Cumulative Major Molecular Response Research Articles

Real-world outcomes of ponatinib treatment in 724 patients with CML and Ph+ ALL: a post-marketing surveillance study with a special interest in arterial occlusive events in Japan.

In September 2016, ponatinib was approved in Japan for the treatment of patients with chronic myeloid leukemia with resistance/intolerance to prior tyrosine kinase inhibitors and patients with relapsed or refractory Philadelphia chromosome-positive acute lymphoblastic leukemia. We conducted a post-marketing all-case surveillance to study the safety and efficacy of ponatinib in clinical practice, focusing on arterial occlusive events. Data from 724 patients were collected for 2years from the initiation of ponatinib. The arterial occlusive events were reported in 6.49% (47/724) with an exposure-adjusted incidence rate of 6.8/100 person-years. The risks associated with arterial occlusive events were age and comorbidities including hypertension and diabetes. At 104weeks, the cumulative major molecular response rate in patients with chronic-phase chronic myeloid leukemia was 67.2% and the complete cytogenetic response in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia was 80.0%. Furthermore, the estimated 1-year overall survival rate was 98.5% for chronic-phase chronic myeloid leukemia and 68.6% for Philadelphia chromosome-positive acute lymphoblastic leukemia. This surveillance demonstrated that ponatinib has a favorable safety and efficacy profile in Japanese patients and also showed the necessity of closely monitoring arterial occlusive events in older adults and patients with predisposing factors for atherosclerosis.

Treatment of chronic-phase chronic myeloid leukemia in patients randomized to dasatinib or imatinib after suboptimal responses to 3 months of imatinib therapy: final 5-year results from DASCERN.

Early molecular response at 3 months is predictive of improved overall survival and progression-free survival in patients with chronic myeloid leukemia in the chronic phase. Although about one-third of patients treated with first-line imatinib do not achieve an early molecular response, long-term overall survival and progression-free survival are still observed in most patients. DASCERN (NCT01593254) is a prospective, phase IIb, randomized trial evaluating a switch to dasatinib in patients who have not achieved an early molecular response after 3 months of treatment with first-line imatinib. Early analysis demonstrated an improved major molecular response (MMR) rate at 12 months with dasatinib versus imatinib (29% vs. 13%, P=0.005). Here, we report results from the final 5-year follow-up. In total, 174 patients were randomized to dasatinib and 86 to remain on imatinib. Forty-six (53%) patients who remained on imatinib but subsequently experienced failure were allowed to cross over to dasatinib per protocol. At a minimum follow-up of 60 months, the cumulative MMR rate was significantly higher in patients randomized to dasatinib than those randomized to imatinib (77% vs. 44%, P<0.001). The median time to MMR was 13.9 months with dasatinib versus 19.7 months with imatinib. The safety profile was consistent with previous reports. These results demonstrate that switching to dasatinib after a suboptimal response to imatinib at 3 months leads to faster MMR, provides earlier deep molecular responses, and improves some outcomes in patients with chronic myeloid leukemia in the chronic phase.

Combination of dasatinib and venetoclax in newly diagnosed chronic phase chronic myeloid leukemia.

The dual inhibition of the BCR::ABL1 tyrosine kinase and BCL-2 could potentially deepen the response rates of chronic myeloid leukemia in chronic phase (CML-CP). This study evaluated the safety and efficacy of the combination of dasatinib and venetoclax. In this phase 2 trial, patients with CML-CP or accelerated phase (clonal evolution) received dasatinib 50 mg/day for three courses; venetoclax was added in course 4 for 3 years. The initial venetoclax dose was 200 mg/day continuously but reduced later to 200 mg/day for 14 days, and to 100 mg/day for 7 days per course once a molecular response (MR)4.5 was achieved. After 3 years of combination, patients were maintained on single-agent dasatinib. The primary end point was the rate of major molecular response (MMR) by 12 months of combination. Sixty-five patients were treated. Their median age was 46 years (range, 23-73). By 12 months of combination, the MMR, MR4, and MR4.5 rates were 86%, 53%, and 45%, respectively. After a median follow-up of 42 months, the 4-year event-free and overall survival rates were 96% and 100%, respectively. Outcomes with the combination were comparable to historical outcomes with single-agent dasatinib (cumulative 12-months MMR rate of 79% with both strategies). The incidence of grade 3-4 neutropenia was 22% with the combination and 11% with single-agent dasatinib (p<.001). Treatment with dasatinib and venetoclax was safe and effective in CML-CP. The cumulative response rates with the combination were similar to those with single-agent dasatinib. Further follow-up is needed to evaluate the rates of durable deep molecular response and treatment-free remission.

Efficacy and safety of bosutinib in patients treated with prior imatinib and/or dasatinib and/or nilotinib: Subgroup analyses from the phase 4 BYOND study

The BYOND study evaluated the efficacy and safety of bosutinib 500 mg once daily in patients with chronic myeloid leukemia (CML) resistant/intolerant to prior tyrosine kinase inhibitors (TKIs). These post-hoc analyses assessed the efficacy and safety of bosutinib by resistance or intolerance to prior TKIs (imatinib-resistant vs dasatinib/nilotinib-resistant vs TKI-intolerant), and cross-intolerance between bosutinib and prior TKIs (imatinib, dasatinib, nilotinib), in patients with Philadelphia chromosome–positive chronic phase CML. Data are reported after ≥3 years’ follow-up. Of 156 patients with Philadelphia chromosome–positive chronic phase CML, 53 were imatinib-resistant, 29 dasatinib/nilotinib-resistant, and 74 intolerant to all prior TKIs; cumulative complete cytogenetic response rates at any time were 83.7%, 61.5%, and 86.8%, and cumulative major molecular response rates at any time were 72.9%, 40.7%, and 82.4%, respectively. Of 141, 95, and 79 patients who received prior imatinib, dasatinib, and nilotinib, 64 (45.4%), 71 (74.7%), and 60 (75.9%) discontinued the respective TKI due to intolerance; of these, 2 (3.1%), 5 (7.0%), and 0 had cross-intolerance with bosutinib. The response rates observed in TKI-resistant and TKI-intolerant patients, and low cross-intolerance between bosutinib and prior TKIs, further support bosutinib use for patients with Philadelphia chromosome–positive chronic phase CML resistant/intolerant to prior TKIs. Trial registrationClinicalTrials.gov: NCT02228382

Phase 2 Study of Dasatinib with and without Venetoclax in Patients with Early Chronic Phase Chronic Myeloid Leukemia (ECP-CML)

Background Treatment-free remission (TFR) is a therapeutic goal for patients with ECP-CML once patients maintain a deep molecular remission (DMR) on tyrosine kinase inhibitors (TKIs). Only a fraction of patients (pts) achieved sustained (3+ years) molecular remission with 4.0- to 4.5-log reduction (MR4.5). Preclinical studies showed that BCL-2 is a key survival factor for CML stem/progenitor cells. Therefore, the combination of TKIs and venetoclax, targeting BCR::ABL1 and BCL-2, has the potential to significantly improve DMR and subsequently the rates of TFR. The aim of this study is to evaluate the safety and efficacy of the combination. Methods Patients with ECP-CML or accelerated phase (AP; defined by clonal evolution only) were eligible; pts with &amp;lt; 1 month of prior TKI therapy were eligible. Pts received single-agent dasatinib 50 mg/d for the first 3 months. From Month 4 and onwards, venetoclax was administered from Days 1 to 14 each month concomitantly with dasatinib for a total of 3 years. The first 16 patients received venetoclax 200 mg/d, with a rapid ramp-up starting 50 mg on Day 1, then 100 mg on Day 2, then 200 mg daily on Day 3 and onwards. Due to neutropenia observed with continuous dose of venetoclax 200 mg/d, the protocol was ameded: from patient #17 and onwards, venetoclax was administered at 200 mg/d for 14 days per month and upon achievement of MR4.5, venetoclax was reduced to 100 mg/d for 7 days per month. After 3 years of combination, patients received single-agent dasatinib. TFR was offered after ≥ 3 years of DMR. The primary endpoint was the rate of major molecular response (MMR) by 12 months of the combination. The secondary endpoints were the 12-month rate of MR4.5 and the cumulative overall rate of MR4.5; the rates of MR4.5 at 6-, 12-, 18-, 24, and 36-months of the combination; the proportion of patients with sustained MR4.5 of 3 years and more; the TFR rate; overall survival; and the safety of the combination. Cumulative response rates were calculated with treatment failure as a competing event. Failure-free survival (FFS) was calculated from the initiation of therapy to loss of major cytogenetic response (MCyR), transformation to AP or blast phase, discontinuation of therapy for any reason except of TFR, or death. Results Sixty-five pts were enrolled and treated between April 2018 and August 2021. The median age at treatment initation was 46 years (range, 23-73) and 57% of the pts were females. Twenty-one (32%) pts had splenomegaly, 46 (71%) had low Sokal risk disease and 3 (5%) had high Sokal risk disease (Table 1). By 12 months of the combination, 85% of the pts had achieved MMR or deeper response. The median time to MMR, MR4, and MR4.5 were 6.2 months, 13 months, and 23.9 months from the time of TKI start, respectively. After a median follow-up of 25.7 months (range, 8.7-48.1), two pts discontinued therapy due to adverse events (GI intolerance, and pleural effusion); the 2 -year FFS was 96%. One pt switched TKI therapy due to the lack of 18-month complete cytogenetic response (CCyR); no loss of CCyR, transformation, or death was observed. We then compared the outcomes with the combination to the outcomes of 85 pts treated with single-agent dasatinib. From the start of TKI therapy, the 12-month cumulative MMR rates were 78% and 79% in the dasatinib single-agent and dasatinib + venetoclax groups, respectively. The cumulative 24-month rates of CCyR, MMR, MR4, and MR4.5 are summarized in Table 2. In the dasatinib single-agent group, 3 pts switched TKI therapy due to the lack of 12-month MCyR, 18-month CCyR, and the acquisition of ABL1 mutation (1 each); 3 pts switched TKI therapy due to loss of CCyR; 2 pts died during therapy (deaths unrelated to CML). Within one year of therapy, the incidence of grade 1/2 neutropenia (absolute neutrophil count, below lower range of normal to 1,000 x10 9/L) was 21% and 52% in the dasatinib single agent and dasatinib + venetoclax groups, respectively ( P&amp;lt;0.001); the incidence of grade 3/4 neutropenia (absolute neutrophil count, below 1,000 x10 9/L) was 8% and 17%, respectively ( P&amp;lt;0.001). There was no incidence of neutropenic fever in the dasatinib + venetoclax. Conclusion The combination of dasatinib 50 mg/d and venetoclax is safe and effective in pts with ECP-CML. With a median follow-up of 2 years, the cumulative resposne of dasatinib + venetoclax is similar to that of dasatinib single-agent without adding significant toxicities. Further follow-up is needed for the evaluation of TFR.

With up to 8 Years of Therapy, Asciminib (ASC) Monotherapy Demonstrated Continued Favorable Efficacy, Safety, and Tolerability in Patients (Pts) with Philadelphia Chromosome-Positive Chronic Myeloid Leukemia in Chronic Phase (Ph+ CML-CP) without the T315I Mutation: Final Results from the Phase 1 X2101 Study

CONCLUSIONS Tyrosine kinase inhibitors (TKIs) have extended the life expectancy for pts with CML, approximating that of the general population, and established BCR::ABL1-targeted therapies as the standard of care for CML. However, multi-TKI resistance and intolerance remain challenges that may lead to treatment (Tx) discontinuation. ASC is the first and only approved BCR::ABL1 inhibitor that Specifically Targets the ABL Myristoyl Pocket (STAMP) with higher selectivity for ABL, reducing off-target effects seen with TKIs. A follow-up analysis (median exposure: 4.2 y) of the phase 1 ASC study in pts with CML-CP without T315I after receiving ≥2 TKIs demonstrated durable efficacy and favorable tolerability, with nearly one-third of pts achieving deep molecular response by cutoff (Jan 6, 2021). Here we present final end-of-study (EOS) efficacy and safety results from the phase 1 ASC study in pts with CML-CP without the T315I mutation (cutoff: Mar 14, 2023). This analysis included adults with Ph+ CML-CP without the T315I mutation and an ECOG performance status of 0-2 who had relapsed disease or were refractory to or intolerant of ≥2 prior TKIs. Pts received ASC monotherapy at starting doses of 10-200 mg twice daily (BID) or 80-200 mg once daily (QD). The study started with dose escalation to estimate the maximum tolerated dose (MTD), followed by expansion to establish safety and tolerability of ASC. Dose adjustments were allowed if pts did not tolerate the dosing schedule. The EOS was declared when all pts completed ≥64 wks within the study or discontinued Tx; pts continuing to receive ASC at the EOS were provided continued access to ASC. A total of 115 pts were enrolled between Apr 2014 and Mar 2023. Across all starting doses, the median exposure duration was 5.9 y, with a maximum exposure of 8.4 y; 112 pts (97.4%) had received ≥2 prior TKIs and 82 (71.3%) had received ≥3 prior TKIs. By data cutoff, 70 pts (60.9%) who completed the study on ASC were provided continued access to ASC. Among 45 pts who ended Tx early, 15 (13.0%) and 8 (7.0%) ended due to adverse events (AEs) and disease progression, respectively. Efficacy of ASC at EOS was sustained and consistent with previous reports, with the majority of pts (65.1%) achieving major molecular response (MMR) by the cutoff. While most responses were observed by wk 48, cumulative MMR rates continued to increase up to wk 144 (Figure 1). The median time to MMR (range) was 58.3 (2-360) wks among pts who achieved MMR but were not in MMR at screening. Among the 56 pts who achieved MMR, 50 maintained or improved the response up to data cutoff. At wks 24, 48, and 96, respectively, 18.9%, 17.9%, and 23.6% of pts achieved MR 4 and 13.2%, 15.1%, and 18.9% achieved MR 4.5. Safety and tolerability of ASC improved with longer durations of exposure. The most frequent all-grade AEs included arthralgia (40.9%), increased lipase (39.1%), fatigue (38.3%), and headache (38.3%), and only 13.0% of pts experienced AEs leading to Tx discontinuation. Even with longer durations of Tx, AEs were less likely to occur after the first year on ASC (Figure 2). The safety and tolerability of ASC remained consistent with prior analyses; there were no new or worsening safety issues compared with those already known for ASC and no new on-Tx deaths. The MTD of ASC was not reached. Based on safety, tolerability, efficacy, and pharmacokinetic data, ASC 40 mg BID was selected as the recommended dose for expansion in adults with CML-CP without the T315I mutation. In this final analysis of the phase 1 ASC trial in pts with CML-CP without the T315I mutation, ASC continued to show favorable efficacy and sustained safety and tolerability over a median exposure duration of 5.9 y, with a maximum exposure of 8.4 y. Pts achieved high rates of MMR with nearly one-fourth of pts achieving deep molecular responses at wk 96, demonstrating durable efficacy of ASC over time. Even with longer exposures, the risk of AEs did not increase and there were no new or worsening safety issues. With ASC, most AEs occurred early, and no new late-emerging safety issues were seen, supporting ASC as a safe and tolerable long-term Tx, highly clinically relevant in the management of resistant/intolerant CML-CP. Based on results from this and the ASCEMBL study, 40 mg BID and 80 mg QD have since been approved for use in this pt population.

The long-term efficacy and safety of nilotinib in pediatric patients with CML: a 5-year update of the DIALOG study

AbstractThe efficacy and safety of nilotinib in pediatric patients with imatinib/dasatinib resistant/intolerant (R/I) or newly diagnosed (ND) Philadelphia chromosome–positive (Ph+) chronic myeloid leukemia in chronic phase (CML-CP) was demonstrated in the phase 2, open-label DIALOG study. In this final analysis, long-term efficacy and safety are presented for patients who completed 66 cycles (of 28 days) of treatment with nilotinib (230 mg/m2 twice daily) or discontinued early. Overall, 59 patients were enrolled and 58 were treated (R/I, n = 33; ND, n = 25; median time on treatment: 60.5 and 51.9 months, respectively). In the R/I cohort, the cumulative major molecular response (MMR; BCR::ABL1 international scale [IS] ≤ 0.1%) rate was 60.6%, and no patients had a confirmed loss of MMR. Among ND patients, the best overall MMR rate was 76.0%; 3 patients had a confirmed loss of MMR. The cumulative molecular response MR4 (BCR::ABL1IS ≤ 0.01%) and MR4.5 (BCR::ABL1IS ≤ 0.0032%) rates by 66 cycles were 27.3% and 12.1% in the R/I cohort, and 56.0% and 44.0% in the ND cohort, respectively. The safety profile of nilotinib was consistent with those of earlier reports. No on-treatment deaths occurred. These long-term (up to ∼5 years) data support the efficacy and safety of nilotinib in pediatric patients with Ph+ CML-CP. This trial was registered at www.clinicaltrials.gov.uk as #NCT01844765.

Population modeling of bosutinib exposure-response in patients with newly diagnosed chronic phase chronic myeloid leukemia.

The BELA and BFORE trials compared bosutinib starting doses of 500 mg once daily (QD) and 400 mg QD, respectively, with imatinib in adults with newly diagnosed chronic phase chronic myeloid leukemia (CP-CML). The B1871048 trial evaluated bosutinib 400 mg QD in Japanese patients with newly diagnosed CP-CML. This analysis assessed the impact of a lower bosutinib starting dose on key efficacy and safety outcomes. A pharmacokinetic model was used to estimate metrics of bosutinib exposure, and logistic regression was used to investigate relationships with efficacy (cumulative major molecular response [MMR] and cumulative complete cytogenetic response [CCyR]) and safety outcomes (eight prespecified adverse events). Totals of 573 and 574 patients were included in the efficacy and safety endpoint analyses, respectively. Cumulative MMR and CCyR were similar across studies. Log(Ctrough ) and log(Cavg ) were significant predictors of MMR and CCyR, and the probability of achieving MMR or CCyR increased 1.3-fold or 2.7-fold for every 1 unit increase in log(Ctrough ) or log(Cavg ), respectively. An exposure-response relationship was identified between time-to-event and risk of diarrhea, nausea, and vomiting. Significant relationships were also observed between time-to-event and log(Cavg ), Ctrough , and Cavg with diarrhea, nausea, and vomiting, respectively. A bosutinib exposure-response relationship with safety and efficacy was observed. Compared with 500 mg QD, a bosutinib starting dose of 400 mg QD improved tolerability in some patients with newly diagnosed CP-CML without compromising efficacy. gov identifiers: NCT00574873; NCT02130557; NCT03128411.

Clinical management of second-generation tyrosine kinase inhibitor therapy in patients with newly diagnosed chronic myeloid leukemia in the chronic phase, focusing on age and dose effects.

ABL1-tyrosine kinase inhibitors (TKIs) are an established treatment choice for patients with chronic myeloid leukemia in the chronic phase (CML-CP). However, effects of TKI dose modification have not been well investigated. In this study, we retrospectively analyzed 178 patients with newly diagnosed CML-CP who were treated with dasatinib or nilotinib, focusing on age and dose effects. Efficacy as measured by cumulative major molecular response (MMR) and molecular response 4.5 rates did not differ significantly between the younger group and elderly group. Elderly patients who started nilotinib at a reduced dose had similar or better efficacy outcomes (including cumulative MMR and continuation ratios) than other groups, and elderly patients who started dasatinib at a reduced dose had the lowest MMR ratio and longest MMR duration. Effects of dose modification based on age and TKI selection can be attributed to flexible management of TKI therapy in real-world practice, but further studies are required to validate the findings of this study.

Outcomes in Patients with Chronic Myeloid Leukemia in the Chronic Phase Randomized to Dasatinib or Imatinib after Suboptimal Responses to 3 Months of Imatinib Therapy: Final 5-Year Results from DASCERN

Introduction: Dasatinib has demonstrated superior responses versus imatinib in patients (pts) with newly diagnosed chronic myeloid leukemia in the chronic phase (CML-CP) (Cortes JCO 2016). Achievement of early molecular response (EMR; BCR::ABL1 ≤ 10% International Scale [IS]) at 3 months increases the probability of subsequent deep molecular response (DMR) and improves survival (Cortes JCO 2016, Hochhaus Leukemia 2016). However, ⅓ of pts treated with imatinib did not reach an EMR (Hughes Blood 2014); there are no standard treatment strategies for these pts. DASCERN (NCT01593254) is the first prospective, randomized, phase 2b trial to demonstrate the potential benefit of switching early to dasatinib in pts with no EMR after 3 months of initiating imatinib. At 12 months, pts randomized to dasatinib had significantly higher major molecular response (MMR) rates versus imatinib (29% vs 13%, primary endpoint) (Cortes Leukemia 2020). At 3 years, cumulative MMR rates were 67% and 40% with dasatinib and imatinib, respectively (Cortes EHA 2020 EP756). Switching to dasatinib did not increase the incidence of treatment-emergent adverse events (AEs). Here we report the results from the final 5-year analysis. Methods: Pts with complete hematologic response but no EMR at 3 months after initiating imatinib 400 mg were randomized 2:1 to an early switch to dasatinib (100 mg) or continue imatinib (≥ 400 mg). Pts who experienced subsequent failure with imatinib (per European LeukemiaNet 2013 recommendations at the time of the study) crossed over to dasatinib. The intent-to-treat (ITT) population included all pts randomized to each arm, irrespective of crossover status. Study endpoints included time to MMR and molecular response 4.5 (MR4.5; 4.5-log reduction in BCR::ABL1 levels; ≤ 0.0032% IS), progression-free survival (PFS), overall survival (OS), and safety. Results: At a median follow-up of 80 months (data cutoff, April 24, 2022), 174 and 86 pts with no EMR after imatinib were randomized to dasatinib and imatinib, respectively; 46 (53%) imatinib-randomized pts experienced subsequent imatinib failure and crossed over to dasatinib in a median of 9.5 months. Detailed baseline characteristics have been previously reported (Cortes EHA 2020 EP756). The median age was 37 years, and 73% of patients were Asian. All pts discontinued treatment, mainly due to study drug toxicity (26 [10%]), and other reasons (176 [68%], mostly study completion); 6 (2%) discontinued due to death. The MMR rate by 5 years in the ITT population was 77% and 44%, respectively, for pts in the dasatinib and imatinib arms. After accounting for crossover, cumulative MMR rates were 74% with dasatinib and 44% with imatinib; 65% of pts who crossed over from imatinib to dasatinib achieved MMR (Figure). Across the 5-year study period, more pts randomized to dasatinib than imatinib achieved MR4 and MR4.5 (MR4, 52% vs 31%; MR4.5, 36% vs 26%). Only 1/46 pts who later crossed over to dasatinib after imatinib failure achieved MR4.5. PFS in the ITT population was 94% in both treatment arms. PFS was numerically lower in pts who later crossed over to dasatinib after imatinib failure (90%). OS in the ITT population was similar between both arms (96% vs 95%). OS in pts who crossed over to dasatinib was 94%. Six additional deaths were reported since the 3-year follow-up. Any grade treatment-related AEs were experienced by 149 pts (87%) randomized to dasatinib, 69 (80%) randomized to imatinib, and 37 patients (80%) who crossed over to dasatinib. Treatment-related pleural effusion occurred in 31 pts (18%) randomized to dasatinib (n = 6 grade 3/4), 9 pts (20%) who crossed over to dasatinib after imatinib failure (n = 2 grade 3/4), and 0 pts who remained on imatinib (no crossover). Conclusions: At the final 5-year follow-up, sustained clinical benefit was observed from an early switch to dasatinib after suboptimal responses to 3 months of imatinib. MMR and DMR rates were higher in pts randomized to dasatinib versus imatinib. Overall, the safety profile was consistent with previous reports. These results complement the previous findings that switching to dasatinib promptly after a lack of EMR with imatinib increases the chance of achieving DMR, which may improve outcomes in pts with CML-CP. Therefore, this study further highlights the significance of achieving optimal responses early during treatment. Study support: Funded by Bristol Myers Squibb. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Efficacy and Safety of Bosutinib Versus Imatinib in US Patients with Newly Diagnosed Chronic Myeloid Leukemia after 5-Years Follow-up in the Bfore Trial

Introduction: Bosutinib is approved for the treatment of patients with Philadelphia chromosome positive, chronic phase (CP) chronic myeloid leukemia (CML). First-line bosutinib was approved based on the results from the phase 3 BFORE trial, which showed the superior efficacy of bosutinib versus imatinib after ≥12 months of follow-up (Cortes et al., J Clin Oncol 2018). The final efficacy and safety results from BFORE after 5-years of follow-up were recently published (Brümmendorf et al., Leukemia 2022). This analysis investigated the efficacy and safety of bosutinib versus imatinib after 5-years follow-up in a subpopulation of US patients enrolled in the BFORE trial. Methods: BFORE (NCT02130557) was a global, multicenter, open-label, randomized, phase 3 study of bosutinib versus imatinib. 536 patients with newly diagnosed BCR-ABL1-positive CP-CML were randomized 1:1 to a starting dose of bosutinib or imatinib 400 mg once daily. Study treatment was continued for 5-years or until treatment failure, unacceptable toxicity, death, or withdrawal of consent. Efficacy was assessed by major molecular response (MMR) rate in the intent-to-treat population (all randomized patients). Safety was assessed by the incidence of treatment-emergent adverse events (TEAEs) and permanent treatment discontinuation in the safety population (patients who received ≥1 dose of study treatment). This analysis is based on the final database lock: June 12, 2020, after 5-years (240 weeks). Results: The US subpopulation in BFORE comprised 88 patients (16% of randomized patients); 39 received bosutinib and 49 received imatinib. Baseline disease characteristics were well balanced between treatment arms. The median (range) duration of treatment with bosutinib and imatinib was 54.8 (0.9-58.9) months and 54.8 (1.2-56.4) months, respectively. The median (range) dose intensity with bosutinib and imatinib was 383.5 (162-562) mg/day and 400.0 (189-754) mg/day, respectively. MMR rate at 12 months was 41.0% for bosutinib versus 32.7% for imatinib (Table 1). Cumulative MMR rate by 60 months was 74.4% for bosutinib versus 63.3% for imatinib (Table 1). All patients in both treatment arms experienced at least one TEAE. In the bosutinib arm, the most common TEAEs (≥30% of patients) were diarrhea (84.6%), nausea (61.5%), fatigue (53.8%), thrombocytopenia (41.0%), headache (35.9%), rash (33.3%), increased alanine aminotransferase (ALT; 30.8%), and constipation (30.8%). In the imatinib arm, the most common TEAEs were nausea (63.3%), diarrhea (55.1%), fatigue (36.7%), periorbital edema (34.7%), and muscle spasm (30.6%). 13 (33.3%) patients in the bosutinib arm permanently discontinued treatment due to AEs, versus 7 (14.3%) in the imatinib arm. The most common causes of permanent treatment discontinuation were increased ALT (7.7%) with bosutinib and increased lipase (4.1%) with imatinib. Additional analyses of the US subpopulation are ongoing and will be presented. Conclusions: The efficacy and safety outcomes in this US subpopulation from BFORE were generally consistent with the overall study population at 5 years (Brümmendorf et al., Leukemia 2022). These results confirm the use of bosutinib as a standard of care in patients with newly diagnosed CP-CML. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Bosutinib versus imatinib for newly diagnosed chronic phase chronic myeloid leukemia: final results from the BFORE trial

This analysis from the multicenter, open-label, phase 3 BFORE trial reports efficacy and safety of bosutinib in patients with newly diagnosed chronic phase (CP) chronic myeloid leukemia (CML) after five years’ follow-up. Patients were randomized to 400-mg once-daily bosutinib (n = 268) or imatinib (n = 268; three untreated). At study completion, 59.7% of bosutinib- and 58.1% of imatinib-treated patients remained on study treatment. Median duration of treatment and time on study was 55 months in both groups. Cumulative major molecular response (MMR) rate by 5 years was higher with bosutinib versus imatinib (73.9% vs. 64.6%; odds ratio, 1.57 [95% CI, 1.08–2.28]), as were cumulative MR4 (58.2% vs. 48.1%; 1.50 [1.07–2.12]) and MR4.5 (47.4% vs. 36.6%; 1.57 [1.11–2.22]) rates. Superior MR with bosutinib versus imatinib was consistent across Sokal risk groups, with greatest benefit seen in patients with high risk. Treatment-emergent adverse events (TEAEs) were consistent with 12-month data. After 5 years of follow-up there was an increase in the incidence of cardiac, effusion, renal, and vascular TEAEs in bosutinib- and imatinib-treated patients, but overall, no new safety signals were identified. These final results support 400-mg once-daily bosutinib as standard-of-care in patients with newly diagnosed CP CML.This trial was registered at www.clinicaltrials.gov as #NCT02130557.

Very Low-Dose Dasatinib Is a Safe and Effective Therapy for Elderly Patients with Newly-Diagnosed Chronic-Phase Chronic Myeloid Leukemia: Results from the Davlec Study, a Single-Arm, Multicenter, Phase 2 Trial

Very Low-Dose Dasatinib Is a Safe and Effective Therapy for Elderly Patients with Newly-Diagnosed Chronic-Phase Chronic Myeloid Leukemia: Results from the Davlec Study, a Single-Arm, Multicenter, Phase 2 Trial

Bosutinib Vs Imatinib for Newly Diagnosed Chronic Myeloid Leukemia in the BFORE Trial: Results By 3-Month BCR-ABL1 Transcript Level

Introduction: Bosutinib is a potent SRC/ABL tyrosine kinase inhibitor approved for treatment of Philadelphia chromosome-positive CML in adults resistant or intolerant to prior therapy. This analysis evaluated the efficacy of first-line bosutinib versus imatinib in the BFORE study (NCT02130557) by 3-month BCR-ABL1 transcripts ≤10% versus >10% and examined baseline and on-treatment characteristics as predictors of time to major molecular response (MMR).Methods: In this ongoing, multinational, phase 3, open-label study, 536 patients were randomized 1:1 to bosutinib 400 mg or imatinib 400 mg once daily. The present analysis is based on ≥12 months of follow-up. Baseline and on-treatment time-dependent covariates were analyzed using a proportional subdistribution hazards model predicting time to initial MMR. No adjustment for multiple comparisons was made.Results: The intent-to-treat (ITT) population included 268 patients in the bosutinib arm and 268 patients (including 3 untreated patients) in the imatinib arm. Among evaluable patients (≥3000 ABL1 analyzed) at 3 months in the ITT population, more patients in the bosutinib arm than in the imatinib arm had BCR-ABL1 transcripts ≤10% (80.6% of 248 patients vs 60.5% of 253 patients; P <0.0001). The MMR rate at 12 months was higher in evaluable patients who had transcripts ≤10% versus >10% at 3 months with bosutinib (117 [58.5%] vs 7 [14.6%], P <0.0001) and with imatinib (83 [54.2%] vs 14 [14.0%], P <0.0001). The cumulative MMR rates were also higher in evaluable patients with transcripts ≤10% with bosutinib (138 [69.0%] vs 12 [25%]; P <0.0001) and with imatinib (100 [65.4%] vs 30 [30.0%]; P <0.0001). In the ITT population, transcripts ≤10% (vs >10% or not evaluable) at 3 months was a predictor of time to MMR in both arms (Table; bosutinib: hazard ratio [HR]=6.44, P <0.0001; imatinib: HR=3.69, P <0.0001). The only other predictor of time to MMR among the covariates examined was not having a bosutinib dose reduction to 300 mg due to an adverse event.Conclusion: BOS treatment was associated with a higher number of patients presenting transcripts ≤10% at 3 months than those treated with IMA. Patients with transcripts ≤10% at 3 months had higher rates of 12-month MMR and achieved response faster than those with transcripts >10%. These findings suggest that the transcript level at 3 months may be a predictor of response to first-line bosutinib and imatinib. [Display omitted] DisclosuresHochhaus:Novartis: Research Funding; Pfizer: Research Funding; Incyte: Research Funding; Ariad: Research Funding; MSD: Research Funding; BMS: Research Funding. Gambacorti-Passerini:Pfizer: Consultancy, Honoraria, Research Funding; BMS: Consultancy. Deininger:BMS: Consultancy, Research Funding; ARIAD: Consultancy; Ariad Pharmaceuticals, Bristol Myers Squibb, CTI BioPharma Corp, Gilead, Incyte, Novartis, Pfizer, Celgene, Blue Print, Galena: Consultancy, Membership on an entity's Board of Directors or advisory committees; Incyte: Consultancy; Gilead: Research Funding; Pfizer: Consultancy; Novartis: Consultancy, Research Funding; Celgene: Research Funding. Mauro:Bristol-Myers Squibb: Consultancy. Chuah:Chiltern: Honoraria; BMS: Honoraria, Other: Travel; Novartis: Honoraria; Avillion: Honoraria. Kim:Il-Yang: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Milojkovic:Novartis: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Incyte: Honoraria, Speakers Bureau; ARIAD: Consultancy, Honoraria. le Coutre:BMS: Honoraria; Pfizer: Honoraria; Novartis: Honoraria, Research Funding; Incyte: Honoraria; ARIAD: Honoraria. García Gutiérrez:Incyte: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding. Reilly:Avillion LLP: Employment. Jeynes-Ellis:Avillion LLP: Employment, Equity Ownership. Crescenzo:Pfizer: Employment, Equity Ownership. Leip:Pfizer: Employment, Equity Ownership. Bardy-Bouxin:Pfizer: Employment, Equity Ownership. Brümmendorf:Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Research Funding. Cortes:ARIAD: Consultancy, Research Funding; Teva: Research Funding; Sun Pharma: Research Funding; ImmunoGen: Consultancy, Research Funding; Novartis Pharmaceuticals Corporation: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; BMS: Consultancy, Research Funding.

Bosutinib (BOS) Versus Imatinib for Newly Diagnosed Chronic Phase (CP) Chronic Myeloid Leukemia (CML): Final 5-Year Results from the Bfore Trial

Bosutinib (BOS) Versus Imatinib for Newly Diagnosed Chronic Phase (CP) Chronic Myeloid Leukemia (CML): Final 5-Year Results from the Bfore Trial

Asciminib, a First-in-Class STAMP Inhibitor, Provides Durable Molecular Response in Patients (pts) with Chronic Myeloid Leukemia (CML) Harboring the T315I Mutation: Primary Efficacy and Safety Results from a Phase 1 Trial

Asciminib, a First-in-Class STAMP Inhibitor, Provides Durable Molecular Response in Patients (pts) with Chronic Myeloid Leukemia (CML) Harboring the T315I Mutation: Primary Efficacy and Safety Results from a Phase 1 Trial

CML-277: Efficacy of Bosutinib in Imatinib-Resistant vs Dasatinib/Nilotinib-Resistant Chronic Phase Chronic Myeloid Leukemia: Results from the Phase 4 BYOND Study

Context Bosutinib is approved for patients with Philadelphia chromosome (Ph)+ chronic myeloid leukemia (CML) resistant/intolerant to prior therapy and newly diagnosed patients in chronic phase (CP). Objective To evaluate the efficacy of bosutinib in patients with Ph+ CP CML according to subgroups of resistance (imatinib vs. dasatinib/nilotinib) or intolerance to prior tyrosine kinase inhibitors (TKIs). Design BYOND ( NCT02228382 ) is an ongoing, phase 4, single-arm, open-label study. Data are reported at ≥1 year after last enrolled patient; 85% of patients had a minimum follow-up of 2 years. Setting Multicenter study in Europe and North America. Patients Patients with CML resistant/intolerant to prior TKIs. Interventions Bosutinib 500 mg QD (starting dose). Main outcome measures Cumulative response rates. Results Of 156 patients with Ph+ CP CML who received bosutinib, 52 had resistance only to imatinib, 31 had resistance to dasatinib and/or nilotinib, and 73 were intolerant to all prior TKIs. Corresponding median treatment duration was 24.1, 8.9, and 25.3 months, and median dose intensity was 360, 431, and 292 mg/day. At the data cut-off, 69.2%, 41.9%, and 53.4% of imatinib-resistant, dasatinib/nilotinib-resistant, and TKI-intolerant patients, respectively, were still receiving treatment. The main reason for discontinuation was adverse events: 19.2%, 25.8%, and 28.8% of imatinib-resistant, dasatinib/nilotinib-resistant, and TKI-intolerant patients, respectively. Corresponding discontinuations due to insufficient response occurred in 3.8%, 16.1%, and 1.4% of patients. No patient experienced on-treatment transformation to advanced phase CML. In patients without baseline complete cytogenetic response (CCyR), CCyR rates by 1 year were 65.0%, 50.0%, and 72.2% in imatinib-resistant, dasatinib/nilotinib-resistant, and TKI-intolerant patients, respectively. In patients without baseline major molecular response (MMR), cumulative MMR rates by 1 year were 55.6%, 28.6%, and 80.6% in imatinib-resistant, dasatinib/nilotinib-resistant, and TKI-intolerant patients, respectively. Deaths occurred in 3, 3, and 4 imatinib-resistant, dasatinib/nilotinib-resistant, and TKI-intolerant patients, respectively. Conclusions Response rates were similar between imatinib-resistant and TKI-intolerant patients. Despite the fact that dasatinib/nilotinib-resistant patients were more heavily pretreated and had a shorter treatment duration, responses were also seen in patients with resistance to these second-generation TKIs. These results further support bosutinib use for patients with Ph+ CP CML and resistance/intolerance to prior TKIs. Study Sponsor Pfizer.

Dasatinib vs. imatinib in patients with chronic myeloid leukemia in chronic phase (CML-CP) who have not achieved an optimal response to 3 months of imatinib therapy: the DASCERN randomized study

Early molecular response is associated with improved probability of deep molecular response and superior survival in patients with CML-CP. However, ~1 in 3 patients on first-line imatinib do not achieve this threshold. The phase 2b DASCERN trial (NCT01593254) assessed the outcome of early switch to dasatinib in patients with suboptimal response to first-line imatinib. Adult patients with CML-CP were randomized (2:1) to receive 100 mg dasatinib (n = 174) or continue imatinib at ≥400 mg (n = 86). The primary endpoint was the rate of major molecular response (MMR) at 12 months, which was 29% (dasatinib) and 13% (imatinib; P = 0.005). After ≥2 years of follow-up, 45 patients (52%) randomized to continue imatinib had crossed over to dasatinib. Considering treatment crossover, the 2-year cumulative MMR rate was 64% with dasatinib and 41% with imatinib (66% and 67%, respectively by intent-to-treat). Adverse events were consistent with the established safety profiles of both drugs. The results of this first prospective study support early monitoring of patients treated with first-line imatinib, and suggest that switching to dasatinib in cases of suboptimal response may offer clinical benefit. Further follow-up is needed to assess the long-term clinical benefit of early switching.

Analysis of the efficacy and influencing factors of nilotinib or dasatinib as second- or third-line treatment in patients with chronic myeloid leukemia in the chronic phase and accelerated phase

目的分析二代酪氨酸激酶抑制剂（TKI）尼洛替尼和达沙替尼作为二三线药物治疗慢性髓性白血病（CML）慢性期（CP）和加速期（AP）患者的治疗反应和预后，以及相关影响因素。方法回顾性分析2008年1月至2018年11月北京大学人民医院收治的一二线TKI治疗失败并接受尼洛替尼或达沙替尼作为二三线治疗的CML-CP和AP患者资料。结果共收集183例尼洛替尼和达沙替尼作为二线治疗和43例尼洛替尼和达沙替尼作为三线治疗的CML-CP或AP患者。二线TKI治疗患者中，中位随访21（1~135）个月，完全血液学反应（CHR）率为80.4%，完全细胞遗传学反应（CCyR）率为56.3%，主要分子学反应（MMR）率为38.3%，3年疾病无进展生存（PFS）和总生存(OS)率分别为78.7%和93.1%。二线TKI治疗中，Sokal积分为高危、女性、一线TKI治疗期间获得最佳反应<CHR、诊断CML距转换二线TKI治疗时间≥18个月、二线TKI治疗前为AP/血液学耐药、二线TKI治疗前未检测出BCR-ABL特殊突变、二线治疗中发生≥3级血液学不良反应是获得细胞遗传学或分子学反应或PFS的不利影响因素。三线TKI治疗患者中，中位随访6（3~129）个月，CHR率为95.7%，CCyR率为29.3%，MMR率为18.6%，2年PFS和OS率分别为66.8%和93.8%。三线TKI治疗中，诊断距一线TKI治疗时间≥6个月、二线TKI治疗期间未获得细胞遗传学反应、诊断距三线TKI治疗时间≥60个月或转换治疗前疾病分期为AP患者获得治疗反应的比例显著降低或预后不良。结论尼洛替尼和达沙替尼作为二三线药物可以有效治疗TKI耐药的CML-CP和AP患者，前次TKI治疗期间获得的最佳反应、换药前疾病分期和本次TKI治疗中是否发生≥3级血液学不良反应等因素影响治疗结果。

Clinical efficacy and safety of imatinib treatment in children and adolescents with chronic myeloid leukemia

Chronic myeloid leukemia (CML) is relatively rare in childhood and few studies have reported the clinical use of imatinib (IM) in pediatric CML. In this study, we evaluated the efficacy and tolerability of IM in children and adolescents with CML.We investigated 21 patients under 18 years of age with newly diagnosed CML and treated with IM in Children's Hospital of Chongqing Medical University between May 2014 and February 2018. The disease was staged according to the European LeukemiaNet criteria and the IM dose was determined based on the disease stage. Cumulative responses and survival probabilities were estimated according to the Kaplan–Meier method.The estimated complete hematologic response rate of chronic phase-chronic myeloid leukemia (CML-CP) was 89.5% at 3 months. The complete cytogenetic response rates increased with time, reaching 47.4%, 73.7%, and 80.3% at 6, 12, and 24 months, respectively. The cumulative major molecular response rates were 42.1% and 76.3% at 12 and 24 months, respectively. With a median follow-up time of 33.8 months (range, 3.2–61.7 months), the estimated 2-year overall survival (OS) rate for CML was 95.2% (95% confidence interval [CI], 70.7%–99.3%). None of the CML-CP patients progressed to the accelerated phase or had a blast crisis. The 2-year OS and progression-free survival rates for the CML-CP cohort were both 100%, while the estimated 2-year event-free survival rate was 68% (95% CI, 42.1%–84.2%). None of the patients in this group had treatment-related deaths or IM discontinuation due to drug toxicities, and only 1 patient had a grade III–IV nonhematologic adverse event. Overall, anemia was the most common adverse effect and 42.9% of patients had a decrease in bone mineral density.IM was effective and the adverse effects were well-tolerated throughout the follow-up period in Chinese CML patients under 18 years of age.