Bispecific Antibody Research Articles

Management of Secondary Immunodeficiency Following T-Cell-Engaging Immunotherapeutic Agents in B-Cell Non-Hodgkin Lymphoma: Implications for Early-Line Treatment Strategies

Anti-CD19 chimeric antigen receptor (CAR) T-cell and anti-CD20 bispecific antibody therapies (BsAbs) are rapidly moving to earlier treatment lines for patients with B-cell non-Hodgkin lymphoma (B-NHL). The rapid pace of the advancement of these T-cell-engaging therapies is juxtaposed by a lack of a comprehensive understanding of the scope and kinetics of immunodeficiency following these treatments. We review emerging studies detailing the safety and efficacy of CD19 CAR-T and CD20 BsAbs in earlier lines for B-NHL, as well as a discussion of the limited knowledge of immune recovery following these treatments. We integrate the limited consensus prevention and management recommendations, advocating that the management of secondary immunodeficiency following these transformative therapies is an urgent unmet need in immune oncology research. A collaboration between hematologists/oncologists and immunologists in the management of these patients is critical to optimize patient care.

Bispecific antibodies targeting BCMA or GPRC5D are highly effective in relapsed myeloma after CAR T-cell therapy

Despite the astonishing outcomes after chimeric antigen receptor (CAR) T-cell therapy for relapsed refractory multiple myeloma (RRMM), most patients eventually relapse. There are only limited data available on salvage therapies following relapse after BCMA-directed CAR T-cell therapy. Here, we analyzed outcomes of post-CAR T-cell therapy relapse and impact of different salvage strategies in an international cohort of 139 patients (n = 130 ide-cel, n = 9 cilta-cel), receiving talquetamab (n = 28), teclistamab (n = 37), combinations of immunomodulating drugs (IMiDs), proteasome inhibitors (PIs) or CD38 monoclonal antibodies (n = 43), and others (n = 31). The median time to relapse after CAR T-cell therapy was 5 months, 53% had the extramedullary disease (EMD) at relapse, associated with dismal post-relapse outcome (P = 0.005). Overall response and complete response upon salvage therapies were 79% and 39% for talquetamab, 64% and 32% for teclistamab, 30% and 0% for IMiDs/PIs/CD38, and 26% and 3% for others (P < 0.001). Duration of response, as well as median survival, was significantly improved with bispecific antibodies (P < 0.001, respectively). Bispecific antibodies seemed to overcome the poor prognosis associated with early relapse and EMD, and were independent predictors for improved survival in multivariable analysis. In summary, these results suggest bispecific antibodies as the standard of care for relapse after CAR T-cell therapy for RRMM.

Visualizing immunotherapy for multiple myeloma worldwide from 2013 to 2023: A bibliometric analysis

ABSTRACT Multiple myeloma (MM) is a malignant, clonal proliferative disease of plasma cells that remains incurable. This paper aims to analyze the current research status and emerging trends in immunotherapy for MM through bibliometric methods, thereby providing valuable references and guidance for future research and clinical practice. This study presents a bibliometric analysis of 1,018 English-language publications related to MM immunotherapy, which were published in the Web of Science (WoS) Core Collection database from 2013 to 2023. VOSviewer and CiteSpace were employed to visualize the research hotspots and trends within the field of MM immunotherapy. The United States had the highest number of publications (n = 432, 42.44%), followed by China (n = 177, 17.39%). Harvard University was the institution with the most publications (n = 85), while Anderson KC (n = 27) was the most prolific researcher in the field. The highly cited literature mainly focuses on the treatment regimen based on daratumumab, the application of BCMA CAR-T therapy and the management of relapsed/refractory MM (RRMM), which represent the current research hotspots in this field. Burst detection highlights that bispecific antibodies and preclinical activity as key areas of interest. The cooperation among countries, institutions, and authors in this field should be strengthened. The treatment regimen utilizing daratumumab, the implementation of BCMA CAR-T therapy, and the management of RRMM represent significant research focal points in this field. Additionally, the development and application of bispecific antibodies have emerged as a frontier in recent years.

Bispecific antibody and chimeric antigen receptor (CAR) modified T-cell in the treatment of multiple myeloma: where do we stand today?

Bispecific antibody and chimeric antigen receptor (CAR) modified T-cell in the treatment of multiple myeloma: where do we stand today?

Translational findings support regimen selection for first-in-human study of ubamatamab (MUC16 × CD3 bispecific antibody) in patients with recurrent ovarian cancer.

Ubamatamab, a Mucin 16 (MUC16) × cluster of differentiation 3 (CD3) bispecific antibody that promotes T-cell-mediated cytotoxicity of MUC16-expressing cells, is being investigated for the treatment of ovarian cancer. Intravenous administration of ubamatamab, with or without the anti-programmed cell death-1 inhibitor cemiplimab, is being evaluated in a first-in-human study in patients with recurrent ovarian cancer. Invitro cytotoxicity and cytokine data and projected ubamatamab human pharmacokinetic (PK) profiles scaled with monkey PK parameters enabled starting-dose selection in humans. Mouse tumor regression studies identified ubamatamab effective concentrations. Preclinical and clinical PK, cytokine, safety, and efficacy data from dose escalation were integrated to determine expansion regimens. A starting dose of 0.1 mg was selected, which showed acceptable safety in patients. A step-up dosing approach was used to effectively manage cytokine release syndrome. Mouse tumor regression models suggested an ubamatamab efficacious concentration range of 0.4-50 mg/L, consistent with clinical activity observed at ubamatamab trough concentrations ≥5 mg/L. Integrating preclinical and clinical data determined a target trough concentration range of 5-30 mg/L, which supports evaluation of ubamatamab 250 mg with or without cemiplimab and 800 mg monotherapy once every 3 weeks in expansion cohorts. Preclinical data (cytokine release, tumor regression, monkey PK) had translational value in supporting regimen selection in dose escalation and subsequently in dose expansion after integration with patient data from dose escalation.

Enhancing NK cell-mediated tumor killing of B7-H6 positive cells with bispecific antibodies targeting allosteric sites of NKp30

Enhancing NK cell-mediated tumor killing of B7-H6 positive cells with bispecific antibodies targeting allosteric sites of NKp30

The first-in-class bispecific antibody IBI318 (LY3434172) targeting PD-1 and PD-L1 in patients with advanced tumors: a phase Ia/Ib study

BackgroundThere is an unmet clinical need to enhance the response rate and safety of anti-PD-1/PD-L1-based cancer immunotherapy (IO). Herein, we presented the clinical study of IBI318 (LY3434172), a first-in-class bispecific antibody (bsAb) targeting PD-1 and PD-L1, in patients with advanced tumors.MethodsIn this open-label, multicenter Phase Ia/Ib study of IBI318, the Phase Ia involved dose escalation and a safety dose expansion, while the Phase Ib focused on preliminary safety and efficacy evaluation in non-small cell lung cancer (NSCLC) and nasopharyngeal carcinoma (NPC). In Phase Ia, patients with advanced tumors received IBI318 doses ranging from 0.3 to 1200 mg every two weeks (Q2W) to determine the recommended Phase 2 dose (RP2D). In Phase Ib, NSCLC or NPC patients from five cohorts with varying treatment histories received IBI318 at the RP2D. The primary endpoint was safety and the secondary endpoints included efficacy assessed by investigators according to RECIST v1.1, pharmacokinetics, immunogenicity, and pharmacodynamics.ResultsFrom February 11, 2019, to January 25, 2022, a total of 103 eligible patients were enrolled (Phase Ia, n = 55; Phase Ib, n = 48). The median follow-up was 10.1 months (range 0.7–28.6). The RP2D was determined to be 300 mg Q2W. Treatment-related adverse events (TRAEs) of any grades occurred in 88 patients (85.4%), while 10 patients (9.7%) experienced grade ≥ 3 TRAEs. The objective response rate (ORR) was 15.5% and the disease control rate (DCR) was 49.5% in all patients. In Phase Ib, the confirmed ORR was 45.5% in treatment-naïve NSCLC patients and 30.0% in IO-naïve NPC patients who had failed or were intolerant to platinum-based treatments.ConclusionsIBI318 demonstrated a favorable safety profile and preliminary efficacy in treatment-naïve NSCLC and IO-naïve NPC patients. Further clinical studies are needed to assess the full therapeutic potential of PD-1/PD-L1 dual inhibition with bsAbs.

The changing treatment landscape of EGFR-mutant non-small-cell lung cancer.

The discovery of the association between EGFR mutations and the efficacy of EGFR tyrosine-kinase inhibitors (TKIs) has revolutionized the treatment paradigm for patients with non-small-cell lung cancer (NSCLC). Currently, third-generation EGFR TKIs, which are often characterized by potent central nervous system penetrance, are the standard-of-care first-line treatment for advanced-stage EGFR-mutant NSCLC. Rational combinations of third-generation EGFR TKIs with anti-angiogenic drugs, chemotherapy, the EGFR-MET bispecific antibody amivantamab or local tumour ablation are being investigated as strategies to delay drug resistance and increase clinical benefit. Furthermore, EGFR TKIs are being evaluated in patients with early stage or locally advanced EGFR-mutant NSCLC, with the ambitious aim of achieving cancer cure. Despite the inevitable challenge of acquired resistance, emerging treatments such as new TKIs, antibody-drug conjugates, new immunotherapeutic approaches and targeted protein degraders have shown considerable promise in patients with progression of EGFR-mutant NSCLC on or after treatment with EGFR TKIs. In this Review, we describe the current first-line treatment options for EGFR-mutant NSCLC, provide an overview of the mechanisms of acquired resistance to third-generation EGFR TKIs and explore novel promising treatment strategies. We also highlight potential avenues for future research that are aimed at improving the survival outcomes of patients with this disease.

Anti-BCMA and GPRC5D bispecific antibodies in relapsed/refractory primary plasma cell leukemia: a case report

Anti-BCMA and GPRC5D bispecific antibodies in relapsed/refractory primary plasma cell leukemia: a case report

Polymeric Multivalent Fc Binding Peptides-Fabricated Clinical Compounding Bispecific Antibody Potentiates Dual Immunotherapy Targeting PD1 and CTLA-4.

Dual Opdivo plus Yervoy immunotherapy, targeting the immune checkpoints PD1 and CTLA-4, is successful in clinical use. However, it is associated with a high incidence of adverse events, and its therapeutic efficacy needs improving. In this study, polymeric multivalent Fc-binding peptides (PLG-Fc-III-4C) are employed to fabricate a bispecific antibody (PD1/CTLA-4 BsAb) to potentiate dual immunotherapy targeting PD1 and CTLA-4. The PD1/CTLA-4 BsAb is prepared by mixing PLG-Fc-III-4C with aPD1 and aCTLA-4 in an aqueous solution for 3 h using the clinically optimal 3:1 proportion of aPD1 to aCTLA-4. PD1/CTLA-4 BsAb significantly inhibits tumors in MC38 colon cancer-bearing mice more effectively than the combination of aPD1 and aCTLA-4, with tumor suppression rates of 96.8% and 77.3%, respectively. It also induces a higher percentage of CD8+ T cells and increases the secretion of effector cytokines while reducing Treg levels in tumors compared to phosphate-buffered saline, indicating significant tumor immunity regulation. Mechanistically, a 6.3-fold increase in PD1/CTLA-4 BsAb accumulation in tumors due to the tumor targeting ability of aPD1, and the PD1/CTLA-4 BsAb significantly reduces the adverse colitis event in healthy mice, compared to aPD1 and aCTLA-4. Thus, these findings provide a novel approach to enhance antitumor therapy using aPD1 and aCTLA-4.

A fully humanized von Willebrand disease type 1 mouse model as unique platform to investigate novel therapeutic options.

Patients suffering from von Willebrand disease (VWD) have reduced quality-of-life despite current treatment options. Moreover, innovation in VWD therapeutic strategies has essentially stalled and available treatments have remained unchanged for decades. Therefore, there is an unmet need to develop new therapeutic strategies for VWD-patients, especially for the large portion of those with VWD-type 1. Due to species differences, the available VWD murine models are not suitable for preclinical studies, making it difficult to test new therapeutic approaches in vivo. With this in mind, we generated mice selectively expressing human von Willebrand factor (VWF) and human GPIbα. Because this fully humanized model was found to express low VWF (12%) and FVIII (40%) levels with normal multimer profile and activity/antigen ratio, we repositioned it as a VWD-type 1 model (hVWD1 mice). In depth characterization of this model confirmed VWD-type 1 features with a decrease in platelet adhesion and thrombus formation in vitro. In vivo, a moderate bleeding phenotype was observed which was corrected upon the administration of recombinant-VWF or upon histamine-induced release of endothelial VWF. In search for new therapeutic options for VWD, we designed a bispecific single-domain antibody that bridges VWF to albumin (KB-V13A12). Remarkably, a single subcutaneous administration of KB-V13A12 coincided with a sustained 2-fold increase in VWF antigen levels for up to 10 days and normalized haemostasis in a tail-clip model in hVWD1 mice. We have developed a unique humanized mouse model for VWD-type 1 and a promising new therapeutic that corrected haemostasis in these mice.

A Phase 1/2 study of teclistamab, a humanized BCMA × CD3 bispecific Ab in Japanese patients with relapsed/refractory MM.

We characterized the safety and efficacy of the bispecific antibody teclistamab in Japanese patients with relapsed/refractory multiple myeloma (RRMM). Patients were pretreated with a proteasome inhibitor (PI), immunomodulatory drug (IMiD), and anti-CD38 monoclonal antibody (mAb). The primary endpoint was frequency and type of treatment-emergent adverse events (TEAEs) in phase 1, and overall response rate (ORR; ≥ partial response [PR]) in phase 2. In phase 1, 14 patients received once-weekly (QW) subcutaneous teclistamab (0.72mg/kg [n = 5]; 1.5mg/kg [n = 5]; 3mg/kg [n = 4]). No dose-limiting toxicities were observed. As of April 2024, 26 phase-2 patients received the recommended phase-2 dose (QW) (RP2D: 1.5mg/kg) of teclistamab. Biweekly (Q2W) dosing was allowed after maintaining response for ≥ 6months. At a median follow-up of 14.32months, ORR was 76.9% (≥ very good PR: 76.9%; ≥ complete response: 65.4%). Median duration of response, progression-free survival, and overall survival were not reached. Common TEAEs included CRS (grade ≤ 2), neutropenia, and infections. No patient had immune effector cell-associated neurotoxicity syndrome (ICANS) and dose reductions. Teclistamab demonstrated deep and durable responses in Japanese patients with RRMM, consistent with the global pivotal MajesTEC-1 study, supporting the potential for a new standard of care for Japanese RRMM patients.

Talquetamab in Multiple Myeloma: Efficacy, Safety, and Future Directions.

Relapsed and refractory multiple myeloma (RRMM) remains a challenging condition despite advances in immunotherapies. Novel bispecific antibodies (BsAbs), including talquetamab, have shown promising efficacy in heavily pretreated patients, even those with triple- and penta-refractory disease. Talquetamab, recently approved by the FDA and EMA, is indicated for patients who have progressed after at least three or four prior lines of therapy (LOTs). Administered following a step-up dosing phase to manage cytokine release syndrome (CRS), talquetamab demonstrated a high overall response rate (ORR) of approximately 70%, including in patients previously treated with T-cell redirecting therapies. Its safety profile is consistent with other BsAbs, with hematologic adverse events such as anemia and neutropenia commonly reported, alongside unique on-target off-tumor toxicities like dysgeusia and skin-related events. Infections were less frequent compared to other BsAbs. The optimal sequencing of talquetamab and other therapies, including CAR-T cell treatments, remains an area of active research, as resistance to anti-BCMA therapies presents ongoing clinical challenges. Current trials are exploring the use of talquetamab in combination therapies, as well as therapeutic strategies post-treating progression. The real-world data further support talquetamab's efficacy, making it a valuable addition to the RRMM treatment landscape.

Development and Characterization of a Lysosome-Targeting SLC3A2/PD-L1 Bispecific Antibody-Drug Conjugate for Enhanced Anti-Tumor Efficacy in Solid Tumors.

Bispecific antibodies (BsAbs) and antibody-drug conjugates (ADCs) have shown significant promise in cancer treatment, enhancing drug selectivity and therapeutic efficacy as demonstrated in multiple clinical studies. Bispecific antibody-drug conjugates (BsADCs), which combine the targeting capabilities of BsAbs with the cytotoxic potential of ADCs, offer a novel approach to overcoming several challenges associated with ADCs, including limited internalization, off-target toxicity, and drug resistance. In this study, we identified solute carrier family 3 member 2 (SLC3A2) as a highly expressed protein in a variety of solid tumors, making it a promising therapeutic target. We developed a bispecific antibody targeting SLC3A2 and PD-L1, and conjugated it to monomethyl auristatin E (MMAE) to create the SLC3A2/PD-L1 BsADC. The SLC3A2/PD-L1 BsAb effectively blocked PD-1 binding to PD-L1 and activated T cells, while also facilitating lysosomal targeting and degradation of poorly internalized PD-L1 antibodies. The SLC3A2/PD-L1 BsADC demonstrated superior anti-tumor efficacy in PD-L1 low-expressing tumor cells compared to single-target ADCs in both in vitro studies and in multiple xenograft and immunocompetent mouse models. Overall, our engineered SLC3A2/PD-L1 BsADC exhibited enhanced internalization and improved tumor cell targeting, highlighting the potential of lysosome-targeting BsAbs in advancing ADC therapeutic strategies for solid tumors.

Preparing Nurses for CD20-CD3 Bispecific Antibody Treatment in Patients With Non-Hodgkin Lymphoma: A Scoping Review of Adverse Events and Management Strategies From Early Phase and Pivotal Trials.

Bispecific T-cell engaging antibodies (BsAbs) are novel agents used to treat B-cell non-Hodgkin lymphoma (B-NHL); these agents demonstrate a different toxicity profile compared with standard chemoimmunotherapy. To describe common adverse events (AEs) experienced by patients with B-NHL during BsAb treatment. MEDLINE, EMCARE, and EMBASE were searched for relevant studies. Prospective interventional clinical trials of CD20-CD3 BsAbs in late development reporting on safety data for B-NHL patients, published until March 2023, were included. This search identified 1481 records; 28 met the inclusion criteria. Cytokine release syndrome (CRS), neutropenia, pyrexia, and anemia were the most commonly reported AEs. CRS primarily occurred during the first cycle of treatment and was mostly low grade; 14 publications (48%) reported a grade ≥3; however, these occurred in less than 10% of patients. Mitigation strategies included premedication with corticosteroids, antipyretics, and antihistamines; step-up dosing; and planned hospitalizations. Two articles reported common signs and symptoms of CRS, which included pyrexia (98% and 99%), chills (13% and 35%), tachycardia (27% and 28%), and hypotension (24% and 38%). Supportive management, tocilizumab, and corticosteroids were widely used (reported in 16/28 studies) for the treatment of CRS. Patient risk factors for CRS included high tumor burden, bone marrow infiltration, and circulating disease. The AE profile of BsAbs requires specialized nurses, skilled in assessing patients for risk factors and recognizing signs and symptoms of AEs. Findings from this review will contribute to cancer nurses' knowledge of CD20-CD3 BsAbs for B-NHL, optimizing the quality and safety of patient care.

Interleukin-17A is a potential therapeutic target predicted by proteomics for systemic sclerosis patients at high risk of pulmonary arterial hypertension

We explored effective therapeutic targets for systemic sclerosis (SSc) patients with high risk for pulmonary arterial hypertension (PAH) by plasma proteomics analysis. A total of fifty-seven patients with SSc were enrolled in the study and the prevalence of PAH was 19.3%. On the other hand, 75.4% of SSc patients showed the ratio of forced vital capacity percentage/diffusing capacity of the lungs for carbon monoxide percentage> 1.6 and met criteria for high risk of PAH. Identification of elevated plasma proteins in SSc patients with high risk of PAH, followed by upstream regulator analysis, predicted interleukin (IL)-17A as a major upstream molecule. Furthermore, we performed in vitro neutralization study using MT-6194, a bispecific antibody targeting both IL-17A and IL-6 receptor. We found that MT-6194 broadly suppressed the increased expression of downstream molecules of IL-17A including IL-17A-related cytokines/chemokines, IL-17A-driven NF\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\kappa$$\\end{document}B pathway and IL-6-driven JAK/STAT pathway which were shown to be increased in SSc patients with high risk of PAH by the proteomics. Consequently, it is revealed that IL-17A is a promising target for early intervention in SSc patients with high risk for PAH.

CD47 predominates over CD24 as a macrophage immune checkpoint in cancer.

Macrophages hold tremendous promise as effectors of cancer immunotherapy, but the best strategies to provoke these cells to attack tumors remain unknown. Here, we evaluated the therapeutic potential of targeting two distinct macrophage immune checkpoints: CD47 and CD24. We found that antibodies targeting these antigens could elicit maximal levels of phagocytosis when combined together in vitro. However, to our surprise, via unbiased genome-wide CRISPR screens, we found that CD24 primarily acts as a target of opsonization rather than an immune checkpoint. In a series of in vitro and in vivo genetic validation studies, we found that CD24 was neither necessary nor sufficient to protect cancer cells from macrophage phagocytosis in most mouse and human tumor models. Instead, anti-CD24 antibodies exhibit robust Fc-dependent activity, and as a consequence, they cause significant on-target hematologic toxicity in mice. To overcome these challenges and leverage our findings for therapeutic purposes, we engineered a collection of 77 novel bispecific antibodies that bind to a tumor antigen with one arm and engage macrophages with the second arm. We discovered multiple novel bispecifics that maximally activate macrophage-mediated cytotoxicity and reduce binding to healthy blood cells, including bispecifics targeting macrophage immune checkpoint molecules in combination with EGFR, TROP2, and CD71. Overall, our findings indicate that CD47 predominates over CD24 as a macrophage immune checkpoint in cancer, and that the novel bispecifics we created may be optimal immunotherapies to direct myeloid cells to eradicate solid tumors.

Total (Immuno)Therapy: Version 2.0.

Among patients with poly-refractory myeloma, autologous chimeric antigen receptor T-cell therapy offers exceptional promise. With the availability of bispecific antibodies, a total immunotherapeutic strategy in combination with chimeric antigen receptor T-cell therapy is now feasible. See related article by Fandrei, p. XX.

Supportive care in myeloma-when treating the clone alone is not enough.

The overall survival in patients with multiple myeloma has increased over recent decades. This trend is anticipated to further advance with the emergence of T-cell-redirecting therapies, including chimeric antigen receptor T-cell (CAR T) therapy and T-cell-engaging bispecific antibodies. Despite these therapeutic improvements, treatment-related adverse events impede quality of life. This underscores the imperative of optimizing supportive care strategies to maximize treatment outcomes. Such optimization is crucial not only for patient well-being but also for treatment adherence, which may translate into long-term disease control. We here describe a) how to prevent bone disease, b) a risk-adapted thrombosis prophylaxis approach, c) the management of on-target, off-tumor toxicity of G-protein-coupled receptor class C group 5 member D-targeting T-cell-redirecting therapies, and d) infectious prophylaxis, with a focus on infections during T-cell-redirecting therapies.

Relapsed/refractory CLL: the role of allo-SCT, CAR-T, and T-cell engagers.

Chronic lymphocytic leukemia (CLL) patients who are refractory to both Bruton's tyrosine kinase and B-cell/CLL lymphoma 2 (BCL2) inhibitors face a significant treatment challenge, with limited and short-lasting disease control options. This underscores the urgent need for novel therapeutic strategies. Immunotherapy has emerged as a promising approach to address this unmet need, offering the potential for durable remissions and improved patient outcomes. Historically, allogeneic stem cell transplantation has been used for high-risk CLL patients, demonstrating promising survival rates. However, its applicability is limited by high treatment-related mortality and chronic graft-versus-host disease, especially in older and frail patients. Chimeric antigen receptor (CAR) T-cell therapy is gaining attention for its potential in relapsed/refractory CLL. Early clinical trials have shown that CAR T cells can induce durable remissions, with encouraging overall response rates in heavily pretreated patients. Additionally, bispecific antibodies are being explored as immunotherapeutic strategies, showing promising preclinical and early clinical results in targeting CLL cells effectively. One of the major challenges in CLL treatment with T-cell-based therapies is the acquired T-cell dysfunction observed in patients. To overcome these limitations, strategies such as combining targeted agents with cellular immunotherapies, modifying CAR designs, and incorporating immunomodulatory compounds into the manufacturing process are being investigated. These innovative approaches aim to enhance T-cell engagement and improve outcomes for CLL patients, offering hope for more effective and sustainable treatments in the future.