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Tyrosine kinase inhibitors (TKIs) are standard therapy for patients with chronic myeloid leukemia. Each of these drugs has a specific profile of tyrosine kinases that they inhibit and, although all are clinically effective, they each have unique toxicity profiles. With the introduction of ponatinib, arterio-occlusive events were first noted and later found to occur with all TKIs to various extents. The recognition of this “class effect” was delayed considering ponatinib was introduced 10 years after the introduction of imatinib. The reasons for the delay in identification of this class effect are likely multifaceted. Importantly, there is an inconsistency in adverse event reporting criteria among the major clinical trials of the various TKIs, likely resulting in mixed reporting of arterio-occlusive events. Reporting events based on a frequency threshold, lack of sufficient follow-up, attempts at causality attribution, and the primary focus on molecular response may all have played an additional role. Considering the increasing rate of arterio-occlusive events over time, the termination of many trials after only 5 years prevents full assessment of the impact of these events. A comprehensive evaluation of TKI adverse effects using uniform Medical Dictionary for Regulatory Activities terms and comprehensive adjudication of these events may be helpful in better assessing the real risk for patients with each TKI. Future clinical trials should use a uniform and comprehensive approach to reporting adverse events without attempting to assign causality to the study drug.

The classification of myeloid neoplasms and acute leukemias was last updated in 2016 within a collaboration between the World Health Organization (WHO), the Society for Hematopathology, and the European Association for Haematopathology. This collaboration was primarily based on input from a clinical advisory committees (CACs) composed of pathologists, hematologists, oncologists, geneticists, and bioinformaticians from around the world. The recent advances in our understanding of the biology of hematologic malignancies, the experience with the use of the 2016 WHO classification in clinical practice, and the results of clinical trials have indicated the need for further revising and updating the classification. As a continuation of this CAC-based process, the authors, a group with expertise in the clinical, pathologic, and genetic aspects of these disorders, developed the International Consensus Classification (ICC) of myeloid neoplasms and acute leukemias. Using a multiparameter approach, the main objective of the consensus process was the definition of real disease entities, including the introduction of new entities and refined criteria for existing diagnostic categories, based on accumulated data. The ICC is aimed at facilitating diagnosis and prognostication of these neoplasms, improving treatment of affected patients, and allowing the design of innovative clinical trials.

Patients with chronic myeloid leukemia in chronic phase (CML-CP) resistant/intolerant to ≥2 tyrosine kinase inhibitors (TKIs) are at high risk of experiencing poor outcomes because of disease biology and inadequate efficacy and/or safety of current therapies. Asciminib, a first-in-class BCR-ABL1 inhibitor Specifically Targeting the ABL Myristoyl Pocket (STAMP), has the potential to overcome resistance/intolerance to approved TKIs. In this phase 3, open-label study, patients with CML-CP previously treated with ≥2 TKIs were randomized (2:1) to receive asciminib 40 mg twice daily vs bosutinib 500 mg once daily. Randomization was stratified by major cytogenetic response (MCyR) status at baseline. The primary objective was to compare the major molecular response (MMR) rate at week 24 for asciminib vs bosutinib. A total of 233 patients were randomized to asciminib (n = 157) or bosutinib (n = 76). Median follow-up was 14.9 months. The MMR rate at week 24 was 25.5% with asciminib and 13.2% with bosutinib. The difference in MMR rate between treatment arms, after adjusting for MCyR at baseline, was 12.2% (95% confidence interval, 2.19-22.30; 2-sided P = .029). Fewer grade ≥3 adverse events (50.6% vs 60.5%) and adverse events leading to treatment discontinuation (5.8% vs 21.1%) occurred with asciminib than with bosutinib. The study showed a superior efficacy of asciminib compared with that of bosutinib, together with a favorable safety profile. These results support the use of asciminib as a new therapy in patients with CML-CP who are resistant/intolerant to ≥2 prior TKIs. This trial was registered at www.clinicaltrials.gov as #NCT03106779.

In PACE (Ponatinib Ph+ ALL and CML Evaluation), a phase 2 trial of ponatinib that included patients with chronic-phase chronic myeloid leukemia (CP-CML) resistant to multiple prior tyrosine kinase inhibitors (TKIs), ponatinib showed deep and durable responses, but arterial occlusive events (AOEs) emerged as notable adverse events. Post hoc analyses indicated that AOEs are dose dependent. We assessed the benefit/risk ratio across 3 ponatinib starting doses in the first prospective study to evaluate a novel, response-based, dose-reduction strategy for TKI treatment. Adults with CP-CML resistant to or intolerant of at least 2 prior BCR-ABL1 TKIs or with a BCR-ABL1 T315I mutation were randomly assigned 1:1:1 to 3 cohorts receiving ponatinib 45, 30, or 15 mg once daily. In patients who received 45 or 30 mg daily the dose was reduced to 15 mg upon response (BCR-ABL1IS transcript levels ≤1%). The primary end point was response at 12 months. From August 2015 through May 2019, 283 patients were randomly assigned to the cohorts: 282 (94 per dose group) received treatment (data cutoff, 31 May 2020). The primary end point (98.3% confidence interval) was achieved in 44.1% (31.7-57.0) in the 45-mg cohort, 29.0% (18.4-41.6) in the 30-mg cohort, and 23.1% (13.4-35.3) in the 15-mg cohort. Independently confirmed grade 3 or above treatment-emergent AOEs occurred in 5, 5, and 3 patients in the 45-, 30-, and 15-mg cohorts, respectively. All cohorts showed benefit in this highly resistant CP-CML population. Optimal benefit/risk outcomes occurred with the 45-mg starting dose, which was decreased to 15 mg upon achievement of a response. This trial is registered on www.clinicaltrials.gov as NCT02467270.

Immune checkpoint therapy has resulted in remarkable improvements in the outcome for certain cancers. To broaden the clinical impact of checkpoint targeting, we devised a strategy that couples targeting of the cytokine-inducible Src homology 2–containing (CIS) protein, a key negative regulator of interleukin 15 (IL-15) signaling, with fourth-generation “armored” chimeric antigen receptor (CAR) engineering of cord blood–derived natural killer (NK) cells. This combined strategy boosted NK cell effector function through enhancing the Akt/mTORC1 axis and c-MYC signaling, resulting in increased aerobic glycolysis. When tested in a lymphoma mouse model, this combined approach improved NK cell antitumor activity more than either alteration alone, eradicating lymphoma xenografts without signs of any measurable toxicity. We conclude that targeting a cytokine checkpoint further enhances the antitumor activity of IL-15–secreting armored CAR-NK cells by promoting their metabolic fitness and antitumor activity. This combined approach represents a promising milestone in the development of the next generation of NK cells for cancer immunotherapy.

Patients with chronic myeloid leukemia (CML) often have comorbidities, at an incidence that might be higher than in the general population. Because of the favorable outcome of most patients with CML treated with tyrosine kinase inhibitors (TKIs), a greater number of comorbidities might be the most significant adverse feature for long-term survival. The presence of comorbidities may also affect the risk of developing adverse events with TKIs. This effect is perhaps best exemplified by the risk of developing arterio-occlusive events, which is greatest for patients who have other risk factors for such events, with the risk increasing with higher numbers of comorbidities. The coexistence of comorbidities in patients with CML not only may affect TKI selection but also demands close monitoring of the overall health condition of the patient to optimize safety and provide the opportunity for an optimal outcome to such patients. With optimal, holistic management of leukemia and all other conditions afflicting them, patients with CML and comorbidities may aim for a near-normal life expectancy, just as the more select patients enrolled in clinical trials now enjoy.

•Better clinical responses to teclistamab correlate with a more functional initial immune T-cell repertoire in the periphery and tumor site.•More durable responses to teclistamab associate with lower Tregs and lower expression of inhibitory receptors on T cells at baseline.

T-ALL relapse usually occurs early but can occur much later, which has been suggested to represent a de novo leukemia. However, we conclusively demonstrate late relapse can evolve from a pre-leukemic subclone harbouring a non-coding mutation that evades initial chemotherapy.

Introduction. Olutasidenib is a small molecule, oral, mutated-IDH1 (mIDH1) inhibitor approved for the treatment of relapsed/refractory (R/R) acute myeloid leukemia (AML). In the pivotal cohort of the registrational phase 1/2 trial, 51/147 (35%) patients achieved a complete remission (CR) or CR with partial hematologic recovery (CRh) to olutasidenib, with a duration of response of 25.9 months and an overall response rate (ORR) of 48%. The phase 1/2 study included 10 cohorts for a total of 335 patients, and there were patient subsets that were R/R to previous hematopoietic stem cell transplant (HSCT), ivosidenib (IVO) or venetoclax (VEN). We conducted post hoc analyses to better understand the response to olutasidenib in these poor-prognosis subgroups of mIDH1 AML.

Introduction. Olutasidenib is an FDA-approved, targeted therapy for IDH1-mutated (mIDH1) AML. Among 147 patients with relapsed/refractory mIDH1 AML, 51 (35%) achieved a complete response (CR) or CR with partial hematologic recovery (CRh) after treatment with olutasidenib, with a duration of response of 25.9 months. We conducted sub-analyses to better understand which factors might be predictive of response to therapy.

Background

Introduction:

Introduction:Multiple myeloma (MM) is the second most prevalent hematologic malignancy. Despite significant advancements in immuno-oncology (IO) therapeutics, such as T-cell dependent bispecific (TDB) antibodies targeting MM antigens, MM remains incurable. This highlights the need for further research to develop personalized and effective treatments. The study of primary MM cells is pivotal for understanding therapeutic effects and patient variability but faces challenges due to cell scarcity and low ex vivoviability. Our microfluidic platform, requiring minimal cell input and no matrices or immobilization, maintains viability and offers versatile, integrated readouts, thereby deepening the breadth and depth of information from ex vivoexperiments. In this study, we developed a multi-omic assay to gain insights into cytotoxicity, cytokine profiling, and gene expression changes to conduct a comprehensive analysis of TDBs targeting MM antigens in primary MM co-cultures.

Keywords: Chimeric Antigen Receptor T cell, Pharmacoeconomic, Pediatric, Clinical Trials

Background:

Introduction:Pancreatic ductal adenocarcinoma (PDAC) is one of the most devastating cancers, and therapies to treat this malignancy have not evolved rapidly to fulfill the need of affected patients. PDAC, like many solid malignancies, is considered a “cold immunological tumor” where the lack of targetable tumor-associated antigens has hampered the development of successful immunotherapies. Despite newer treatment approaches, PDAC patients with advanced disease have a dismal prognosis. Therefore, there is an urgent need to develop new therapies. Plectin-1 is a high molecular weight protein (∼500 kDa) that participates in cytoskeleton network organization linking intermediate filaments to microtubules and microfilaments. Plectin-1 is aberrantly expressed in the PDAC cellular membrane, contributes to PDAC pathogenesis, and confers a poor prognosis. Plectin-1-targeting peptides (PTP) in mice and humans have been successfully explored for their use in PDAC imaging and targeted payload delivery (small molecules, radioisotopes, and chemotherapy). We sought to take advantage of the specific binding of PTP and develop a peptide-based plectin-1 chimeric antigen receptor (CAR), and test T-cell transduced with this construct in vitroagainst PDAC cell lines.

Introduction:

Background:The current standard of care (SoC) for newly diagnosed patients (pts) with chronic myeloid leukemia in chronic phase (CML-CP) is treatment with 1 of the 4 tyrosine kinase inhibitors (TKIs) approved for this use (first generation [1G] imatinib [IMA] and second generation [2G] bosutinib [BOS], dasatinib [DAS], and nilotinib [NIL]). Although TKIs have vastly improved treatment outcomes, pts with newly diagnosed CML-CP experience lack of efficacy and intolerance to available treatments. A large number of pts treated with IMA do not achieve major molecular response (MMR) and even fewer pts achieve deep molecular response, a key requirement to attempt treatment-free remission. Treatment with 2G TKIs results in larger proportions of pts achieving deep responses albeit still with a sizeable minority not reaching this goal. Also, many pts are intolerant to 2G TKIs, resulting in therapy switching, frequently multiple times. For pts who remain on treatment, even low-grade adverse events (AEs) may significantly impact quality of life (QoL) given the long-term nature of treatment. Improved treatments with high efficacy and improved tolerability are needed to limit therapy switching, reduce treatment discontinuation, maintain, or improve pt QoL, and allow pts to remain on treatment at an optimal dose for longer duration to achieve deep responses.

Relapsed/refractory T-cell malignancies have a particularly poor prognosis and novel therapies are direly needed. CD5 is a great candidate for adoptive cellular therapy to target T-cell malignancies since it is ubiquitously expressed on T cells with restricted expression on other hematopoietic cells. NK cells are an attractive platform for CAR engineering to target CD5 since, unlike T cells, they do not express CD5 on their surface, which eliminates the risk of fratricide. Another advantage of NK cells for CAR engineering is their safety profile; in contrast to T cells, they do not cause cytokine release syndrome (CRS) or immune effector cell-associated neurotoxicity syndrome (ICANS) and they are not associated with graft-versus-host disease (GVHD) in the allogeneic setting, opening the potential for a completely off-the-shelf cellular product to be used at point of care. Therefore, we sought to develop CD5 targeting CAR-NK cells for the treatment of T-cell malignancies.

Introduction

Introduction:Talquetamab (tal), a novel GPRC5D×CD3 bispecific antibody (BsAb), has shown deep and durable responses with overall response rates (ORRs) >71%, including in high-risk populations, and a clinically manageable safety profile in patients (pts) with relapsed/refractory multiple myeloma (MM) in the MonumenTAL-1 study (NCT03399799/NCT04634552). To better understand mechanisms of resistance and relapse in pts treated with tal, baseline and longitudinal GPRC5D expression and immune profiles were assessed in pts treated with the 0.4 mg/kg weekly (QW) recommended phase 2 dose, including a separate cohort of pts who received prior T-cell redirection therapy (prior TCR; chimeric antigen receptor [CAR]-T cell and BsAb therapies).

Background

Background:

Myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) belong to the same spectrum of myeloid malignancies and have extremely poor outcomes in the relapsed/refractory setting. Despite advances in the understanding of the pathogenesis and molecular mechanisms of these disorders, and incremental improvements in treatment regimens, patients with MDS and AML often relapse and fail to achieve cure. These and other factors underscore the urgent need for new therapeutic alternatives that will improve the clinical outcomes of these patients. Immunotherapy using checkpoint molecule inhibitors and adoptive cell therapy using autologous immune effector cells have been mostly unsuccessful in patients with MDS and AML. This could be due to the immunosuppressive tumor microenvironment in the bone marrow niche or to intrinsic dysfunction in the immune effector cells of these patients.

Introduction:

T-cell lymphomas (TCL) are a heterogenous group of non-Hodgkin lymphoma characterized by resistance to conventional therapies posing an urgent need for safe and effective therapies. CAR-NK cells have emerged as a promising “off-the-shelf” cancer immunotherapy and are especially attractive for the treatment of T-cell malignancies. This is especially the case given the challenge of targeting T cell malignancies with CAR T cells due to shared antigens across the therapeutic, normal and malignant T cells posing the risk of CAR T cell fratricide, T-cell aplasia, and contamination of the CAR T products with malignant T cells. We have developed an FDA-approved system for ex vivoNK cell expansion, which reliably generates clinically relevant doses of GMP-grade NK cells from a cord blood (CB) unit. We have used this platform to engineer NK cells to express a CAR targeting CD19 using GMP-grade retroviral vectors and demonstrated the safety and efficacy of this platform in the clinic. We now propose to expand this approach to target TCL. CD70, a surface ligand of CD27, is overexpressed in a variety of cancers, including TCL. Signaling mediated by CD70-CD27 is thought to induce proliferation of TCL cells via activation of the NF-κB pathway. Thus, CD70 is an attractive target for CAR NK-cell therapy against TCL. We analyzed the publicly available primary TCL dataset (GSE19069) including anaplastic large cell lymphoma (30 samples), angioimmunoblastic TCL (37 samples), peripheral TCL (PTCL; 50 samples), and adult T cell leukemia/lymphoma (13 samples) for CD70 expression. The majority of the samples expressed CD70 transcript with a variable level of expression ( Figure 1). Using flow cytometry, we screened a panel of TCL cell lines with diverse histologic, cytogenetic and molecular properties for the expression of CD70. We demonstrated positive CD70 expression on most of the TCL cell lines profiled encompassing anaplastic large cell lymphoma (ALK+: KAR299; ALK-: MAC2A; fusion gene NPM-ALK+: SU-DHL1 and SUP-M2), hepatosplenic gamma-delta TCL (DERL-7), Sezary syndrome (SS; H9 and HuT78), and PTCL NOS (OCI-LY12). The CD70 intensity was highest on MAC2A, HuT78, KAR299 and SUP-M2, intermediate to low on DERL-7 and H9, and negative on SU-DHL1 and OCI-LY12. We designed a novel retroviral vector targeting CD70 that: 1) encodes the CD70-targeting CAR gene based on the CD27 extracellular domain; 2) ectopically produces interleukin (IL)-15 to support NK cell proliferation; and 3) expresses the suicide gene inducible caspase 9 ( iC9) that can be pharmacologically activated to eliminate transduced cells in the event of toxicity. The construct will be referred to as CAR.70/IL-15. Non-transduced (NT) NK cells and NK cells transduced with a construct that leads to IL-15 production without a CAR (IL-15 NK cells) were used as controls. We demonstrated that CAR.70/IL-15 NK cells had a significantly enhanced cytotoxicity compared to NT- and IL-15 NK cells against the CD70+ cell lines while there was no difference in cytotoxicity between the NK cell conditions in the negative cell lines pointing to a CD70-targeted fashion of anti-TCL NK cell cytotoxicity. Moreover, CAR.70/IL-15 NK cells exhibited greater cytotoxicity against CD70+ cell lines in long-term cytotoxicity assays ( Figure 2). In a tumor rechallenge assay against KAR299 where fresh tumor cells were added every 3-4 days, CAR.70/IL-15 NK cells showed superior potency in continuous tumor control. In addition, CAR.70/IL-15 NK cells exhibited higher levels of degranulation (CD107a) and cytokine production (TNFα and INF-γ) when cocultured with CD70+ TCL cell lines, compared to NT and IL-15 NK cells. Furthermore, these CAR NK cells targeting CD70 outperformed CAR NK cells engineered to target CD19, which is an irrelevant target for TCL, further confirming the specific CD70-targeted activity of CAR.70/IL-15 NK cells. CyTOF immunophenotyping revealed that CAR.70/IL-15 NK cells are characterized by the increased expression of markers of cytotoxicity such as granzyme-b, perforin, TRAIL; and activating coreceptors/proliferation markers such as DNAM, CD25 and Ki67. Taken together, our findings validate CD70 as a promising target for TCL treatment using CAR NK cells. Our approach provides a solid foundation for the clinical translation of CD70-targeting CAR NK-cell therapy for patients with TCL.

Background: Patients with intermediate and higher-risk MDS are generally treated with the DNA hypomethylating agents (HMAs) azacytidine and decitabine. These agents improve survival and cytopenias in ~50% of those treated; but only responders derive clinical benefit, and no pre-treatment response prediction has proven efficacy. There is thus an urgent need to develop new approaches to complement or enhance the response to standard-of-care HMA therapies. Studies suggest that HMAs might act in part via activation of anti-tumor immune mechanisms. Based upon this hypothesis a series of early phase trials combining immune checkpoint inhibitors (ICI: both anti-PD1/PDL1 and CTLA4) with azacitidine in MDS/AML patients were undertaken but clinical and immunological efficacy have proven disappointing. In these studies, the lack of antigen specificity made systematic assessment of the anti-MDS immune response and milieuchallenging. Antigen specific assessments are particularly important in MDS patients treated with ICIs because distinct from solid tumors, myeloid stem cell cancers involve the populations of antigen presenting cells that modify the capacity for T-cell response, such as dendritic cells. Our group has shown that MDS/AML patients treated with decitabine show increased expression of NY-ESO-1, a well-characterized tumor antigen whose expression is normally suppressed through dense promoter hypermethylation. In our prior Phase I study, MDS patients received vaccination against NY-ESO-1 in combination with standard decitabine. This combination was not only safe, but it also induced NY-ESO-1 specific CD4 +and CD8 +T cell responses in most patients. We hypothesized that combining anti-NY-ESO-1 vaccination (an antigen specific approach) with decitabine and an ICI would allow us to understand the immune synapse in patients with MDS. Methods: We developed an investigator-initiated Phase 1 trial in transplant-ineligible patients with MDS/low blast count AML adding an anti-PD-1 ICI to our established combination of decitabine + NY-ESO-1 vaccination (#NCT 0335871). This open-label, non-randomized single center Phase 1 study used an HLA unrestricted NY-ESO-1 vaccine (CDX-1401 (1 mg) + poly-ICLC (1.8 mg)) in combination with standard dose decitabine (20mg/m2/d x 5 days) and nivolumab (3 mg/kg every 2 weeks), 4 cycles of combination therapy were planned on study; patients deriving clinical benefit could continue treatment at the discretion of the treating physician. The study was conducted in accordance with the Declaration of Helsinki and approved by the Roswell Park Cancer Institute (RPCI) Internal Review Board. Six patients were enrolled, treated, and completed > 4 cycles of decitabine; serial bone marrow and peripheral blood samples were collected for analysis. The combination was safe. Results: Two patients developed CR and the remainder had stable disease as the best response to therapy (Table 1). The majority of patients mounted NY-ESO-1 specific CD4 +T cell responses associated with up-regulation of anti-PD-1 immunotherapy gene signatures in the CD4 +memory T cell compartment. No responses in CD8 +T cells were seen. In seeking explanation for the disparate findings in CD4 +and CD8 +T-cell compartments, we examined conventional dendritic cell populations associated with activation of CD8 +T cells and identified that our patients had markedly reduced numbers of conventional dendritic cells marked by high expression of CD141 (cDC1). This population is critical for a successful response to immunotherapy. cDC1 from MDS patients also showed reduced expression of genes that are key for optimal T-cell activation and expansion. Conclusions: These results suggest that the use of immunotherapy to induce effective, cytotoxic anti-tumor T cell responses depends upon the myeloid immunologic milieuin MDS patients. The critical importance of cDC1 function has recently been described and appreciated in the context of solid tumor immunotherapy. The observation of both numerical and functional defects of this cell population in patients with myeloid neoplasia provides a possible explanation for the disappointing efficacy of immunotherapies in this disease state. Approaches to augment the number and function of specific cDC1 populations in myeloid disease might overcome this defect and thereby enhance the efficacy of immunotherapy for patients with MDS.

Background