Salvage Chemoimmunotherapy With Inotuzumab Ozogamicin Combined With Mini-Hyper-CVD for Patients With Relapsed or Refractory Philadelphia Chromosome-Negative Acute Lymphoblastic Leukemia: A Phase 2 Clinical Trial

Inotuzumab ozogamicin in adult acute lymphoblastic leukemia: Development, current status, and future directions

Inotuzumab ozogamicin (InO) is an antibody-drug conjugate approved for the treatment of relapsed/refractory B-cell acute lymphoblastic leukemia (ALL). Several clinical trials are investigating InO in combination with low-intensity chemotherapy or other anti-ALL-targeted therapies in the salvage and frontline settings, notably in older adults who often cannot tolerate intensive chemotherapy and tend to have higher-risk disease. InO is also increasingly used to bridge patients to hematopoietic stem cell transplantation (HSCT), in sequence with chimeric antigen receptor T-cell therapy, to eliminate measurable residual disease and to prevent post-HSCT relapse. Veno-occlusive disease/sinusoidal obstruction syndrome is a potential complication of InO treatment, particularly when followed by HSCT. Herein, the authors review the historical development and current status of InO, strategies for mitigating the risk of InO-related veno-occlusive disease/sinusoidal obstruction syndrome, and future directions for InO research and clinical use.

Combination low-intensity chemotherapy plus inotuzumab ozogamicin, blinatumomab and rituximab for pediatric patients with relapsed/refractory B-cell acute lymphoblastic leukemia

Not available.

Antibody-drug conjugates in cancer therapy: mechanisms and clinical studies

Antibody-drug conjugates (ADCs) consist of monoclonal antibodies that target tumor cells and cytotoxic drugs linked through linkers. By leveraging antibodies' targeting properties, ADCs deliver cytotoxic drugs into tumor cells via endocytosis after identifying the tumor antigen. This precise method aims to kill tumor cells selectively while minimizing harm to normal cells, offering safe and effective therapeutic benefits. Recent years have seen significant progress in antitumor treatment with ADC development, providing patients with new and potent treatment options. With over 300 ADCs explored for various tumor indications and some already approved for clinical use, challenges such as resistance due to factors like antigen expression, ADC processing, and payload have emerged. This review aims to outline the history of ADC development, their structure, mechanism of action, recent composition advancements, target selection, completed and ongoing clinical trials, resistance mechanisms, and intervention strategies. Additionally, it will delve into the potential of ADCs with novel markers, linkers, payloads, and innovative action mechanisms to enhance cancer treatment options. The evolution of ADCs has also led to the emergence of combination therapy as a new therapeutic approach to improve drug efficacy.

Dose-Adjusted EPOCH Plus Inotuzumab Ozogamicin in Adults With Relapsed or Refractory B-Cell ALL: A Phase 1 Dose-Escalation Trial

Importance

Options for adults with relapsed or refractory B-cell acute lymphoblastic leukemia or lymphoma (B-ALL) are limited, and new approaches are needed. Inotuzumab ozogamicin (InO) has been combined with low-intensity chemotherapy, with modest improvements over historical controls, and dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (DA-EPOCH) treatment is safe and active for newly diagnosed ALL.

Objective

To assess the safety and clinical activity of DA-EPOCH and InO in adults with relapsed or refractory B-ALL.

Design, Setting, and Participants

This single-center, single-arm, nonrandomized, phase 1 dose-escalation trial included adults with relapsed or refractory CD22+ B-ALL and was conducted between September 2019 and November 2022. At least 5% blood or marrow blasts or measurable extramedullary disease (EMD) was required for enrollment.

Interventions

DA-EPOCH was given on days 1 to 5, while InO was given on day 8 and day 15 of a 28-day cycle. Three dose levels were studied using a bayesian optimal interval design.

Main Outcomes and Measures

The primary outcome was the maximum tolerated dose of InO when combined with DA-EPOCH, defined as the highest dose level that produced a rate of dose-limiting toxicity below 33%. Secondary objectives included response rates, survival estimates, and descriptions of toxic effects.

Results

A total of 24 participants were screened and enrolled (median age, 46 [range, 28-76] years; 15 [62%] male). The median number of lines of prior therapy was 3 (range, 1-12). Three of 11 participants (27%) treated at the highest dose level (InO, 0.6 mg/m2, on day 8 and day 15) experienced dose-limiting toxicity, making this the maximum tolerated dose. No deaths occurred during the study, and only 1 patient (4%; 95% CI, 0.1%-21%) developed sinusoidal obstructive syndrome after poststudy allograft. The morphologic complete response rate was 84% (95% CI, 60%-97%), 88% (95% CI, 62%-98%) of which was measurable residual disease negative by flow cytometry. Five of 6 participants with EMD experienced treatment response. The overall response rate was 83% (95% CI, 63%-95%). Median overall survival, duration of response, and event-free survival were 17.0 (95% CI, 8.4-not reached), 15.0 (95% CI, 6.7-not reached), and 9.6 (95% CI, 4.5-not reached) months, respectively.

Conclusions

In this study, adding InO to DA-EPOCH in adults with relapsed or refractory B-ALL was feasible, with high response rates and sinusoidal obstructive syndrome occurring rarely in a heavily pretreated population. Many patients were able to proceed to poststudy consolidative allogeneic hematopoietic cell transplant and/or chimeric antigen receptor T-cell therapy. Further investigation of this combination is warranted.

Trial Registration

ClinicalTrials.gov Identifier: NCT03991884.

Advances in the treatment of Philadelphia chromosome negative acute lymphoblastic leukemia

There have been major paradigm shifts in the treatment of Philadelphia chromosome negative (Ph-) acute lymphoblastic leukemia (ALL) in the last decade with the introduction of new immunotherapies and targeted agents, adoption of pediatric-type chemotherapy protocols in younger adults as well as chemotherapy light approaches in older adults and the incorporation of measurable residual disease (MRD) testing to inform clinical decision making. With this, treatment outcomes in adult Ph- ALL have improved across all age groups. However, a subset of patients will still develop relapsed disease, which can be challenging to treat and associated with poor outcomes. Here we review the treatment of Ph- ALL in both younger and older adults, including the latest advancements and future directions.

Naked antibodies and antibody-drug conjugates: targeted therapy for childhood acute lymphoblastic leukemia

The treatment of childhood acute lymphoblastic leukemia (ALL) has reached overall survival rates exceeding 90%. The present and future challenges are to cure the remainder of patients still dying from disease, and to reduce morbidity and mortality in those who can be cured with standard-of-care chemotherapy by replacing toxic chemotherapy elements while retaining cure rates. With the novel therapeutic options introduced in the last years, including immunotherapies and targeted antibodies, the treatment of ALL is undergoing major changes. For B-cell precursor ALL, blinatumomab, an anti-CD19 bispecific antibody, has established its role in the consolidation treatment for both high- and standard-risk first relapse of ALL, in the presence of bone marrow involvement, and may also have an impact on the outcome of high-risk subsets such as infant ALL and Philadelphia chromosome-positive ALL. Inotuzumab ozogamicin, an anti-CD22 drug conjugated antibody, has demonstrated high efficacy in inducing complete remission in relapsed ALL, even in the presence of high tumor burden, but randomized phase III trials are still ongoing. For T-ALL the role of CD38-directed treatment, such as daratumumab, is gaining interest, but randomized data are needed to assess its specific benefit. These antibodies are currently being tested in patients with newly diagnosed ALL and may lead to major changes in the present paradigm of treatment of pediatric ALL. Unlike the past, lessons may be learned from innovations in adult ALL, in which more drastic changes are piloted that may need to be translated to pediatrics.

Inotuzumab ozogamicin for the treatment of adult acute lymphoblastic leukemia: past progress, current research and future directions

Inotuzumab ozogamicin (INO) is an anti-CD22 antibody-drug conjugate that was first evaluated in B-cell lymphomas but was subsequently shown to be highly effective in acute lymphoblastic leukemia (ALL). INO improved response rates and survival in a randomized study in adults with relapsed/refractory B-cell ALL, leading to its regulatory approval in the United States in 2017. While the formal approval for INO is as monotherapy in relapsed/refractory ALL, subsequent studies with INO administered in combination with chemotherapy and/or blinatumomab both in the frontline and salvage settings have yielded promising results. In this review, we discuss the clinical development of INO in ALL, highlighting lessons learned from the initial clinical trials of INO, as well as the many ongoing studies that are seeking to expand the role of INO in ALL.

Safety and long-term survival results of the addition of inotuzumab ozogamicin to the conditioning regimen of allogeneic stem cell transplantation: A single-center phase 1,2 trial

Here we report on the first prospective study evaluating the safety and long-term survival when an escalating dose of inotuzumab ozogamicin (INO) (0.6, 1.2, or 1.8 mg/m2 on day 13) was added to one alkylator-containing conditioning regimen in patients with relapsed CD22 (+) lymphoid malignancies who were candidates for hematopoietic stem cell transplantation (HSCT). Twenty-six patients were enrolled. Six (23%) of these patients entered the phase 1 study: four were treated at an INO dose of 0.6 mg/m2 and two at dose of 1.2 mg/m2. None of these patients experienced dose-limiting toxicities. The remaining 20 (77%) patients entered the phase 2 part of the study at the maximum dose of 1.8 mg/m2. One patient developed VOD; this patient had received nivolumab immediately before HSCT while simultaneously experiencing hyperacute graft-vs-host disease (GVHD). Treatment-related mortality (TRM) at 5 years was 12%. With a median follow-up of 48.7 months, the 5-year overall survival (OS) and progression-free survival (PFS) rates were 84% and 80%, respectively. Compared with a historical cohort who received same conditioning for HSCT but without INO (n = 56), the INO group showed no significant differences in incidence of liver toxicity, engraftment time, TRM, or risk of acute GVHD. Patients with lymphoma who received INO had a trend for a better 5-year OS (93% versus 68%) and PFS (93% versus 58%) than those in the control group. In conclusion, our results showed that INO is safe with no increased risk of VOD when combined with one alkylator-containing regimen of HSCT.

A phase 1/2 study of mini-hyper-CVD plus venetoclax in patients with relapsed/refractory acute lymphoblastic leukemia

ABSTRACT

Preclinical studies suggest that Bcl-2 inhibition with venetoclax has antileukemic activity in acute lymphoblastic leukemia (ALL) and may synergize with conventional chemotherapy. We designed a phase 1/2 clinical trial to evaluate the safety and efficacy of low-intensity chemotherapy in combination with venetoclax in adults with relapsed or refractory ALL. Patients received the mini-hyper-CVD regimen (dose-attenuated hyperfractionated cyclophosphamide, vincristine, and dexamethasone alternating with methotrexate and cytarabine) in combination with venetoclax (200 mg or 400 mg daily) on days 1 to 14 in cycle 1 and on days 1 to 7 in consolidation cycles. Twenty-two patients were treated. The median number of prior therapies was 2 (range, 1-6). Thirteen patients (59%) had undergone prior allogeneic stem cell transplant (allo-SCT), and 7 of 18 patients (39%) with B-cell ALL had previously received both inotuzumab ozogamicin and blinatumomab. The recommended phase 2 dose of venetoclax in the combination regimen was 400 mg daily. The composite complete remission (CR) and CR with incomplete hematologic recovery (CRi) rate was 57% (CR, 43%; CRi, 14%), and 45% of responders achieved measurable residual disease negativity by multiparameter flow cytometry. Four patients proceeded to allo-SCT. The median duration of response was 6.3 months. The median overall survival was 7.1 months, and the 1-year overall survival rate was 29%. The most common grade ≥3 nonhematologic adverse events were infection in 17 patients (77%) and febrile neutropenia in 4 patients (18%). Overall, the combination of mini-hyper-CVD plus venetoclax was active in heavily pretreated relapsed/refractory ALL. Further development of venetoclax-based combinations in ALL is warranted. This trial is registered at www.clinicaltrials.gov as #NCT03808610.

Diagnostic and therapeutic advances in adults with acute lymphoblastic leukemia in the era of gene analysis and targeted immunotherapy

Acute lymphoblastic leukemia (ALL) is one of the most rapidly changing hematological malignancies with advanced understanding of the genetic landscape, detection methods of minimal residual disease (MRD), and the development of immunotherapeutic agents with good clinical outcomes. The annual incidence of adult ALL in Korea is 300-350 patients per year. The WHO classification of ALL was revised in 2022 to reflect the molecular cytogenetic features and suggest new adverse- risk subgroups, such as Ph-like ALL and ETP-ALL. We continue to use traditional adverse-risk features and cytogenetics, with MRD-directed post-remission therapy including allogeneic hematopoietic cell transplantation. However, with the introduction of novel agents, such as ponatinib, blinatumomab, and inotuzumab ozogamicin incorporated into frontline therapy, good MRD responses have been achieved, and overall survival outcomes are improving. Accordingly, some clinical trials have suggested a possible era of chemotherapy-free or transplantation-free approaches in the near future. Nevertheless, relapse of refractory ALL still occurs, and some poor ALL subtypes, such as Ph-like ALL and ETP-ALL, are unsolved problems for which novel agents and treatment strategies are needed. In this review, we summarize the currently applied diagnostic and therapeutic practices in the era of advanced genetic analysis and targeted immunotherapies in United States and Europe and introduce real-world Korean data.

[Treatment response of a two-dose regimen of dose-adjusted inotuzumab ozogamicin in relapsed/refractory B-cell acute lymphoblastic leukemia]

Objective: To observe the treatment response of a two-dose regimen of inotuzumab ozogamicin (inotuzumab), a monoclonal antibody targeting CD22, for patients with heavily treated relapsed/refractory B-cell acute lymphoblastic leukemia (R/R B-ALL), including those failed or relapsed after chimeric antigen receptor (CAR) -T-cell therapy. Methods: Pediatric and adult patients who received two doses of inotuzumab and who were evaluated after inotuzumab treatment were included. Antibody infusions were performed between March 2020 and September 2022. All patients expressed CD22 antigen as detected by flow cytometry (>80% leukemic cells displaying CD22) before treatment. For adults, the maximum dosage per administration was 1 mg (with a total of two administrations). For children, the maximum dosage per administration was 0.85 mg/m(2) (no more than 1 mg/dose; total of two administrations). The total dosage administered to each patient was less than the standard dosage of 1.8 mg/m(2). Results: Twenty-one patients with R/R B-ALL were included, including five children (<18 years old) and sixteen adults. Seventeen patients presented with 5.0% -99.0% leukemic blasts in the bone marrow/peripheral blood or with extramedullary disease, and four patients were minimal residual disease (MRD) -positive. Fourteen patients underwent both CD19 and CD22 CAR-T-cell therapy, four underwent CD19 CAR-T-cell therapy, and three underwent blinatumomab therapy. Eleven patients underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT). After inotuzumab treatment, 14 of 21 patients (66.7% ) achieved a complete response (CR, one was MRD-positive CR), and all four MRD-positive patients turned MRD-negative. Four of six patients who failed recent CD22 CAR-T-cell therapy achieved a CR after subsequent inotuzumab treatment. Seven patients (33.3% ) demonstrated no response. Grade 1-3 hepatotoxicity occurred in five patients (23.8% ), one child with no response experienced hepatic veno-occlusive disease (HVOD) during salvage transplantation and recovered completely. Conclusion: For patients with heavily treated R/R B-ALL, including those who had undergone allo-HSCT and CD19/CD22 CAR-T-cell therapy, the two-dose regimen of inotuzumab resulted in a CR rate of 66.7%, and the frequency of hepatotoxicity and HVOD was low.

Immunotherapy in hematologic malignancies: achievements, challenges and future prospects

The immune-cell origin of hematologic malignancies provides a unique avenue for the understanding of both the mechanisms of immune responsiveness and immune escape, which has accelerated the progress of immunotherapy. Several categories of immunotherapies have been developed and are being further evaluated in clinical trials for the treatment of blood cancers, including stem cell transplantation, immune checkpoint inhibitors, antigen-targeted antibodies, antibody-drug conjugates, tumor vaccines, and adoptive cell therapies. These immunotherapies have shown the potential to induce long-term remission in refractory or relapsed patients and have led to a paradigm shift in cancer treatment with great clinical success. Different immunotherapeutic approaches have their advantages but also shortcomings that need to be addressed. To provide clinicians with timely information on these revolutionary therapeutic approaches, the comprehensive review provides historical perspectives on the applications and clinical considerations of the immunotherapy. Here, we first outline the recent advances that have been made in the understanding of the various categories of immunotherapies in the treatment of hematologic malignancies. We further discuss the specific mechanisms of action, summarize the clinical trials and outcomes of immunotherapies in hematologic malignancies, as well as the adverse effects and toxicity management and then provide novel insights into challenges and future directions.

Inotuzumab ozogamicin in B-cell precursor acute lymphoblastic leukemia: efficacy, toxicity, and practical considerations

Inotuzumab ozogamicin (InO) is an antibody drug conjugate composed of a humanized monoclonal antibody targeting the cell surface receptor CD22 coupled to a cytotoxic calicheamicin payload via an acid labile linker. InO has shown significant activity in relapsed and refractory B-cell precursor acute lymphoblastic leukemia (BCP-ALL) in both single agent and combination chemotherapy regimens in adult and pediatric trials. Its use in newly diagnosed elderly patients has also been established while clinical trials investigating its use in newly diagnosed pediatric patients and fit adults are ongoing. Notable toxicities include sinusoidal obstruction syndrome (SOS), particularly in patients who undergo hematopoietic stem cell transplantation (HSCT) after InO as well as myelosuppression and B-cell aplasia which confer increased infection risk, particularly in combination with cytotoxic chemotherapy. In the relapsed/refractory (R/R) setting, the planned subsequent curative therapy modality must be considered when using InO to mitigate SOS risk if proceeding to HSCT and account for potential B-cell aplasia if proceeding to chimeric antigen receptor CAR-T therapy. Studies exploring mechanisms of resistance or failure of InO are ongoing but modulation or loss CD22 expression, alternative CD22 splicing, and high Bcl-2 expression have been implicated. In this review, we will summarize the currently available data on InO, with an emphasis on pediatric trials, and explore future directions including combinatorial therapy.

Evaluation of the inpatient use of inotuzumab ozogamicin and creation of appropriate use guidelines

Inpatient use of inotuzumab ozogamicin (IO) at our academic medical center has increased since its FDA approval in 2017. Administration of IO does not require hospitalization and is appropriate for outpatient use. The aim of this report is to assess the appropriateness of use, overall inpatient utilization, and cost of IO. This is a retrospective chart review of patients that received at least one dose of IO while admitted to the hospital. Data points included rationale for inpatient IO administration, hospital admission reason, number of IO doses and number of vials used, length of stay, in-hospital mortality, percentage of admissions that were new-starts, outpatient continuation of IO, use of concomitant regimens, and CD22 positivity. Between September 1, 2017, and June 30, 2022, 55 doses of IO were identified. Of the 29 unique admissions, common rationales for inpatient IO use included high disease burden/tumor lysis syndrome risk (31%) and use of a regimen requiring hospitalization (28%). The rationale for hospitalization was most commonly 'chemotherapy administration' (34%) and 'relapsed/refractory disease' (38%). Median length of stay was 23 days, most were new starts (76%), and 5 patients died during the associated admission. Only 63% of patients continued therapy in the outpatient setting. The inpatient use of IO was associated with a prolonged length-of-stay, a 17% in-hospital mortality, and represents a significant cost burden to the health system. As a result of these findings, guidelines for inpatient use of IO were implemented across the health system.

Mini-hyper-CVD plus inotuzumab ozogamicin, with or without blinatumomab, in the subgroup of older patients with newly diagnosed Philadelphia chromosome-negative B-cell acute lymphocytic leukaemia: long-term results of an open-label phase 2 trial

BACKGROUND

The outcome of older patients with B-cell acute lymphocytic leukaemia is inferior to that in younger patients due to the adverse disease biology and their inability to tolerate intensive therapy. We aimed to study the long-term outcomes of inotuzumab ozogamicin with or without blinatumomab in combination with low-intensity chemotherapy in these patients.

METHODS

For this open-label phase 2 trial, patients aged 60 years or older with newly diagnosed, Philadelphia-chromosome negative, B-cell acute lymphocytic leukaemia, and an ECOG performance status of 3 or lower were eligible. This study was conducted at the University of Texas MD Anderson Cancer Center. The induction chemotherapy consisted of mini-hyper-CVD and has been published before; inotuzumab ozogamicin was administered intravenously on day 3 of the first four cycles at a dose of 1·3-1·8 mg/m2 in cycle 1, followed by 1·0-1·3 mg/m2 in subsequent cycles (cycles 2-4). Maintenance therapy with dose-reduced POMP (6-mercaptopurine, vincristine, methotrexate, and prednisone) was given for 3 years. From patient 50 onwards, the study protocol was amended to fractionate inotuzumab ozogamicin to a maximum cumulative dose of 2·7 mg/m2 (0·9 mg/m2 during cycle 1 fractionated into 0·6 mg/m2 on day 2 and 0·3 mg/m2 on day 8 of cycle 1, and 0·6 mg/m2 in cycles 2-4 fractionated into 0·3 mg/m2 on day 2 and 0·3 mg/m2 on day 8) followed by blinatumomab for four cycles (cycles 5-8). POMP maintenance was shortened to 12 cycles with one cycle of blinatumomab administered by continuous infusion after every three cycles of POMP. The primary endpoint was progression-free survival and was analysed on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov (NCT01371630) and the present data is from the newly diagnosed, older subgroup of patients treated on the phase 2 portion of this trial; the trial is still enrolling patients.

RESULTS

Between Nov 11, 2011, and March 31, 2022, 80 patients were enrolled and treated (32 female and 48 male patients; median age 68 years [IQR 63-72]), 31 of whom were treated after the protocol amendment. With a median follow-up of 92·8 months (IQR 8·8-67·4), the 2-year progression-free survival was 58·2% (95% CI 46·7-68·2) and 5-year progression-free survival was 44·0% (31·2-54·3). At a median follow-up of 104·4 months (IQR 6·6-89·2) for the patients treated before the protocol amendment and 29·7 months (8·8-41·0) for those treated after the protocol amendment, median progression-free survival did not differ significantly between the two groups (34·7 months [95% CI 15·0-68·3] vs 56·4 months [11·3-69·7]; p=0·77). The most common grade 3-4 events were thrombocytopenia in 62 (78%) patients and febrile neutropenia in 26 (32%) patients. Six (8%) patients developed hepatic sinusoidal obstruction syndrome. There were eight (10%) deaths due to infectious complications, nine (11%) from complications related to secondary myeloid malignancy, and four (5%) from sinusoidal obstruction syndrome.

INTERPRETATION

Inotuzumab ozogamicin with or without blinatumomab added to low-intensity chemotherapy showed promising activity in terms of progression-free survival in older patients with B-cell acute lymphocytic leukaemia. Further attenuation of the chemotherapy regimen might improve tolerability while maintaining efficacy in older patients.

FUNDING

Pfizer and Amgen.

Results of salvage therapy with mini-hyper-CVD and inotuzumab ozogamicin with or without blinatumomab in pre-B acute lymphoblastic leukemia

BACKGROUND

Historically, adults with relapsed-refractory acute lymphoblastic leukemia (ALL) experienced poor outcomes with intensive chemotherapy. This mature analysis explores the benefit of the addition of sequential blinatumomab to low-intensity mini-Hyper-CVD chemotherapy with inotuzumab ozogamicin in this setting.

METHODS

Mini-Hyper-CVD (cyclophosphamide and dexamethasone at 50% dose reduction, no anthracycline, methotrexate at 75% dose reduction, cytarabine at 83% dose reduction) was combined with inotuzumab during the first 4 courses. From Patient #68 and onwards, inotuzumab was given in reduced and fractionated doses, and blinatumomab was added sequentially for 4 courses. Maintenance therapy with prednisone, vincristine, 6-mercaptopurine and methotrexate was given for 12 courses, and blinatumomab for 4 additional courses.

RESULTS

Among 110 patients (median age, 37 years) treated, 91 (83%) responded (complete response, 69 patients, 63%). Measurable residual disease negativity was documented in 75 patients (82% of responders). Fifty-three patients (48%) received allogeneic stem cell transplantation (SCT). Hepatic sinusoidal obstruction syndrome occurred in 9/67 patients (13%) on the original inotuzumab schedule and in 1/43 (2%) on the modified schedule. With a median follow-up of 48 months, the median overall survival (OS) was 17 months, and the 3 year OS was 40%. The 3 year OS was 34% with mini-Hyper-CVD plus inotuzumab and 52% with additional blinatumomab (P = 0.16). By landmark analysis at 4 months, the 3 year OS was 54%, similar between patients who did or did not receive allogeneic SCT.

CONCLUSION

Low-intensity mini-Hyper-CVD plus inotuzumab with or without blinatumomab showed efficacy in patients with relapsed-refractory ALL, with better survival after the addition of blinatumomab. Trial registration The trial was registered on clinicaltrials.gov with the identifier NCT01371630.

Expert Recommendations for the Diagnosis, Treatment, and Management of Adult B-Cell Acute Lymphoblastic Leukemia in Latin America

PURPOSE

Despite strong induction chemotherapy response rates, only 30%-40% of patients with adult B-cell acute lymphoblastic leukemia (ALL) attain long-term remission. This study analyzes ALL in Latin America (LA) and recommends diagnosis, treatment, and management protocols.

METHODS

The Americas Health Foundation organized a panel of hematologists from Argentina, Brazil, Chile, Colombia, and Mexico to examine ALL diagnosis and therapy and produce recommendations.

RESULTS

Lack of regional data, unequal access to diagnosis and therapy, inadequate treatment response, and uneven health care distribution complicate adult ALL management. The panel recommended diagnosis, first-line and refractory treatment, and post-transplantation maintenance. Targeted treatments, including rituximab, blinatumomab, and inotuzumab ozogamicin, are becoming available in LA and must be equitably accessed.

CONCLUSION

This review adapts global information on treating ALL to LA. Governments, the medical community, society, academia, industry, and patient advocates must work together to improve policies.

Antibody-drug conjugate [ADC] treatment of leukaemia

Three ADCs: Mylotarg, Besponda and Lumoxiti have improved overall survival and event=free survival as well as reduced relapse in 3 types of Leukaemia: AML, ALL and HCL, respectively. Lessons from these three SOC successful ADCs should guide other new ADCs in addressing the ADC-related off target toxicity due to the cytotoxic payload that limits their therapeutic index by using the successful approach of administrating lower doses in a fractionated regimen over time in separate days of the cycle to reduce the severity and frequency of the ADC-related serious toxicities that include ocular damage, long-term peripheral neuropathy and hepatic toxicity etc.

Sequencing antigen-targeting antibodies and cellular therapies in adults with relapsed/refractory B-cell acute lymphoblastic leukemia

The recent approvals of four CD19-or CD22-targeted therapies for B-cell acute lymphoblastic leukemia (B-ALL) have transformed the treatment of relapsed/refractory (r/r) disease. Adults with r/r B-ALL are usually eligible for all options, but there are no studies directly comparing these agents, and the treating physician must decide which to select. Each therapy has notable activity as a single agent but has limitations in particular settings, and the optimal choice varies. These therapies can be complementary and used either sequentially or concomitantly. Here, we review the current landscape of antigen-targeted therapies for r/r B-ALL and discuss considerations for their use.

Translational advances in the treatment of childhood acute lymphoblastic leukemia: narrative review of current and emerging molecular and immunotherapies

Background and Objective

Acute lymphoblastic leukemia (ALL) is the most common hematologic malignancy of lymphoid origin in children. The prognosis for newly diagnosed ALL in the pediatric population is generally favorable, with a 5-year overall survival rate of more than 90%. Though conventional therapy has led to meaningful improvements in cure rates for new-onset pediatric ALL, one-third of patients still experience a relapse or refractory disease, contributing to a significant cause of pediatric cancer-related mortality.

Methods

An extensive literature review was undertaken via various databases of medical literature, focusing on both results of larger clinical trials, but also with evaluation of recent abstract publications at large hematologic conferences.

Key Content and Findings

Remission is achievable in most of these patients by re-induction with currently available therapies, but the long-term overall survival rate is deemed suboptimal and remains a therapeutic challenge. As part of never-ceasing efforts to improve pediatric ALL outcomes, newer modalities, including targeted molecular therapies as well as immunotherapy, and chimeric antigen receptor (CAR) T-cell therapy, are currently being employed to increase treatment effectiveness as well as lessen the side effects from conventional chemotherapy. These approaches explore the use of early genome-based disease characterization and medications developed against actionable molecular targets.

Conclusions

Additional clinical research is nonetheless required to learn more about the potentially harmful effects of targeted therapies and investigate the possibility of these agents replacing or decreasing the use of conventional chemotherapy in treating pediatric ALL.

The evolution of acute lymphoblastic leukemia research and therapy at MD Anderson over four decades

Progress in the research and therapy of adult acute lymphoblastic leukemia (ALL) is accelerating. This analysis summarizes the data derived from the clinical trials conducted at MD Anderson between 1985 and 2022 across ALL subtypes. In Philadelphia chromosome-positive ALL, the addition of BCR::ABL1 tyrosine kinase inhibitors (TKIs) to intensive chemotherapy since 2000, improved outcomes. More recently, a chemotherapy-free regimen with blinatumomab and ponatinib resulted in a complete molecular remission rate of 85% and an estimated 3-year survival rate of 90%, potentially reducing the role of, and need for allogeneic stem cell transplantation (SCT) in remission. In younger patients with pre-B Philadelphia chromosome-negative ALL, the integration of blinatumomab and inotuzumab into the frontline therapy has improved the estimated 3-year survival rate to 85% across all risk categories. Our future strategy is to evaluate the early integration of both immunotherapy agents, inotuzumab and blinatumomab, with low-dose chemotherapy (dose-dense mini-Hyper-CVD-inotuzumab-blinatumomab) into the frontline setting followed by CAR T cells consolidation in high-risk patients, without any further maintenance therapy. In older patients, using less intensive chemotherapy (mini-Hyper-CVD) in combination with inotuzumab and blinatumomab has improved the 5-year survival rate to 50%. Among patients ≥ 65-70 years, the mortality in complete remission (CR) is still high and is multifactorial (old age, death in CR with infections, development of myelodysplastic syndrome or acute myeloid leukemia). A chemotherapy-free regimen with inotuzumab and blinatumomab is being investigated. The assessment of measurable residual disease (MRD) by next-generation sequencing (NGS) is superior to conventional assays, with early MRD negativity by NGS being associated with the best survival. We anticipate that the future therapy in B-ALL will involve less intensive and shorter chemotherapy regimens in combination with agents targeting CD19 (blinatumomab), CD20, and CD22 (inotuzumab). The optimal timing and use of CAR T cells therapy may be in the setting of minimal disease, and future trials will assess the role of CAR T cells as a consolidation among high-risk patients to replace allogeneic SCT. In summary, the management of ALL has witnessed significant progress during the past four decades. Novel combination regimens including newer-generation BCR::ABL1 TKIs and novel antibodies are questioning the need and duration of intensive chemotherapy and allogeneic SCT.

Recent progress in pediatric lymphoblastic leukemia

The probability of long-term survival for children with lymphoblastic leukemia has improved dramatically over recent decades, mainly owing to advances in genomic analysis techniques, which have improved our understanding of the nature of leukemic cells and prognostic prediction based on the evaluation of precise treatment response. Risk-adjusted chemotherapy based on these advances has simultaneously reduced relapse rates and minimized complications. In addition, recent genomic analyses have deepened our understanding of the pathogenesis of leukemia and revealed the involvement of germline variations in the clinical course of leukemia treatment. Additionally, advances in minimal residual disease assays and the introduction of immunotherapy are expected to further improve therapeutic analyses. Further advances in clinical and translational research are anticipated to improve survival to 100% in a healthy state.

Switching from salvage chemotherapy to immunotherapy in adult B-cell acute lymphoblastic leukemia

About one-half of adults with acute B-cell lymphoblastic leukemia (B-ALL) who do not achieve molecular complete remission or who subsequently relapse are not cured by current chemo- or targeted therapies. Previously, the sole therapeutic option for such persons was a hematopoietic stem cell transplant. Recently, several immune therapies including monoclonal antibodies, bispecific T-cell engagers (BiTEs), antibody-drug conjugates (ADCs), and chimeric antigen receptor T-cells (CARs) have been shown safe and effective in this setting. In this manuscript, we summarize data on US FDA-approved immune therapies of advanced adult B-ALL including rituximab, blinatumomab, inotuzumab ozogamicin, tisagenlecleucel and brexucabtagene autoleucel. We consider the results of clinical trials focusing on efficacy, safety, and quality of life (QoL). Real-world evidence is presented as well. We also briefly discuss pharmacodynamics, pharmacokinetics, and pharmacoeconomics followed by risk-benefit analyses. Lastly, we present future directions of immune therapies for advanced B-ALL in adults.

Post-Hematopoietic Cell Transplantation Relapsed Acute Lymphoblastic Leukemia: Current Challenges and Future Directions

Allogeneic hematopoietic cell transplantation (allo-HCT) represents an important and potentially curative treatment option for adult patients with acute lymphoblastic leukemia. Relapse continues to remain the most important factor influencing overall survival post allo-HCT. We discuss early identification, clinical manifestations, and management of relapsed disease. Routine evaluation of measurable residual disease (MRD) and change in donor chimerism play a crucial role in early detection. Pivotal clinical trials have led to FDA approval of multiple novel agents like blinatumomab and inotuzumab. Combining targeted therapy with cellular immunotherapy serves as the backbone for prolonging overall survival in these patients. Donor lymphocyte infusions have traditionally been used in relapsed disease with suboptimal outcomes. This review provides insight into use of cellular therapy in MRD positivity and decreasing donor chimerism. It also discusses various modalities of combining cellular therapy with novel agents and discussing the impact of chimeric antigen receptor T-cell therapy in the setting of post allo-HCT relapse both as consolidative therapy and as a bridge to second transplant.

Comparing the efficacy of salvage regimens for relapsed/refractory B-cell acute lymphoblastic leukaemia: a systematic review and network meta-analysis

The complete remission (CR) rate and overall survival (OS) of relapsed/refractory (R/R) B-cell acute lymphoblastic leukaemia (B-ALL) are not satisfactory. The available salvage regimens include standard chemotherapy, inotuzumab ozogamicin, blinatumomab and cluster of differentiation (CD)19 chimeric antigen receptor T cells (CAR T), and the NCCN guidelines recommend all of these therapies with no preference. Dual CD19/CD22 CAR T-cells have emerged as new treatments and have shown some efficacy, with high CR rates and preventing CD19-negative relapse. However, direct comparisons of the CR rate and long-term survival among the different salvage therapies are lacking. Databases including PubMed, Embase, Web of Science and Cochrane were searched from inception to January 31, 2022, for relevant studies. The outcomes of interest were complete remission/complete remission with incomplete haematologic recovery (CR/CRi) rates and 1-year overall survival (OS) rates. Odds ratios (ORs) were generated for binary outcomes, and the mean difference (MD) was generated for consecutive outcomes by network meta-analysis. CD19 CAR T-cells demonstrated a significantly better effect in improving the CR/CRi rate than blinatumomab (OR = 8.32, 95% CI: 1.18 to 58.44) and chemotherapy (OR = 16.4, 95% CI: 2.76 to 97.45). In terms of OS, CD19 CAR T-cells and dual CD19/CD22 CAR T-cells both had a higher 1-year OS rate than blinatumomab, inotuzumab ozogamicin and chemotherapy. There was no significant difference between CD19 CAR T-cells and dual CD19/CD22 CAR T-cells in terms of 1-year OS and CR/CRi rates. CD19 CAR T-cells are effective in inducing CR, and CD19 CAR T-cells and dual CD19/CD22 CAR T-cells show benefits for overall survival. More high-quality randomized controlled trials and longer follow-ups are needed to confirm and update the results of this analysis in the future.

Mini-hyper CVD + CRIB (condensed rituximab, inotuzumab ozogamicin, and blinatumomab) for refractory pediatric B-acute lymphoblastic leukemia

Relapsed or refractory pediatric patients with B-acute lymphoblastic leukemia (B-ALL) have high rates of toxicities and relapse, and novel therapy is needed. We present a case of a 5-year-old male child with high-risk B-ALL that was refractory to several re-induction regimens. He was put into minimal residual disease-negative remission after re-induction with chemotherapy plus overlapping rituximab, inotuzumab ozogamicin, and blinatumomab, termed mini-hyper-CVD (cyclophosphamide, vincristine, and dexamethasone) plus CRIB (condensed rituximab, inotuzumab ozogamicin, and blinatumomab). This regimen was well tolerated, and he received his transplant and engrafted with no significant infections, toxicities, or sinusoidal obstruction syndrome. This is the first reported use of a condensed sequential immunotherapy/chemotherapy regimen in a pediatric leukemia patient.

Therapeutic Advances in Immunotherapies for Hematological Malignancies

Following the success of immunotherapies such as chimeric antigen receptor transgenic T-cell (CAR-T) therapy, bispecific T-cell engager therapy, and immune checkpoint inhibitors in the treatment of hematologic malignancies, further studies are underway to improve the efficacy of these immunotherapies and to reduce the complications associated with their use in combination with other immune checkpoint inhibitors and conventional chemotherapy. Studies of novel therapeutic strategies such as bispecific (tandem or dual) CAR-T, bispecific killer cell engager, trispecific killer cell engager, and dual affinity retargeting therapies are also underway. Because of these studies and the discovery of novel immunotherapeutic target molecules, the use of immunotherapy for diseases initially thought to be less promising to treat with this treatment method, such as acute myeloid leukemia and T-cell hematologic tumors, has become a reality. Thus, in this coming era of new transplantation- and chemotherapy-free treatment strategies, it is imperative for both scientists and clinicians to understand the molecular immunity of hematologic malignancies. In this review, we focus on the remarkable development of immunotherapies that could change the prognosis of hematologic diseases. We also review the molecular mechanisms, development processes, clinical efficacies, and problems of new agents.

The expression and methylation of PITX genes is associated with the prognosis of head and neck squamous cell carcinoma

Background: The PITX gene family, comprising PITX1, PITX2, and PITX3, is critical in organogenesis and has been evolutionary conserved in animals. PITX genes are associated with the advanced progression and poor prognosis of multiple cancers. However, the relationship between the PITX genes and head and neck squamous cell carcinoma (HNSC) has not been reported.

Methods: We used data from The Cancer Genome Atlas (TCGA) to analyze the association between PITX mRNA expression and clinicopathological parameters of patients with HNSC. The prognostic value of PITX genes was evaluated using the Kaplan-Meier plotter. Multivariate Cox analysis was used to screen out prognosis-associated genes to identify better prognostic indicators. The potential roles of PITX1 and PITX2 in HNSC prognosis were investigated using the protein-protein interaction (PPI) network, Gene Ontology (GO) analysis, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. The correlation between PITX1 and PITX2 expression or methylation and immune cell infiltration was evaluated using the tumor-immune system interaction database (TISIDB). MethSurv was used to identify DNA methylation and its effect on HNSC prognosis.

Results:PITX genes expression was correlated with different cancers. PITX1 and PITX2 expression was lower in the patients with HNSC. In HNSC, PITX1 expression was significantly related to the clinical stage, histologic grade, and N stage, while PITX2 expression was only significantly related to the histologic grade. The high expression of PITX3 was significantly related to the histologic grade, T stage, and N stage. Survival analysis revealed that PITX genes had prognostic value in HNSC, which was supported by multivariate Cox analysis. PPI network and enrichment analysis showed that the genes interacting with PITX1 and PITX2 belonged predominantly to signaling pathways associated with DNA binding and transcription. Of the CpG DNA methylation sites in PITX1 and PITX2, 28 and 22 were related to the prognosis of HNSC, respectively. Additionally, PITX1 and PITX2 expression and methylation was associated with tumor-infiltrating lymphocytes (TILs).

Conclusion: The PITX genes were differentially expressed in patients with HNSC, highlighting their essential role in DNA methylation and tumor-infiltrating immune cell regulation, as well as overall prognostic value in HNSC.

FDA Approval Summary: Brexucabtagene Autoleucel for Treatment of Adults With Relapsed or Refractory B-Cell Precursor Acute Lymphoblastic Leukemia

In October 2021, the FDA approved brexucabtagene autoleucel (brexu-cel), a CD19-directed chimeric antigen receptor (CAR) T-cell therapy, for the treatment of adult patients with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (B-ALL). Approval was based on the phase II portion of ZUMA-3, a single-arm, open-label, multicenter trial that evaluated a single infusion of brexu-cel, preceded by lymphodepleting chemotherapy with cyclophosphamide and fludarabine, in this population. Efficacy was established on the basis of complete remission (CR) within 3 months after infusion and the duration of CR (DOCR). Among 54 patients in the efficacy analysis population, the CR rate was 52% (95% CI: 38, 66) with a median time-to-response of 56 days. With a median follow-up for responders of 7.1 months, the median DOCR was not reached. For all leukapheresed patients in the phase II portion of this trial (n = 71), the CR rate was 41% (95% CI: 29, 53). Among the 78 patients treated with the approved dose of brexu-cel, serious adverse reactions occurred in 79% and fatal adverse reactions occurred in 5% and included cerebral edema and infections. Cytokine release syndrome occurred in 92% (grade ≥3, 26%) and neurologic toxicities occurred in 87% (grade ≥3, 35%), leading to implementation of a risk evaluation and mitigation strategy (REMS). Postmarketing study with 15 years of follow-up will further evaluate long-term safety in adult patients with relapsed or refractory B-ALL.

SOHO State of the Art Updates and Next Questions: Novel Transplant and Post-Transplant Options in Acute Lymphoblastic Leukemia

Allogeneic hematopoietic cell transplantation (alloHCT) is a potentially curative treatment approach for patients with high-risk acute lymphoblastic leukemia (ALL). Despite development of several novel therapies targeting B-cell ALL, alloHCT continues to play an essential role in management, but the identification of patients who are most likely to benefit from alloHCT in first or subsequent remissions continues to evolve. Broader donor options, including haploidentical donors and umbilical cord blood, have enabled alloHCT for more patients, but improvements in front-line therapy and increasing use of high-sensitivity measurable residual disease (MRD) quantification continue to modify the calculus for selecting which patients require transplantation. MRD quantification has become increasingly important as a prognostic indicator, as well as a trigger for therapeutic intervention, since the achievement of MRD negative complete remission is well-established to be associated with improved transplant outcomes. ALL remains the only malignancy with approved therapy for MRD positivity after achievement of remission, and use of Blinatumomab in this setting currently appears to be most effective when used as a bridge-to-transplant, rather than a destination or purely consolidative therapy. Expanding options for those with relapsed/refractory disease, including chimeric antigen receptor (CAR)-T cells, also render more patient in suitably deep remissions to enable alloHCT with a high likelihood of success. It remains unclear whether CAR-T cell therapies may obviate the need for alloHCT in some patients, and currently available data suggest there remains a role for alloHCT after CAR-T. Together, these therapeutic advances appear to be improving post-transplant outcomes. Nevertheless, more remains to be studied regarding how to optimize use of available and emerging cellular and immune modulating therapies to maximize the likelihood of long-term post-alloHCT remission in high-risk ALL.

Monoclonal antibodies: new chance in the management of B-cell acute lymphoblastic leukemia

OBJECTIVES

This review aims to see the progress of several clinically-used monoclonal antibodies in treating ALL patients and how they improved patients' outcomes.

METHODS

We searched Web of Science, Elsevier and PubMed for relevant published studies, and summarized eligible evidence on the management of newly-diagnosed and relapsed or refractory ALL with monoclonal antibodies. Ongoing trials were identified from ClinicalTrials.gov.

RESULTS

Rituximab, an anti-CD20 monoclonal antibody, prolonged patients' complete remission duration and overall survival when combined with hyper-CVAD regimen. Another anti-CD20 monoclonal antibody, Ofatumumab, was reported to have similar benefits. Blinatumomab allows endogenous CD3-positive cytotoxic T cells to target and eliminate CD19-positive blasts. FDA has approved its efficacy in patients with R/R B-ALL and eliminating minimal residual disease (MRD). It serves as a bridge to eradicate MRD before transplantation, and may also be a new choice for patients unable to undergo transplantation. An anti-CD22 monoclonal antibody named Inotuzumab Ozogamicin showed great improvement in patients' outcome, but its toxicity to liver is also worthy of our attention.

CONCLUSION

Monoclonal antibodies are proven to be a promising immunotherapeutic strategy to improve ALL patients' outcome in the long term. There's still a need for individualized treatment with effective and well-tolerated medicines.Trial registration: ClinicalTrials.gov identifier: NCT01363128.Trial registration: ClinicalTrials.gov identifier: NCT01466179.Trial registration: ClinicalTrials.gov identifier: NCT02013167.Trial registration: ClinicalTrials.gov identifier: NCT02000427.Trial registration: ClinicalTrials.gov identifier: NCT01564784.Trial registration: ClinicalTrials.gov identifier: NCT03677596.Trial registration: ClinicalTrials.gov identifier: NCT01363297.Trial registration: ClinicalTrials.gov identifier: NCT02981628.Trial registration: ClinicalTrials.gov identifier: NCT03094611.Trial registration: ClinicalTrials.gov identifier: NCT01371630.Trial registration: ClinicalTrials.gov identifier: NCT04224571.Trial registration: ClinicalTrials.gov identifier: NCT02458014.Trial registration: ClinicalTrials.gov identifier: NCT04546399.Trial registration: ClinicalTrials.gov identifier: NCT02879695.Trial registration: ClinicalTrials.gov identifier: NCT03913559.Trial registration: ClinicalTrials.gov identifier: NCT03441061.Trial registration: ClinicalTrials.gov identifier: NCT03739814.Trial registration: ClinicalTrials.gov identifier: NCT02877303.Trial registration: ClinicalTrials.gov identifier: NCT03698552.Trial registration: ClinicalTrials.gov identifier: NCT04601584.Trial registration: ClinicalTrials.gov identifier: NCT04684147.Trial registration: ClinicalTrials.gov identifier: NCT04681105.

Monoclonal antibodies for the treatment of acute lymphocytic leukemia: A literature review

BACKGROUND

Acute lymphocytic leukemia (ALL) is a type of blood cancer that is more prevalent in children. Several treatment methods are available for ALL, including chemotherapy, upfront treatment regimens, and pediatric-inspired regimens for adults. Monoclonal antibodies (Mabs) are the novel Food and Drug Administration (FDA) approved remedies for the relapsed/refractory (R/R) adult ALL. In this article, we aimed to review studies that investigated the efficacy and safety of Mabs on ALL.

METHODS

We gathered studies through a complete search with all proper related keywords in ISI Web of Science, SID, Scopus, Google Scholar, Science Direct, and PubMed for English language publications up to 2020.

RESULTS

The most commonly studied Mabs for ALL therapies are CD-19, CD-20, CD-22, and CD-52. The best results have been reported in the administration of blinatumomab, rituximab, ofatumumab, and inotuzumab with acceptable low side effects.

CONCLUSION

Appling personalized approach for achieving higher efficacy is one of the most important aspects of treatment. Moreover, we recommend that the wide use of these Mabs depends on designing further cost-effectiveness trials in this field.

VANDA regimen followed by blinatumomab leads to favourable outcome in patients with Philadelphia chromosome-negative B-precursor acute lymphoblastic leukaemia in first relapse

Adults with relapsed or refractory B-precursor acute lymphoblastic leukaemia (R/R BCP-ALL) have very poor outcome. Blinatumomab as single agent has shown activity in R/R BCP-ALL. We aimed to assess the activity of blinatumomab in concomitant association with intensive chemotherapy. Seventeen patients with R/R BCP-ALL were treated with combination of blinatumomab and VANDA (etoposide, cytarabine, mitoxantrone, dexamethasone and asparaginase) regimen. Complete remission (CR) was achieved in 14/17 patient (82%) and 11/17 (65%) were transplanted. One-year leukaemia-free survival was 58.8% for the whole cohort and 90.9% for transplanted patients. These preliminary data suggest that the VANDA-blinatumomab salvage regimen leads to a very high rate of CR and HSCT in suitable patients.

Updates in the Management of Relapsed and Refractory Acute Lymphoblastic Leukemia: An Urgent Plea for New Treatments Is Being Answered!

The treatment of acute lymphoblastic leukemia (ALL) has dramatically changed over the past three decades. However, relapsed and/or refractory ALL still remains with a very low survival and high morbidity associated with its treatment. Here, we will review the outstanding progress that has been made in the treatment of relapsed and/or refractory ALL and discuss future directions and challenges that require further investigation.

Infectious complications of targeted drugs and biotherapies in acute leukemia. Clinical practice guidelines by the European Conference on Infections in Leukemia (ECIL), a joint venture of the European Group for Blood and Marrow Transplantation (EBMT), the European Organization for Research and Treatment of Cancer (EORTC), the International Immunocompromised Host Society (ICHS) and the European Leukemia Net (ELN)

The 9th web-based European Conference on Infections in Leukemia (ECIL-9), held September 16-17, 2021, reviewed the risk of infections and febrile neutropenia associated with more recently approved immunotherapeutic agents and molecular targeted drugs for the treatment of acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). Novel antibody based treatment approaches (inotuzumab ozogamicin, gemtuzumab ozogamicin, flotetuzumab), isocitrate dehydrogenases inhibitors (ivosidenib, enasidenib, olutasidenib), FLT3 kinase inhibitors (gilteritinib, midostaurin, quizartinib), a hedgehog inhibitor (glasdegib) as well as a BCL2 inhibitor (venetoclax) were reviewed with respect to their mode of action, their immunosuppressive potential, their current approval and the infectious complications and febrile neutropenia reported from clinical studies. Evidence-based recommendations for prevention and management of infectious complications and specific alerts regarding the potential for drug-drug interactions were developed and discussed in a plenary session with the panel of experts until consensus was reached. The set of recommendations was posted on the ECIL website for a month for comments from members of EBMT, EORTC, ICHS and ELN before final approval by the panelists. While a majority of these agents are not associated with a significantly increased risk when used as monotherapy, caution is required with combination therapy such as venetoclax plus hypomethylating agents, gemtuzumab ozogamicin plus cytotoxic drugs or midostaurin added to conventional AML chemotherapy.

Phase II Trial of Inotuzumab Ozogamicin in Children and Adolescents With Relapsed or Refractory B-Cell Acute Lymphoblastic Leukemia: Children's Oncology Group Protocol AALL1621

PURPOSE

Children's Oncology Group trial AALL1621 was conducted to prospectively determine the safety and efficacy of inotuzumab ozogamicin (InO) in pediatric and adolescent patients with relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL).

PATIENTS AND METHODS

This single-arm phase II trial enrolled patients age 1-21 years with R/R CD22-positive B-ALL. In cycle 1, InO dosing was 0.8 mg/m2 intravenously on day 1 and 0.5 mg/m2 on days 8 and 15 of a 28-day cycle with response evaluation at day 28. Using a two-stage design, the trial was continuously monitored for dose-limiting toxicities and sinusoidal obstruction syndrome (SOS). CD22 expression was retrospectively evaluated by central flow cytometry.

RESULTS

Forty-eight patients were evaluable for response and toxicity; 19 had complete response (CR) and nine CR with incomplete count recovery (CRi) after cycle 1 (CR/CRi rate: 58.3%; two-sided 90% CI, 46.5 to 69.3). Twenty-seven of 28 patients with CR or CRi had minimal residual disease measured by flow cytometry; 18 (66.7%) had minimal residual disease < 0.01%. Seven of 28 patients (25%) with CR or CRi had delayed count recovery past day 42 in cycle 1. Three (6.3%) patients had grade 3 ALT elevation and one patient had grade 3 hyperbilirubinemia in cycle 1. Of 21 patients undergoing hematopoietic stem-cell transplantation after InO, 6 (28.6%) developed grade 3 SOS. Partial CD22 expression and lower CD22 site density were associated with lower likelihood of response to InO.

CONCLUSION

InO is effective and well tolerated in heavily pretreated children and adolescents with R/R CD22-positive B-ALL. SOS after hematopoietic stem-cell transplantation and prolonged cytopenias were notable. CD22 modulation was identified as a mechanism of resistance. Expanded study of InO combined with chemotherapy is underway.

Evaluation of the efficacy of ursodiol for prevention of hepatotoxicity in patients receiving gemtuzumab ozogamicin and inotuzumab ozogamicin

Gemtuzumab ozogamicin (GO) and inotuzumab ozogamicin (InO) are indicated for newly diagnosed or relapsed/refractory CD33-positive acute myeloid leukemia and relapsed/refractory B-cell precursor acute lymphoblastic leukemia respectively. Patients undergoing therapy with these agents are at increased risk for hepatotoxicity. Forty-nine patients received either GO or InO with concomitant ursodiol (n=14) or no ursodiol (n=35) for hepatotoxicity prophylaxis. Hepatotoxicity occurred in 2 (14%) patients in the ursodiol group compared to 15 (43%) patients in the no ursodiol group (p=0.10). Median days (17 versus 11; p=0.66) and doses (4 versus 2; p=0.28) to development of hepatotoxicity were higher in the ursodiol versus no ursodiol group. After adjusting for concomitant hepatotoxic medications and prior chemotherapy, ursodiol did not significantly reduce the incidence of hepatotoxicity. Ursodiol prophylaxis was associated with a similar incidence of hepatotoxicity compared to no ursodiol, but may delay the time to occurrence.

The cure of leukemia through the optimist's prism

Progress is occurring at a dizzying rate across all leukemias. Since the authors' review of the topic in Cancer in 2018, numerous discoveries have been made that have improved the therapy and outcomes of several leukemia subsets. Hairy cell leukemia is potentially curable with a single course of cladribine followed by rituximab (10-year survival, ≥90%). Acute promyelocytic leukemia is curable at a rate of 80% to 90% with a nonchemotherapy regimen of all-trans retinoic acid and arsenic trioxide. The cure rate for core-binding factor acute myeloid leukemia (AML) is ≥75% with fludarabine, high-dose cytarabine, and gemtuzumab ozogamicin. Survival for patients with chronic myeloid leukemia is close to that for an age-matched normal population with BCR-ABL1 tyrosine kinase inhibitors (TKIs). Chronic lymphocytic leukemia, a previously incurable disease, may now be potentially curable with a finite duration of therapy with Bruton tyrosine kinase inhibitors and venetoclax. The estimated 5-year survival rate for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL) exceeds 70% with intensive chemotherapy and ponatinib, a third-generation BCR-ABL1 TKI, and more recent nonchemotherapy regimens using dasatinib or ponatinib with blinatumomab are producing outstanding results. Survival in both younger and older patients with ALL has improved with the addition of antibodies targeting CD20, CD19 (blinatumomab), and CD22 (inotuzumab) to chemotherapy. Several recent drug discoveries (venetoclax, FLT3 and IDH inhibitors, and oral hypomethylating agents) are also improving outcomes for younger and older patients with AML and for those with higher risk myelodysplastic syndrome.

Assessment of liver stiffness measurement and ultrasound findings change during inotuzumab ozogamicin cycles for relapsed or refractory acute lymphoblastic leukemia

In adult patients, acute lymphoblastic leukemia (ALL) is a rare hematological cancer with a cure rate below 50% and frequent relapses. With traditional therapies, patients with relapsed or refractory (R/R) ALL have a survival that may be measured in months; in these patients, inotuzumab ozogamicin (IO) is an effective therapy. IO was linked to increased risk of veno-occlusive disease/sinusoid obstruction syndrome (VOD/SOS), liver injury, and various grade of liver-related complications during clinical trials and real-life settings; however, hepatologic monitoring protocol is not established in this population. In our institution, 21 patients who received IO (median of 6 doses of IO administered) for R/R ALL were prospectively followed for hepatologic surveillance, including clinical evaluation, ultrasonography, and liver stiffness measurement (LSM) biochemistry. After a median follow-up of 17.2 months, two SOS events were reported (both after allogeneic transplant) as IO potentially related clinically relevant adverse event. Mild alterations were reported in almost the totality of patients and moderate-severe liver biochemical alterations in a quarter of patients. Within biochemicals value, AST and ALP showed an augment related to IO administration. LSM linearly augmented for each IO course administered. Baseline LSM was related to liver-related changes, especially with the severity of portal hypertension (PH)-related complications. Pre-transplant LSM was higher in patients receiving IO when compared with a control cohort. PH-related complications were discovered in nearly 77% of patients, with clinically significant PH occurrence and development of ascites in 38% and 14%, respectively. This prospective experience constitutes the rationale to design a hepatologic monitoring program in patients receiving IO. LSM may be of pivotal importance in this program, constituting a rapid and effective screening that quantitatively correlates with liver alterations.

Emerging Monoclonal Antibody Therapy for the Treatment of Acute Lymphoblastic Leukemia

The treatment of adults with ALL has undergone tremendous progress over the past 15 years. The advances have been particularly marked with B-lineage ALL. The development of bispecific antibodies directed against CD19 ushered in a new era in overcoming persistent minimal disease in newly diagnosed ALL patients as well as successfully treating those with relapsed disease. The immune-conjugates targeting CD22 have also had a similarly impressive role in improving the outcome in such patients. These advances are now being extended to frontline regimens for B-lineage ALL, including the Philadelphia-chromosome-positive subtype. Over the past decade, the development of chimeric antigen receptor T-cell therapy (CAR-T) has ushered in a new era, opening up hope when none was available for patients with particularly advanced disease. Such advances come at a considerable price for toxicity, which, however, are lessening with experience and the development of new agents to ameliorate some of the toxicities. Unfortunately, the progress for T-cell in ALL has lagged behind that of B-lineage ALL. Of late, however, there are preliminary results of potentially exciting data using monoclonal antibodies against CD38, in the form of daratumumab, and it is hoped that these will lead to an equally successful advance in the treatment of T-ALL. Despite all these advances, ALL in adults remains a formidable disease. While ongoing progress is being made, also in the therapy of older patients, we are still lagging behind the almost totally curative potential of current therapy for childhood ALL.

Acute Lymphoblastic Leukemia, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Acute Lymphoblastic Leukemia (ALL) focus on the classification of ALL subtypes based on immunophenotype and cytogenetic/molecular markers; risk assessment and stratification for risk-adapted therapy; treatment strategies for Philadelphia chromosome (Ph)-positive and Ph-negative ALL for both adolescent and young adult and adult patients; and supportive care considerations. Given the complexity of ALL treatment regimens and the required supportive care measures, the NCCN ALL Panel recommends that patients be treated at a specialized cancer center with expertise in the management of ALL This portion of the Guidelines focuses on the management of Ph-positive and Ph-negative ALL in adolescents and young adults, and management in relapsed settings.

Relapsed Babesia microti Infection Following Allogeneic Hematopoietic Cell Transplantation in a Patient With B-cell Acute Lymphoblastic Leukemia: Case Report and Review of the Literature

A patient with relapsed/refractory B-cell acute lymphoblastic leukemia developed babesiosis before allogeneic hematopoietic cell transplantation while on atovaquone for Pneumocystis jirovecii pneumonia prophylaxis. Despite receiving a prolonged course of atovaquone and azithromycin until whole-blood Babesia microti DNA was no longer detected by polymerase chain reaction, her post-transplant course was complicated by relapsed babesiosis. We investigate the potential host and parasite characteristics causing relapsing/persistent infection.

A case series of patients treated with inotuzumab ozogamicin for acute lymphoblastic leukemia relapsed after allogeneic hematopoietic cell transplantation

This single-center retrospective study was performed in consecutive patients with acute lymphoblastic leukemia who relapsed after allogeneic hematopoietic cell transplantation (HCT) and received salvage therapy using inotuzumab ozogamicin (InO). Ten patients (median age: 27 years) treated between June 2018 and July 2020 who met the eligibility criteria were included in this study. Nine patients received InO in one cycle and seven of these patients achieved complete hematological remission after salvage chemotherapy including InO. Negative minimal residual disease was confirmed in all four evaluable patients. Eight patients were successfully bridged to the subsequent HCT. After HCT, veno-occlusive disease (VOD) developed in three patients, and caused the death of one. No patient received maintenance therapy. At present, five patients are disease-free and alive, and the overall and progression-free survival rates at 1 year were 60% and 40%, respectively. High rates of disease remission and bridging to HCT with comprehensive treatments including InO may have contributed to favorable outcomes. However, further investigation is needed to reduce post-HCT complications including VOD.

Vincristine in Combination Therapy of Cancer: Emerging Trends in Clinics

Treatment of blood malignancies and other cancer diseases has been mostly unfeasible, so far. Therefore, novel treatment regimens should be developed and the currently used ones should be further elaborated. A stable component in various cancer treatment regimens consists of vincristine, an antimitotic compound of natural origin. Despite its strong anticancer activity, mostly, it cannot be administered as monotherapy due to its unspecific action and severe side effects. However, vincristine is suitable for combination therapy. Multidrug treatment regimens including vincristine are standardly applied in the therapy of non-Hodgkin lymphoma and other malignancies, in which it is combined with drugs of different mechanisms of action, mainly with DNA-interacting compounds (for example cyclophosphamide), or drugs interfering with DNA synthesis (for example methotrexate). Besides, co-administration of vincristine with monoclonal antibodies has also emerged, the typical example of which is the anti-CD20 antibody rituximab. Although in some combination anticancer therapies, vincristine has been replaced with other drugs exhibiting lesser side effects, though, in most cases, it is still irreplaceable. This is strongly evidenced by the number of active clinical trials evaluating vincristine in combination cancer therapy. Therefore, in this article, we have reviewed the most common cancer treatment regimens employing vincristine and bring an overview of current trends in the clinical development of this compound.

Antibody and cellular immunotherapies for acute lymphoblastic leukemia in adults

Despite improvements in the outcomes of patients with acute lymphoblastic leukemia (ALL), traditional therapies (including hematopoietic stem cell transplant) often still fail. Antigen-specific immunotherapies for the treatment of ALL such as monoclonal antibodies, antibody-drug conjugates, bispecific T-cell engagers (BiTEs), and chimeric antigen receptor (CAR) T-cells have demonstrated remarkable clinical efficacy and are rapidly evolving. With indisputable activity in patients with relapsed or refractory ALL, efforts now hope to integrate these agents into earlier phases of treatment. In this review, we will discuss the available antibody and cellular-based immunotherapies for the treatment of patients with ALL and provide a clinical and biologic framework with which to inform treatment approaches.

Optimizing the treatment of acute lymphoblastic leukemia in younger and older adults: new drugs and evolving paradigms

In the past decade, the available treatments for patients with acute lymphoblastic leukemia (ALL) have rapidly expanded, in parallel with an increased understanding of the genomic features that impact the disease biology and clinical outcomes. With the development of the anti-CD22 antibody-drug conjugate inotuzumab ozogamicin, the CD3-CD19 bispecific T-cell engager antibody blinatumomab, CD19 chimeric antigen receptor T-cell therapy, and the potent BCR-ABL1 tyrosine kinase inhibitor ponatinib, the outlook of ALL in both younger and older adults has substantially improved. The availability of highly effective drugs raised important questions concerning the optimal combination and sequence of these agents, their incorporation into frontline regimens, and the role of hematopoietic stem cell transplantation. In this review, we discuss the rapidly evolving paradigms in the treatment of ALL, highlighting both established and effective regimens, as well as promising new therapies that are being evaluated in ongoing clinical trials. We specifically focus on novel combination regimens in both the frontline and salvage settings that are leading to new standards of care in the treatment of ALL.

The promising role of antibody drug conjugate in cancer therapy: Combining targeting ability with cytotoxicity effectively

Introduction

Traditional cancer therapy has many disadvantages such as low selectivity and high toxicity of chemotherapy, as well as insufficient efficacy of targeted therapy. To enhance the cytotoxic effect and targeting ability, while reducing the toxicity of antitumor drugs, an antibody drug conjugate (ADC) was developed to deliver small molecular cytotoxic payloads directly to tumor cells by binding to specific antibodies via linkers.

Method

By reviewing published literature and the current progress of ADCs, we aimed to summarize the basic characteristics, clinical progress, and challenges of ADCs to provide a reference for clinical practice and further research.

Results

ADC is a conjugate composed of three fundamental components, including monoclonal antibodies, cytotoxic payloads, and stable linkers. The mechanisms of ADC including the classical internalization pathway, antitumor activity of antibodies, bystander effect, and non‐internalizing mechanism. With the development of new drugs and advances in technology, various ADCs have achieved clinical efficacy. To date, nine ADCs have received US Food and Drug Administration (FDA) approval in the field of hematologic tumors and solid tumors, which have become routine clinical treatments.

Conclusion

ADC has changed traditional treatment patterns for cancer patients, which enable the same treatment for pancreatic cancer patients and promote individualized precision treatment. Further exploration of indications could focus on early‐stage cancer patients and combined therapy settings. Besides, the mechanisms of drug resistance, manufacturing techniques, optimized treatment regimens, and appropriate patient selection remain the major topics.

Molecular-based and antibody-based targeted pharmacological approaches in childhood acute lymphoblastic leukemia

Introduction: Despite the significant survival improvement in childhood acutelymphoblastic leukemia (ALL), 15-20% of patients continue to relapse; outcomes following relapse remain suboptimal and have room for further improvement. Advances in genomics have shed new insights on the biology of ALL, led to the discovery of novel genomically defined ALL subtypes, refined prognostic significance and revealed new therapeutic vulnerabilities.Areas covered: In this review, the authors provide an overview of the genomic landscape of childhood ALL and highlight recent advances in molecular-based and antibody-based pharmacological approaches in the treatment of childhood ALL, from emerging preclinical evidence to published results of completed clinical trials.Expert opinion: Molecularly targeted therapies and immunotherapies have expanded the horizons of ALL therapy and represent promising therapeutic avenues for high-risk and relapsed/refractory ALL. These novel therapies are now moving into frontline ALL therapy and may define new treatment paradigms that aim to further improve survival and reduce chemotherapy-related toxicities in the management of pediatric ALL.