Combination chemotherapy plus dasatinib leads to comparable overall survival and relapse-free survival rates as allogeneic hematopoietic stem cell transplantation in Philadelphia positive acute lymphoblastic leukemia

A review of immunotargeted therapy for Philadelphia chromosome positive acute lymphoblastic leukaemia: making progress in chemotherapy-free regimens

Philadelphia chromosome-positive acute lymphoblastic leukemia (PH + ALL) is the most common cytogenetic abnormality of B-ALL in adults and is associated with poor prognosis. Previously, the only curative treatment option in PH + ALL was allogeneic hematopoietic stem cell transplantation (Allo-HSCT). Since 2000, targeted therapy combined with chemotherapy, represented by the tyrosine kinase inhibitor Imatinib, has become the first-line treatment for PH + ALL. Currently, the remission rate and survival rate of Imatinib are superior to those of simple chemotherapy, and it can also improve the efficacy of transplantation. More recently, some innovative immune-targeted therapy greatly improved the prognosis of PH + ALL, such as Blinatumomab and Inotuzumab Ozogamicin. For patients with ABL1 mutations and those who have relapsed or are refractory to other treatments, targeted oral small molecule drugs, monoclonal antibodies, Bispecific T cell Engagers (BiTE), and chimeric antigen receptor (CAR) T cells immunotherapy are emerging as potential treatment options. These new therapeutic interventions are changing the treatment landscape for PH + ALL. In summary, this review discusses the current advancements in targeted therapeutic agents shift in the treatment strategy of PH + ALL towards using more tolerable chemotherapy-free induction and consolidation regimens confers better disease outcomes and might obviate the need for HSCT.

Asciminib Maintains Antibody-Dependent Cellular Cytotoxicity against Leukemic Blasts

B cell acute lymphoblastic leukemia (B-ALL) is characterized by an accumulation of malignant precursor cells. Treatment consists of multiagent chemotherapy followed by allogeneic stem cell transplantation in high-risk patients. In addition, patients bearing the BCR-ABL1 fusion gene receive concomitant tyrosine kinase inhibitor (TKI) therapy. On the other hand, monoclonal antibody therapy is increasingly used in both clinical trials and real-world settings. The introduction of rituximab has improved the outcomes in CD20 positive cases. Other monoclonal antibodies, such as tafasitamab (anti-CD19), obinutuzumab (anti-CD20) and epratuzumab (anti-CD22) have been tested in trials (NCT05366218, NCT04920968, NCT00098839). The efficacy of monoclonal antibodies is based, at least in part, on their ability to induce antibody-dependent cellular cytotoxicity (ADCC). Combination treatments, e.g., chemotherapy and TKI, should therefore be screened for potential interference with ADCC. Here, we report on in vitro data using BCR-ABL1 positive and negative B-ALL cell lines treated with rituximab and TKI. NK cell activation, proliferation, degranulation, cytokine release and tumor cell lysis were analyzed. In contrast to ATP site inhibitors such as dasatinib and ponatinib, the novel first-in-class selective allosteric ABL myristoyl pocket (STAMP) inhibitor asciminib did not significantly impact ADCC in our settings. Our results suggest that asciminib should be considered in clinical trials.

Potential clinical impact of T-cell lymphocyte kinetics monitoring in patients with B cell precursors acute lymphoblastic leukemia treated with blinatumomab: a single-center experience

Blinatumomab is a bispecific anti-CD3 and anti-CD19 antibody that acts as a T-cell engager: by binding CD19+ lymphoblasts, blinatumomab recruits cytotoxic CD3+ T-lymphocytes to target the cancer cells. Here we describe seven different patients affected by B-cell precursor acute lymphoblastic leukemia (Bcp-ALL) and treated with blinatumomab, on which we evaluated the potential association between the amount of different T-cells subsets and deep molecular response after the first cycle, identified as a complete remission in the absence of minimal residual disease (CR/MRD). The immune-system effector cells studied were CD3+, CD4+ effector memory (T4-EM), CD8+ effector memory (T8-EM), and T-regulatory (T-reg) lymphocytes, and myeloid-derived suppressor cells (MDSC). Measurements were performed in the peripheral blood using flow cytometry of the peripheral blood at baseline and after the first cycle of blinatumomab. The first results show that patients with a higher proportion of baseline T-lymphocytes achieved MRD negativity more frequently with no statistically significant difference (p=0.06) and without differences in the subpopulation count following the first treatment. These extremely preliminary data could potentially pave the way for future studies, including larger and less heterogeneous cohorts, in order to assess the T-cell kinetics in a specific set of patients with potential synergy effects in targeting myeloid-derived suppressor cells (MDSC), commonly known to have an immune evasion mechanism in Bcp-ALL.

Chemotherapy with the use of next-generation TKIs based on MRD has the potential to avoid hematopoietic stem cell transplantation in treatment for adults with Philadelphia chromosome-positive acute lymphoblastic leukemia

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) as postremission treatment is recommended for Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL) in current guidelines. However, comparisons of later generation tyrosine kinase inhibitors (TKIs) plus chemotherapy with allo-HSCT have yielded similar outcomes. This meta-analysis was performed to evaluate allo-HSCT in first complete remission (CR1) versus chemotherapy for adult Ph+ ALL in the TKI era.

METHODS

Pooled assessment of the hematologic and molecular complete response rates was performed after 3-month TKI treatment. Hazard ratios (HRs) were determined for disease-free survival (DFS) and overall survival (OS) benefit with allo-HSCT. The effect of measurable residual disease status on survival benefit was also analyzed.

RESULTS

Thirty-nine retrospective and prospective single-arm cohort studies involving 5054 patients were included. Combined HRs indicated that in the general population, allo-HSCT favorably influenced DFS and OS. Achieving complete molecular remission (CMR) within 3 months after starting induction was a favorable survival prognostic factor regardless of whether the patient had undergone allo-HSCT. Among the patients with CMR, survival rates in the nontransplant subgroup were comparable with those in the transplant subgroup, with the estimated 5-year OS of 64% versus 58% and 5-year DFS of 58% versus 51%, respectively. The use of next-generation TKIs results in a higher proportion of patients achieving CMR (ponatinib 82% vs. imatinib 53%), while improving survival in nontransplant patients.

CONCLUSION

Our novel findings suggest that combination chemotherapy plus TKIs leads to a comparable survival benefit as with allo-HSCT for MRD-negative (CMR) patients. This study provides novel evidence for allo-HSCT indications for Ph+ ALL in CR1 in the TKI era.

Outcomes of Tyrosine Kinase Inhibitors Maintenance Therapy with or without Allogeneic Hematopoietic Stem Cell Transplantation in Philadelphia Chromosome Positive Acute Lymphoblastic Leukemia in First Complete Remission: A Systematic Review and Meta-Analysis

We conducted a systematic review and meta-analysis to compare outcomes of tyrosine kinase inhibitor (TKI) maintenance therapy with or without allogeneic hematopoietic stem cell transplantation (HSCT) in Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) in first remission (CR1). A literature search was performed on PubMed, Cochrane, and Clinical trials.gov. After screening 1720 articles, 12 studies were included. Proportions and odds ratios (OR) with 95% confidence intervals (CI) were computed. I² provides an estimate of the percentage of variability in results across studies that is due to real differences and not due to chance. Of 1039 patients, 635 (61%) had TKI alone and 404 (39%) patients had HSCT followed by TKI. At 3 years, a trend towards poor overall survival (OS; OR 0.67, 95% CI 0.39-1.15, I² = 68%), (disease-free survival; OR 0.58, 95% CI 0.26-1.29, I² = 76%), and higher relapse rate (RR; OR = 2.52, 95% CI = 1.66-3.83, I² = 26%) was seen with TKI alone compared to HSCT-TKI. Although HSCT followed by TKI maintenance in Ph+ ALL has long been considered standard of care, the introduction of potent third-generation TKIs and bispecific T-cell engagers such as Blinatumomab has significantly improved outcomes while sparing the need for HSCT in newly diagnosed patients.

BCR::ABL1 tyrosine kinase inhibitors hamper the therapeutic efficacy of blinatumomab in vitro

PURPOSE

Acute B-lymphoblastic leukemia (B-ALL) is a malignant disease characterized by accumulation of clonal immature lymphocytes in the bone marrow and peripheral blood. The approval of BCR::ABL1 tyrosine kinase inhibitors (TKI) such as imatinib, dasatinib, nilotinib and ponatinib marked a milestone in targeted therapy only for a subset of patients carrying the translocation t(9;22)(q34;q11). Immunotherapy with the bispecific antibody (bsAb) blinatumomab targeting CD19xCD3 revolutionized treatment of all B-ALL cases. The combination of both TKI and bsAb, so-called "dual targeting", is currently under clinical investigation, although TKI might influence T cell effects.

METHODS

We here investigated the combination of different TKI and blinatumomab in BCR::ABL1⁺ and BCR::ABL1^- B-ALL cell lines and primary samples regarding T cell proliferation, differentiation, cytokine release and killing of tumor cells.

RESULTS

In vitro analysis revealed profound reduction of T cell proliferation, differentiation, cytokine release and killing of tumor cells upon application of BCR::ABL1 TKI with blinatumomab. Inhibition was more pronounced with dasatinib and ponatinib compared to nilotinib and imatinib. T cell signalling after CD3 stimulation was impaired by TKI mirrored by inhibition of LCK phosphorylation. This known off-target effect might influence the efficacy of bsAb therapy when combined with BCR::ABL1 TKI.

CONCLUSION

In conclusion, we propose that nilotinib and imatinib might also be suitable substances for combination with blinatumomab and suggest evaluation in clinical trials.

Comparison of allogeneic hematopoietic stem cell transplantation and TKI combined with chemotherapy for adult philadelphia chromosome positive acute lymphoblastic leukemia: a systematic review and meta-analysis

OBJECTIVE

This study seeks to clarify whether allogeneic hematopoietic stem cell transplantation (allo-HSCT) is necessary for adult patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) in post-remission based on a comparison with tyrosine kinase inhibitor (TKI) combined with chemotherapy.

METHODS

We searched the Pubmed, Embase, and Web of Science databases and limited the date range for the studies from January 2010 to August 2020. A hazard ratio (HR) with a 95% confidence interval (CI) was employed to assess overall survival (OS) and relapse-free survival (RFS), and an odds ratio (OR) with a 95% CI was used to evaluate the ratio of non-relapsed mortality (NRM) and non-relapsed survival (NRS). All analyses were conducted with Stata software 16.0 and Revman 5.3.

RESULTS

Fifteen studies, totaling 959 patients, were included in our analysis. Among those patients, 473 underwent allo-HSCT, and 486 received TKI plus chemotherapy. The pooled results showed no difference in OS between outcomes for patients receiving TKI plus chemotherapy and those treated with allo-HSCT (HR = 0.76, 95% CI [0.51-1.12], p = 0.16). Patients undergoing allo-HSCT did better than those receiving TKI plus chemotherapy regarding RFS (HR = 0.48, 95% CI [0.37-0.63], p = 0.00), and NRS (OR = 2.64, 95% CI [1.25-5.57], p = 0.00). The NRM rate of the TKI plus chemotherapy group was significantly lower than the allo-HSCT group (OR = 2.33, 95% CI [1.51-3.59], p = 0.00).

CONCLUSION

TKI combined with chemotherapy can be considered a post-remission treatment option for adult Ph+ ALL patients who are ineligible for allo-HSCT. However, more prospective studies with large sample sizes should be carried out in the future.

Outcomes in adolescent and young adult patients (16 to 30 years) compared to younger patients treated for high-risk B-lymphoblastic leukemia: report from Children's Oncology Group Study AALL0232

Adolescent and young adult (AYA) patients 16-30 years old with high-risk acute lymphoblastic leukemia (HR-ALL) have inferior outcomes compared to younger HR-ALL patients. AALL0232 was a Phase 3 randomized Children's Oncology Group trial for newly diagnosed HR B-ALL (1-30 years). Between 2004 and 2011, 3154 patients enrolled with 3040 eligible and evaluable for induction. AYA patients comprised 20% of patients (16-21 years, n = 551; 22-30 years, n = 46). 5-year event-free survival and overall survival was 65.4 ± 2.2% and 77.4 ± 2.0% for AYA patients compared to 78.1 ± 0.9% and 87.3 ± 0.7% for younger patients (p < 0.0001). Five-year cumulative incidence of relapse was 18.5 ± 1.7% for AYA patients and 13.5 ± 0.7% for younger patients (p = 0.006), largely due to increased marrow relapses (14.0 ± 1.5% versus 9.1 ± 0.6%; p < 0.0001). Additionally, induction failure rate was higher in AYA (7.2 ± 1.1% versus 3.5 ± 0.4%; p < 0.001) and post-induction remission deaths were significantly higher in AYA (5.7 ± 1.0% versus 2.4 ± 0.3%; p < 0.0001). AALL0232 enrolled the largest number of AYA B-ALL patients to date, demonstrating significantly inferior survival and greater rates of treatment-related toxicities compared to younger patients. Although treatment intensification has improved outcomes in younger patients, they have not been associated with the same degree of improvement for older patients.

A multicenter total therapy strategy for de novo adult Philadelphia chromosome positive acute lymphoblastic leukemia patients: final results of the GIMEMA LAL1509 protocol

The GIMEMA LAL1509 protocol, designed for adult (≥18-60 years) de novo Philadelphia chromosome positive (Ph+) acute lymphoblastic leukemia (ALL) patients, was based on dasatinib plus steroids induction - with central nervous system prophylaxis - followed by dasatinib alone in patients in complete molecular response or by chemotherapy and/or allogeneic transplant in patients not reaching complete molecular response. Sixty patients (median age 41.9 years) were enrolled: 33 were p190+, 18 p210+ and nine p190/p210+. At the end of induction (day +85), 58 patients (97%) achieved complete hematologic remission. No deaths in induction were recorded. Eleven patients (18.3%) obtained complete molecular response. Among the incomplete molecular responders (n=47), 22 underwent an allogeneic transplant. Seventeen hematologic relapses occurred (median 7 months; range, 3-40.1): 13 during consolidation and four post-transplant. ABL1 mutations (five T315I, three V299L, one E281K and one G254E) were found in ten of 13 relapsed cases. With a median follow-up of 57.4 months (range, 4.2-75.6), overall survival and disease-free survival were 56.3% and 47.2%. A better disease-free survival was observed in patients who obtained a molecular response at day +85 compared to cases who did not. The presence of additional copy number aberrations - IKZF1 plus CDKN2A/B and/or PAX5 deletions - was the most important unfavorable prognostic factor on overall and disease-free survival (P=0.005 and P=0.0008). This study shows that in adult Ph+ ALL long-term survivals can be achieved with a total-therapy strategy based on a chemotherapyfree induction and, in complete molecular responders, also without further systemic chemotherapy. Finally, the screening of additional copy number aberrations should be included in the diagnostic work-up (clinicatrial gov. Identifier: EudraCT 2010-019119-39).

Is stem cell transplantation still needed for adult Philadelphia chromosome-positive acute lymphoblastic leukemia receiving tyrosine kinase inhibitors therapy?: A systematic review and meta-analysis

Background

Hematopoietic stem cell transplantation (HSCT) is the current mainstay treatment for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph⁺ ALL). However, tyrosine kinase inhibitors (TKI) also play a significant role in the treatment of these patients. We conducted this systematic review and meta-analysis to compare the efficacy of allogeneic (allo-) HSCT, autologous (auto-) HSCT, and chemotherapy (CMT) alone–all in combination with TKIs in adult Ph⁺ ALL patients.

Materials and methods

This systematic review identified studies from the EMBASE and MEDLINE databases from inception to April 2021 using search terms related to “ALL” and “HSCT.” Eligible studies could be randomized controlled trials or cohort studies that included adult Ph⁺ ALL patients who received a TKI and either allo-HSCT, auto-HSCT, or CMT alone, and that reported the number of patients in each group for each of our primary outcomes of interest: overall survival (OS) or disease-free survival (DFS). Point estimates and associated 95% confidence intervals (CI) from each study were combined using the Hantel-Maenszel method.

Results

After two rounds of review, 26 cohort studies were determined to be eligible for the meta-analysis. Adult Ph⁺ ALL patients who received HSCT had better survival outcomes than those who did not receive any HSCT (pooled odds ratio [OR] for OS of 1.61, 95%CI: 1.08–2.40; I² = 59%, and for DFS of 3.23, 95%CI: 2.00–5.23; I² = 62% for allo-HSCT; and, pooled OR for OS of 7.04, 95%CI: 1.97–25.15; I² = 0%, and for DFS of 5.78, 95%CI: 1.04–32.19; I² = 42% for auto-HSCT). Allo-HSCT recipients had comparable OS and DFS, but lower relapse rate compared to auto-HSCT recipients. Funnel plot generally demonstrated no presence of publication bias.

Conclusions

This systematic review and meta-analysis demonstrated superior results of HSCT in Ph⁺ ALL patients compared to CMT alone. Moreover, auto-HSCT could be implemented with comparable survival outcomes to allo-HSCT in patients with no available donor or when haploidentical HSCT is not feasible.

The impact of tyrosine kinase inhibitors on allogeneic hematopoietic stem cell transplantation for adult patients with Philadelphia chromosome-positive acute lymphoblastic leukemia

In the tyrosine kinase inhibitor (TKI) era, allogeneic hematopoietic stem cell transplantation (allo-HSCT) is still the most potential approach for cure of adult patients with Philadelphia chromosome-positive acute lymphocytic leukemia (Ph⁺ ALL). TKI plus chemotherapy has strikingly increased response rates and depth of response, and facilitated allo-HSCT, which decreases relapse and improves survival eventually. Meanwhile, for those with older age or comorbidities at diagnosis, TKI in combination with reduced-intensity chemotherapy or chemotherapy-free strategy reduces treatment-related mortality, deferred intensive chemotherapy increases molecular responses and reduced-intensity conditioning (RIC) allo-HSCT improves survival finally. Of note, according to minimal residual disease (MRD) and BCR/ABL1 kinase domain mutation screening, prophylactic or preemptive maintenance therapy with a sensitive TKI decreases relapse further. Regarding transplantation-related mortality and impaired quality of life related to complications of allo-HSCT, autologous-HSCT (auto-HSCT) among those with early and persistent molecular remission and the most potent TKI ponatinib plus intensive chemotherapy has exhibited non-inferior survival to allo-HSCT. Even so, risk-adapted strategy isn't available now. Lastly, outcomes of relapse after allo-HSCT are dismal due to TKIs exposure, and new therapeutic interventions combined with TKIs shed light on this thorny problem.

[Dasatinib combined with multi-agent chemotherapy regimen in newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia: a prospective study from a single center]

目的

评价达沙替尼联合多药化疗方案在Ph染色体阳性急性淋巴细胞白血病（Ph⁺ ALL）患者中的疗效及安全性。

方法

前瞻性、单臂、开放的临床研究。2016年1月至2018年4月中国医学科学院血液病医院收治的30例初诊成人Ph⁺ ALL患者入组。采用多药化疗方案，标准诱导化疗为期4周，自诱导化疗第8天开始口服达沙替尼（商品名依尼舒，正大天晴药业集团股份有限公司产品）100 mg/d，持续应用至整体治疗结束。有条件和意愿进行移植者，可进行异基因造血干细胞移植或自体造血干细胞移植。

结果

所有30例患者在诱导治疗4周后均达到血液学完全缓解（HCR），累积完全分子学反应（MCR）率为70.0％（21/30）。中位随访时间为37.8（32.0～46.6）个月。3年总生存（OS）率为68.1％，3年无血液学复发生存（HRFS）率为61.6％。63.3％的患者在治疗3个月时达到主要分子学反应（MMR）（其中有43.3％患者达到MCR）。6个月时60.0％的患者达到MCR，达到MCR的患者具有更好的OS（P＝0.004）、HRFS（P＝0.049）和EFS（P＝0.001）。15例（50.0％）患者在第1次HCR期内进行移植，移植组患者HRFS（P＝0.030）和EFS（P＝0.010）优于化疗组。

结论

达沙替尼联合多药化疗方案治疗初诊Ph⁺ALL安全有效。

临床试验注册

ClinicalTrials.gov，NCT02523976。

New Approaches to Treating Challenging Subtypes of ALL in AYA Patients

PURPOSE OF REVIEW

The treatment of acute lymphoblastic leukemia (ALL) in adolescent and young adult (AYA) patients has markedly improved with the adoption of pediatric-inspired protocols. However, there remain several subtypes of ALL that represent significant therapeutic challenges. Here, we review the current evidence guiding treatment of Philadelphia chromosome-positive (Ph+), Philadelphia chromosome-like (Ph-L), and early T-precursor (ETP) ALL in the AYA population.

RECENT FINDINGS

Clinical trials in Ph + ALL have demonstrated the superior efficacy of second- and third-generation tyrosine kinase inhibitors (TKIs) to induce and maintain remission. Current efforts now focus on determining the durability of these remissions and which patients will benefit from transplant. For Ph-like and ETP ALL, recent studies are investigating the addition of novel agents to standard treatment. The treatment of Ph + ALL has significantly improved with the addition of potent TKIs. However, the treatment of Ph-like and ETP ALL remains a challenge. At this time, the judicious use of allogenic transplant is the only current approach to modify this increased risk.

Combination chemotherapy plus dasatinib leads to comparable overall survival and relapse-free survival rates as allogeneic hematopoietic stem cell transplantation in Philadelphia positive acute lymphoblastic leukemia

Background

The Philadelphia chromosome is associated with a poor prognosis in acute lymphoblastic leukemia (ALL). While hematopoietic stem cell transplantation (HSCT) has been regarded as a favorable treatment option in adult Philadelphia‐positive (Ph+) ALL, its benefit is less clear in the era of newer generation tyrosine kinase inhibitors (TKIs) like dasatinib.

Methods

This was a retrospective study that analyzed the outcomes of adult patients with Ph+ ALL treated with either combination chemotherapy plus dasatinib or combination chemotherapy plus dasatinib followed by allogeneic HSCT.

Results

A total of 70 patients were included; 30 (42.9%) underwent allogeneic HSCT while 40 (57.1%) received only chemotherapy plus dasatinib. In comparing overall survival (OS) rates, results between the 2 groups were similar with a 1‐year OS of 93.3% versus 100% (P = 0.20), 2‐year OS of 89.8% versus 86.2% (P = 0.72), and 3‐year OS of 76% versus 71.3% (P = 0.56) in the transplant versus nontransplant groups, respectively. The 3‐year relapse‐free survival (RFS) rates were also similar at 70.5% in the transplant group and 80.1% in the nontransplant group (P = 0.94). Subgroup analyses were performed for patients with specific poor prognostic factors (higher white blood count, older age, positive minimal residual disease status), but results again showed no significant survival difference between transplant and nontransplant patients.

Conclusions

While HSCT has historically led to a survival advantage in Ph+ ALL, the results of our study demonstrate that it may have a less beneficial role in the era of newer generation TKIs such as dasatinib.