such strategy is ongoing. [Display omitted] [Display omitted] [Display omitted] DisclosuresKantarjian:ARIAD: Research Funding; Bristol-Myers Squibb: Research Funding; Amgen: Research Funding; Pfizer Inc: Research Funding; Delta-Fly Pharma: Research Funding; Novartis: Research Funding. Jabbour:ARIAD: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Novartis: Research Funding; BMS: Consultancy. Ravandi:BMS: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding. Konopleva:AbbVie: Research Funding; Genentech: Research Funding. Wierda:Novartis: Research Funding; Abbvie: Research Funding; Acerta: Research Funding; Gilead: Research Funding; Genentech: Research Funding. Daver:Pfizer: Consultancy, Research Funding; Kiromic: Research Funding; BMS: Research Funding; Otsuka: Consultancy, Honoraria; Sunesis: Consultancy, Research Funding; Karyopharm: Honoraria, Research Funding; Ariad: Research Funding.

Prognostic Value of BCR-ABL1 Transcript Type in Chronic Myeloid Leukemia Patients Treated Frontline with Nilotinib

Background. The fusion protein encoded by the BCR-ABL1 fusion gene may differ in size, but the great majority of chronic myeloid leukemia (CML) patients have a e13a2 (b2a2) or a e14a2 (b3a2) junction. In CML patients treated frontline with imatinib, the e14a2 transcript has been recently associated to faster and deeper molecular responses; in some studies a better outcome has been also reported. Very limited information on the prognostic impact of the BCR-ABL1 transcript type in CML patients treated frontline with second generation tyrosine kinase inhibitors (TKIs) is still available: a study from MDACC reported lower molecular response rates and a trend for inferior event-free survival in e13a2 patients.Aim. To evaluate if the BCR-ABL1 transcript type (e14a2 vs e13a2) affect the response and the clinical outcome in newly diagnosed adult CML patients treated frontline with nilotinib (NIL).Methods. An analysis of 345 CML patients in early chronic phase (ECP) enrolled within 3 multicentric prospective studies of the GIMEMA CML Working Party (ClinicalTrials.gov NCT00481052, NCT00769327, NCT01535391) was performed. The initial treatment was NIL 300 mg BID or NIL 400 mg BID. Definitions: major molecular response (MMR), BCR-ABL1IS ratio < 0.1%; deep molecular response (MR4.0), BCR-ABL1IS ratio < 0.01% with > 10,000 ABL1 copies; progression, transformation to advanced phases; death, at any time and for any reason. Cumulative incidences of response were estimated under consideration of competing risks (progression, death) and compared by Gray test. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method and compared by log-rank test.Results. Seven patients expressing rare transcripts (e1a2 or e19a2) and 10 patients with unknown transcript type were excluded: 328 out of 345 patients were evaluable, 124 (38%) with e13a2 transcript, 174 (53%) with e14a2 transcript and 30 (9%) expressing both transcripts. The baseline characteristics of patients with e13a2 or e14a2 transcripts were comparable: no significant differences in age, gender, Sokal or EUTOS long-term survival score distribution, presence of clonal chromosomal abnormalities in Ph+ cells, NIL dose were observed; the only difference was a higher platelet count in patients with e14a2 transcript (median 374 vs 313 x 103/µl, p=0.006). The median follow-up was 60 months in both groups (range 24-82 months). The response rates and the survival probabilities were uniformly lower in patients with e13a2 transcript (N=124) compared to patients with e14a2 transcript (N=174), but the differences were not significant: MMR by 12 months, 66% vs 72%, p=0.244; MR4.0 by 36 months, 56% vs 66%, p=0.067; estimated cumulative incidence of MMR, 82% vs 88%, p=0.135; estimated cumulative incidence of MR4.0, 60% vs 69%, p=0.101; estimated PFS, 88% vs 93%, p=0.547; estimated OS, 89% vs 94%, p=0.436 (Figure 1). The responses and the survival probabilities of patients co-expressing the e13a2 and the e14a2 transcripts (N=30) were similar to or even better than the ones of e14a2 patients. Grouping together the patients with e14a2 transcript alone and the patients with co-expression of both transcripts (N=174+30=204), and comparing them to patients with e13a2 transcript alone (N=124), the response differences became significant (cumulative incidence of MMR and MR4.0, p=0.050 and p=0.036, respectively), but no outcome differences emerged (PFS and OS, p=0.340 and p=0.276, respectively).Conclusions. Despite a trend for lower response rates and inferior outcome in patients with e13a2 transcript, the observed differences were small and mostly not significant. Further studies in larger patient cohorts are required to clarify whether nilotinib and other second generation TKIs are able to overcome the adverse prognostic impact of transcript type, potentially affecting the speed and the depth of molecular response, the probability of achieving a treatment-free remission and the patient outcome. [Display omitted] DisclosuresCastagnetti:Bristol-Myers Squibb: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; ARIAD Pharmaceuticals: Consultancy, Honoraria; Novartis: Consultancy, Honoraria. Gugliotta:Bristol Myers Squibb: Consultancy, Honoraria; Novartis: Consultancy, Honoraria. Breccia:Ariad: Honoraria; Bristol Myers Squibb: Honoraria; Novartis: Consultancy, Honoraria; Pfizer: Honoraria; Celgene: Honoraria. Carella:Millenium: Speakers Bureau; Genentech: Speakers Bureau. Tiribelli:Ariad Pharmaceuticals: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Speakers Bureau. Bocchia:Janssen: Honoraria; Novartis: Honoraria; Bristol-Myers Squibb: Honoraria. Soverini:Ariad: Consultancy; Bristol-Myers Squibb: Consultancy; Novartis: Consultancy. Cavo:Bristol-Myers Squibb: Consultancy, Honoraria; Millennium: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Janssen-Cilag: Consultancy, Honoraria; Celgene: Consultancy, Honoraria. Martinelli:ARIAD: Consultancy; Roche: Consultancy; MSD: Consultancy; Novartis: Speakers Bureau; Genentech: Consultancy; Amgen: Consultancy; BMS: Speakers Bureau; Pfizer: Consultancy, Speakers Bureau; Pfizer: Consultancy, Speakers Bureau; ARIAD: Consultancy; Roche: Consultancy; MSD: Consultancy; Amgen: Consultancy; Genentech: Consultancy. Rosti:Roche: Honoraria, Research Funding, Speakers Bureau; Incyte: Honoraria, Research Funding, Speakers Bureau; Pfizer: Honoraria, Research Funding, Speakers Bureau; BMS: Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau.

The Prospective Analysis Of Clinical Efficacy and Adverse Events In Chronic Myeloid Leukemia In Chronic Phase (CML-CP) Patients With Imatinib Resistance Or Intolerance, Evaluated By European Leukemia Net (ELN) 2013 Criteria

BackgroundDasatinib is a highly potent BCR-ABL inhibitor, with a 325-fold higher potency than imatinib and a 16-fold higher potency than nilotinib in vitro. Across a series of phase II and III trials with more than 2 years of follow-up, dasatinib has demonstrated durable efficacy in patients with CML following resistance or intolerance to imatinib. We conducted a phase II study to evaluate the efficacy and safety of dasatinib in Japanese patients with imatinib resistance or intolerance CML. MethodsFifty- five CML-CP patients from 2009 to 2011 with resistance (n=40) or intolerance (n=26) to imatinib were registered to dasatinib administration (100mg once daily). Eleven among 26 patients with intolerance also showed resistance to imatinib at the registration. Imatinib resistance was defined as a lack of partial cytogenetical response at 3 months, a lack of complete cytogenetic response at 6 months or a lack of a major molecular response at 12 months of imatinib treatment. This criteria was identical to the criteria in ELN 2013 recommendation for first line. In another words, the resistance in this study means non-optimal criteria (warning and failure) of definition of the response to TKIs, first line, in ELN 2013 recommendation. Efficacy and safety were assessed using rates of major molecular response (MMR)/ MR4.5 (either (i) detectable disease with<0.0032% BCR-ABL1 IS or (ii) undetectable disease in cDNA with >32,000 ABL1 transcripts in the same volume of cDNA used to test for BCR-ABL1) at 12 months and drug-related adverse events (AEs) respectively. All analyses were based on the modified to intension-to treat. ResultsOne patient was withdrawal before dasatinib administration. The median duration of imatinib therapy was 545 days. The overall incidence of MMR (primary endopoint) and MR4.5 at 12 months was 67.2% (95% confidence interval, 53.3-81.1%), and 20.2 % (95% CI, 8.4–32.0 %), respectively. Forty patients with resistance to imatinib, who were warning and failure patients judged by ELN 2013 criteria, were reassessed. Cumulative MMR and MR4.5 rate were 63.4% (95% CI: 46.3-80.6) and 18.0% (95% CI: 4.9-31.1) respectively at 12 months. Eleven patients, who showed more than 1% IS at 3 months of dasatinib treatment, did not reach to MMR at 12 months or discontinued dasatinib due to insufficient efficacy in this resistance cohort. However, progression to the accelerated or blastic phase had not been observed. When imatinib were changed to dasatinib, 5 patients showed the mutations, which were effective in dasatinib therapy. New mutations have not been observed during the treatment of dasatinib.Among 54 patients, most non-hematological AEs were in grade 1/2. including diarrhea (12.7%), rash (7.3%), myalgia (5.5%) and vomiting (3.6%). Grade 3/4 non-hematological AEs were infrequent, including decreased potassium (3.6%), and increased creatinine (3.6%). Grade 1/2 fluid retention AEs were shown in 9.1% of patients, including edema (3.6%). Pleural effusion, which was only in Grade 1/2, was shown in 32.7% of patients. Grade 3/4 hematological toxicities included anemia (7.3%) and thrombocytopenia (3.6 %). Only 3 patients have permanently discontinued dasatinib treatment due to AEs. ConclusionsThe patients with non-optimal responses (warning and failure) judged by ELN 2013 criteria should have early intervention to dasatinib, which is less toxicity in CML-CP patients. This intervention might induce good prognosis. The BCR-ABL1 IS less than 1% at 3 months of dasatinib administration will be the valuable landmark for outcome. [Display omitted] Disclosures:No relevant conflicts of interest to declare.