Signal-on fluorescent sensing strategy for Pb2+ detection based on 8-17 DNAzyme-mediated molecular beacon-type catalytic hairpin assembly circuit

Based on a Pb²⁺-specific 8-17 DNAzyme-induced catalytic hairpin assembly (CHA), a simple signal-on fluorescence strategy for lead ion detection was established. 8-17 DNAzyme was used as the recognition element of Pb²⁺, which catalyzed the cleavage of the RNA base embedded in the DNA substrate strand, while releasing part of the substrate strand (S') as CHA initiator. And two hairpin probes (H1 and H2-FQ) were designed according to the sequence of S' for CHA, in which H2-FQ was labeled with the fluorophore FAM and quencher BHQ-1 as fluorescent "molecular switch" based on fluorescence resonance energy transfer (FRET). In the presence of Pb²⁺, the CHA reaction was triggered to form a large number of H1-H2 complexes, enabling enzyme-free isothermal amplification and a signal-on fluorescence strategy. In the concentration range of 0.5-1000 nM, the fluorescence signal increases with the increase of Pb²⁺ concentration. The quantitative detection limit of Pb²⁺ by this method is 0.5 nM, which has better detection performance compared with the FQ-labeled 8-17 DNAzyme method. The established biosensor exhibits good specificity and can be effectively used for the detection of Pb²⁺ in real samples of river water and grass carp. Through ingenious nucleic acid sequence design, DNAzyme and CHA reactions are integrated to realize the enzyme-free isothermal amplifications and sensitive detection of Pb²⁺, which holds potential versatility in food supervision and environmental monitoring.

Efficacy and safety of intravenous daratumumab-based treatments for AL amyloidosis: a systematic review and meta-analysis

BACKGROUND

Intravenous daratumumab (DARA IV) has been increasingly used in the treatment of amyloid light-chain (AL) amyloidosis. However, the outcomes for patients administered with DARA IV have not been aggregated. The objective of this systematic review and meta-analysis was to investigate the efficacy and safety of DARA IV for AL amyloidosis.

METHODS

We searched Medline, EMBASE, Cochrane Library and Web of Science up to 17 June 2021. Response rates and survival rates, and the corresponding 95% confidence intervals (CIs) were pooled and calculated using a fixed-effects model.

RESULTS

Thirty studies (5 cohort studies and 25 single-arm studies) with 997 patients were included. In patients receiving DARA IV-based treatments, very good partial response or better response rate, complete response rate, very good partial response rate, partial response rate and overall response rate were 66% (95% CI, 62-69%), 30% (95% CI, 23-36%), 40% (95% CI, 33-46%), 17% (95% CI, 14-21%), and 77% (95% CI, 73-80%), respectively. Cardiac and renal responses were 41% (95% CI, 34-49%) and 43% (95% CI, 32-54%), respectively. 58% (95% CI, 49-66%) of patients achieved PFS one year or longer. 2.5% (range, 1-10.0%) of patients experienced grade 3 or 4 adverse events, of which the most common adverse event was lymphocytopenia (range, 13.6-25.0%).

CONCLUSION

This study supports the efficacy and safety of DARA IV for the treatment of patients with AL amyloidosis.

The surface structure, stability, and catalytic performances toward O2 reduction of CoP and FeCoP2

The systematic atomistic level investigation of low-index surface structures, stabilities, and catalytic performances of CoP and FeCoP₂ towards the O₂ reduction reaction (ORR) is vital for their applications. Employing first-principles calculations, it is revealed that CoP and FeCoP₂ present the same surface stability in the order of (101) ≈ (011) > (111) > (001) > (110) > (010) > (100). They also possess a similar Wulff equilibrium crystal shape with (101) and (011) exposing the largest surface area. From the electronic view, FeCoP₂ presents improved electronic conductivity compared with CoP. From the energy view, whether FeCoP₂ delivers improved electrocatalytic activity toward the ORR with respect to CoP depends on the reactive surfaces and sites. Among the 4 surfaces considered, only CoP(101), FeCoP₂(101) and FeCoP₂(011) delivered ORR performances theoretically when the bridge metal-metal site acts as the reactive center, which makes CoP(011) the only exception. CoP(101)-b_Co-Co and FeCoP₂(011)-b_Fe-Co exhibit a larger thermodynamic limiting potential than FeCoP₂(101)-b_Co-Co, suggesting their higher performances toward the ORR. The last step of HO* desorption as the rate-limiting step accounts for 3/4. The third step of transformation from O* to HO* as the most sluggish step accounts for 1/4. The work function, d-band center, Bader charge, and electronic localization function calculations are performed to reveal the HO adsorption nature. The present work provides fundamental insight into the effect of Fe doping into CoP, the determination of the catalyst surface and the key species adsorption nature to guide the rational design of high-performance materials.

Abstract 2894: QL401, a dual PD-L1/CD47 blocker effective against both solid and hematological malignancies with improved blood safety

Upregulation of CD47, a “Do Not Eat Me” signal, is observed in nearly all solid and hematological malignancies. Engagement of CD47 on tumor cells with SIRPα on macrophages inhibits phagocytosis of tumor cells. Anti-CD47 antibodies block the CD47 - SIRPα engagement and reactivate phagocytosis of tumor cells by macrophages. Yet the ubiquitous expression of CD47 on normal cells, including red blood cells, presents a therapeutic challenge. Systemic targeting of CD47, by either anti-CD47 monoclonal antibodies or SIRPα-Fc fusion proteins, yielded only moderate clinical benefit due to severe adverse side effects, mainly anemia. QL401 is PD-L1 x CD47 bispecific antibody engineered to reduce binding to red blood cells while retaining potent phagocytic activation of macrophages in vitro and delayed tumor growth in vivo. QL401 comprises three functional components: a PD-L1 binding Fab arm, a CD47 binding scFv arm, and a human IgG4 backbone. The PD-L1 binding arm provides both tumor targeting and blocking of PD-1 for reactivating T cells. The CD47 arm blocks the binding of SIRPα, the “Do Not Eat Me” signal, while the IgG4 Fc retains Fc gamma receptor binding to provide a phagocytic “Eat Me” signal. Therefore, QL401 is multi-functional antibody that re-actives both the innate and adaptive immune response. In preclinical efficacy studies, QL401 potently blocked SIRPα to promote phagocytosis of tumor cells with sub-nanomolar potency. In vivo efficacy studies in mouse models of solid and hematological tumors showed QL401 to be comparable or superior to PD-L1 or CD47 monoclonal antibodies alone and in combination. In vitro safety evaluation of Q401 showed significantly reduced binding and phagocytosis of red blood cells, in contrast to CD47 monoclonal antibodies. In addition, Q401 did not induce hemagglutination. In non-human primates, QL401 was well tolerated up to 100 mg/kg without reduction of red blood cells below normal range. A phase 1 dose escalation and expansion study is expected to start Q1 2022 to evaluate the safety, tolerability, and early efficacy of QL401.

Citation Format: Irene Tang, Lauren Schwimmer, Shenda Gu, Wei Wei Prior, Hieu V. Tran, Allan Chan, Anna McClain, Shihao Chen, Chuanzeng Cao, Chunyan Sun, Meimei Si, Guijiang Wang. QL401, a dual PD-L1/CD47 blocker effective against both solid and hematological malignancies with improved blood safety [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2894.

Ratiometric fluorescent hydrogel for point-of-care monitoring of organophosphorus pesticide degradation

The residues of organophosphorus pesticides have caused the potential risk in environment and human health, arousing worldwidely great concern. Herein, we fabricated a robust gold nanoclusters/MnO₂ composites-based hydrogel portable kit for accurate monitoring of paraoxon residues and degradation in Chinese cabbages. With the immobilization of gold nanoclusters/MnO₂ composites into a hydrogel, a ratiometric fluorescent signal is generated by catalyzing the oxidation of o-phenylenediamine, which possesses a built-in correction with low background interference. Coupling with acetylcholinesterase catalytic reactions and pesticide inhibition effect, the portable kit can sensitively detect paraoxon residues with a detection limit of 5.0 ng mL^-1. For on-site quantification, the fluorescent color variations of portable kit are converted into digital information that exhibits applicative linear range toward pesticide. Notably, the hydrogel portable kit was successfully applied for precisely monitoring the residue and degradation of paraoxon in Chinese cabbage, providing a potential pathway toward practical point-of-care testing in food safety monitoring.

Enhanced photodegradation of decabromodiphenyl ether on oxygen vacancy-enriched Bi2MoO6

Debromination is a primary and critical procedure in the treatment of polybrominated diphenyl ethers (PBDEs) in the environment. Herein, oxygen vacancy-enriched Bi₂MoO₆ is firstly applied in the photoreduction debromination of PBDEs under visible light illumination. The introduction of oxygen vacancies not only promotes the red-shift of the light absorption band by Bi₂MoO₆, but also activates the C–Br bond through the formation of Br–O halogen bonds, thus realizing efficient visible light reduction of decabromodiphenyl ether (BDE209). The activation adsorption mode inferred by tracking analysis of the degradation process shows that the meta-position adsorption mode is the main adsorption configuration during the activation process, while the ortho-position adsorption mode is the most difficult. Thence, the oxygen vacancy-dominated photocatalytic BDE209 process is a position-selective multi-electron reduction process. The study shows that oxygen vacancy assisted C–Br activation is an excellent strategy for photocatalytic treatment of halogenated persistent organic pollutants.

The photocatalytic debromination of decabromodiphenyl ether is successfully achieved on oxygen vacancy-enriched Bi₂MoO₆via a position selective multi-electron mechanism.

Construction of α-Fe2O3/Sulfur-Doped Polyimide Direct Z-Scheme Photocatalyst with Enhanced Solar Light Photocatalytic Activity

A novel two-dimensional α-Fe₂O₃/sulfur-doped polyimide (FO/SPI) direct Z-scheme photocatalyst was successfully constructed by a facile thermal treatment method. The effects of α-Fe₂O₃ nanosheets on the morphology, chemical structure, and photoelectronic properties of FO/SPI composites were systematically characterized by different spectroscopic means. These methods include X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, transient fluorescence spectra, and so forth. It was confirmed that the small amounts of α-Fe₂O₃ can availably facilitate exfoliation of bulk SPI, resulting in a transformation of SPI from bulk to 2D layered composite that illustrates tight interface through the coordination Fe-N bond and an all-solid-state direct Z-scheme junction. Thus, the transfer and separation efficiency of photogenerated electron/hole pairs were significantly enhanced, which greatly promoted improvement of the photocatalytic activity of the FO/SPI composite for methyl orange degradation under solar light. This work provides a new approach to constructing efficient inorganic-organic Z-scheme photocatalyst based on strong interface interaction.

The application of metal-organic frameworks in the adsorptive removal of harmful species from aqueous solutions

Abstract:

Removing harmful species from water is essential for the protection of the environment and human health. Among various treatment techniques, adsorption is particularly attractive because of its advantages of easy operation, high removal efficiency, environmental friendliness, and simple regeneration of the adsorbent. As the key factor of this technique, the choice of adsorbent is vital. Metal-organic frameworks (MOFs) have been widely used as adsorbents for the removal of dyes, pharmaceuticals and personal care products (PPCPs), and metal ions from aqueous solutions because of their high porosity, structural diversity, and highly tunable pore shape/size and surface functionality. This work systematically reviews the recent progress on the application of different types of MOFs, e.g., ZIF, MIL, and UiO series, in the field of adsorption of these harmful species. Modification of novel MOF materials can greatly improve their adsorption performance. This review provides a direction for the rational design of MOF adsorbents to effectively remove various pollutants from water.

Cardiovascular-specific mortality among multiple myeloma patients: a population-based study

Introduction:

Multiple myeloma (MM) survival has greatly improved in recent decades. MM is usually diagnosed at a median age of 66–70 years. MM patients do not necessarily die from primary cancer, so cardiovascular health may be a key factor threatening long-term survival. This study was designed to explore the cardiovascular disease mortality (CVM) trends in MM patients and compare them with those in the general population.

Methods:

In total, 88,328 MM patients from the Surveillance, Epidemiology, and End Results (SEER) database (1975–2016) were included. Standardized mortality ratios (SMRs) were used to assess CVM risk.

Results:

The CVM risk was significantly higher in MM patients than in the general population (SMR, 1.84 (95% CI, 1.78–1.89)). MM patients had the highest CVM SMR, at 2.62 (95% CI, 2.49–2.75), in the first year after diagnosis, and it decreased over the follow-up period. Over the study period, the incidence of CVM continued to decrease in MM patients diagnosed at age 65–74 (APC, −1.2% (95% CI, −1.9% to −0.4%)) and ⩾75 years (APC, −1.9% (95% CI, −2.6% to −1.2%)) but not younger. CVM was the second-most common cause of death in patients ⩾75 years. In only MM case analyses, male sex, Black race, older age at diagnosis, and earlier year of diagnosis were poor prognostic factors for heart-specific mortality.

Conclusion:

The CVM risk in MM patients was significantly higher than that in the general population. To improve survival, cardiovascular health should receive attention upon diagnosis.

FTO promotes multiple myeloma progression by posttranscriptional activation of HSF1 in an m6A-YTHDF2-dependent manner

N⁶-methyladenosine (m⁶A), as the most pervasive internal modification of eukaryotic mRNA, plays a crucial role in various cancers, but its role in multiple myeloma (MM) pathogenesis has not yet been investigated. In this study, we revealed significantly decreased m⁶A methylation in plasma cells (PCs) from MM patients and showed that the abnormal m⁶A level resulted mainly from upregulation of the demethylase fat mass and obesity-associated protein (FTO). Gain- and loss-of-function studies demonstrated that FTO plays a tumor-promoting and pro-metastatic role in MM. Combined m⁶A and RNA sequencing (RNA-seq) and subsequent validation and functional studies identified heat shock factor 1 (HSF1) as a functional target of FTO-mediated m⁶A modification. FTO significantly promotes MM cell proliferation, migration, and invasion by targeting HSF1/HSPs in a YTHDF2-dependent manner. FTO inhibition, especially when combined with bortezomib (BTZ) treatment, synergistically inhibited myeloma bone tumor formation and extramedullary spread in NOD-Prkdc^em26Cd52il2rg^em26Cd22/Nju (NCG) mice. We demonstrated the functional importance of m⁶A demethylase FTO in MM progression, especially in promoting extramedullary myeloma (EMM) formation, and proposed the FTO-HSF1/HSP axis as a potential novel therapeutic target in MM.

Integrated Proteomics and Metabolomics Analysis of Nitrogen System Regulation on Soybean Plant Nodulation and Nitrogen Fixation

The specific mechanisms by which nitrogen affects nodulation and nitrogen fixation in leguminous crops are still unclear. To study the relationship between nitrogen, nodulation and nitrogen fixation in soybeans, dual-root soybean plants with unilateral nodulation were prepared by grafting. At the third trifoliate leaf (V3) to fourth trifoliate leaf (V4) growth stages (for 5 days), nitrogen nutrient solution was added to the non-nodulated side, while nitrogen-free nutrient solution was added to the nodulated side. The experiment was designed to study the effects of exogenous nitrogen on proteins and metabolites in root nodules and provide a theoretical reference for analyzing the physiological mechanisms of the interaction between nitrogen application and nitrogen fixation in soybean root nodules. Compared with no nitrogen treatment, exogenous nitrogen regulated the metabolic pathways of starch and sucrose metabolism, organic acid metabolism, nitrogen metabolism, and amino acid metabolism, among others. Additionally, exogenous nitrogen promoted the synthesis of signaling molecules, including putrescine, nitric oxide, and asparagine in root nodules, and inhibited the transformation of sucrose to malic acid; consequently, the rhizobia lacked energy for nitrogen fixation. In addition, exogenous nitrogen reduced cell wall synthesis in the root nodules, thus inhibiting root nodule growth and nitrogen fixation.

Structure-switching aptamer triggering signal amplification strategy for tobramycin detection based on hybridization chain reaction and fluorescence synergism

Based on hybridization chain reaction (HCR) and fluorescence synergism, a novel aptasensor for tobramycin was successfully constructed. Tobramycin competed with cDNA-FAM to bind aptamers immobilized on magnetic beads. After magnetic separation, the released cDNA-FAM acted as initiator to trigger HCR amplification, thus the fluorescence was significantly enhanced due to binding of SYBR Green Ⅰ (SGI) to the formed long double-stranded DNA and the synergistic fluorescence of FAM. In the absence of tobramycin, the initiator was magnetically separated and no HCR occurred, more importantly, graphene oxide can quench the fluorescence of excessive hairpins/SGI and cDNA-FAM, so almost no background signal was detected. This aptasensor can monitor tobramycin in the range of 0.3-50 μM with low detection limit of 17.37 nM. Due to the potential generality of structure-switching aptamers and effectiveness of fluorescence synergism, this enzyme-free amplification strategy can be extended to other applications by rational design of nucleic acid sequences.

Exploring the pharmacological mechanism of calculus bovis in cerebral ischaemic stroke using a network pharmacology approach

ETHNOPHARMACOLOGICAL RELEVANCE

Calculus bovis is commonly used in traditional Chinese medicine for the treatment of cerebrovascular diseases given its roles in clearing away heat, detoxification and pain relief. Calculus bovis is used the treatment of cerebral ischaemia, liver and gallbladder diseases and various inflammatory conditions. However, the mechanism of action of calculus bovis in the treatment of ischaemic stroke is not well understood.

AIM OF THE STUDY

In this study, the anti-inflammatory, antioxidative and antiapoptotic effects of calculus bovis on neurovascular units were studied, and the mechanism of action of calculus bovis on neurovascular units was also discussed.

MATERIALS AND METHODS

Neurons, astrocytes, and endothelial cells were used to construct models of brain neurovascular units in vitro. The oxygen-glucose deprivation/reoxygenation and glucose (OGD/R) model was used to assess the effects of in vitro cultured calculus bovis on inflammatory factors, oxidative stress, and apoptosis. ZO-1, Occludin, Claudin-5, HIF-1, VEGF, PI3K, Akt, Bax, Bcl-2, and Caspase-3 expression was detected.

RESULTS

In vitro cultured calculus bovis protects the blood-brain barrier; repairs tight junction proteins; increases ZO-1, Occludin and Claudin-5 protein expression; maintains TEER(transepithelial electrical resistance) values; repairs damaged endothelial cells; increases γ-GT activity; reduces LDH and inflammatory injury; and reduces TNF-α, LI-6, and IL-1β levels. In vitro cultured calculus bovis reduces oxidative stress damage and NO and improves SOD activity. In vitro cultured calculus bovis protects neurons through antiapoptotic activities, including reductions in the apoptotic proteins Bax and Caspase-3, increases in Bcl-2 protein expression, and protection of brain neurovascular units through the HIF/VEGF and PI3K/Akt signalling pathways.

CONCLUSION

In summary, the protective effect of calculus bovis on neurovascular units is achieved through antioxidative, anti-inflammatory and antiapoptotic effects. The mechanism of action of in vitro cultured calculus bovis in ischaemic stroke involves multiple targets and signalling pathways. The PI3K/Akt, HIF-1α and VEGF pathways effectively protect neurovascular units in the brain.

[Research progress on the application of time-restricted eating in adult obesity and related metabolic diseases]

The soaring prevalence of obesity and its complications presents a significant health care burden, and there is currently a lack of effective and sustainable treatment methods. Time-restricted eating (TRE) is a specific intermittent fasting (IF) protocol involving consistent fasting and eating periods within a 24-hour cycle. Time-restricted eating can restore robust circadian rhythms and improve metabolic health, providing an emerging dietary strategy for the prevention and treatment of obesity and related metabolic diseases. Previous TRE trials laid the groundwork, and indicate a need for further clinical research including large-scale controlled trials to determine TRE efficacy and the mechanisms by which it may affect humans.

TEMPI Syndrome: Update on Clinical Features, Management, and Pathogenesis

TEMPI (telangiectasias, elevated erythropoietin level and erythrocytosis, monoclonal gammopathy, perinephric fluid collections, and intrapulmonary shunting) syndrome is a rare and newly defined multisystemic disease, which belongs to "monoclonal gammopathy of clinical significances". Due to its rarity, the etiology, pathogenesis, and clinical features of this disease remain largely unknown. Owing to its hidden and diverse clinical manifestations, missed diagnosis and misdiagnosis are common. In recent years, as more patients (including three fatal cases) were identified, some special clinical manifestations other than the typical pentad of TEMPI syndrome have been reported. Meanwhile, several studies attempting to identify the pathogenesis of TEMPI syndrome were conducted. In this review, we summarize the reported clinical characteristics of TEMPI syndrome and discuss the current and potential treatment options for patients with TEMPI syndrome, including those with relapsed/refractory disease. Furthermore, we provide an overview of current knowledge on the pathophysiology of TEMPI syndrome.

A signal-on fluorescent aptasensor by sensitized Tb3+ luminescence for detection of melamine in milk

A fluorescent aptasensor based on sensitized terbium(III) luminescence was constructed to detect melamine in milk. Tb³⁺ as the fluorescence probe can be sensitized by a guanine-rich single-stranded DNA sequence, so the complementary sequence of the polythymidine aptamer (cDNA) was modified with six consecutive guanine bases (G6). In the absence of melamine, melamine aptamer combined with cDNA to form a double helix structure, and G6 hybridized with the extended cytosine bases in the aptamer, resulting in low fluorescence intensity of Tb³⁺. In the presence of melamine, cDNA was released due to the specific recognition of melamine to the aptamer, resulting in stronger sensitized fluorescence intensity of Tb³⁺. Under the optimum conditions, the linear concentration of melamine in the milk ranged from 1.0 μg/mL to 10.0 μg/mL. This aptasensor can be used for the accurate and rapid detection of melamine in milk with a detection limit of 0.02 μg/mL, and has the advantages of high sensitivity, high efficiency, simple operation and low cost.

Facile and High-yield Synthesis of N-doped Carbon Quantum Dots from Biomass Quinoa Saponin for the Detection of Co2

Hydrothermal synthesis of carbon quantum dots (CQDs) from natural biomass is a green and sustainable route for CQDs applications in various fields. In this work, the preparation and characterization of CQDs based on quinoa saponin were investigated. The optimum synthetic conditions determined by orthogonal experiments were as follows: 2 g quinoa saponin powder and 0.04 mol ethylenediamine reacted at 200°C for 10 h. The relative fluorescence quantum yield (QY = 22.2%) can be obtained, which is higher than some results reported in the literatures. The prepared CQDs had a small and uniform size (∼2.25 nm) and exhibited excitation wavelength-dependent blue light emission behavior. The CQDs displayed excellent sensitivity for Co²⁺ detection along with good linear correlation ranging from 20 to 150 µM and the detection limit of 0.49 µM. The CQDs prepared in this experiment were successfully implanted into soybean sprouts for fluorescence imaging. The sprouts could grow healthily even soaked in the CQDs solution for two weeks, demonstrating the low toxicity of the CQDs. The advantages of the CQDs, such as low cost, ease of manufacture, nontoxicity, and stability, have potential applications in many areas such as metal ion detection and biosensing.

International Prognostic Index-Based Immune Prognostic Model for Diffuse Large B-Cell Lymphoma

Background

The International Prognostic Index (IPI) is widely used to discriminate the prognosis of patients with diffuse large B-cell lymphoma (DLBCL). However, there is a significant need to identify novel valuable biomarkers in the context of targeted therapy, such as immune checkpoint blockade (ICB).

Methods

Gene expression data and clinical DLBCL information were obtained from The Cancer Genome Atlas and Gene Expression Omnibus datasets. A total of 371 immune-related genes in DLBCL patients associated with different IPI risk groups were identified by weighted gene co-expression network analysis, and eight genes were selected to construct an IPI-based immune prognostic model (IPI-IPM). Subsequently, we analyzed the somatic mutation and transcription profiles of the IPI-IPM subgroups as well as the potential clinical response to immune checkpoint blockade (ICB) in IPI-IPM subgroups.

Results

The IPI-IPM was constructed based on the expression of CMBL, TLCD3B, SYNDIG1, ESM1, EPHA3, HUNK, PTX3, and IL12A, where high-risk patients had worse overall survival than low-risk patients, consistent with the results in the independent validation cohorts. The comprehensive results showed that high IPI-IPM risk scores were correlated with immune-related signaling pathways, high KMT2D and CD79B mutation rates, and upregulation of inhibitory immune checkpoints, including PD-L1, BTLA, and SIGLEC7, indicating a greater potential response to ICB therapy.

Conclusion

The IPI-IPM has independent prognostic significance for DLBCL patients, which provides an immunological perspective to elucidate the mechanisms of tumor progression and sheds light on the development of immunotherapy for DLBCL.

A bispecific CAR-T cell therapy targeting BCMA and CD38 in relapsed or refractory multiple myeloma

Background

BCMA-specific chimeric antigen receptor-T cells (CAR-Ts) have exhibited remarkable efficacy in refractory or relapsed multiple myeloma (RRMM); however, primary resistance and relapse exist with single-target immunotherapy. Bispecific CARs are proposed to mitigate these limitations.

Methods

We constructed a humanized bispecific BM38 CAR targeting BCMA and CD38 and tested the antimyeloma activity of BM38 CAR-Ts in vitro and in vivo. Twenty-three patients with RRMM received infusions of BM38 CAR-Ts in a phase I trial.

Results

BM38 CAR-Ts showed stronger in vitro cytotoxicity to heterogeneous MM cells than did T cells expressing an individual BCMA or CD38 CAR. BM38 CAR-Ts also exhibited potent antimyeloma activity in xenograft mouse models. In the phase I trial, cytokine release syndrome occurred in 20 patients (87%) and was mostly grade 1–2 (65%). Neurotoxicity was not observed. Hematologic toxicities were common, including neutropenia in 96% of the patients, leukopenia in 87%, anemia in 43% and thrombocytopenia in 61%. At a median follow-up of 9.0 months (range 0.5 to 18.5), 20 patients (87%) attained a clinical response and minimal residual disease-negativity (≤ 10^–4 nucleated cells), with 12 (52%) achieving a stringent complete response. Extramedullary plasmacytoma was eliminated completely in 56% and partially in 33% and of 9 patients. The median progression-free survival was 17.2 months. Two relapsed patients maintained BCMA and CD38 expression on MM cells. Notably, BM38 CAR-Ts cells were detectable in 77.8% of evaluable patients at 9 months and 62.2% at 12 months.

Conclusion

Bispecific BM38 CAR-Ts were feasible, safe and significantly effective in patient with RRMM.

Trial registration: Chictr.org.cn ChiCTR1800018143.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13045-021-01170-7.