Phase 2 study of inotuzumab ozogamicin for measurable residual disease in acute lymphoblastic leukemia in remission.

ABSTRACT: The detection of measurable residual disease (MRD) is the strongest predictor of relapse in acute lymphoblastic leukemia (ALL). Using inotuzumab ozogamicin in the setting of MRD may improve outcomes. Patients with ALL in first complete remission (CR1) or beyond (CR2+) with MRD ≥ 1 × 10-4 were enrolled in this phase 2 trial. Inotuzumab was administered at 0.6 mg/m2 on day 1 and 0.3 mg/m2 on day 8 of cycle 1, then at 0.3 mg/m2 on days 1 and 8 of cycles 2-6. Twenty-six consecutive patients with a median age of 46 years (range, 19-70 years) were treated. Nineteen (73%) were in CR1 and seven (27%) in CR2+; 16 (62%) had Philadelphia chromosome-positive ALL. Fifteen (58%) had baseline MRD ≥ 1 × 10-3. A median of 3 cycles (range, 1-6) were administered. Eighteen (69%) patients responded and achieved MRD negativity. After a median follow-up of 24 months (range, 9-43), the 2-year relapse-free survival rate was 54% and the 2-year overall survival rate was 60% in the entire cohort. Most adverse events were low grade; sinusoidal obstruction syndrome was noted in 2 patients (8%). In summary, inotuzumab ozogamicin resulted in favorable survival, MRD negativity rates, and safety profiles for patients with ALL and MRD-positive status. This study was registered at www.ClinicalTrials.gov as #NCT03441061.

Results of ponatinib as frontline therapy for chronic myeloid leukemia in chronic phase.

BACKGROUND: Ponatinib is a third-generation BCR::ABL1 tyrosine kinase inhibitor (TKI) with robust activity in Philadelphia chromosome-positive leukemias. Herein, we report the long-term follow-up of the phase 2 trial of ponatinib in chronic myeloid leukemia in chronic phase. METHODS: Patients received ponatinib 30 to 45 mg/day. The primary end point was the rate of 6-month complete cytogenetic response (CCyR). The study was held in June 2014 because of the risk of cardiovascular toxicity, requiring patients to change TKI. RESULTS: Fifty-one patients were treated with ponatinib (median dose, 45 mg/day). Median age was 48 years (range, 21-75); 30 (59%) had baseline cardiovascular comorbidities. Median treatment duration was 13 months (range, 2-25). Fourteen patients (28%) discontinued ponatinib because of toxicities, 36 (71%) after the Food and Drug Administration warning/study closure, and one for noncompliance. Dasatinib was the most frequently chosen second-line TKI (n = 34; 66%). Among 46 patients evaluable at 6 months, 44 (96%) achieved CCyR, 37 (80%) major molecular response, 28 (61%) MR4, and 21 (46%) MR4.5. The cumulative 6-month rates of CCyR, major molecular response, MR4, and MR4.5 were 96%, 78%, 50%, and 36%, respectively. Durable MR4 ≥24 or ≥60 months was observed in 67% and 51% of patients, respectively. The 24-month event-free survival rate was 97%. After a median follow-up of 128 months, the 10-year overall survival rate was 90%. Eight patients (16%) had serious grade 2 to 3 cardiovascular adverse events, leading to permanent discontinuation in five (10%). CONCLUSION: Ponatinib yielded high cytogenetic and molecular responses in newly diagnosed chronic myeloid leukemia in chronic phase. Its use in the frontline setting is hindered by arterio-/vaso-occlusive and other severe toxicities.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Navigating the Management of Chronic Phase CML in the Era of Generic BCR::ABL1 Tyrosine Kinase Inhibitors.

Over the past several years, advances in research, treatment, and market dynamics have impacted treatment strategies in chronic myeloid leukemia in chronic phase (CML-CP). They include the broader availability of cost-effective generic imatinib, and soon other generic second-generation tyrosine kinase inhibitors (TKIs). Access to affordable generics means that all patients with CML-CP should have access to safe and highly effective lifelong therapies. When overall survival is the treatment endpoint, imatinib provides a good treatment value. Second-generation TKIs may be the best frontline strategy when treatment-free remission is the goal. Recent studies have shown maintained efficacy and reduced toxicity when TKIs are used at reduced dosing. Reduced-dose schedules of second-generation TKIs (which are less toxic and induce faster deep molecular responses) may render generic second-generation TKIs a more attractive treatment option. Adjusting the dose of TKI in the presence of mild-to-moderate, or even severe but reversible, adverse events may be preferable to switching to a different TKI. The selection of second-line and beyond therapies depends on the evolving patterns observed with frontline treatment. Dose-adjusted ponatinib schedules have demonstrated improved efficacy and safety in patients resistant to second-generation TKIs or those with T315I-mutated disease. For asciminib, longer-term follow-up is needed to better evaluate its safety and efficacy compared with ponatinib. Allogeneic stem cell transplantation represents a valid alternative to newer-generation TKIs, with a better treatment value when TKIs are priced at >$40,000/year.

Ponatinib-review of historical development, current status, and future research.

Ponatinib is a third-generation BCR::ABL1 tyrosine kinase inhibitor (TKI) with high potency against Philadelphia chromosome (Ph)-positive leukemias, including T315I-mutated disease, which is resistant to first- and second-generation TKIs. Ponatinib was approved for T315I-mutated chronic myeloid leukemia (CML), CML resistant/intolerant to ≥2 prior TKIs, advanced phase CML and Ph-positive acute lymphoblastic leukemia (ALL) where no other TKIs are indicated, and T315I-mutated CML and Ph-positive ALL. The response-based dosing of ponatinib in chronic phase CML (CP-CML) improved treatment tolerance and reduced the risk of toxicities, including cardiovascular risks. Ponatinib-based therapy also resulted in significantly better outcomes in frontline Ph-positive ALL compared with prior TKIs and is becoming a new standard of care in this setting. As the clinical development of third-generation TKIs and their rational combinations progresses, we envision further transformative changes in the treatment of CML and Ph-positive ALL.

Failure of treatment-free remission after a prolonged deep molecular response in patients with chronic myeloid leukemia.

Patients with chronic myeloid leukemia in chronic phase (CML-CP) can have a normal life expectancy when treated with the BCR::ABL1 tyrosine kinase inhibitors. In recent years, treatment discontinuation and treatment-free remission (TFR) emerged as the new goal of therapy in patients with CML-CP. Deep and sustained molecular remissions for more than 3 to 5 years are associated with higher chances of a successful TFR. However, although uncommon, some patients may still experience molecular or hematological relapse after treatment discontinuation, even after a prolonged duration of remission. In this case series, we report the outcome of four patients with CML-CP who were treated with tyrosine kinase inhibitors and achieved a deep molecular response for ≥8 years, but eventually experienced disease relapse after treatment discontinuation. We discuss the importance of regular monitoring after treatment discontinuation as well as future strategies to increase the chances of TFR in patients with CML-CP.

Outcome of Philadelphia chromosome-positive chronic myeloid leukemia in the United States since the introduction of imatinib therapy-The Surveillance, Epidemiology, and End Results database, 2000-2019.

BACKGROUND: Since the introduction of BCR::ABL1 tyrosine kinase inhibitors (TKIs) in 2000, the treatment of Philadelphia chromosome (Ph)-positive chronic myeloid leukemia (CML) has improved significantly. METHODS: This study aimed to evaluate Ph-positive CML outcomes in the TKI therapy era, considering factors like age, ethnicity, and income. Using the Surveillance, Epidemiology, and End Results (SEER) database, 2857 patients with Ph-positive CML diagnosed from 2000 to 2019 were analyzed. RESULTS: The overall 5-year survival rates in Ph-positive CML increased to above 80%, compared with pre-TKIs historical data reporting 5-year overall survival (OS) rates of less than 50%. The 5-year OS rate was 73% for patients diagnosed in 2000-2004, 82% in 2005-2009, and 78% in 2010-2014; the 4-year OS rate was 83% in 2015-2019. The 5-year OS rate for younger patients (<60 years old) was 88% in 2000-2009 and 90% in 2010-2019 (p value .426). In older patients (60+ years old), the 5-year OS rates were 64% and 65%, respectively (p value, .303). Lower household income was associated with inferior survival across the 2000-2019. These results are inferior to European studies where TKIs are universally available and affordable, and relative OS in CML is similar to age-matched normal populations. CONCLUSIONS: Although the outcome of Ph-positive CML has improved significantly since 2000, the SEER data still shows differences in outcomes among patient subsets, some anticipated (worse OS in older patients accounted by the relative OS), but others that suggest less than universal access and affordability of this therapy (among poorer patients) in the United States.

Association between bariatric surgery and outcomes in chronic myeloid leukemia.

BACKGROUND: Bariatric surgery is the most effective weight loss intervention. However, it can also decrease the bioavailability of oral medications. Tyrosine kinase inhibitors, the mainstay treatment for chronic myeloid leukemia (CML), are the most successful example of an oral targeted therapy. The impact of bariatric surgery on CML outcomes is unknown. METHODS: In a retrospective analysis, we screened 652 patients with CML and identified 22 with prior bariatric surgery, and compared their outcomes to a matched cohort of 44 patients with no prior bariatric surgery. RESULTS: The rate of early molecular response (3-month BCR::ABL1 < 10% International Scale) was lower in the bariatric surgery group compared with the control group (68% vs. 91%; p = .05), with longer median times to achieve complete cytogenetic (6 vs. 3 months; p = .001) or major molecular responses (12 vs. 6 months; p = .001). Bariatric surgery was associated with inferior event-free survival (5-year, 60% vs. 77%; p = .004) and failure-free survival (5-year, 32% vs. 63%; p < .0001). In a multivariate analysis, bariatric surgery was the only independent predictor for the risk of treatment failure (hazard ratio, 9.40; 95% CI, 2.71-32.55; p = .0004) or event-free survival (hazard ratio, 4.24; 95% CI, 1.67-12.23; p = .008). CONCLUSIONS: Bariatric surgery is associated with suboptimal responses that require adapted treatment strategies.

Moving away from chemotherapy in newly diagnosed Philadelphia chromosome-positive B-cell acute lymphoblastic leukaemia.

Chemotherapy-free regimens are reshaping the treatment landscape of Philadelphia chromosome-positive acute lymphoblastic leukaemia. The report by Xie et al. suggests that the combination of dasatinib and prednisone is effective as induction and early consolidation. Survival was improved in patients who subsequently underwent allogeneic stem cell transplantation. Commentary on: Xie et al. Dasatinib plus prednisone as induction and consolidation for adults with Ph-positive acute lymphoblastic leukaemia: A single-arm, multicentre, phase 2 trial. Br J Haematol 2023;202:1119-1126.

PD-L1 protein expression by Combined Positive Score (CPS) in patients with muscle invasive or advanced urothelial carcinoma: a single institution experience.

INTRODUCTION: Immune checkpoint inhibitors have revolutionized the treatment of patients with advanced urothelial carcinoma (UC) in the frontline and relapsed settings. Lebanon has one of the highest incidence of UC worldwide, yet no data exists regarding the expression of PD-L1 by Combined Positive Score (CPS) in advanced disease. METHODS: We reviewed all patients treated at our institution for high grade UC, stage pT2 and above, between January 2017 and March 2021. We assessed the expression of PD-L1 by immunohistochemistry using 22C3 clone, and analyzed the association between PD-L1 expression and clinicopathological characteristics. PD-L1 positivity was defined as CPS score ≥ 10. RESULTS: A total of 101 patients with advanced UC were included, with a median age of 71 years (range, 38 to 96 years); 78% were ever-smokers. Ninety-three of 101 patients (92%) had conventional UC and 43 patients (43%) had positive PD-L1 expression, with 12 patients having CPS of 100. The analysis by molecular subtype showed that patients with maximal CPS of 100 were enriched in "basal" molecular subtype. However, no association was found between PD-L1 expression (positive versus negative) and clinicopathological characteristics. CONCLUSION: The positivity of PD-L1 expression as assessed by CPS using the 22C3 clone in our population was almost comparable to the results reported in the occidental literature. Therefore, PD-L1 expression, as a potential predictor of response to immunotherapy, concerns the same percentage of the Lebanese UC patients.

The outcomes of patients with chronic myeloid leukemia treated with third-line BCR::ABL1 tyrosine kinase inhibitors.

The BCR::ABL1 tyrosine kinase inhibitors (TKIs) have improved the outcomes of patients with chronic myeloid leukemia (CML). After failing second-generation TKI (2G-TKI), the optimal third-line therapy in chronic phase CML (CML-CP) is not well established. We analyzed 354 patients with CML-CP treated with a third-line BCR::ABL1 TKI at our institution, and in the PACE and OPTIC trials, and evaluated the outcome after alternate 2G-TKIs or ponatinib. We performed a propensity score matching analysis to compare outcomes and multivariate analysis to identify variables associated with survival. One hundred seventy-three (49%) patients received 2G-TKIs and 181 (51%) ponatinib. Patients in the ponatinib group had more cardiovascular risk factors (34% versus 19%) and higher disease burden (BCR::ABL1 transcript levels >1%, 165/175 [94%] versus 75/135 [55%]; p < .001) compared with the 2G-TKI group. Among the 173 evaluable patients treated with ponatinib, 89 (52%) achieved 2 + -log reduction of baseline transcripts (20% 2-log reduction and 32% 3 + -log reduction). Among the 128 evaluable patients treated with 2G-TKIs, 44 (34%) achieved 2 + -log reduction of baseline transcripts (13% 2-log reduction and 21% 3 + -log reduction). With a median follow-up of 46 months, the 3-year progression-free survival was 59% (60% before matching) with 2G-TKI and 83% (81% before matching) with ponatinib (p < .001). The 3-year survival was 83% (81% before matching) with 2G-TKI and 87% (89% before matching) with ponatinib (p = .03). By multivariate analysis, third-line therapy with ponatinib was the only independent factor associated with better survival (p = .003). In conclusion, ponatinib is an optimal treatment for patients with CML-CP failing two prior TKIs.

Characteristics and outcomes of patients with chronic myeloid leukemia and T315I mutation treated in the pre- and post-ponatinib era.

Patients with chronic myeloid leukemia (CML) and T315I mutation generally have a poor prognosis. Their outcome in the post-ponatinib era remains unclear. We reviewed patients with CML in chronic (CP) or accelerated phase (AP) who developed a T315I mutation between March 15, 2004, and July 26, 2022. Patients were divided into CP, AP, or blastic phase (BP) at the time of mutation detection. Overall survival (OS) was defined from the time of mutation detection to the date of death or last follow-up. We identified a total of 107 patients: 54 (51%) in CP, 14 (13%) in AP, and 39 (36%) in BP. One hundred and two patients received subsequent therapy after the T315I mutation was detected. At a median follow-up of 75 months (95% CI, 41-110), the median OS was 49 months (95% CI, 26-73) and the 5-year OS rate was 44%. Patients who were in CML-CP at the time of mutation detection had better survival compared with those in AP or BP, with a median OS of 132, 31, and 6 months, and 5-year OS rates of 70%, 37%, and 10%, respectively (p < .001). Patients with CML-CP treated with ponatinib and/or asciminib had a 5-year OS of 77% compared with 50% in those who received other treatments (chemotherapy, second-generation tyrosine kinase inhibitors, homoharringtonine, and investigational drugs) (p = .14). In summary, patients with CML-CP at the time of T315I mutation detection may have a relatively indolent disease course with a long-term OS of 70%. Treatment with third-generation tyrosine kinase inhibitors seemed to improve survival in patients with CML-CP.

Frontline combination of ponatinib and hyper-CVAD in Philadelphia chromosome-positive acute lymphoblastic leukemia: 80-months follow-up results.

The combination of ponatinib, a third-generation BCR::ABL1 tyrosine kinase inhibitor, with hyper-CVAD chemotherapy resulted in high rates of complete molecular remissions and survival, without the need for stem cell transplantation (SCT) in most patients with Philadelphia chromosome(Ph)-positive acute lymphocytic leukemia (ALL). Confirming these results in a large cohort of patients with longer follow-up would establish this regimen as a new standard of care. Adults with newly diagnosed Ph-positive ALL were treated with the hyper-CVAD regimen. Ponatinib was added as 45 mg daily × 14 during induction, then 45 mg daily continuously (first 37 patients) or 30 mg daily continuously, with dose reduction to 15 mg daily upon achievement of a complete molecular response (CMR; absence of a detectable BCR::ABL1 transcript by quantitative reverse transcription polymerase-chain reaction at a sensitivity of 0.01%). Maintenance therapy consisted of daily ponatinib and vincristine-prednisone monthly for 2 years, followed by daily ponatinib indefinitely. Twelve intrathecal injections of cytarabine alternating with methotrexate were given as central nervous system prophylaxis. The trial is registered on clinicaltrials.gov with the identifier NCT01424982. Eighty-six patients were treated. Their median age was 46 years (range, 21-80). All 68 patients with active disease at the initiation of therapy achieved complete response (CR) The cumulative CMR rate was 86%. Twenty- patients (23%) underwent allogeneic SCT. With a median follow-up of 80 months (range, 16-129 months), the estimated 6-year event-free survival rate was 65% and the overall survival rate was 75%. There was no difference in outcome by performance of allogeneic SCT in first CR. Common grade 3-5 adverse events included infection (n = 80, 93%), increased liver transaminases (n = 26, 31%) and total bilirubin (n = 13, 15%), hypertension (n = 15, 17%), pancreatitis (n = 13, 15%), hemorrhage (n = 12, 13%), and skin rash (n = 9, 10%). Two ponatinib-related deaths from myocardial infarction (3%; at months 2.6 and 4.3, respectively; both in CR) in the first 37 patients treated led to the ponatinib dose-modifications mentioned earlier, with no further ponatinib-related deaths observed. The long-term results of ponatinib and hyper-CVAD continue to demonstrate excellent outcome results and acceptable safety data, indicating that this strategy is another standard of care approach in frontline Ph-positive ALL.

Ultrasensitive NGS MRD assessment in Ph+ ALL: Prognostic impact and correlation with RT-PCR for BCR::ABL1.

Reverse transcription polymerase chain reaction (RT-PCR) for BCR::ABL1 is the most common and widely accepted method of measurable residual disease (MRD) assessment in Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL); however, RT-PCR may not be an optimal measure of MRD in many cases of Ph+ ALL. We evaluated the clinical impact of a highly sensitive next-generation sequencing (NGS) MRD assay (sensitivity of 10-6 ) and its correlation with RT-PCR for BCR::ABL1 in patients with Ph+ ALL. Overall, 32% of patients had a discordance between MRD assessment by RT-PCR and NGS, and 31% of patients who achieved NGS MRD negativity were PCR+ at the same timepoint. Among eight patients with long-term detectable BCR::ABL1 by PCR, six were PCR+/NGS-. These patients generally had stable PCR levels that persisted despite therapeutic interventions, and none subsequently relapsed; in contrast, patients who were PCR+/NGS+ had more variable PCR values that responded to therapeutic intervention. In a separate cohort of prospectively collected clinical samples, 11 of 65 patients (17%) with Ph+ ALL who achieved NGS MRD negativity had detectable BCR::ABL1 by PCR, and none of these patients relapsed. Relapse-free survival and overall survival were similar in patients who were PCR+/NGS- and PCR-/NGS-, suggesting that PCR for BCR::ABL1 did not provide additional prognostic information in patients who achieved NGS MRD negativity. NGS-based assessment of MRD is prognostic in Ph+ ALL and identifies patients with low-level detectable BCR::ABL1 who are unlikely to relapse nor to benefit from therapeutic interventions.

Treatment-free remission in patients with chronic myeloid leukemia following the discontinuation of tyrosine kinase inhibitors.

Tyrosine kinase inhibitors (TKIs) discontinuation in patients with Philadelphia-chromosome-positive chronic myeloid leukemia (Ph-positive CML) is increasingly considered. We aim to evaluate the outcome of patients with CML who discontinued TKIs, and determine the factors associated with differences in the success rates of treatment-free remission (TFR). Patients with Ph-positive CML treated between October 1999 and February 2017 who discontinued therapy were analyzed. A major molecular response (MMR) was defined as BCR-ABL1/ABL1 ratio on the International Scale ≤0.1%. TFR failure was defined as the loss of MMR on any single test. We analyzed TFR rates according to duration and depth of response, and conducted a multivariate analysis for factors associated with loss of MMR. Two-hundred and eighty-four patients were analyzed; 199 patients (70%) electively discontinued TKIs. At a median follow-up of 36 months (95% confidence interval, 32-40) after TKI discontinuation, 53 patients (19%) lost MMR. The estimated 5-year TFR rate was 79%. All but one patient regained MMR after resuming therapy. The estimated 5-year TFR rates were higher with MR4 and MR4.5 ≥5 years, compared with MR4 <5 years (87% vs. 92% vs. 64%; p < .0001). By multivariate analysis, only the duration of MR4 or MR4.5 ≥5 years before stopping treatment was associated with a lower risk of loss of MMR. In summary, TFR is safe and feasible in patients with Ph-positive CML on TKI therapy. Achieving MR4 or MR4.5 for at least 5 years is correlated with a better outcome.

Low-dose dasatinib 50 mg/day versus standard-dose dasatinib 100 mg/day as frontline therapy in chronic myeloid leukemia in chronic phase: A propensity score analysis.

Low-dose dasatinib is safe and effective in patients with chronic myeloid leukemia in chronic phase (CML-CP). No randomized trials have compared the outcome with standard-dose dasatinib. This study aims to compare the outcome of patients with CML-CP treated with frontline dasatinib 50 versus 100 mg/day. We analyzed 233 patients with newly diagnosed CML-CP treated with low-dose dasatinib (N = 83) or standard-dose dasatinib (N = 150). Propensity score analysis with 1:1 matching was performed and identified 77 patients in each cohort without significant baseline differences. Response rates were reported as the cumulative incidences of complete cytogenetic response, major molecular response (MMR), molecular response (MR)4, and MR4.5. Failure-free survival (FFS), event-free survival (EFS), transformation-free survival (TFS), and overall survival (OS) were also compared. Patients on low-dose dasatinib with suboptimal response by European LeukemiaNet (ELN) 2013 criteria had the option to increase the dose to 100 mg/day. The overall median follow-up time was 60 months. The 3-year MMR rates were 92% and 84% for low-dose and standard-dose dasatinib, respectively (p = .23). Dasatinib 50 mg/day induced higher cumulative incidence of MR4 (77% vs. 66%; p = .04) and MR4.5 (77% vs. 62%; p = .02) at 3 years. The 4-year FFS, EFS and OS rates were 89% versus 77% (p = .04), 95% versus 92% (p = .06), and 97% versus 96% (p = .78) with low-dose and standard-dose dasatinib, respectively. The rate of any grade pleural effusion was 5% with dasatinib 50 mg/day compared to 21% with 100 mg/day. Dasatinib 50 mg/day is at least as effective as 100 mg/day with a better safety profile and drug exposure.