T-cell Engager Research Articles

Phase I/II trial of LAVA-1207, a novel bispecific gamma-delta T-cell engager alone, or with low dose IL-2 or pembrolizumab, in metastatic castration resistant prostate cancer (mCRPC).

TPS2672 Background: LAVA-1207 is a humanized bispecific antibody that binds with high affinity to the Vδ2 chain of Vγ9Vδ2-T cells and to prostate-specific membrane antigen (PSMA). It comprises a heterodimer of two fusion proteins, each consisting of a VHH linked to a human IgG1 Fc domain. Preclinical evidence demonstrates that, upon binding both targets, LAVA-1207 leads to potent Vγ9Vδ2-T cell degranulation and cytolytic activity against PSMA-expressing prostate cancer cells. IL-2 is an immune modulator which has been shown to support expansion of activated Vγ9Vδ2-T cells. PD-1 is an inhibitory immune checkpoint receptor that can dampen (Vγ9Vδ2-) T cell reactivity, suggesting that pembrolizumab could potentiate the effect of LAVA-1207. Methods: This trial is a phase 1/2a open label study with a 3+3 design in patients with refractory mCRPC to assess the safety of LAVA-1207 alone or with low dose IL-2 or with pembrolizumab, and to determine the recommended Phase 2a dose (RP2D). Secondary objectives include evaluation of pharmacokinetics, pharmacodynamics, immunogenicity, and preliminary antitumor activity. Exploratory endpoints include evaluation of the effect of study treatment on circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA). LAVA-1207 is administered IV every two weeks. Two parallel cohorts assessing LAVA-1207 with low dose subcutaneous IL-2 have been implemented: (1) single IL-2 administration and (2) three IL-2 administrations on consecutive days per cycle for up to four cycles. An additional dose escalation arm evaluates LAVA-1207 in combination with pembrolizumab, 400mg Q6W, IV. Patients with mCRPC that have failed at least one prior AR therapy and taxane-based chemotherapy (unless deemed medically unsuitable to receive a taxane) will be enrolled on the study. Patients should have progressive disease either by PSA or by RECIST 1.1 or appearance of 2 or more bone metastases. Patients must have ECOG performance status of 0-1. PSMA-PET is performed at baseline. Paired biopsies are requested to further assess LAVA-1207 activity. Dose escalation is ongoing. Expansion arm(s) will be included based on available data from part 1 of the study and may include one or more of LAVA-1207, LAVA-1207 with low dose IL-2, or LAVA-1207 in combination with pembrolizumab. Clinical trial information: NCT05369000 .

Outpatient blinatumomab with digital monitoring in patients with measurable residual disease positive (MRD+) B-ALL in a phase 4 study.

6544 Background: Blinatumomab, a CD3/CD19-directed BiTE® (bispecific T-cell engager) molecule, is an effective therapy for patients (pts) with MRD+ B-ALL. Hospitalization is recommended for days (D) 1–3 of cycle (C) 1 and D1–2 of C2 for these pts receiving blinatumomab to monitor for serious adverse events (SAEs). This phase 4 study evaluated the safety and feasibility of outpatient (outpt) digital monitoring to replace hospitalization in pts with MRD+ B-ALL (NCT04506086). Methods: Enrolled adults with MRD+ B-ALL in complete remission received continuous intravenous (cIV) blinatumomab at 28 μg/day. Current Health Wearable Monitoring System (CHWMS) was worn by pts at home for D1–3 (C1) and D1–2 (C2), in the presence of a caregiver, and provided heart rate, respiratory rate, and oxygen saturation; a separate patch monitored temperature. Manual blood pressure measurements were taken every 3-6 hrs. Vital signs (VS) were streamed to a provider smartphone/laptop; changes outside a predetermined threshold generated audible alarms. The primary endpoint was incidence of grade (G) ≥3 cytokine release syndrome (CRS), neurotoxicity, or any adverse event (AE) requiring hospitalization during the monitoring period. Results: As of 12/15/2023, 9 pts (median age 43 [20-73] years) received outpt blinatumomab for (completed C1, n=7; C2, n=6). During outpt monitoring, dose interruption was reported in 5 of 9 pts (1 pt had 2 dose interruptions: AE, n=2; dose administration error, n=2; other, n=2). CRS was reported in 2 pts (SAE, n=1; G≥3, n=0; led to interruption, n=1) and neurologic events in 4 pts (SAE, n=0; G≥3, n=0; led to interruption, n=0). Two pts experienced AEs requiring hospitalization (CRS, n=1; fever, n=1). Most VS changes were physiological or from routine pt activity. Median (range) number of alarms triggered/pt was 79 (12-135); among 3 pts, 1.2%, 5.1% and 8.9% of alarms led to therapeutic intervention (Table). Conclusions: To date, outpt administration of cIV blinatumomab in pts with MRD+ B-ALL was feasible and safe with appropriate outpt digital monitoring. Study enrollment is ongoing. Clinical trial information: NCT04506086 . [Table: see text]

Associations of T-cell fitness prior to B-cell maturation antigen (BCMA)–targeted chimeric antigen receptor T-cell (CART) and bispecific T-cell engager (BiTE) therapies and efficacy/toxicity in relapsed/refractory multiple myeloma (RRMM).

7549 Background: While CART and BiTE have led to unprecedented responses in RRMM, some patients (pts) do not respond or have short-lived responses. Currently no predictive markers exist to identify these pts. This study explored pretreatment T-cell fitness and efficacy/toxicity in RRMM using a novel single-cell secretome analysis. We hypothesized that pretreatment Polyfunctional Strength Index (PSI) may predict efficacy to BCMA-directed T-cell therapies. Methods: We included 14 RRMM pts treated with idecabtagene vicleucel or teclistamab at Yale Cancer Center with ≥6 mos post-treatment follow-up. Peripheral blood prior to treatment was frozen and then PBMC’s thawed for analysis. PSI, a metric for T-cell fitness combining polyfunctional T-cells % with the intensity of secreted cytokines, was obtained using the IsoPlexis’ Single-Cell Secretome Platform. The overall PSI was an average of CD4+ and CD8+ PSIs. Response was assessed by the International Myeloma Working Group criteria and response duration was defined as time from response to disease progression. Responder (R) was defined as ≥very good partial response for ≥6 mos. Non-responder (NR) was defined as stable or progressive disease ≤3 mos. Cytokine release syndrome (CRS) and immune-effector cell associated neurotoxicity syndrome (ICANS) were graded using the American Society for Transplantation & Cellular Therapy system. Statistics were performed with Mann-Whitney U test using GraphPad PRISM v.9. Results: There were 7 pts in R group (2 BiTE & 5 CART) and 7 pts in NR group (3 BiTE & 4 CART). Median follow-up time was 13.5 mos(range, 7-27). Median age at treatment was 64 yrs in R and 63 yrs in NR. Extramedullary disease (EM) was present in 14.3%(n=1) in R and 71.4%(n=5) in NR. High-risk cytogenetics, defined as del17p, t(4;14), t(14;16), t(14;20), 1q gain/amplification and del1p, were seen in 42.9%(n=3) in R and 85.7%(n=6) in NR. Median prior lines of therapy was 6(range, 4-9) in R and 8(range, 4-10) in NR. CRS/ICANS occurred 85.7%(n=6) in R and 28.6%(n=2) in NR. Overall PSI was 184 in R and 91 in NR(p=0.1649). CD4+ PSI was 160 in R and 75 in NR(p=0.1649). CD8+ PSI was 207 in R and 108 in NR(p=0.1981). Overall PSI was 143 in CRS/ICANS and 130 in no CRS/ICANS(p=0.7546). Conclusions: Overall PSI, CD4+ PSI and CD8+ PSI were 1.9-2.1 times higher in R compared to NR and overall PSI was slightly higher in CRS/ICANS compared to no CRS/ICANS though the difference was not statistically significant. One limitation was a small sample size and thus testing PSI in a larger cohort might yield statistically significant results. The NR group had more high-risk cytogenetics and higher EM. One confounder could be that measuring peripheral T-cell fitness may not be sufficient to predict response in EM where spatial determinants of T-cell influx play a role.

CRPA1A2: A novel TCR-based T-cell engager targeting MAGEA1-positive solid tumors.

e14589 Background: MAGEA1, identified as a cancer/testis antigen, is highly expression in various solid tumors, including hepatocellular carcinoma, non-small cell lung cancer, but absent in normal tissues except male germ cells and placenta, both of which lacking HLA class molecules. This selective expression of HLA-MAGEA1 epitope makes it a promising target for cancer therapy. However, its intracellular localization poses a challenge for conventional antibodies designed to target surface-expressed antigens. TCR-based T-cell engagers, such as Tebentafusp, overcome this hurdle by targeting intracellular protein-derived peptides presented on cancer cell surfaces via HLA, enabling precise cytotoxic T cell attacks. Notably, Tebentafusp has shown significant clinical benefits by improving survival rates in metastatic uveal melanoma, underscoring the efficacy of TCR-based T-cell engagers in treating MAGEA1-positive tumors. Methods: We have developed an advanced structural format, CR62, consisting of a anti-CD3 single chain fragment, a soluble modified TCR, and an Fc region. Additionally, the use of CorreGene's SMART-TCR system has facilitated the acquisition of TCRs with high affinities in the pico-molar range. By leveraging CR62 and a high-affinity TCR, we have conceptualized the TCR-based T-cell engager, CRPA1A2. Comprehensive preclinical assessments have been conducted to evaluate CRPA1A2's safety and efficacy. Results: CRPA1A2 is designed to specifically target the HLA-A*02:01-restricted MAGEA1 epitope, effectively inhibiting tumor growth. CRPA1A2 is characterized by its exceptional soluble expression in CHO cells, minimal homodimer miss-assembly and simplifying purification. It is strategically engineered with a high-affinity TCR and a low-affinity anti-CD3 scFv to optimize the efficacy and safety. In vitro studies, CRPA1A2 showed strong ability to eliminate tumor cells and induce IFN-γ release, effective even at low MAGEA1 epitope densities, with a therapeutic window that spans over three orders of magnitude, suggesting a 1000-fold greater activity against antigen-positive cancer cells compared to antigen-negative cells. In vivo, using a tumor-bearing mouse model, CRPA1A2 has been shown to recruit T cells into subcutaneous solid tumors, expand CD8+ T cell populations, and significantly reduce tumor mass. Notably, CRPA1A2 has an extended half-life of 120 hours and demonstrates preferential accumulation in tumor tissues, thereby enhancing its therapeutic potential. Moreover, the safety assessments for CRPA1A2 highlight its exceptional specificity, with in vitro studies showing no evidence of off-target toxicity, on-target off-tumor toxicity, or alloreactivity and favorable tolerance in mice during in vivo studies. Conclusions: CRPA1A2 has emerged as a superior TCR-based T-cell engager with exceptional antitumor efficacy and promising safety profile.

A phase 1/2, open-label, multicenter trial investigating the safety, tolerability, and preliminary antineoplastic activity of IPH6501, a first-in-class NK cell engager, in patients with relapsed and/or refractory CD20-expressing non-Hodgkin lymphoma.

TPS7095 Background: The therapeutic landscape for relapsed and/or refractory B-cell non-Hodgkin lymphoma (B-NHL) is evolving to include targeted T-cell based immunotherapies. However, there remains an unmet medical need for patients who are refractory to, relapsing from, or are ineligible for these therapies. Leveraging natural killer (NK) cells emerges as a promising strategy, as demonstrated in a Phase 1 study with IPH6101/SAR’579 in R/R AML (Stein, ASCO 2023; Bajel, ASH 2023), and offers a novel approach that could complement or provide an alternative to T-cell therapies. IPH6501 is a first-in-class tetraspecific antibody-based NK cell engager that simultaneously targets the CD16a and NKp46 receptors on NK cells and CD20 on B-NHL cells. It also includes an engineered IL-2 variant designed with mutations to avoid binding to CD25 (IL-2Rα), limiting Treg activation and potential IL-2 related side effects, whilst inducing NK proliferation. In preclinical animal models, IPH6501 boosted NK cell proliferation and activation, and CD20+ target cell elimination in peripheral blood and tissues, at well-tolerated doses. In samples obtained from R/R B-NHL patients, IPH6501 demonstrated greater killing efficacy compared to a CD3xCD20 T-cell engager, and yet lower cytokine secretion, suggesting a potentially safer profile. Methods: This is a global first-in-human, multicenter, open-label Phase 1/2 study to evaluate the safety profile (DLTs and MTD), tolerability according to NCI-CTCAE v5.0 and to determine the RP2D of IPH6501 for patients with B-NHL (NCT06088654). Secondary objectives are to characterize the pharmacokinetic profile and evaluate the immunogenicity of IPH6501. Eligible subjects are aged ≥18 years with advanced, histologically confirmed, CD20+ B-NHL with an ECOG PS ≤2, and without established alternative therapy. Subjects must have received ≥2 prior systemic therapies which may have included astem cell transplant or CAR-T cell therapy. The Phase 1 part of the study will consist of a dose escalation part which will follow a3+3 design to determine the MTD or the highest dose to be tested as defined in protocol if the MTD has not been reached, and a dose assessment part to randomize ≥2 dose levels to determine the RP2D. The Phase 2 part will enroll one or more cohorts of selected B-cell NHL subtypes to be determined at a later stage. Up to 184 subjects will be enrolled, and the study is open in the United States, Australia and Europe. Clinical trial information: NCT06088654 .

Breaking the Mold: Trailblazing Melanoma Therapy Beyond Checkpoint Through Innovative Approaches.

Melanoma has long been a difficult malignancy to treat with low response rates to standard chemotherapies. In recent years, the use of immune checkpoint inhibitors have demonstrated promising results, paving the way for the use of the rapidly developing novel immune targeting therapies. In this review, we look beyond immune checkpoint inhibitor treatments and summarize several emerging treatment strategies for melanoma, including neoantigen vaccines, conventional antibody drug-conjugates, and bispecific T-cell engager therapies.

Evaluation of Bispecific T-Cell Engagers Targeting Murine Cytomegalovirus.

Human cytomegalovirus is a ubiquitous herpesvirus that, while latent in most individuals, poses a great risk to immunocompromised patients. In contrast to directly acting traditional antiviral drugs, such as ganciclovir, we aim to emulate a physiological infection control using T cells. For this, we constructed several bispecific T-cell engager (BiTE) constructs targeting different viral glycoproteins of the murine cytomegalovirus and evaluated them in vitro for their efficacy. To isolate the target specific effect without viral immune evasion, we established stable reporter cell lines expressing the viral target glycoprotein B, and the glycoprotein complexes gN-gM and gH-gL, as well as nano-luciferase (nLuc). First, we evaluated binding capacities using flow cytometry and established killing assays, measuring nLuc-release upon cell lysis. All BiTE constructs proved to be functional mediators for T-cell recruitment and will allow a proof of concept for this treatment option. This might pave the way for strikingly safer immunosuppression in vulnerable patient groups.

Camelid-derived Tcell engagers harnessing human γδ Tcells as promising antitumor immunotherapeutic agents.

In the last decade, there has been a surge in developing immunotherapies to enhance the immune system's ability to eliminate tumor cells. Bispecific antibodies known as Tcell engagers (TCEs) present an attractive strategy in this pursuit. TCEs aim to guide cytotoxic Tcells toward tumor cells, thereby inducing a strong activation and subsequent tumor cell lysis. In this study, we investigated the activity of different TCEs on both conventional alpha-beta (αβ) Tcells and unconventional gamma delta (γδ) Tcells. TCEs were built using camelid single-domain antibodies (VHHs) targeting the tumor-associated antigen CEACAM5 (CEA), together with Tcell receptor chains or a CD3 domain. We show that Vγ9Vδ2 Tcells display stronger in vitro antitumor activity than αβ Tcells when stimulated with a CD3xCEA TCE. Furthermore, restricting the activation of fresh human peripheral Tcells to Vγ9Vδ2 Tcells limited the production of protumor factors and proinflammatory cytokines, commonly associated with toxicity in patients. Taken together, our findings provide further insights that γδ Tcell-specific TCEs hold promise as specific, effective, and potentially safe molecules to improve antitumor immunotherapies.

Timing antigenic escape in multiple myeloma treated with T-cell redirecting immunotherapies.

Recent data highlight genomic events driving antigen escape as a recurring cause of chimeric antigen receptor T-cell (CAR-T) and bispecific T-cell engager (TCE) resistance in multiple myeloma (MM). Yet, it remains unclear if these events, leading to clonal dominance at progression, result from acquisition under treatment selection or selection of pre-existing undetectable clones. This differentiation gains importance as these immunotherapies progress to earlier lines of treatment, prompting the need for innovative diagnostic testing to detect these events early on. By reconstructing phylogenetic trees and exploring chemotherapy mutational signatures as temporal barcodes in 11 relapsed refractory MM patients with available whole genome sequencing data before and after CART/TCE treatment, we demonstrated that somatic antigen escape mechanisms for BCMA- and GPRC5D-targeting therapies are acquired post-diagnosis, likely during CART/TCE treatment. Longitudinal tracking of these mutations using digital PCR in 4 patients consistently showed that genomic events promoting antigen escape were not detectable during the initial months of therapy but began to emerge nearly 1 year post therapy initiation. This finding reduces the necessity for a diagnostic panel to identify these events before CART/TCE. Instead, it underscores the importance of surveillance and identifying patients at higher risk of acquiring these events.

HPN328, a Trispecific T Cell-Activating Protein Construct Targeting DLL3-Expressing Solid Tumors.

Delta-like ligand 3 (DLL3) is expressed in more than 70% of small cell lung cancers (SCLCs) and other neuroendocrine-derived tumor types. SCLC is highly aggressive, and limited therapeutic options lead to poor prognosis for patients. HPN328 is a trispecific T cell-activating construct (TriTAC) consisting of three binding domains: a CD3 binder for T-cell engagement, an albumin binder for half-life extension, and a DLL3 binder for tumor cell engagement. In vitro assays, rodent models, and non-human primates were used to assess the activity of HPN328. HPN328 induces potent dose-dependent killing of DLL3-expressing SCLC cell lines in vitro, concomitant with T-cell activation and cytokine release. In an NCI-H82 xenograft model with established tumors, HPN328 treatment led to T-cell recruitment and anti-tumor activity. In an immunocompetent mouse model expressing a human CD3ε epitope, mice previously treated with HPN328 withstood tumor rechallenge, demonstrating long-term anti-tumor immunity. When repeat doses were administered to cynomolgus monkeys, HPN328 was well tolerated up to 10 mg/kg. Pharmacodynamic changes, such as transient cytokine elevation, were observed, consistent with the expected mechanism of action of T-cell engagers. HPN328 exhibited linear pharmacokinetics in the given dose range with a serum half-life of 78 to 187 hours, supporting weekly or less frequent administration of HPN328 in humans. Preclinical and nonclinical characterization suggests that HPN328 is a highly efficacious, safe, and novel therapeutic candidate. A phase 1/2 clinical trial is currently underway testing safety and efficacy in patients with DLL3-expressing malignancies.

Unlocking hope: talquetamab in multiple myeloma treatment: a bispecific breakthrough targeting CD3 and GPRC5D

Multiple myeloma (MM) presents a significant global health burden, with disparities in incidence and outcomes reflecting challenges in recognition and treatment. Talquetamab, a bispecific CD3 T-cell engager targeting G-protein coupled receptor family C group 5 member D (GPRC5D), has emerged as a promising immunotherapy for relapsed/refractory MM (RRMM). In August 2023, talquetamab received accelerated approval from the US FDA for RRMM treatment, followed by conditional marketing authorization from the EMA. Clinical trials demonstrated talquetamab's efficacy, with overall response rates (ORR) of 69% and 76% in heavily pretreated RRMM patients. The phase I monumenTAL-1 trial showcased talquetamab's effectiveness, particularly in high-risk MM and extramedullary disease, with ORRs around 71-74%. Subsequent phase 2 results reaffirmed its efficacy, even in patients with prior T-cell redirection therapies. Combination therapy with daratumumab further enhanced talquetamab's efficacy, addressing concerns of T cell exhaustion. Pharmacokinetic studies revealed sustained responses and manageable adverse events with subcutaneous administration, facilitating convenient dosing regimens. However, talquetamab carries risks of cytokine release syndrome (CRS) and neurologic toxicity, necessitating close monitoring and prompt management. Common adverse events included fever, CRS, musculoskeletal pain, and infections, although severe events were infrequent. Vigilant management strategies, including prophylactic measures and supportive care, mitigate these risks. In conclusion, talquetamab represents a significant advancement in RRMM treatment, offering a promising avenue for T-cell redirection therapy. Ongoing research aims to optimize treatment sequencing and combination strategies, fostering improved outcomes for MM patients. Continued investigation will refine the strategic integration of talquetamab and other immunotherapies, paving the way for enhanced treatment efficacy and patient care in RRMM.

CEA-CD3 bispecific antibody cibisatamab with or without atezolizumab in patients with CEA-positive solid tumours: results of two multi-institutional Phase 1 trials

Cibisatamab is a bispecific antibody-based construct targeting carcinoembryonic antigen (CEA) on tumour cells and CD3 epsilon chain as a T-cell engager. Here we evaluated cibisatamab for advanced CEA-positive solid tumours in two open-label Phase 1 dose-escalation and -expansion studies: as a single agent with or without obinutuzumab in S1 (NCT02324257) and with atezolizumab in S2 (NCT02650713). Primary endpoints were safety, dose finding, and pharmacokinetics in S1; safety and dose finding in S2. Secondary endpoints were anti-tumour activity (including overall response rate, ORR) and pharmacodynamics in S1; anti-tumour activity, pharmacodynamics and pharmacokinetics in S2. S1 and S2 enrolled a total of 149 and 228 patients, respectively. Grade ≥3 cibisatamab-related adverse events occurred in 36% of S1 and 49% of S2 patients. The ORR was 4% in S1 and 7% in S2. In S2, patients with microsatellite stable colorectal carcinoma (MSS-CRC) given flat doses of cibisatamab and atezolizumab demonstrated an ORR of 14%. In S1 and S2, 40% and 52% of patients, respectively, developed persistent anti-drug antibodies (ADAs). ADA appearance could be mitigated by obinutuzumab-pretreatment, with 8% of patients having persistent ADAs. Overall, cibisatamab warrants further exploration in immunotherapy combination strategies for MSS-CRC.

Optimizing Clinical Translation of Bispecific T-cell Engagers through Context Unification with a Quantitative Systems Pharmacology Model.

Bispecific T-cell engagers (bsTCEs) have emerged as a promising class of cancer immunotherapy. BsTCEs enable physical connections between T cells and tumor cells to enhance T-cell activity against cancer. Despite several marketing approvals, the development of bsTCEs remains challenging, especially at early clinical translational stages. The intricate design of bsTCEs makes their pharmacologic effects and safety profiles highly dependent on patient's immunological and tumor conditions. Such context-dependent pharmacology introduces considerable uncertainty into translational efforts. In this study, we developed a Quantitative Systems Pharmacology (QSP) model, through context unification, that can facilitate the translation of bsTCEs preclinical data into clinical activity. Through characterizing the formation dynamics of immunological synapse (IS) induced by bsTCEs, this model unifies a broad range of contexts related to target affinity, tumor characteristics, and immunological conditions. After rigorous calibration using both experimental and clinical data, the model enables consistent translation of drug potency observed under diverse experimental conditions into predictable exposure-response relationships in patients. Moreover, the model can help identify optimal target-binding affinities and minimum efficacious concentrations across different clinical contexts. This QSP approach holds significant promise for the future development of bsTCEs.

Potent antitumor activity of a bispecific T-cell engager antibody targeting the intracellular antigen KRAS G12V.

Kirsten Rat Sarcoma viral oncogene homolog (KRAS) is one of the most frequent oncogenes. However, there are limited treatment options due to its intracellular expression. To address this, we developed a novel bispecific T-cell engager (BiTE) antibody targeting HLA-A2/KRAS G12V complex and CD3 (HLA-G12V/CD3 BiTE). We examined its specific binding to tumor cells and T cells, as well as its anti-tumor effects in vivo. HLA-G12V/CD3 BiTE was expressed in Escherichia coli and its binding affinities to CD3 and HLA-A2/KRAS G12V were measured by flow cytometry, along with T-cell activation. In a xenograft pancreatic tumor model, the HLA-G12V/CD3 BiTE's anti-tumor effects were assessed through tumor growth, survival time, and safety. Our results demonstrated specific binding of HLA-G12V/CD3 BiTE to tumor cells with an HLA-A2/KRAS G12V mutation and T cells. The HLA-G12V/CD3 BiTE also activated T-cells in the presence of tumor cells in vitro. HLA-G12V/CD3 BiTE in vivo testing showed delayed tumor growth without severe toxicity to major organs and prolonged mouse survival. This study highlights the potential of constructing BiTEs recognizing an HLA-peptide complex and providing a novel therapy for cancer treatment targeting the intracellular tumor antigen.

Clinical and Immunologic Characteristics of Colorectal Cancer Tumors Expressing LY6G6D.

The identification of targets that are expressed on the cell membrane is a main goal in cancer research. The Lymphocyte Antigen 6 Family Member G6D (LY6G6D) gene codes for a protein that is mainly present on the surface of colorectal cancer (CRC) cells. Therapeutic strategies against this protein like the development of T cell engagers (TCE) are currently in the early clinical stage. In the present work, we interrogated public genomic datasets including TCGA to evaluate the genomic and immunologic cell profile present in tumors with high expression of LY6G6D. We used data from TCGA, among others, and the Tumor Immune Estimation Resource (TIMER2.0) platform for immune cell estimations and Spearman correlation tests. LY6G6D expression was exclusively present in CRC, particularly in the microsatellite stable (MSS) subtype, and was associated with left-side tumors and the canonical genomic subgroup. Tumors with mutations of APC and p53 expressed elevated levels of LY6G6D. This protein was expressed in tumors with an inert immune microenvironment with an absence of immune cells and co-inhibitory molecules. In conclusion, we described clinical, genomic and immune-pathologic characteristics that can be used to optimize the clinical development of agents against this target. Future studies should be performed to confirm these findings and potentially explore the suggested clinical development options.

FLT3-Mutated Leukemic Stem Cells: Mechanisms of Resistance and New Therapeutic Targets.

Despite the availability of target drugs in the first and second line, only 30% of FLT3mut AMLs are cured. Among the multiple mechanisms of resistance, those of FLT3mut LSC are the most difficult to eradicate because of their metabolic and genomic characteristics. Reactivation of glycogen synthesis, inhibition of the RAS/MAPK pathway, and degradation of FLT3 may be potential aids to fight the resistance of LSC to FLT3i. LSC is also characterized by the expression of a CD34+/CD25+/CD123+/CD99+ immunophenotype. The receptor and ligand of FLT3, the natural killer group 2 member D ligand (NKGD2L), and CD123 are some of the targets of chimeric antigen receptor T cells (CAR-T), bispecific T-cell engager molecules (BiTEs), CAR-NK and nanoparticles recently designed and reported here. The combination of these new therapeutic options, hopefully in a minimal residual disease (MRD)-driven approach, could provide the future answer to the challenge of treating FLT3mut AML.

Identification of a Fully Human Antibody VH Domain Targeting Anaplastic Lymphoma Kinase (ALK) with Applications in ALK-Positive Solid Tumor Immunotherapy.

The anaplastic lymphoma kinase (ALK, CD247) is a potential target for antibody-based therapy. However, no antibody-based therapeutics targeting ALK have entered clinical trials, necessitating the development of novel antibodies with unique therapeutic merits. Single-domain antibodies (sdAb) bear therapeutic advantages compared to the full-length antibody including deeper tumor penetration, cost-effective production and fast washout from normal tissues. In this study, we identified a human immunoglobulin heavy chain variable domain (VH domain) (VH20) from an in-house phage library. VH20 exhibits good developability and high specificity with no off-target binding to ~6000 human membrane proteins. VH20 efficiently bound to the glycine-rich region of ALK with an EC50 of 0.4 nM and a KD of 6.54 nM. Both VH20-based bispecific T cell engager (TCE) and chimeric antigen receptor T cells (CAR Ts) exhibited potent cytolytic activity to ALK-expressing tumor cells in an ALK-dependent manner. VH20 CAR Ts specifically secreted proinflammatory cytokines including IL-2, TNFα and IFNγ after incubation with ALK-positive cells. To our knowledge, this is the first reported human single-domain antibody against ALK. Our in vitro characterization data indicate that VH20 could be a promising ALK-targeting sdAb with potential applications in ALK-expressing tumors, including neuroblastoma (NBL) and non-small cell lung cancer.

Safety and tolerability of AMG 330 in adults with relapsed/refractory AML: a phase 1a dose-escalation study

AMG 330, a bispecific T-cell engager (BiTE®) that binds CD33 and CD3 on T cells facilitates T-cell–mediated cytotoxicity against CD33+ cells. This first-in-human, open-label, dose-escalation study evaluated the safety, pharmacokinetics, pharmacodynamics, and preliminary efficacy of AMG 330 in adults with relapsed/refractory acute myeloid leukemia (R/R AML). Amongst 77 patients treated with AMG 330 (0.5 µg/day–1.6 mg/day) on 14-day or 28-day cycles, maximum tolerated dose was not reached; median duration of treatment was 29 days. The most frequent treatment-related adverse events were cytokine release syndrome (CRS; 78%) and rash (30%); 10% of patients experienced grade 3/4 CRS. CRS was mitigated with stepwise dosing of AMG 330, prophylactic dexamethasone, and early treatment with tocilizumab. Among 60 evaluable patients, eight achieved complete remission or morphologic leukemia-free state; of the 52 non-responders, 37% had ≥50% reduction in AML bone marrow blasts. AMG 330 is a promising CD33-targeted therapeutic strategy for R/R AML.

Allogeneic transplantation after immunotherapy for relapsed/refractory non-Hodgkin lymphoma: a comparison with a historical cohort

Background aimsNew immunotherapy drugs, such as bispecific T-cell engager antibodies, checkpoint inhibitors and antibody–drug conjugates, are commonly used as salvage therapy for patients with non-Hodgkin lymphoma relapsing after chimeric antigen receptor (CAR) T-cell therapy. Nevertheless, their potential long-term effects on the outcome of allogeneic stem cell transplantation (Allo-SCT) are not well known. MethodsWe retrospectively analyzed the outcomes of 27 relapsed/refractory non-Hodgkin lymphoma patients receiving Allo-SCT after immunotherapy in the pre-CAR T-cell therapy era and compared them with a historical cohort of 28 subjects undergoing Allo-SCT after conventional therapy. ResultsThe two cohorts had similar outcomes in terms of graft-versus-host disease/relapse-free survival (4 years, 59% versus 46%), overall survival (4 years, 77% versus 44%), non-relapse mortality (4 years, 19% versus 22%) and acute (6 months, 15% versus 21%) and chronic (4 years, 18% versus 24%) graft-versus-host disease. Of note, the cumulative incidence of relapse was lower after immunotherapy (4 years, 4% versus 14%), although significance was not reached. The cumulative incidence of cytomegalovirus and fungal infection did not differ among the two cohorts. ConclusionsConsolidation with Allo-SCT is a safe and curative option for patients achieving disease response after new immunotherapy drugs that could represent a desirable salvage strategy for patients relapsing after CAR T-cell therapy.

Anticytokine Therapy and Corticosteroids for Cytokine Release Syndrome and for Neurotoxicity Following T-Cell Engager or CAR T-Cell Therapy

What Is the Issue? Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) are the most common toxicities secondary to T-cell engager or chimeric antigen receptor (CAR) T-cell therapy. The US FDA and Health Canada approved tocilizumab, an anti-interleukin-6 receptor antagonist, for the management of severe or life-threatening cases of CRS. Corticosteroids also play an important role in CRS management and are the mainstay of ICANS management. Decision-makers are interested in understanding the use of anticytokine drugs (i.e., tocilizumab, anakinra, siltuximab) and/or corticosteroids in the management of CRS and ICANS following T-cell engager or CAR T-cell therapy. What Did We Do? We identified and summarized the literature comparing the clinical effectiveness and safety of anticytokine therapy and/or corticosteroids with alternative care or treatment as usual for treating and preventing of CRS and ICANS. We also searched for evidence-based recommendations for the use of anticytokine therapy and/or corticosteroids to treat and prevent CRS and ICANS. A research information specialist conducted a literature search of peer-reviewed and grey literature sources published between January 1, 2019 and February 26, 2024 for CRS; and between January 1, 2019 and March 4, 2024 for ICANS. One reviewer screened citations for inclusion based on predefined criteria, critically appraised the included studies, and narratively summarized the findings. What Did We Find? This report presents evidence-based findings on 3 retrospective chart review studies, 2 prospective cohort studies, and 4 consensus guidelines. Limited and low-quality clinical evidence from studies with a high risk of bias suggested that early use of tocilizumab or corticosteroids, or prophylactic use of tocilizumab or anakinra may reduce the risk of a high-grade CRS without a negative impact on neurotoxicity or immunotherapy treatment outcomes. The included guidelines recommend the use of tocilizumab for treatment of higher-grade CRS, or for treatment of grade 1 CRS if symptoms persist for 3 days or more. Corticosteroids could be added in conjunction if there is no improvement or persistent symptoms after tocilizumab therapy. For the management of ICANS in the absence of concurrent CRS, supportive care is the preferred treatment option for grade 1 ICANS, while corticosteroids are recommended for the management of grade 2 to 4 ICANS. In the presence of concurrent CRS, guidelines recommend tocilizumab therapy as per management of CRS, and corticosteroids should be continued until improvement to grade 1. We did not identify any clinical evidence regarding the clinical efficacy and safety of anticytokine therapy and/or corticosteroids for treatment of CRS and ICANS compared with alternative treatment or treatment as usual. We also did not identify any guidelines for the use of prophylactic anticytokine therapy, corticosteroids, or both for the prevention of CRS and ICANS. What Does This Mean? Despite limited and low-quality evidence, the findings suggest some potential benefits of prophylactic or early use of anticytokine therapy and corticosteroids for the management of immunotherapy-related toxicities. Guidelines offer guidance on the management of CRS, ICANS and other less common toxicities related to immunotherapy based on the available low-quality evidence. When using the clinical evidence and recommendations summarized in this report to inform decisions, decision-makers should consider that the evidence is limited and of low quality. To improve the certainty of findings, there is a need for more robust prospective clinical trials with larger sample sizes, and lower risk of bias.