Dasatinib-Blinatumomab for Ph-Positive Acute Lymphoblastic Leukemia in Adults

Gene Deletions and Prognostic Values in B-Linage Acute Lymphoblastic Leukemia

Although pediatric-like treatment regimen has remarkably improved the survival rates of adults with acute lymphoblastic leukemia (ALL), the outcome of some adult patients is still poor owing to adverse genetic features. These molecular abnormalities, especially gene deletions, may be considered for the prognosis assessment for adult patients with ALL. In this study, using multiplex ligation-dependent probe amplification (MLPA) method, gene deletions were analyzed in from 211 adult B-ALL patients treated in our center. The data showed that 68.2% (144/211) adult B-ALL patients carried gene deletions, and the frequency is much higher in Ph⁺B-ALL patients. IKZF1 gene deletion is the most common gene deletion in adult B-ALL, followed by CDKN2A/B deletion. In Ph^-B-ALL patients, the overall survival of patients with gene deletions is inferior to that of patients without any gene deletions. More obviously, patients with IKZF1 or CDKN2A/B deletion had a worse prognosis, whereas, allogeneic hematopoietic stem cell transplantation could improve OS in patients with IKZF1 deletion, but not in patients with CDKN2A/B deletion. Moreover, the outcome of Ph^-B-ALL patients with double deletion of IKZF1and CDKN2A/B may be much worse than that of patients with IKZF1 or CDKN2A/B alone. Minimal residual disease (MRD) was also analyzed together with gene deletions and demonstrated that gene deletions have a negative impact on survival only in MRD positive Ph^-B-ALL patients. In conclusion, gene deletions are closely related with the prognosis of adult Ph^-B-ALL patients.

Philadelphia-like acute lymphoblastic leukemia is associated with minimal residual disease persistence and poor outcome. First report of the minimal residual disease-oriented GIMEMA LAL1913

Early recognition of Philadelphia-like (Ph-like) acute lymphoblastic leukemia (ALL) cases could impact on the management and outcome of this subset of B-lineage ALL. In order to assess the prognostic value of the Ph-like status in a pediatric-inspired, minimal residual disease (MRD)- driven trial, we screened 88 B-lineage ALL cases negative for major fusion genes (BCR-ABL1, ETV6-RUNX1, TCF3-PBX1 and KTM2Ar) enrolled in the GIMEMA LAL1913 front-line protocol for adult BCR/ABL1-negative ALL. The screening - performed using the “BCR/ABL1-like predictor” - identified 28 Ph-like cases (31.8%), characterized by CRLF2 overexpression (35.7%), JAK/STAT pathway mutations (33.3%), IKZF1 (63.6%), BTG1 (50%) and EBF1 (27.3%) deletions, and rearrangements targeting tyrosine kinases or CRLF2 (40%). The correlation with outcome highlighted that: i) the complete remission rate was significantly lower in Ph-like compared to non-Phlike cases (74.1% vs. 91.5%, P=0.044); ii) at time point 2, decisional for transplant allocation, 52.9% of Ph-like cases versus 20% of non-Ph-like were MRD-positive (P=0.025); iii) the Ph-like profile was the only parameter associated with a higher risk of being MRD-positive at time point 2 (P=0.014); iv) at 24 months, Ph-like patients had a significantly inferior event-free and disease-free survival compared to non-Ph-like patients (33.5% vs. 66.2%, P=0.005 and 45.5% vs. 72.3%, P=0.062, respectively). This study documents that Ph-like patients have a lower complete remission rate, event-free survival and disease-free survival, as well as a greater MRD persistence also in a pediatric-oriented and MRD-driven adult ALL protocol, thus reinforcing that the early recognition of Ph-like ALL patients at diagnosis is crucial to refine risk-stratification and to optimize therapeutic strategies. Clinicaltrials gov. Identifier: 02067143.

Efficacy of Inotuzumab Ozogamicin plus Ponatinib Followed by Allogeneic Stem Cell Transplantation in a Patient with Relapsed Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph + ALL) is an aggressive disease with poor outcomes. Despite the incorporation of tyrosine kinase inhibitors (TKIs) in the therapeutic strategies, patients who relapse after chemotherapy plus TKI have poor overall survival (OS) and less chance to proceed to hematopoietic stem cell transplantation (HSCT) which remains the only curative approach. Therefore, new drugs, such as antibody-targeted therapies alone or in combination with TKIs, offer new therapeutic options for those patients. However, the combination of inotuzumab plus ponatinib has limited application. We present a case of a patient affected by Ph + ALL with T315I mutation successfully treated after early relapse with inotuzumab plus ponatinib, followed by allogeneic HSCT and ponatinib maintenance.

Bispecific T cell engagers: an emerging therapy for management of hematologic malignancies

Harnessing the power of immune cells, especially T cells, to enhance anti-tumor activities has become a promising strategy in clinical management of hematologic malignancies. The emerging bispecific antibodies (BsAbs), which recruit T cells to tumor cells, exemplified by bispecific T cell engagers (BiTEs), have facilitated the development of tumor immunotherapy. Here we discussed the advances and challenges in BiTE therapy developed for the treatment of hematologic malignancies. Blinatumomab, the first BiTE approved for the treatment of acute lymphocytic leukemia (ALL), is appreciated for its high efficacy and safety. Recent studies have focused on improving the efficacy of BiTEs by optimizing treatment regimens and refining the molecular structures of BiTEs. A considerable number of bispecific T cell-recruiting antibodies which are potentially effective in hematologic malignancies have been derived from BiTEs. The elucidation of mechanisms of BiTE action and neonatal techniques used for the construction of BsAbs can improve the treatment of hematological malignancies. This review summarized the features of bispecific T cell-recruiting antibodies for the treatment of hematologic malignancies with special focus on preclinical experiments and clinical studies.

Genetic Alterations and Therapeutic Targeting of Philadelphia-Like Acute Lymphoblastic Leukemia

Philadelphia-like (Ph-like) acute lymphoblastic leukemia (ALL) is a subgroup of B-cell precursor ALL which by gene expression analysis clusters with Philadelphia-positive ALL although lacking the pathognomonic BCR-ABL1 oncoprotein. Its prevalence increases with age and similar to BCR-ABL1-positive ALL, Ph-like ALL is characterized by IKZF1 or other B-lymphoid transcription factor gene deletions and by poor outcome to conventional therapeutic approaches. Genetic alterations are highly heterogenous across patients and include gene fusions, sequence mutations, DNA copy number changes and cryptic rearrangements. These lesions drive constitutively active cytokine receptor and kinase signaling pathways which deregulate ABL1 or JAK signaling and more rarely other kinase-driven pathways. The presence of activated kinase alterations and cytokine receptors has led to the incorporation of targeted therapy to the chemotherapy backbone which has improved treatment outcome for this high-risk subtype. More recently, retrospective studies have shown the efficacy of immunotherapies including both antibody drug-conjugates and chimeric antigen receptor T cell therapy and as they are not dependent on a specific genetic alteration, it is likely their use will increase in prospective clinical trials. This review summarizes the genomic landscape, clinical features, diagnostic assays, and novel therapeutic approaches for patients with Ph-like ALL.

Advances in the Diagnosis and Treatment of Pediatric Acute Lymphoblastic Leukemia

The outcomes of pediatric acute lymphoblastic leukemia (ALL) have improved remarkably during the last five decades. Such improvements were made possible by the incorporation of new diagnostic technologies, the effective administration of conventional chemotherapeutic agents, and the provision of better supportive care. With the 5-year survival rates now exceeding 90% in high-income countries, the goal for the next decade is to improve survival further toward 100% and to minimize treatment-related adverse effects. Based on genome-wide analyses, especially RNA-sequencing analyses, ALL can be classified into more than 20 B-lineage subtypes and more than 10 T-lineage subtypes with prognostic and therapeutic implications. Response to treatment is another critical prognostic factor, and detailed analysis of minimal residual disease can detect levels as low as one ALL cell among 1 million total cells. Such detailed analysis can facilitate the rational use of molecular targeted therapy and immunotherapy, which have emerged as new treatment strategies that can replace or reduce the use of conventional chemotherapy.

Novel agents and regimens for hematological malignancies: recent updates from 2020 ASH annual meeting

Antibodies and chimeric antigen receptor-engineered T cells (CAR-T) are increasingly used for cancer immunotherapy. Small molecule inhibitors targeting cellular oncoproteins and enzymes such as BCR-ABL, JAK2, Bruton tyrosine kinase, FLT3, BCL-2, IDH1, IDH2, are biomarker-driven chemotherapy-free agents approved for several major hematological malignancies. LOXO-305, asciminib, "off-the-shelf" universal CAR-T cells and BCMA-directed immunotherapeutics as well as data from clinical trials on many novel agents and regimens were updated at the 2020 American Society of Hematology (ASH) Annual Meeting. Major developments and updates for the therapy of hematological malignancies were delineated at the recent Winter Symposium and New York Oncology Forum from the Chinese American Hematologist and Oncologist Network (CAHON.org). This study summarized the latest updates on novel agents and regimens for hematological malignancies from the 2020 ASH annual meeting.

Outcome of patients with chronic myeloid leukemia in lymphoid blastic phase and Philadelphia chromosome-positive acute lymphoblastic leukemia treated with hyper-CVAD and dasatinib

BACKGROUND

Dasatinib monotherapy has demonstrated modest clinical activity in chronic myeloid leukemia in lymphoid blastic phase (CML-LBP). The outcome of Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL) has dramatically improved with hyperfractionated cyclophosphamide, vincristine sulfate, doxorubicin hydrochloride, and dexamethasone (hyper-CVAD) in combination with tyrosine kinase inhibitors (TKIs).

METHODS

The authors reviewed 85 patients (23 with CML-LBP and 62 with newly diagnosed Ph-positive ALL) who received hyper-CVAD plus dasatinib.

RESULTS

In the CML-LBP cohort, 19 had prior chronic myeloid leukemia as chronic phase (n = 17; 74%), accelerated phase (n = 1; 4%), or myeloid blastic phase (n = 1; 4%); 4 (17%) presented with de novo CML-LBP. The BCR-ABL1 transcript was p210 in 22 patients (96%) and p190 in 1 patient (4%). In the Ph-positive ALL cohort, p210 and p190 transcripts were detected in 13 patients (21%) and 48 patients (77%), respectively. Patients with CML-LBP were less likely to achieve deep molecular remission than patients with Ph-positive ALL: the major molecular response (MMR) rates were 70% and 95%, respectively (P = .007), and the complete molecular response (CMR) rates were 55% and 74%, respectively (P = .16). Survival outcomes were similar for CML-LBP and Ph-positive ALL: the 5-year overall survival (OS) rates were 59% and 48%, respectively (P = .97). Allogeneic stem cell transplantation was associated with a better outcome in CML-LBP (5-year OS rate, 88% vs 57%; P = .04). In Ph-positive ALL, the outcome was driven by deeper molecular remission: the 5-year OS rates were 63% and 25% with CMR and MMR, respectively (P = .002).

CONCLUSIONS

The outcome of CML-LBP has improved with hyper-CVAD plus dasatinib therapy with survival comparable to that of Ph-positive ALL. Further improvement may be achieved with the use of novel TKIs and targeted agents.

Multi-institutional study evaluating clinical outcome with allogeneic hematopoietic stem cell transplantation after blinatumomab in patients with B-cell acute lymphoblastic leukemia: real-world data

Safety and efficacy of allogeneic hematopoietic stem cell transplantation (alloHCT) consolidation after blinatumomab is largely undetermined. To address this issue, we assembled multi-center data of relapsed refractory (RR) acute lymphocytic leukemia (ALL) patients who received alloHCT after blinatumomab. From December 2014 to May 2019, 223 patients who received blinatumomab for RR ALL outside clinical trials were identified. Among them, 106 (47%) patients transplanted post blinatumomab were evaluated for response and toxicity. Ninety-two (87%) patients received alloHCT after achieving CR, while remaining received subsequent salvage prior to undergoing alloHCT. Progression free survival (PFS) and overall survival (OS) at 2 years post alloHCT was 48% (95% CI: 36-59%) and 58% (95% CI: 45-69%), respectively. The cumulative incidence of GIII-IV aGVHD at 3 months was 9.9% (95% CI: 5.0-16.6%). Similarly, cumulative incidence of moderate to severe cGVHD at 2 years was 34.4% (95% CI: 23.7-45.3%). The overall survival at 2 years was not significantly different in patient who achieved CR with MRD negative (68.4% [95% CI: 28.5-89.1%]) compared to CR with MRD positive (63.4% [95% CI: 47.8-75.4%]) prior to alloHCT (p = 0.8). Our real-world analysis suggests that alloHCT is feasible and effective post blinatumomab in patients with RR ALL.

Molecular remission after combination therapy with blinatumomab and ponatinib with relapsed/refractory Philadelphia chromosome-positive acute lymphocytic leukemia: two case reports

Background

The outcomes of Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) can improve with allogeneic hematopoietic stem cell transplantation (HSCT) during the first complete remission after treatment with a tyrosine kinase inhibitor (TKI) combined with chemotherapy. However, frail patients who are not eligible for allogeneic HSCT or those with TKI-resistant mutations within the BCR–ABL kinase domain have a poor clinical course. Blinatumomab (BLIN) is a bispecific T-cell engager antibody construct that directs cytotoxic T cells to CD19-expressing B-ALL cells. To date, only a few studies have shown the safety and efficacy of Blinatumomab (BLIN) + TKI combination therapy for relapsed/refractory (R/R) Ph+ ALL. Here we report the case of two patients with R/R Ph+ ALL who were treated with BLIN + TKI with durable molecular response.

Case presentation

Patient 1: A 69-year-old Japanese male with R/R Ph+ ALL was treated with conventional chemotherapy and dasatinib in April 2016. In May 2018, he developed molecular relapse due to the acquisition of T315I during dasatinib maintenance therapy. Thereafter, he achieved molecular complete remission (mCR) after switching from dasatinib to ponatinib. However, he developed a second relapse after the emergence of triple compound mutations (G250E/D276G/T315I) in November 2018. He subsequently received a total of nine cycles of BLIN and ponatinib combination therapy, which resulted in sustained mCR without any adverse events. Patient 2: A 69-year-old Japanese female with R/R Ph+ ALL was treated with chemotherapy and imatinib in April 2008. She developed molecular relapse due to the emergence of the T315I mutation in October 2017. She achieved mCR after switching from imatinib to ponatinib. However, she developed a second relapse after acquiring ABL exon4 skipping in addition to T315I. She subsequently received a total of seven cycles of BLIN and ponatinib combination therapy, which resulted in sustained mCR.

Conclusion

In our two cases, BLIN + ponatinib combination therapy was highly effective for R/R Ph+ ALL without any incidence of severe adverse events. Further studies with larger cohorts are warranted to validate the safety and efficacy of this potent combination therapy.

Immune Therapies for Hematologic Malignancies

The era of immunotherapy for hematologic malignancies began with the first allogeneic hematopoietic stem cell transplant (HSCT) study published by E [...].

A Systematic Review of Blinatumomab in the Treatment of Acute Lymphoblastic Leukemia: Engaging an Old Problem With New Solutions

OBJECTIVE

To assess the current literature for blinatumomab in the treatment of adult and pediatric B-cell acute lymphoblastic leukemia (ALL).

DATA SOURCES

We conducted a PubMed (inception to December 11, 2020) and ClinicalTrials.gov systematic literature search using the following terms: blinatumomab, Blincyto, lymphoblastic leukemia, and bispecific T-cell engager.

STUDY SELECTION AND DATA EXTRACTION

All relevant published articles, package inserts, and meeting abstracts evaluating the use of blinatumomab in ALL were considered for inclusion.

DATA SYNTHESIS

Blinatumomab, a first-in-class bispecific T-cell engager monoclonal antibody, facilitates cytotoxic T-cell activation and subsequent eradication of CD19-positive B cells. The confirmatory phase III TOWER trial demonstrated superior overall survival (OS) with blinatumomab compared with standard chemotherapy (7.7 months vs 4.0 months) in relapsed and refractory (R/R) B-cell ALL. In the phase II BLAST trial, blinatumomab achieved a complete measurable residual disease (MRD) response in 78% of evaluable patients, with a median OS of 36.5 months. Potentially life-threatening cytokine release syndrome and neurotoxicity occurred in approximately 15% and 65% of patients, respectively.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Following initial Food and Drug Administration approval in 2014, blinatumomab gained expanded approval in pediatric patients and in Philadelphia chromosome-positive R/R ALL. In 2018, blinatumomab became the first and only drug approved for the treatment of persistent MRD in any hematologic malignancy. Emerging data demonstrate promising efficacy with blinatumomab in specific ALL settings, including frontline therapy, as a bridge to transplantation, and in "chemotherapy-free" combination regimens.

CONCLUSIONS

Blinatumomab provides a paradigm-shifting treatment option; however, many questions surrounding optimal patient selection, sequencing, and cost-effectiveness remain.

Recent updates for antibody therapy for acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is a hematologic malignancy arising from precursors of the lymphoid lineage. Conventional cytotoxic chemotherapies have resulted in high cure rates of up to 90% in pediatric ALL, but the outcomes for adult patients remain suboptimal with 5-year survival rates of only 30%-40%. Current immunotherapies exploit the performance of antibodies through several different mechanisms, including naked antibodies, antibodies linked to cytotoxic agents, and T-cell re-directing antibodies. Compared with chemotherapy, the application of an antibody-drug conjugates (ADC) called inotuzumab ozogamicin in relapsed or refractory (R/R) CD22+. ALL resulted in a complete remission (CR) rate of 81% and an overall median survival of 7.7 months with reduced toxicity. Similarly, blinatumomab, the first FDA-approved bispecific antibody (BsAb), produced a 44% complete response rate and an overall median survival of 7.7 months in a widely treated ALL population. In addition, approximately 80% of patients getting complete remission with evidence of minimal residual disease (MRD) achieved a complete MRD response with the use of blinatumomab. These results highlight the great promise of antibody-based therapy for ALL. How to reasonably determine the place of antibody drugs in the treatment of ALL remains a major problem to be solved for ongoing and future researches. Meanwhile the combination of antibody-based therapy with traditional standard of care (SOC) chemotherapy, chimeric antigen receptor (CAR) T-cell therapy and HSCT is also a challenge. Here, we will review some important milestones of antibody-based therapies, including combinational strategies, and antibodies under clinical development for ALL.