Obstructive hypertrophic cardiomyopathy (oHCM) is a subtype of HCM characterized by left ventricular outflow tract obstruction resulting from cardiac muscle hypertrophy and anatomic alterations in the mitral valve and apparatus. Mavacamten, a cardiac myosin inhibitor metabolized primarily by CYP2C19 in the liver, is the first and only targeted medication approved for the treatment of symptomatic New York Heart Association (NYHA) class II-III oHCM. Previous pharmacokinetic (PK) results of mavacamten in healthy Caucasian, Japanese, and Asian participants demonstrated that mavacamten exposure was affected by CYP2C19 metabolism status. This open-label, parallel-group, phase I trial aimed to determine the PK and safety of mavacamten in healthy Chinese participants with different CYP2C19 genotypes. The primary outcome was to define the PK of mavacamten in healthy Chinese participants; the secondary outcome was to examine safety and tolerability. After a single oral dose of 15 or 25 mg mavacamten in fasted healthy adult Chinese individuals, Cmax was reached within a median Tmax of 0.6-1.5 h, indicating rapid absorption. Inter-individual variability was moderate, and individuals carrying non-functional CYP2C19 alleles (*2/*2, *3/*3, or *2/*3) exhibited longer half-life and increased total exposure. After stratification of CYP2C19 genotypes, total mavacamten exposures were similar among different ethnic groups when compared with prior PK studies. No significant adverse events were observed in this study. Single oral administration of mavacamten at 15 mg was well tolerated across all CYP2C19 genotypes, and 25 mg dose was well tolerated in healthy participants with CYP2C19 genotypes UM/RM/NM. The PK profile of mavacamten in the healthy Chinese population was consistent with that in other healthy populations.

Aim: The objective of this study was to compare adverse event (AE) management costs for fruquintinib, regorafenib, trifluridine/tipiracil (T/T) and trifluridine/tipiracil+bevacizumab (T/T+bev) for patients with metastatic colorectal cancer (mCRC) previously treated with at least two prior lines of therapy from the US commercial and Medicare payer perspectives. Materials & methods: A cost-consequence model was developed to calculate the per-patient and per-patient-per-month (PPPM) AE costs using rates of grade 3/4 AEs with incidence ≥5% in clinical trials, event-specific management costs and duration treatment. Anchored comparisons of AE costs were calculated using a difference-in-differences approach with best supportive care (BSC) as a common reference. AE rates and treatment duration were obtained from clinical trials: FRESCO and FRESCO-2 (fruquintinib), RECOURSE (T/T), CORRECT (regorafenib) and SUNLIGHT (T/T, T/T+bev). AE management costs for the commercial and Medicare perspectives were obtained from publicly available sources. Results: From the commercial perspective, the AE costs (presented as per-patient, PPPM) were: $4015, $1091 for fruquintinib (FRESCO); $4253, $1390 for fruquintinib (FRESCO-2); $17,110, $11,104 for T/T (RECOURSE); $9851, $4691 for T/T (SUNLIGHT); $8199, $4823 for regorafenib; and $11,620, $2324 for T/T+bev. These results were consistent in anchored comparisons: the difference-in-difference for fruquintinib based on FRESCO was -$1929 versus regorafenib and -$11,427 versus T/T; for fruquintinib based on FRESCO-2 was -$2257 versus regorafenib and -$11,756 versus T/T. Across all analyses, results were consistent from the Medicare perspective. Conclusion: Fruquintinib was associated with lower AE management costs compared with regorafenib, T/T and T/T+bev for patients with previously treated mCRC. This evidence has direct implications for treatment, formulary and pathways decision-making in this patient population.

Single-agent TAS102 (trifluridine/tipiracil) and regorafenib are FDA-approved treatments for metastatic colorectal cancer (mCRC). We previously reported that regorafenib combined with a fluoropyrimidine can delay disease progression in clinical case reports of multidrug-resistant mCRC patients. We hypothesized that the combination of TAS102 and regorafenib may be active in CRC and other gastrointestinal (GI) cancers and may in the future provide a treatment option for patients with advanced GI cancer. We investigated the therapeutic effect of TAS102 in combination with regorafenib in preclinical studies employing cell culture, colonosphere assays that enrich for cancer stem cells, and in vivo. TAS102 in combination with regorafenib has synergistic activity against multiple GI cancers in vitro including colorectal and gastric cancer, but not liver cancer cells. TAS102 inhibits colonosphere formation and this effect is potentiated by regorafenib. In vivo anti-tumor effects of TAS102 plus regorafenib appear to be due to anti-proliferative effects, necrosis and angiogenesis inhibition. Growth inhibition by TAS102 plus regorafenib occurs in xenografted tumors regardless of p53, KRAS or BRAF mutations, although more potent tumor suppression was observed with wild-type p53. Regorafenib significantly inhibits TAS102-induced angiogenesis and microvessel density in xenografted tumors, as well inhibits TAS102-induced ERK1/2 activation regardless of RAS or BRAF status in vivo. TAS102 plus regorafenib is a synergistic drug combination in preclinical models of GI cancer, with regorafenib suppressing TAS102-induced increase in microvessel density and p-ERK as contributing mechanisms. The TAS102 plus regorafenib drug combination may be further tested in gastric and other GI cancers.

The rise in cyanobacterial blooms due to eutrophication and climate change has increased cyanotoxin presence in water. Most current water treatment plants do not effectively remove these toxins, posing a potential risk to public health. This study introduces a water treatment approach using nanostructured beads containing magnetic nanoparticles (MNPs) for easy removal from liquid suspension, coated with different adsorbent materials to eliminate cyanotoxins. Thirteen particle types were produced using activated carbon, CMK-3 mesoporous carbon, graphene, chitosan, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidised cellulose nanofibers (TOCNF), esterified pectin, and calcined lignin as an adsorbent component. The particles\' effectiveness for detoxification of microcystin-LR (MC-LR), cylindrospermopsin (CYN), and anatoxin-A (ATX-A) was assessed in an aqueous solution. Two particle compositions presented the best adsorption characteristics for the most common cyanotoxins. In the conditions tested, mesoporous carbon nanostructured particles, P1-CMK3, provide good removal of MC-LR and Merck-activated carbon nanostructured particles, P9-MAC, can remove ATX-A and CYN with high and fair efficacy, respectively. Additionally, in vitro toxicity of water treated with each particle type was evaluated in cultured cell lines, revealing no alteration of viability in human renal, neuronal, hepatic, and intestinal cells. Although further research is needed to fully characterise this new water treatment approach, it appears to be a safe, practical, and effective method for eliminating cyanotoxins from water.

In this study, we report a multiplexed platform for the simultaneous determination of five marine toxins. The proposed biosensor is based on a disposable electrical printed (DEP) microarray composed of eight individually addressable carbon electrodes. The electrodeposition of gold nanoparticles on the carbon surface offers high conductivity and enlarges the electroactive area. The immobilization of thiolated aptamers on the AuNP-decorated carbon electrodes provides a stable, well-orientated and organized binary self-assembled monolayer for sensitive and accurate detection. A simple electrochemical multiplexed aptasensor based on AuNPs was designed to synchronously detect multiple cyanotoxins, namely, microcystin-LR (MC-LR), Cylindrospermopsin (CYL), anatoxin-α, saxitoxin and okadaic acid (OA). The choice of the five toxins was based on their widespread presence and toxicity to aquatic ecosystems and humans. Taking advantage of the conformational change of the aptamers upon target binding, cyanotoxin detection was achieved by monitoring the resulting electron transfer increase by square-wave voltammetry. Under the optimal conditions, the linear range of the proposed aptasensor was estimated to be from 0.018 nM to 200 nM for all the toxins, except for MC-LR where detection was possible within the range of 0.073 to 150 nM. Excellent sensitivity was achieved with the limits of detection of 0.0033, 0.0045, 0.0034, 0.0053 and 0.0048 nM for MC-LR, CYL, anatoxin-α, saxitoxin and OA, respectively. Selectivity studies were performed to show the absence of cross-reactivity between the five analytes. Finally, the application of the multiplexed aptasensor to tap water samples revealed very good agreement with the calibration curves obtained in buffer. This simple and accurate multiplexed platform could open the window for the simultaneous detection of multiple pollutants in different matrices.

β-l-5-((E)-2-Bromovinyl)-1-((2S,4S)-2-(hydroxymethyl)-1,3-(dioxolane-4-yl) uracil (l-BHDU, 17) is a potent and selective inhibitor of the varicella-zoster virus (VZV). l-BHDU (17) has demonstrated excellent anti-VZV activity and is a preclinical candidate to treat chickenpox, shingles (herpes zoster), and herpes simplex virus 1 (HSV-1) infections. Its monophosphate prodrug (POM-l-BHDU-MP, 24) demonstrated an enhanced pharmacokinetic and antiviral profile. POM-l-BHDU-MP (24), in vivo, effectively reduced the VZV viral load and was effective for the topical treatment of VZV and HSV-1 infections. Therefore, a viable synthetic procedure for developing POM-l-BHDU-MP (24) is needed. In this article, an efficient approach for the synthesis of l-BHDU (17) from a readily available starting material is described in 7 steps. An efficient and practical methodology for both chiral pure l- & d-dioxolane 11 and 13 were developed via diastereomeric chiral amine salt formation. Neutralization of the amine carboxylate salt of l-dioxolane 10 provides enantiomerically pure l-dioxane 11 (ee ≥ 99%). Optically pure 11 was utilized to construct the final nucleoside l-BHDU (17) and its monophosphate ester prodrug (POM-l-BHDU-MP, 24). Notably, the reported process eliminates expensive chiral chromatography for the synthesis of chiral pure l- & d-dioxolane, which offers avenues for the development and structure-activity relationship studies of l- & d-dioxolane-derived nucleosides.

The fat mass and obesity-associated fatso (FTO) protein is a member of the Alkb family of dioxygenases and catalyzes oxidative demethylation of N6-methyladenosine (m6A), N1-methyladenosine (m1A), 3-methylthymine (m3T), and 3-methyluracil (m3U) in single-stranded nucleic acids. It is well established that the catalytic activity of FTO proceeds via two coupled reactions. The first reaction involves decarboxylation of alpha-ketoglutarate (αKG) and formation of an oxyferryl species. In the second reaction, the oxyferryl intermediate oxidizes the methylated nucleic acid to reestablish Fe(II) and the canonical base. However, it remains unclear how binding of the nucleic acid activates the αKG decarboxylation reaction and why FTO demethylates different methyl modifications at different rates. Here, we investigate the interaction of FTO with 5-mer DNA oligos incorporating the m6A, m1A, or m3T modifications using solution NMR, molecular dynamics (MD) simulations, and enzymatic assays. We show that binding of the nucleic acid to FTO activates a two-state conformational equilibrium in the αKG cosubstrate that modulates the O2 accessibility of the Fe(II) catalyst. Notably, the substrates that provide better stabilization to the αKG conformation in which Fe(II) is exposed to O2 are demethylated more efficiently by FTO. These results indicate that i) binding of the methylated nucleic acid is required to expose the catalytic metal to O2 and activate the αKG decarboxylation reaction, and ii) the measured turnover of the demethylation reaction (which is an ensemble average over the entire sample) depends on the ability of the methylated base to favor the Fe(II) state accessible to O2.

Inherited cardiomyopathies are common cardiac diseases worldwide, leading in the late stage to heart failure and death. The most promising treatments against these diseases are small molecules directly modulating the force produced by β-cardiac myosin, the molecular motor driving heart contraction. Omecamtiv mecarbil and Mavacamten are two such molecules that completed phase 3 clinical trials, and the inhibitor Mavacamten is now approved by the FDA. In contrast to Mavacamten, Omecamtiv mecarbil acts as an activator of cardiac contractility. Here, we reveal by X-ray crystallography that both drugs target the same pocket and stabilize a pre-stroke structural state, with only few local differences. All-atom molecular dynamics simulations reveal how these molecules produce distinct effects in motor allostery thus impacting force production in opposite way. Altogether, our results provide the framework for rational drug development for the purpose of personalized medicine.

BACKGROUND: In most patients with advanced human epidermal growth factor receptor-2-positive (HER2+) breast cancer, anti-HER2 therapies fail due to the development of acquired resistance, potentially mediated through phosphoinositide-3-kinase (PI3K) signaling. We investigated adding taselisib, an α-selective potent oral inhibitor of PI3K, to different HER2-directed regimens in order to improve disease control.
METHODS: Patients (n = 68) with advanced HER2+ breast cancer were enrolled to this open-label, dose-escalation phase Ib study. The primary endpoint was defining the maximal tolerated dose (MTD) for the various taselisib-containing combinations. The secondary endpoint was safety. Exploratory endpoints included circulating tumor DNA analysis. The study included four cohorts: (A) taselisib + trastuzumab emtansine (T-DM1), (C) taselisib + trastuzumab and pertuzumab (TP), (D) taselisib + TP + paclitaxel, and (E) taselisib + TP + fulvestrant.
RESULTS: Following dose escalation, the taselisib MTD was defined as 4 mg once daily. Treatment was associated with significant toxicities, as 34 out of 68 patients experienced grade ≥3 adverse events (AEs) attributed to taselisib, the most common all-grade AEs being diarrhea, fatigue, and oral mucositis. At a median follow-up of 43.8 months, median progression-free survival (PFS) for the MTD-treated population in cohorts A, C, and E was 6.3 [95% confidence interval (CI) 3.2-not applicable (NA)] months, 1.7 (95% CI 1.4-NA) months, and 10.6 (95% CI 8.3-NA) months, respectively. The median PFS for patients in cohort A with prior T-DM1 use was 10.4 (95% CI 2.7-NA) months.
CONCLUSIONS: PIK3CA targeting with taselisib in combination with HER2-targeted therapies was associated with both promising efficacy and substantial toxicities.

The combination of trifluridine/tipiracil hydrochloride (FTD/TPI) plus ramucirumab has demonstrated clinical activity in patients with advanced gastric cancer (AGC). We evaluated the efficacy and safety of this combination compared with those of FTD/TPI monotherapy in patients with AGC. We retrospectively reviewed data of patients with AGC who received FTD/TPI plus ramucirumab or FTD/TPI monotherapy as third- or later-line treatment. This study included 36 patients treated with FTD/TPI plus ramucirumab and 70 patients receiving FTD/TPI monotherapy. The objective response rate (ORR) and disease control rate (DCR) were 25.8% and 58.1%, respectively, in the FTD/TPI plus ramucirumab group and 5.0% and 38.3%, respectively, in the FTD/TPI group (ORR, P = 0.007; DCR, P = 0.081). The median progression-free survival (PFS) was significantly longer in the FTD/TPI plus ramucirumab group (median PFS, 2.9 vs. 1.8 months; hazard ratio [HR]: 0.52; P = 0.001). A numerical survival benefit was also observed (median overall survival, 7.9 months vs. 5.0 months; HR: 0.68, P = 0.089). In the multivariate analysis, PFS was significantly longer in the FTD/TPI plus ramucirumab group than in the FTD/TPI monotherapy group (HR: 0.61, P = 0.030). The incidence of febrile neutropenia was higher in the FTD/TPI plus ramucirumab group than in the FTD/TPI group (13.8% vs. 2.9%); however, no new safety signals were identified. Compared with FTD/TPI monotherapy, FTD/TPI plus ramucirumab offers clinical benefits with acceptable toxicity in heavily pretreated patients with AGC. Further investigation via randomized trials is warranted to confirm these findings.