Limited Toxicity Research Articles

Analytical fingerprint of the interactions between quinones and bioenergetic membranes in Chlamydomonas reinhardtii

The use of intact photosynthetic organisms (e.g. microalgae or cyanobacteria) for biotechnological approaches is a promising avenue to extract sustainable energy from oxygenic photosynthesis. More particularly, exogenous quinones can act as electron shuttles to reroute part of the photosynthetic electron flow of living cells to an outer collecting electrode. This encouraging approach is however hampered by reported poisoning or side-effects of exogenous quinones on the cell bioenergetics. In order to contribute to understand those effects, we investigated the modes and sites of interaction of two model quinones (2,6-DCBQ and 2,6-DMBQ) with the respiratory and photosynthetic electron transfer chains of the green alga Chlamydomonas reinhardtii. By considering different analytical tools (chlorophyll a fluorescence, transient absorption spectrometry, O2 consumption rate), the two exogenous quinones are shown to hamper the photosynthetic electron transfer from photosystem II (PSII) to the cytochrome b6f and, at longer term, PSII damage. In addition, the investigated quinones initiate the suppression of mitochondrial respiration, illustrated by the decrease of O2 consumption. This results in the diminution of the ATP exchanges between mitochondrion and chloroplast responsible for the generation of the proton motive force across the thylakoid in darkness, and in turn affects the performances of the CF1FO ATPase. For all those effects, 2,6-DCBQ was more effective than 2,6-DMBQ in agreement with its higher redox potential and partition coefficient values. This work provides a new framework for the study of biophotovoltaic devices using photosynthetic organisms and quinones as mediators and could be extended to find the best candidates combining efficient bioelectricity production and limited toxicity.

PH/GSH dual-responsive nanoparticle for auto-amplified tumor therapy of breast cancer

Breast cancer remains a malignancy that poses a serious threat to human health worldwide. Chemotherapy is one of the most widely effective cancer treatments in clinical practice, but it has some drawbacks such as poor targeting, high toxicity, numerous side effects, and susceptibility to drug resistance. For auto-amplified tumor therapy, a nanoparticle designated GDTF is prepared by wrapping gambogic acid (GA)-loaded dendritic porous silica nanoparticles (DPSNs) with a tannic acid (TA)-Fe(III) coating layer. GDTF possesses the properties of near-infrared (NIR)-enhanced and pH/glutathione (GSH) dual-responsive drug release, photothermal conversion, GSH depletion and hydroxyl radical (·OH) production. When GDTF is exposed to NIR laser irradiation, it can effectively inhibit cell proliferation and tumor growth both in vitro and in vivo with limited toxicity. This may be due to the synergistic effect of enhanced tumor accumulation, and elevated reactive oxygen species (ROS) production, GSH depletion, and TrxR activity reduction. This study highlights the enormous potential of auto-amplified tumor therapy.

Heavy metal and metalloid concentrations in red deer (Cervus elaphus) and their human health implications from One Health perspective

The red deer is an ungulate and large game species. The contamination of the ecosystems by metal(loid)s may lead to the exposure of animals (as well as humans) through water and food resources. The direct contact of hunters and wild animal meat consumers with deer carcasses may be a potential contaminant source. This study aimed to determine the metal(loid)s’ concentrations in the liver and kidney of red deer from two regions of Portugal (Idanha-a-Nova and Lousã), and to relate these with histopathologic lesions. Thirteen young male deer were submitted to metal(loid) determination (As, Cd, Co, Cr, Cu, Pb, and Zn) by inductively coupled plasma mass spectrophotometry (ICP-MS) and histopathology examination. Renal Cd (8.072 ± 5.766 mg/kg dw) and hepatic Pb (3.824 ± 6.098 mg/kg dw) mean values were high, considering the maximum values for consumption established by the European Commission. The hepatic mean value of Cu was significantly higher in Idanha-a-Nova (150.059 ± 33.321 mg/kg dw), and it is at the Cu toxicity limit considered for ruminants (150 mg/kg). The pollution induced by Panasqueira mines (Castelo Branco) may be a possible explanation for some of the findings, especially the higher values of hepatic Cu and Pb found in Idanha-a-Nova deer. These results have high importance under a One Health perspective, since they have implications in public health, and pose at risk the imbalance of animal populations and ecosystems.

Piezoceramic membrane with built-in ultrasound for reactive oxygen species generation and synergistic vibration anti-fouling

Piezoceramic membranes have emerged as a prominent solution for membrane fouling control. However, the prevalent use of toxic lead and limitations of vibration-based anti-fouling mechanism impede their wider adoption in water treatment. This study introduces a Mn/BaTiO3 piezoceramic membrane, demonstrating a promising in-situ anti-fouling efficacy and mechanism insights. When applied to an Alternating Current at a resonant frequency of 20 V, 265 kHz, the membrane achieves optimal vibration, effectively mitigating various foulants such as high-concentration oil (2500 ppm, including real industrial oil wastewater), bacteria and different charged inorganic colloidal particles, showing advantages over other reported piezoceramic membranes. Importantly, our findings suggest that the built-in ultrasonic vibration of piezoceramic membranes can generate reactive oxygen species. This offers profound insights into the distinct anti-fouling processes for organic and inorganic wastewater, supplementing and unifying the traditional singular vibrational anti-fouling mechanism of piezoceramic membranes, and potentially propelling the development of piezoelectric catalytic membranes.

Exploiting bacteria for cancer immunotherapy.

Immunotherapy has revolutionized the treatment of cancer but continues to be constrained by limited response rates, acquired resistance, toxicities and high costs, which necessitates the development of new, innovative strategies. The discovery of a connection between the human microbiota and cancer dates back 4,000 years, when local infection was observed to result in tumour eradication in some individuals. However, the true oncological relevance of the intratumoural microbiota was not recognized until the turn of the twentieth century. The intratumoural microbiota can have pivotal roles in both the pathogenesis and treatment of cancer. In particular, intratumoural bacteria can either promote or inhibit cancer growth via remodelling of the tumour microenvironment. Over the past two decades, remarkable progress has been made preclinically in engineering bacteria as agents for cancer immunotherapy; some of these bacterial products have successfully reached the clinical stages of development. In this Review, we discuss the characteristics of intratumoural bacteria and their intricate interactions with the tumour microenvironment. We also describe the many strategies used to engineer bacteria for use in the treatment of cancer, summarizing contemporary data from completed and ongoing clinical trials. The work described herein highlights the potential of bacteria to transform the landscape of cancer therapy, bridging ancient wisdom with modern scientific innovation.

First-in-human phase I/II safety and preliminary efficacy of PM1032, a bispecific antibody targeting CLDN18.2 and 4-1BB, in patients with advanced solid tumors.

2662 Background: PM1032 is an anti-CLDN18.2 x 4-1BB bispecific antibody that activates immune cells, such as T and NK cells, via CLDN18.2-mediated crosslinking of 4-1BB. Potent anti-tumor efficacy is facilitated with limited toxicity as immune activation is only stimulated in the context of CLDN18.2 expression on target cells. Here, we present the preliminary safety and efficacy results from an ongoing Phase I/II trial, which is a first-in-human (FIH), dose-escalation, and expansion study of PM1032 in patients (pts) with advanced solid tumors. Methods: This FIH study of PM1032 with adults with previously treated, advanced or metastatic solid tumors includes dose escalation (3+3 design; regardless of CLDN18.2 expression) and dose expansion stages (CLDN18.2+ gastrointestinal (GI) cancers). During the dose escalation stage, PM1032 was administered at doses of 0.3, 1, 3, 5, 8 and 12 mg/kg for the assessment of drug limiting toxicity (DLT) after 3 weeks, followed by administration Q2W until disease progression (PD) or observations of intolerable toxicity. Responses were evaluated according to RECIST 1.1. Adverse events (AEs) were graded using CTCAE v5.0. CLDN18.2 positivity was defined as ≥1% of tumor cells with ≥1+ signal intensity by immunohistochemistry. Results: As of January 12, 2024, a total of 30 pts received PM1032 (18 pts during dose escalation and 12 pts during dose expansion) with no DLTs observed (median age 54y; most pts had ≥2 metastatic sites). CLDN18.2 expression was evaluable in 80% of the pts and 66.7% were positive. The most common tumor types were GI cancers including 14 gastric and gastroesophageal junction cancers (GC/GEJ), 10 pancreatic adenocarcinoma (PDAC) and 5 other GI cancers. All pts had ≥1 line of prior therapy and 17 pts (56.7%) had prior immunotherapy. TRAEs occurred in 22 subjects (73.3%), and ≥ Grade 3 TRAEs occurred in 3 subjects (10%). The most common TRAEs were nausea (20%) and aspartate transaminase increase (16.7%). Among a total of 16 CLDN18.2+ pts enrolled at the 5, 8, and 12 mg/kg dose levels who completed at least one tumor evaluation, 2 pts achieved PR, 7 pts had SD and 3 pts were Non-CR/Non-PD. Additionally, the ORR was 20% in 10 measurable and evaluable CLDN18.2+ GC/GEJ pts. The longest treatment duration was 18 months and 5 pts had treatment durations ≥ 6 months. Pharmacokinetics (AUC0-336h & Cmax) were dose-proportional across the dose ranges of 0.3 mg/kg – 12 mg/kg with a terminal half-life of 6.0~10.1 days. Conclusions: PM1032 was well-tolerated up to 12 mg/kg Q2W and demonstrated preliminary anti-tumor activity in CLDN18.2+ tumors. Further development of PM1032 as a monotherapy and/or combination therapy for CLDN18.2-positive cancers is planned. Clinical trial information: NCT05839106 .

Follow-up on phase 1 study of AT101, a novel anti-CD19 chimeric antigen receptor cell therapy (CAR-T) in patients with relapsed or refractory (r/r) b-cell non-Hodgkin lymphoma.

7035 Background: All the FDA-approved CD19 CAR-T products are based on FMC63 scFv, which binds to the membrane-distal region of CD19. We developed a novel anti-CD19 antibody clone (1218) binding to a membrane-proximal epitope of CD19 with fast on/off kinetics. AT101 is an autologous CAR-T cell transduced with a lentiviral vector encoding CAR comprised of a humanized scFv of 1218, 4-1BB costimulatory, and CD3zeta domain. Methods: In the phase 1 trial, patients (n=3 per dose level; up to n=18 in total) are treated with AT101 in 3 dose-escalation cohorts based on a standard 3 + 3 design. Each patient received a single intravenous dose of AT101 at dose level (DL) 1 (0.2 x 106 cells/kg), DL2 (1.0 x 106 cells/kg), or DL3 (5.0 x 106 cells/kg). The primary objective is to determine the safety, the maximum tolerated dose, and the recommended phase 2 dose of AT101. Key eligibility criteria include patients aged ≥19 with histologically confirmed relapsed or refractory B-cell non-Hodgkin lymphoma (NHL). Tumor responses were evaluated using Lugano 2014 criteria at 4 weeks before AT101 infusion as well as at 4 weeks and 3, 6, 9, 12, and 18 months after AT101 infusion. Results: From March 2022 to December 2022, fourteen patients were enrolled and 12 patients were treated, who were their median age of 62.5 years (range 39 to 84) and received a median of three prior lines of therapy (range 2-9). Their subtypes were as follows: diffuse large B cell lymphoma (DLBCL; n=7, 58.3%), follicular lymphoma (FL; n=3, 25.0%), mantle cell lymphoma (MCL; n=1, 8.3%), or marginal zone lymphoma (MZL; n=1, 8.3%)). The data collection cut-off date was January 31, 2024. Based on the best overall response up to three months, eleven patients responded with an overall response rate (ORR) of 91.7%, and a complete response (CR) was observed in nine patients (75%). Remarkably, in DL2 and DL3 groups, the CR was 100.0%. Among nine patients who achieved CR, seven patients have remained in CR during the median follow-up of 13.6 months (1.6-22.3 months). One patient experienced relapse and another one died from septic shock. The median duration of response (DOR), progression-free survival (PFS), overall survival (OS), and event-free survival (EFS) were 19.5, 17.2, 18.9 and 17.2 months, respectively. The median DOR, PFS, OS and EFS were not reached. Conclusions: In this first-in-human phase 1 trial, AT101 was tolerable with limited and manageable toxicities. In comparison to current FMC63 scFv-based CD19 CAR-T therapies, AT101 exhibited potent and more enduring efficacy with a remarkable suppression of relapse after CR. A phase 2 clinical trial is currently under-going for DLBCL patients. Clinical trial information: NCT05338931 .

Open-label, phase 1, multicenter study to evaluate the safety and preliminary anti-tumor activity of NT-175 in human leukocyte antigen-a*02:01-positive adult subjects with unresectable, advanced and/or metastatic solid tumors that are positive for the TP53 R175H mutation.

e14514 Background: The TP53 tumor suppressor gene is the most commonly mutated gene across all cancer types, and TP53 R175H is the most common recurrent mutation across indications, identified in 6.7% of patients with breast cancer, 6% of patients withs colorectal cancer, and 4.2% of patients with pancreatic cancer. No therapy is approved for treatment directly targeting TP53 R175H. NT-175 is an armored autologous T-cell product expressing an HLA-A*02:01-restricted TCR recognizing TP53 R175H with disruption of the endogenous TCR and the transforming growth factor beta receptor type 2 (TGFBR2) genes. Methods: This first-in-human phase I, open label study will assess the safety and preliminary anti-tumor activity, identify the maximum tolerated dose (MTD), and evaluate the persistence, and functional capacity of NT-175 in subjects with advanced, recurrent unresectable/metastatic solid tumors refractory to treatment options. The study will enroll approximately 24 subjects harboring TP53 R175H and HLA-A*02:01. Enrolled patients will undergo leukapheresis from which CD4 and CD8 T cells will be enriched and activated ex vivo. The endogenous TCR α and β chain gene are knocked out utilizing clustered Regularly Interspaced Short Palindromic repeats (CRISPR-Cas9) and the TCR encoding an HLA-A*02:01-restricted TCR specific to the TP53 R175H mutation is inserted in the TCR α locus. Additionally, the T cells are edited to disrupt the gene encoding the TGFBR2 to reduce the immunosuppressive effect of TGF-β in the tumor microenvironment. Subjects will undergo lymphodepletion chemotherapy with fludarabine and cyclophosphamide followed by a single infusion of NT-175 and subcutaneous recombinant IL-2 administration for up to 8 days. Dose escalation will occur across 3 ascending dose levels following the BOIN design. Subjects will be monitored for dose-limiting toxicities for 28 days after NT-175 infusion. Tumor response will be assessed by RECISTv1.1 criteria. All subjects will be followed for up to 15 years. Primary endpoints include safety, dose limited toxicities, MTD determination, and recommended Phase II dose. Secondary endpoints include preliminary efficacy measures. Translational analysis will evaluate potential biomarkers for insights into mechanism of action, response prediction, or resistance mechanisms. The study was activated in March 2023 and is open to accrual; 5 patients have been enrolled as of 4 Jan 2024.

Next generation imidazothiazole and imidazooxazole derivatives as potential drugs against brain-eating amoebae.

Managing primary amoebic meningoencephalitis, induced by Naegleria fowleri poses a complex medical challenge. There is currently no specific anti-amoebic drug that has proven effectiveness against N. fowleri infection. Ongoing research endeavours are dedicated to uncovering innovative treatment strategies, including the utilization of drugs and immune modulators targeting Naegleria infection. In this study, we explored the potential of imidazo[2,1-b]thiazole and imidazooxazole derivatives that incorporate sulfonate and sulfamate groups as agents with anti-amoebic properties against N. fowleri. We assessed several synthesized compounds (1f, 1m, 1q, 1s,and 1t) for their efficacy in eliminating amoebae, their impact on cytotoxicity, and their influence on the damage caused to human cerebral microvascular endothelial (HBEC-5i) cells when exposed to the N. fowleri (ATCC 30174) strain. The outcomes revealed that, among the five compounds under examination, 1m, 1q, and 1t demonstrated notable anti-parasitic effects against N. fowleri (P ≤ 0.05). Compound 1t exhibited the highest anti-parasitic activity, reducing N. fowleri population by 80%. Additionally, three compounds, 1m, 1q, and 1t, significantly mitigated the damage inflicted on host cells by N. fowleri. However, the results of cytotoxicity analysis indicated that while 1m and 1q had minimal cytotoxic effects on endothelial cells, compound 1t caused moderate cytotoxicity (34%). Consequently, we conclude that imidazo[2,1-b]thiazole and imidazooxazole derivatives containing sulfonate and sulfamate groups exhibit a marked capacity to eliminate amoebae viability while causing limited toxicity to human cells. In aggregate, these findings hold promise that could potentially evolve into novel therapeutic options for treating N. fowleri infection.

Phase Ib study of a high potent PI3K-mTOR dual inhibitor WX390 combined with toripalimab in patients with advanced solid tumors.

e14627 Background: WX390 is a high potent PI3K-mTOR dual inhibitor targeting pan-PI3K and mTOR. It modulates the tumor immune microenvironment by decreasing tumor Treg and myeloid-derived suppressor cells (MDSC) and improves the immune response to checkpoint inhibitors (CPI) in preclinical models. Methods: The Phase Ib study was designed to evaluate safety, pharmacokinetics (PK), and preliminary clinical activity, to determine recommended phase 2 dose (RP2D) of WX390 combined with Toripalimab in patients with advanced solid tumors. WX390 was administered orally daily at escalating doses of 0.7 mg, 0.9mg and 1.1mg, with Toripalimab at 240 mg IV every 3 weeks until confirmed progressive disease, intolerable toxicity or withdrawal of consent. Plasma PK samples were collected up to 24 hours after the first dose at C1D1, and up to 24 hours before and after the morning dose at C1D21. Results: As of December 31, 2023, total 18 patients had been treated in 3 WX390 cohorts: 0.7 mg (n = 3), 0.9 mg (n = 3), and 1.1 mg (n = 12) once daily (QD). No dose limit toxicity (DLT) was observed, and the RP2D of WX390 in combination was 1.1 mg QD, which was consistent with the single agent RP2D. The treatment related adverse events (TRAEs) (≥20%) included hyperglycemia (17/18, 94.4%), creatinine increased (12/18, 66.7%), weight loss (10/18, 55.6%), diarrhea (9/18, 50%), proteinuria (9/18, 50%), nausea (7/18, 38.9%), lymphocytopenia (7/18, 38.9%), vomiting (7/18, 38.9%), rash (7/18, 38.9%), decreased appetite (6/18, 33.3%), hypokalemia (6/18, 33%), fatigue (5/18, 27.8%), hyponatremia (4/18, 22.2%), and thrombocytopenia (4/18, 22.2%). Grade 3 TRAEs included hyperglycemia (5/18), lymphocytopenia (4/18), rash (2/18), weight loss (2/18), leukopenia (1/18), infusion-related reaction (1/18), nausea (1/18), and stomatitis (1/18). There was no TRAE leading to treatment permanent discontinuation and no grade 4/5 TRAE were observed. PK of WX390 in combination showed similar PK profile with the single agent. Among the 16 efficacy-evaluable patients with cervical (N=8), head and neck (N=5), and urothelial cancer (N=3), 5 patients (31.3%) previously received immune checkpoint inhibitors. 3 of 5 (60%) cervical cancer patients at RP2D and 2 of 5 head and neck cancer patient (40%) have achieved confirmed partial response (PR). In addition, 3 cervical patients who were treated with 0.7 or 0.9mg QD and 1of 3 urothelial carcer patients experienced tumor shrinkage (SD). The medium progression free survival (PFS) was 5.49 months (95% CI: 2.53, 6.37). Conclusions: WX390 in combination with Toripalimab had a manageable safety profile and encouraging antitumor effects in patients with advanced solid tumors. An RP2D of 1.1 mg qd of WX390 in combination was selected to be explored in further phase II study, which is ongoing in different tumor types. Clinical trial information: NCT06117566 .

SWOG S2302, PRAGMATICA-LUNG: A prospective randomized study of ramucirumab plus pembrolizumab (PR) versus standard of care (SOC) for participants previously treated with immunotherapy for stage IV or recurrent non-small cell lung cancer.

TPS8657 Background: Most patients (pts) with advanced non-small cell lung cancer (NSCLC) will receive treatment with immunotherapy and develop tumor resistance. Several trials investigating combination therapy have not shown benefit over chemotherapy. Additional therapeutic options are needed. Complex clinical trials increase barriers to enrollment. Pragmatic trial designs may overcome challenges with accrual and representativeness in the appropriate setting. S1800A was a randomized phase II trial within Lung-MAP that showed a statistically significant improvement in overall survival (OS) with PR versus SOC for pts with advanced NSCLC who had tumor progression on prior chemotherapy and immunotherapy (JCO 2023). As a follow-on, we designed a pragmatic, randomized, registration intent trial to validate OS results and enhance representative accrual reflecting real-world practice. Methods: S2302 is a registration-intent randomized trial for pts who previously received PD-(L)1 inhibitor therapy for at least 84 days and platinum-based therapy, stratified by immediate prior line of therapy including PD-(L)1 inhibition (yes/no) and PS (0/1 v. 2). Pts are randomized to PR or investigator’s choice SOC (recommended to be based on NCCN guidelines). The primary objective is to compare OS between the arms. The only secondary objective is to summarize serious and unexpected high-grade (Grade 3-4) treatment-related adverse events and all Grade 5 adverse events. The accrual goal is 700 pts based on a design with 85% power to detect a hazard ratio of 0.77, using a 1-sided 2.5% level log-rank test. Estimated accrual duration is 24 months. As of January 2024, 286 pts were randomized, and enrollment is ongoing. S2302 Pragmatica-Lung presents a novel and potentially practice-changing paradigm to conduct a study with a combination of FDA approved drugs with well-known safety profiles and limited toxicity overlap. There are no onerous radiology or specimen requirements, and SOC treatment is provided as per FDA-approved package inserts and institutional policies. The goal is to empower practicing clinicians to enroll pts they see every day by reducing the study barriers and burden of clinical trial participation. The resulting pts enrolled will be more representative than other registration-intent trials. This approach allows the trial to reach more patients and holds the potential to better inform the field across a more representative set of pts with broader impact. Clinical trial information: NCT05633602 .

Analysis of nickel oxide as a counter electrode for dye-sensitized solar cells using OghmaNano software

Dye-sensitized solar cells (DSSCs), a promising green technology, convert solar energy into electricity more cost-effectively than traditional solar cells. While platinum (Pt) is commonly used in DSSCs, its high cost and toxicity limit practical applications. Recent research aims to develop low-cost counter electrodes with high efficiency. Nickel oxide (NiO), a p-type semiconductor with a wide bandgap, good transmittance, and suitable work function, emerges as a potential alternative for counter electrode of DSSCs. In this work, DSSCs with NiO of thicknesses varying from 100 nm to 1000 nm were simulated to determine its influence on photovoltaic performance using OghmaNano software. The structure of simulated solar cells consists of NiO as counter electrode, zinc oxide (ZnO) as photoanode, N719 as dyes, electrolyte as charge carrier transport, and fluorine-doped tin oxide (FTO) as a contact layer. There are five data of NiO used as an active layer. From the simulation results, NiO-doped gold exhibits the highest power conversion efficiency (PCE) of 15.95% at a thickness of 700 nm, while pure NiO shows the lowest PCE with 4.53% at a thickness of 600 nm. These results have demonstrated that NiO can replace Pt as a counter electrode for DSSCs and doping plays a vital role in increasing efficiency.

4-Deoxy-ε-Pyrromycinone: A Promising Drug/Lead Compound to Treat Tumors.

Anthraquinone drugs are widely used in the treatment of tumors. However, multidrug resistance and severe cardiac toxicity limit its use, which have led to the discovery of new analogues. In this paper, 4-Deoxy-ε-pyrromycinone (4-Deo), belonging to anthraquinone compounds, was first been studied with the anti-tumor effects and the safety in vitro and in vivo as a new anti-tumor drug or lead compound. The quantitative analysis of 4-Deo was established by UV methodology. The anti-cancer effect of 4-Deo in vitro was evaluated by cytotoxicity experiments of H22, HepG2 and Caco2, and the anti-cancer mechanism was explored by cell apoptosis and cycle. The tumor-bearing mouse model was established by subcutaneous inoculation of H22 cells to evaluate the anti-tumor effect of 4-Deo in vivo. The safety of 4-Deo was verified by the in vitro safety experiments of healthy cells and the in vivo safety experiments of H22 tumor-bearing mice. Tumor tissue sections were labeled with CRT, HMGB1, IL-6 and CD115 to explore the preliminary anti-cancer mechanism by immunohistochemistry. In vitro experiments demonstrated that 4-Deo could inhibit the growth of H22 by inducing cell necrosis and blocking cells in S phase, and 4-Deo has less damage to healthy cells. In vivo experiments showed that 4-Deo increased the positive area of CRT and HMGB1, which may inhibit tumor growth by triggering immunogenic cell death (ICD). In addition, 4-Deo reduced the positive area of CSF1R, and the anti-tumor effect may be achieved by blocking the transformation of tumor-associated macrophages (TAMs) to M2 phenotype. In summary, this paper demonstrated the promise of 4-Deo for cancer treatment in vitro and in vivo. This paper lays the foundation for the study of 4-Deo, which is beneficial for the further development anti-tumor drugs based on the lead compound of 4-Deo.

Adaptive MRI-guided stereotactic body radiation therapy for locally advanced pancreatic cancer – A phase II study

PurposeStereotactic body radiotherapy (SBRT) has emerged as a promising new modality for locally advanced pancreatic cancer (LAPC). The current study evaluated the efficacy and toxicity of SBRT in patients with LAPC (NCT03648632). MethodsThis prospective single institution phase II study recruited patients with histologically or cytologically proven adenocarcinoma of the pancreas after more than two months of combination chemotherapy with no sign of progressive disease. Patients were prescribed 50–60 Gy in 5–8 fractions. Patients were initially treated on a standard linac (n = 4). Since 2019, patients were treated using online magnetic resonance (MR) image-guidance on a 1.5 T MRI-linac, where the treatment plan was adapted to the anatomy of the day. The primary endpoint was resection rate. ResultsTwenty-eight patients were enrolled between August 2018 and March 2022. All patients had non-resectable disease at time of diagnosis. Median follow-up from inclusion was 28.3 months (95 % CI 24.0-NR). Median progression-free and overall survival from inclusion were 7.8 months (95 % CI 5.0–14.8) and 16.5 months (95 % CI 10.7–22.6), respectively. Six patients experienced grade III treatment-related adverse events (jaundice, nausea, vomiting and/or constipation). One of the initial four patients receiving treatment on a standard linac experienced a grade IV perforation of the duodenum. Six patients (21 %) underwent resection. A further one patient was offered resection but declined. ConclusionThis study demonstrates that SBRT in patients with LAPC was associated with promising overall survival and resection rates. Furthermore, SBRT was safe and well tolerated, with limited severe toxicities.

Combining Mefloquine with an Mcl-1 Inhibitor as a Novel Therapeutic Strategy for the Treatment of Nasopharyngeal Carcinoma

Considering the established pharmacokinetics and toxicity profiles, drug repurposing has emerged as an alternative therapeutic approach for treating cancer. Mefloquine has previously demonstrated inhibitory effects on multiple cancer types. This study aims to explore the impact of mefloquine on nasopharyngeal carcinoma (NPC). We found that mefloquine, at pharmacologically achievable concentrations, displayed anti-NPC activity while sparing normal counterparts. Mefloquine inhibits proliferation and induces death by reducing the levels of Cyclin A2, Bcl-2, and Bcl-xL. Intriguingly, we observed an increase in the levels of the anti-apoptotic protein Mcl-1. Mefloquine exerts its effects on NPC cells by inducing lysosomal-mediated ROS production, and the heightened expression of Mcl-1 is a consequence of ROS generation in mefloquine-treated NPC cells. The combination of an Mcl-1 inhibitor with mefloquine synergistically inhibits NPC growth in mice without causing substantial toxicity. These findings demonstrate the effectiveness and limited toxicity of mefloquine as a monotherapy and in combination with an Mcl-1 inhibitor. Our research underscores the promise of the mefloquine and Mcl-1 inhibitor combination as a potential treatment for NPC. Additionally, the elevation of Mcl-1 is a compensatory response in cells exposed to oxidative stress, offering a potential target to overcome resistance induced by pro-oxidant therapies.

Screening and characterization of 133 physiologically-relevant environmental chemicals for reproductive toxicity

Reproduction is a functional outcome that relies on complex cellular, tissue, and organ interactions that span the developmental period to adulthood. Thus, the assessment of its disruption by environmental chemicals would benefit significantly from scalable and innovative approaches to testing using functionally comparable reproductive models such as the nematode C. elegans. We adapted a previously described low-throughput in vivo chromosome segregation assay using C. elegans predictive of reproductive toxicity and leveraged available public data sources (ToxCast, ICE) to screen and characterize 133 physiologically-relevant chemicals in a high-throughput manner. The screening outcome was further validated in a second, independent in vivo assay assessing embryonic viability. In total, 13 chemicals were classified as reproductive toxicants with the two most active chemicals belonging to the large family of Quaternary Ammonium Compounds (QACs) commonly used as disinfectants but with limited available reproductive toxicity data. We compared the results from the C. elegans assay with ToxCast in vitro data compiled from 700+ cell response assays and 300+ signaling pathways-based assays. We did not observe a difference in the bioactivity or in the average potency (AC50) between the top and bottom chemicals. However, the intended target categories were significantly different between the classified chemicals with, in particular, an over-representation of steroid hormone targets for the high Z-score chemicals. Taken together, these results point to the value of in vivo models that scale to high-throughput level for reproductive toxicity assessment and to the need to prioritize the assessment of QACs impacts on reproduction.

Abstract PS17-09: An FGFR1/2 degrader overcomes antiestrogen resistance in ER+/FGFR1-amplified breast cancer

Abstract We previously reported that nuclear FGFR1 promotes antiestrogen resistance in ER+/FGFR1-amplified breast cancer. Nuclear FGFR1 activity was not affected by FGFR tyrosine kinase inhibitors (TKIs). Furthermore, pan-FGFR TKIs are not well tolerated. Therefore, new therapeutic strategies that inhibit nuclear FGFR1 while sparing FGFR3 and FGFR4 would be required to overcome antiestrogen resistance and limit toxicity. For this study, we used the proteolysis-targeting chimera (PROTAC) DGY-09-192, consisting of the FGFR TKI BCJ398 linked with a VHL recruiting ligand, to degrade FGFR1 and FGFR2. We aimed to determine whether selective degradation of FGFR1/2 overcomes endocrine resistance. Treatment with 50-100 nM DGY-09-192 strongly induced FGFR1 degradation and suppressed phosphorylation of FGFR1 and its downstream targets FRS2, AKT, and ERK1/2 in ER+/FGFR1-amplified CAMA1 and MDA-MB-134 breast cancer cells. FGFR1 degradation was evident within 4 h and lasted 48-96 h after drug washout. The proteasome inhibitor MG132 (10 µM) rescued both FGFR degradation and phosphorylation of downstream signaling molecules induced by DGY-09-192, confirming that FGFR1 degradation is dependent on ubiquitination and proteasomal degradation. At equivalent concentrations, DGY-09-192 suppressed phosphorylation of FGFR1 and its downstream targets more potently than BGJ398. Subcellular fractionation showed treatment with DGY-09-192 (100 nM) degraded FGFR1 in membrane, nuclear, and chromatin-bound fractions in both CAMA1 and MDA-MB-134 cells. Treatment of >CAMA1 cells with DGY-09-192 (>100 nM) downregulated nuclear FGFR1 target genes and canonical ERα target genes, such as CCND1, VEGFA, and CDK12 as measured by qRT-PCR whereas treatment with BGJ398 (100 nM) did not. Treatment with DGY-09-192 (500 nM) reversed resistance to the ER degrader fulvestrant in CAMA1 cells as measured by colony formation assays and using the Incucyte Live-Cell Analysis System. Each drug alone showed a modest effect on cell proliferation whereas the combination completed blocked cell growth (p < 0.0001). Finally, treatment of NOD scid gamma (NSG) mice with established ER+/FGFR1-amplified HCI-011 patient-derived xenografts with DGY-09-192 (40 mg/kg daily x2-6) induced FGFR1 degradation and blocked phosphorylation of downstream targets in the tumors. Studies using the combination of DGY-09-192 and fulvestrant in mice bearing established HCI-011 xenografts are in progress. We next investigated the effect of DGY-09-192 on cancer cells harboring FGFR1 and FGFR2 activating mutations. DGY-09-192 treatment induced FGFR2 degradation and blocked downstream signaling in MFE296 endometrial cancer and EFM-19 breast cancer cells that harbor the FGFR2N549K and FGFR2K659E hotspot mutations, respectively. In addition, DGY-09-192 strongly suppressed MFE296 cell proliferation. We are currently investigating whether DGY-09-192 blocks signaling and cell proliferation induced by the N546K and K656E hotspot FGFR1 mutations in ER+ breast cancer cells. Notably, a recent clinical study showed that tumors harboring these FGFR1 activating mutations are refractory to the pan-FGFR TKI pemigatinib. Conclusions: The FGFR1/2 PROTAC DGY-09-192 induced degradation of nuclear and membrane-bound FGFR1 and blocked FGFR1-induced signaling and nuclear activity in ER+/FGFR1-amplified breast cancer cells. The combination of DGY-09-192 and fulvestrant synergistically suppressed proliferation of these cells. Therefore, FGFR1 degradation represents a promising therapeutic strategy to block FGFR1 activity more completely and selectively in ER+ breast cancers harboring activating FGFR1 alterations. Citation Format: Yasuaki Uemoto, Chang-Ching Lin, Alberto Servetto, Bingnan Wang, Dan Ye, Fabiana Napolitano, Hima Milan Patel, Luigi Formisano, M Rosario Chica-Parrado, Emmanuel Bikorimana, Saurabh Mendiratta, Chuo Chen, Ariella Hanker, Carlos Arteaga. An FGFR1/2 degrader overcomes antiestrogen resistance in ER+/FGFR1-amplified breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS17-09.

Abstract PO1-04-01: Phase 1 dose escalation study of ARX788, a next-generation anti-HER2 antibody drug conjugate, in heavily pretreated breast cancer patients

Abstract Introduction: ARX788 is a next-generation anti-HER2 antibody-drug conjugate (ADC) conjugated to amberstatin269 (AS269), a potent cytotoxic tubulin inhibitor. ARX788 is highly stable with nearly identical PK profiles for the total ADC and the total antibody due to proprietary site-specific oxime conjugation chemistry. The stability of ARX788 results in limited systemic toxicity and increased targeted delivery of payload to tumor cells. Clinical benefit of ARX788 has been observed in patients (pts) with HER2-positive (HER2-pos) breast cancer (BC) in multiple clinical trials and recently in a randomized, controlled, phase 3 registrational trial conducted in China. Methods: ARX788-1711 (NCT03255070)was a phase 1 dose-escalation study of ARX788 monotherapy in pts with advanced solid tumors with HER2 expression. There was no limit to the number of prior therapies. An objective of the trial was investigating the safety and tolerability of ARX788 in pts with BC. Results: Between August 2020 and June 2023, 42 pts with HER2-pos and HER2-low BC with a median of 6 prior lines of therapy received intravenous ARX788 at either 1.5, 1.6, or 1.7 mg/kg every 21 days (Q3W) or every 28 days (Q4W). Treatment regimens were combined for these analyses. ARX788 was generally well tolerated. Most adverse events (AEs) were grade (Gr) 1 or 2, the most common being ocular, alopecia, nausea, and fatigue. Gr3 treatment-related AEs (TRAEs) occurred in 23.8% of pts and included nausea, ocular, AST and ALP increase (4.8% each); one pt (2.4%) had Gr3 pneumonitis/interstitial lung disease. A Gr3 ocular SAE occurred 48 days after the pt’s last study dose and was resolving 9 days after onset. There were no Gr4 or Gr5 events. Treatment discontinuation due to drug-related AEs occurred in 7.1% of pts. Overall response rate (ORR) per RECIST v1.1 was analyzed in groups by HER2-low or HER2-pos tumor status. In pts with HER2-pos BC (n=11) the ORR was 54.5% (4 confirmed, 2 unconfirmed); in pts with HER2-low BC (n=30) the ORR was 23.3% (5 confirmed, 2 unconfirmed). The disease control rate (confirmed complete or partial response + stable disease) was 81.8% and 76.7%, for HER2-pos and HER2-low BC, respectively. Six of 9 pts with confirmed responses had a duration of response greater than 5 months. Six of eight pts with prior trastuzumab deruxtecan (T-DXd) exposure also had prior trastuzumab emtansine (T-DM1). Two pts with prior T-DM1 and T-DXd had significant target lesion reductions of 55% and 32%; these were a HER2-low pt with 6 prior cancer therapy regimens and a HER2-pos pt with 9 prior cancer therapy regimens, respectively. Both pts came off treatment before response confirmation. As of the data cut-off (19 Jun 2023), 4 of 9 confirmed responders remain on treatment and continue to experience clinical benefit including one pt with prior T-DM1 exposure with a durable response of 15.8 months. Importantly, significant target lesion reductions were observed in heavily pretreated pts who also received prior T-DXd and T-DM1. Discussion: Based on the promising safety and antitumor activity of ARX788 in this heavily pretreated pt population, a phase 2 study is open (NCT04829604) and enrolling pts with HER2-pos BC who have been previously treated with T-DXd. Citation Format: Sophia Frentzas, Haesong Park, George Budd, Vinod Ganju, Catherine Shannon, Sara Hurvitz, Katharine Cuff, Peter Lau, Richard Eek, Joyce O'Shaughnessy, Fran Boyle, Sandra Aung, Colin Hessel, Janice Lu. Phase 1 dose escalation study of ARX788, a next-generation anti-HER2 antibody drug conjugate, in heavily pretreated breast cancer patients [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-04-01.

Chromatographic Methods for the Determination of Glyphosate in Cereals Together with a Discussion of Its Occurrence, Accumulation, Fate, Degradation, and Regulatory Status.

The European Union's recent decision to renew the authorization for the use of glyphosate until 15 December 2033 has stimulated scientific discussion all around the world regarding its toxicity or otherwise for humans. Glyphosate is a chemical of which millions of tons have been used in the last 50 years worldwide to dry out weeds in cultivated fields and greenhouses and on roadsides. Concern has been raised in many areas about its possible presence in the food chain and its consequent adverse effects on health. Both aspects that argue in favor of toxicity and those that instead may indicate limited toxicity of glyphosate are discussed here. The widespread debate that has been generated requires further investigations and field measurements to understand glyphosate's fate once dispersed in the environment and its concentration in the food chain. Hence, there is a need for validated analytical methods that are available to analysts in the field. In the present review, methods for the analytical determination of glyphosate and its main metabolite, AMPA, are discussed, with a specific focus on chromatographic techniques applied to cereal products. The experimental procedures are explained in detail, including the cleanup, derivatization, and instrumental conditions, to give the laboratories involved enough information to proceed with the implementation of this line of analysis. The prevalent chromatographic methods used are LC-MS/MS, GC-MS/SIM, and GC-MS/MS, but sufficient indications are also given to those laboratories that wish to use the better performing high-resolution MS or the simpler HPLC-FLD, HPLC-UV, GC-NPD, and GC-FPD techniques for screening purposes. The concentrations of glyphosate from the literature measured in wheat, corn, barley, rye, oats, soybean, and cereal-based foods are reported, together with its regulatory status in various parts of the world and its accumulation mechanism. As for its accumulation in cereals, the available data show that glyphosate tends to accumulate more in wholemeal flours than in refined ones, that its concentration in the product strictly depends on the treatment period (the closer it is to the time of harvesting, the higher the concentration), and that in cold climates, the herbicide tends to persist in the soil for a long time.

Hydrogen Sulfide Delivery to Enhance Bone Tissue Engineering Cell Survival.

Though crucial for natural bone healing, local calcium ion (Ca2+) and phosphate ion (Pi) concentrations can exceed the cytotoxic limit leading to mitochondrial overload, oxidative stress, and cell death. For bone tissue engineering applications, H2S can be employed as a cytoprotective molecule to enhance mesenchymal stem cell (MSC) tolerance to cytotoxic Ca2+/Pi concentrations. Varied concentrations of sodium hydrogen sulfide (NaSH), a fast-releasing H2S donor, were applied to assess the influence of H2S on MSC proliferation. The results suggested a toxicity limit of 4 mM for NaSH and that 1 mM of NaSH could improve cell proliferation and differentiation in the presence of cytotoxic levels of Ca2+ (32 mM) and/or Pi (16 mM). To controllably deliver H2S over time, a novel donor molecule (thioglutamic acid-GluSH) was synthesized and evaluated for its H2S release profile. Excitingly, GluSH successfully maintained cytoprotective level of H2S over 7 days. Furthermore, MSCs exposed to cytotoxic Ca2+/Pi concentrations in the presence of GluSH were able to thrive and differentiate into osteoblasts. These findings suggest that the incorporation of a sustained H2S donor such as GluSH into CaP-based bone graft substitutes can facilitate considerable cytoprotection, making it an attractive option for complex bone regenerative engineering applications.