Cabozantinib plus atezolizumab versus sorafenib for advanced hepatocellular carcinoma (COSMIC-312): a multicentre, open-label, randomised, phase 3 trial.

BACKGROUND: Cabozantinib has shown clinical activity in combination with checkpoint inhibitors in solid tumours. The COSMIC-312 trial assessed cabozantinib plus atezolizumab versus sorafenib as first-line systemic treatment for advanced hepatocellular carcinoma. METHODS: COSMIC-312 is an open-label, randomised, phase 3 trial that enrolled patients aged 18 years or older with advanced hepatocellular carcinoma not amenable to curative or locoregional therapy and previously untreated with systemic anticancer therapy at 178 centres in 32 countries. Patients with fibrolamellar carcinoma, sarcomatoid hepatocellular carcinoma, or combined hepatocellular cholangiocarcinoma were not eligible. Tumours involving major blood vessels, including the main portal vein, were permitted. Patients were required to have measurable disease per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1), Barcelona Clinic Liver Cancer stage B or C disease, an Eastern Cooperative Oncology Group performance status of 0 or 1, adequate organ and marrow function, and Child-Pugh class A. Previous resection, tumour ablation, radiotherapy, or arterial chemotherapy was allowed if more than 28 days before randomisation. Patients were randomly assigned (2:1:1) via a web-based interactive response system to cabozantinib 40 mg orally once daily plus atezolizumab 1200 mg intravenously every 3 weeks, sorafenib 400 mg orally twice daily, or single-agent cabozantinib 60 mg orally once daily. Randomisation was stratified by disease aetiology, geographical region, and presence of extrahepatic disease or macrovascular invasion. Dual primary endpoints were progression-free survival per RECIST 1.1 as assessed by a blinded independent radiology committee in the first 372 patients randomly assigned to the combination treatment of cabozantinib plus atezolizumab or sorafenib (progression-free survival intention-to-treat [ITT] population), and overall survival in all patients randomly assigned to cabozantinib plus atezolizumab or sorafenib (ITT population). Final progression-free survival and concurrent interim overall survival analyses are presented. This trial is registered with ClinicalTrials.gov, NCT03755791. FINDINGS: Analyses at data cut-off (March 8, 2021) included the first 837 patients randomly assigned between Dec 7, 2018, and Aug 27, 2020, to combination treatment of cabozantinib plus atezolizumab (n=432), sorafenib (n=217), or single-agent cabozantinib (n=188). Median follow-up was 15·8 months (IQR 14·5-17·2) in the progression-free survival ITT population and 13·3 months (10·5-16·0) in the ITT population. Median progression-free survival was 6·8 months (99% CI 5·6-8·3) in the combination treatment group versus 4·2 months (2·8-7·0) in the sorafenib group (hazard ratio [HR] 0·63, 99% CI 0·44-0·91, p=0·0012). Median overall survival (interim analysis) was 15·4 months (96% CI 13·7-17·7) in the combination treatment group versus 15·5 months (12·1-not estimable) in the sorafenib group (HR 0·90, 96% CI 0·69-1·18; p=0·44). The most common grade 3 or 4 adverse events were alanine aminotransferase increase (38 [9%] of 429 patients in the combination treatment group vs six [3%] of 207 in the sorafenib group vs 12 [6%] of 188 in the single-agent cabozantinib group), hypertension (37 [9%] vs 17 [8%] vs 23 [12%]), aspartate aminotransferase increase (37 [9%] vs eight [4%] vs 18 [10%]), and palmar-plantar erythrodysaesthesia (35 [8%] vs 17 [8%] vs 16 [9%]); serious treatment-related adverse events occurred in 78 (18%) patients in the combination treatment group, 16 (8%) patients in the sorafenib group, and 24 (13%) in the single-agent cabozantinib group. Treatment-related grade 5 events occurred in six (1%) patients in the combination treatment group (encephalopathy, hepatic failure, drug-induced liver injury, oesophageal varices haemorrhage, multiple organ dysfunction syndrome, and tumour lysis syndrome), one (<1%) patient in the sorafenib group (general physical health deterioration), and one (<1%) patient in the single-agent cabozantinib group (gastrointestinal haemorrhage). INTERPRETATION: Cabozantinib plus atezolizumab might be a treatment option for select patients with advanced hepatocellular carcinoma, but additional studies are needed. FUNDING: Exelixis and Ipsen.

Cabozantinib for previously treated radioiodine-refractory differentiated thyroid cancer: Updated results from the phase 3 COSMIC-311 trial.

BACKGROUND: At an interim analysis (median follow-up, 6.2 months; n = 187), the phase 3 COSMIC-311 trial met the primary end point of progression-free survival (PFS): cabozantinib improved PFS versus a placebo (median, not reached vs. 1.9 months; p < .0001) in patients with previously treated radioiodine-refractory differentiated thyroid cancer (RAIR-DTC). The results from an exploratory analysis using an extended datacut are presented. METHODS: Patients 16 years old or older with RAIR-DTC who progressed on prior lenvatinib and/or sorafenib were randomized 2:1 to oral cabozantinib tablets (60 mg/day) or a placebo. Placebo patients could cross over to open-label cabozantinib upon radiographic disease progression. The objective response rate (ORR) in the first 100 randomized patients and the PFS in the intent-to-treat population, both according to Response Evaluation Criteria in Solid Tumors version 1.1 by blinded, independent review, were the primary end points. RESULTS: At the data cutoff (February 8, 2021), 258 patients had been randomized (cabozantinib, n = 170; placebo, n = 88); the median follow-up was 10.1 months. The median PFS was 11.0 months (96% confidence interval [CI], 7.4-13.8 months) for cabozantinib and 1.9 months (96% CI, 1.9-3.7 months) for the placebo (hazard ratio, 0.22; 96% CI, 0.15-0.32; p < .0001). The ORR was 11.0% (95% CI, 6.9%-16.9%) versus 0% (95% CI, 0.0%-4.1%) (p = .0003) with one complete response with cabozantinib. Forty placebo patients crossed over to open-label cabozantinib. Grade 3/4 treatment-emergent adverse events occurred in 62% and 28% of the cabozantinib- and placebo-treated patients, respectively; the most common were hypertension (12% vs. 2%), palmar-plantar erythrodysesthesia (10% vs. 0%), and fatigue (9% vs. 0%). There were no grade 5 treatment-related events. CONCLUSIONS: At extended follow-up, cabozantinib maintained superior efficacy over a placebo in patients with previously treated RAIR-DTC with no new safety signals.

Cabozantinib for radioiodine-refractory differentiated thyroid cancer (COSMIC-311): a randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: Patients with radioiodine-refractory differentiated thyroid cancer (DTC) previously treated with vascular endothelial growth factor receptor (VEGFR)-targeted therapy have aggressive disease and no available standard of care. The aim of this study was to evaluate the tyrosine kinase inhibitor cabozantinib in this patient population. METHODS: In this global, randomised, double-blind, placebo-controlled, phase 3 trial, patients aged 16 years and older with radioiodine-refractory DTC (papillary or follicular and their variants) and an Eastern Cooperative Oncology Group performance status of 0 or 1 were randomly assigned (2:1) to oral cabozantinib (60 mg once daily) or matching placebo, stratified by previous lenvatinib treatment and age. The randomisation scheme used stratified permuted blocks of block size six and an interactive voice-web response system; both patients and investigators were masked to study treatment. Patients must have received previous lenvatinib or sorafenib and progressed during or after treatment with up to two VEGFR tyrosine kinase inhibitors. Patients receiving placebo could cross over to open-label cabozantinib on disease progression confirmed by blinded independent radiology committee (BIRC). The primary endpoints were objective response rate (confirmed response per Response Evaluation Criteria in Solid Tumours [RECIST] version 1.1) in the first 100 randomly assigned patients (objective response rate intention-to-treat [OITT] population) and progression-free survival (time to earlier of disease progression per RECIST version 1.1 or death) in all patients (intention-to-treat [ITT] population), both assessed by BIRC. This report presents the primary objective response rate analysis and a concurrent preplanned interim progression-free survival analysis. The study is registered with ClinicalTrials.gov, NCT03690388, and is no longer enrolling patients. FINDINGS: Between Feb 27, 2019, and Aug 18, 2020, 227 patients were assessed for eligibility, of whom 187 were enrolled from 164 clinics in 25 countries and randomly assigned to cabozantinib (n=125) or placebo (n=62). At data cutoff (Aug 19, 2020) for the primary objective response rate and interim progression-free survival analyses, median follow-up was 6·2 months (IQR 3·4-9·2) for the ITT population and 8·9 months (7·1-10·5) for the OITT population. An objective response in the OITT population was achieved in ten (15%; 99% CI 5·8-29·3) of 67 patients in the cabozantinib group versus 0 (0%; 0-14·8) of 33 in the placebo (p=0·028) but did not meet the prespecified significance level (α=0·01). At interim analysis, the primary endpoint of progression-free survival was met in the ITT population; cabozantinib showed significant improvement in progression-free survival over placebo: median not reached (96% CI 5·7-not estimable [NE]) versus 1·9 months (1·8-3·6); hazard ratio 0·22 (96% CI 0·13-0·36; p<0·0001). Grade 3 or 4 adverse events occurred in 71 (57%) of 125 patients receiving cabozantinib and 16 (26%) of 62 receiving placebo, the most frequent of which were palmar-plantar erythrodysaesthesia (13 [10%] vs 0), hypertension (11 [9%] vs 2 [3%]), and fatigue (ten [8%] vs 0). Serious treatment-related adverse events occurred in 20 (16%) of 125 patients in the cabozantinib group and one (2%) of 62 in the placebo group. There were no treatment-related deaths. INTERPRETATION: Our results show that cabozantinib significantly prolongs progression-free survival and might provide a new treatment option for patients with radioiodine-refractory DTC who have no available standard of care. FUNDING: Exelixis.

Mechanistic Aspects of Microbe-Mediated Nanoparticle Synthesis.

In recent times, nanoparticles (NPs) have found increasing interest owing to their size, large surface areas, distinctive structures, and unique properties, making them suitable for various industrial and biomedical applications. Biogenic synthesis of NPs using microbes is a recent trend and a greener approach than physical and chemical methods of synthesis, which demand higher costs, greater energy consumption, and complex reaction conditions and ensue hazardous environmental impact. Several microorganisms are known to trap metals in situ and convert them into elemental NPs forms. They are found to accumulate inside and outside of the cell as well as in the periplasmic space. Despite the toxicity of NPs, the driving factor for the production of NPs inside microorganisms remains unelucidated. Several reports suggest that nanotization is a way of stress response and biodefense mechanism for the microbe, which involves metal excretion/accumulation across membranes, enzymatic action, efflux pump systems, binding at peptides, and precipitation. Moreover, genes also play an important role for microbial nanoparticle biosynthesis. The resistance of microbial cells to metal ions during inward and outward transportation leads to precipitation. Accordingly, it becomes pertinent to understand the interaction of the metal ions with proteins, DNA, organelles, membranes, and their subsequent cellular uptake. The elucidation of the mechanism also allows us to control the shape, size, and monodispersity of the NPs to develop large-scale production according to the required application. This article reviews different means in microbial synthesis of NPs focusing on understanding the cellular, biochemical, and molecular mechanisms of nanotization of metals.

Population Pharmacokinetics and Exposure-Response Analyses for CPX-351 in Patients With Hematologic Malignancies.

CPX-351, a dual-drug liposomal encapsulation of cytarabine and daunorubicin at a synergistic ratio, is approved in the United States for adults with newly diagnosed therapy-related acute myeloid leukemia or acute myeloid leukemia with myelodysplasia-related changes. Population pharmacokinetics analyses were performed using nonlinear mixed-effect modeling on pooled data from 3 clinical studies, and the impact of CPX-351 exposures on efficacy and safety was assessed. The pharmacokinetics of cytarabine and daunorubicin were described using 2-compartment models with linear elimination. None of the evaluated covariates had a clinically significant impact on plasma exposure to total cytarabine or daunorubicin, while bilirubin and formulation showed statistically significant effects on pharmacokinetic parameters of cytarabine and daunorubicin, respectively. In patients with mild/moderate renal impairment or serum bilirubin ≤3 mg/dL, plasma exposures to cytarabine and daunorubicin following CPX-351 were within the variability range for patients with normal kidney function or serum bilirubin levels. Exposure-response analysis demonstrated that better efficacy outcomes were associated with higher CPX-351 exposure quartiles. Early mortality rates in all CPX-351 exposure quartiles were lower vs the 7 + 3 control group, and lower mortality rates were associated with higher exposure quartiles. A trend toward greater frequency of grade 3 treatment-emergent adverse events (but not grade 4/5 events) was observed at higher CPX-351 exposure quartiles. Overall, the population pharmacokinetic analyses indicate no adjustments to the recommended dose and schedule of CPX-351 are warranted for patients with mild/moderate renal impairment or serum bilirubin ≤3 mg/dL. Results from the exposure-response analyses suggest the current CPX-351 regimen provides a favorable risk-benefit profile.

Toward development of generic inhibitors against the 3C proteases of picornaviruses.

Development of novel antivirals, which requires knowledge of the viral life cycle in molecular detail, is a daunting task, involving extensive investments, and frequently resulting in failure. As there exist significant commonalities among virus families in the manner of host interaction, identifying and targeting common rather than specific features may lead to the development of broadly useful antivirals. Here, we have targeted the 3C protease of Hepatitis A Virus (HAV), a feco-orally transmitted virus of the family Picornaviridae, for identification of potential antivirals. The 3C protease is a viable drug target as it is required by HAV, as well as by other picornaviruses, for post-translational proteolysis of viral polyproteins and for inhibiting host innate immune pathways. Computational screening, followed by chemical synthesis and experimental validation resulted in identification of a few compounds which, at low micromolar concentrations, could inhibit HAV 3C activity. These compounds were further tested experimentally against the 3C protease of Human Rhinovirus, another member of the Picornaviridae family, with comparable results. Computational studies on 3C proteases from other members of the picornavirus family have indicated that the compounds identified could potentially be generic inhibitors for picornavirus 3C proteases.

A phase 2 study to assess the pharmacokinetics and pharmacodynamics of CPX-351 and its effects on cardiac repolarization in patients with acute leukemias.

PURPOSE: Daunorubicin can induce left ventricular dysfunction and QT interval prolongation. This study assessed the effects of CPX-351, a liposomal encapsulation of cytarabine and daunorubicin, on cardiac repolarization. METHODS: Twenty-six adults with acute leukemia were treated with CPX-351 for 1-2 induction cycles and ≤ 4 consolidation cycles. The primary endpoint was mean change in QTcF from baseline. RESULTS: Mean QTcF changes were < 10 ms at all time points. No clinically meaningful effects on heart rate, QRS interval, PR interval, or QTcB were observed. Estimated mean half-lives for total cytarabine and daunorubicin were > 30 h. Thirteen (50%) patients achieved remission. The most common adverse events were febrile neutropenia, fatigue, and nausea. CONCLUSIONS: The cytarabine and daunorubicin in CPX-351 liposomes were metabolized and excreted similarly to conventional formulation; however, plasma pharmacokinetics were altered. CPX-351 did not prolong the QT interval, suggesting that CPX-351 may induce less cardiotoxicity than previously reported for conventional daunorubicin. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02238925.

CPX-351 (cytarabine and daunorubicin) Liposome for Injection Versus Conventional Cytarabine Plus Daunorubicin in Older Patients With Newly Diagnosed Secondary Acute Myeloid Leukemia.

Purpose CPX-351 is a dual-drug liposomal encapsulation of cytarabine and daunorubicin that delivers a synergistic 5:1 drug ratio into leukemia cells to a greater extent than normal bone marrow cells. Prior clinical studies demonstrated a sustained drug ratio and exposure in vivo and prolonged survival versus standard-of-care cytarabine plus daunorubicin chemotherapy (7+3 regimen) in older patients with newly diagnosed secondary acute myeloid leukemia (sAML). Patients and Methods In this open-label, randomized, phase III trial, 309 patients age 60 to 75 years with newly diagnosed high-risk/sAML received one to two induction cycles of CPX-351 or 7+3 followed by consolidation therapy with a similar regimen. The primary end point was overall survival. Results CPX-351 significantly improved median overall survival versus 7+3 (9.56 v 5.95 months; hazard ratio, 0.69; 95% CI, 0.52 to 0.90; one-sided P = .003). Overall remission rate was also significantly higher with CPX-351 versus 7+3 (47.7% v 33.3%; two-sided P = .016). Improved outcomes were observed across age-groups and AML subtypes. The incidences of nonhematologic adverse events were comparable between arms, despite a longer treatment phase and prolonged time to neutrophil and platelet count recovery with CPX-351. Early mortality rates with CPX-351 and 7+3 were 5.9% and 10.6% (two-sided P = .149) through day 30 and 13.7% and 21.2% (two-sided P = .097) through day 60. Conclusion CPX-351 treatment is associated with significantly longer survival compared with conventional 7+3 in older adults with newly diagnosed sAML. The safety profile of CPX-351 was similar to that of conventional 7+3 therapy.

The C-terminal region of the non-structural protein 2B from Hepatitis A Virus demonstrates lipid-specific viroporin-like activity.

Viroporins are virally encoded, membrane-active proteins, which enhance viral replication and assist in egress of viruses from host cells. The 2B proteins in the picornaviridae family are known to have viroporin-like properties, and play critical roles during virus replication. The 2B protein of Hepatitis A Virus (2B), an unusual picornavirus, is somewhat dissimilar from its analogues in several respects. HAV 2B is approximately 2.5 times the length of other 2B proteins, and does not disrupt calcium homeostasis or glycoprotein trafficking. Additionally, its membrane penetrating properties are not yet clearly established. Here we show that the membrane interacting activity of HAV 2B is localized in its C-terminal region, which contains an alpha-helical hairpin motif. We show that this region is capable of forming small pores in membranes and demonstrates lipid specific activity, which partially rationalizes the intracellular localization of full-length 2B. Using a combination of biochemical assays and molecular dynamics simulation studies, we also show that HAV 2B demonstrates a marked propensity to dimerize in a crowded environment, and probably interacts with membranes in a multimeric form, a hallmark of other picornavirus viroporins. In sum, our study clearly establishes HAV 2B as a bona fide viroporin in the picornaviridae family.

Computational and functional characterization of Angiogenin mutations, and correlation with amyotrophic lateral sclerosis.

The Angiogenin (ANG) gene is frequently mutated in patients suffering from the neurodegenerative disease--amyotrophic lateral sclerosis (ALS). Most of the ALS-causing mutations in Angiogenin affect either its ribonucleolytic or nuclear translocation activity. Here we report the functional characterization of two previously uncharacterized missense mutations in Angiogenin--D22G and L35P. We predict the nature of loss-of-function(s) in these mutants through our previously established Molecular Dynamics (MD) simulation extended to 100 ns, and show that the predictions are entirely validated through biochemical studies with wild-type and mutated proteins. Based on our studies, we provide a biological explanation for the loss-of-function of D22G-Angiogenin leading to ALS, and suggest that the L35P-Angiogenin mutation would probably cause ALS symptoms in individuals harboring this mutation. Our study thus highlights the strength of MD simulation-based predictions, and suggests that this method can be used for correlating mutations in Angiogenin or other effector proteins with ALS symptoms.

Functional co-evolutionary study of glucosamine-6-phosphate synthase in mycoses causing fungi.

Invasive fungal opportunistic infections or mycoses have been on the rise with increase in the number of immuno-compromised patients accounting for associated high morbidity and mortality rates. The antifungal drugs are not completely effective due to increased resistance and varied susceptibility of fungi. Hence, the functional diversification study of novel targets has to be carried out. The enzyme glucosamine-6-phosphate synthase [EC 2.6.1.16], a novel drug target, catalyzes the rate-limiting step of the fungal cell-wall biosynthetic pathway, comprising four conserved domains, two glutaminase and sugar-isomerising (SIS) domains with active site. The amino acids within these domains tend to mutate simultaneously and exert mutual selective forces which might result in untoward fungal adaptations that are fixed through random genetic drift over time. The current study is an attempt to investigate such 'non-independent' coevolving residues which play critical functional and structural role in the protein. Residues with Shannon entropy ≦1 (calculated by the Protein Variability Server) were considered and subsequently, positional correlations were estimated by InterMap3D 1.3 server. It was observed that majority of coevolving pairs of first SIS domain involved interactions with hydrophobic leucine and found to be spatially coupled in 3-dimensional structure of the enzyme. The coevolving groups of Aspergillus niger and Rhizopus oryzae species might play a role in drug resistance. Such coevolutionary analysis is important for understanding the receptor-ligand interactions and effective drug designing.

Variability analyses of functional domains within glucosamine-6-phosphate synthase of mycosescausing fungi.

The immunosuppressive individuals are highly prone to get afflicted with invasive opportunistic fungal infections such as Candidiasis, Aspergillosis, Histoplasmosis, Coccidioidomycosis, Blastomycosis, Penicilliosis, Cryptococcosis and Zygomycosis which are becoming a cause of concern to the mankind due to their high morbidity and mortality rates. The existing antifungal agents are not completely effective due to their severe side-effects and recurrent drug resistance in fungi. Hence, there is an urgent need to develop newer and better antifungal drugs. The enzyme Glucosamine-6-phosphate (G-6-P) synthase catalyzes the ratelimiting step of the fungal cell-wall biosynthetic pathway and targeting it can inhibit the growth of the fungus. The present study attempts to investigate the inherent variations in functional domain viz. Glutaminase (GATase II) and Sugar Isomerising (SIS) of Glucosamine-6-phosphate (G-6-P) synthase enzyme of mycoses-causing fungi. These domains may be identified as probable active site(s). Multiple sequence alignment performed using ClustalX2 and construction of phylogenetic tree of individual domains by MEGA v5.0 helped in the analyses of several variable amino acid sites within the domains suggesting their vital role in the pathogenesis of the fungi. Further, the online server ConSurf implied that mostly, the highly conserved residues of the domains were functional and exposed on the surface of the active site, making it an easy target for the drugs. Consequently, variable analysis of functional domains of target implicated the importance of target specific drug discovery for the treatment of invasive fungal infections or mycoses.

Molecular docking of glucosamine-6-phosphate synthase in Rhizopus oryzae.

Recent expansion of immunocompromised population has led to significant rise in zygomycosis caused by filamentous fungus Rhizopus oryzae. Due to emergence of fungal resistance and side-effects of antifungal drugs, there is increased demand for novel drug targets. The current study elucidates molecular interactions of peptide drugs with G-6-P synthase (catalyzing the rate-limiting step of fungal cell wall biosynthetic pathway) of R.oryzae by molecular docking studies. The PDB structures of enzyme in R.oryzae are not known which were predicted using I-TASSER server and validated with PROCHECK. Peptide inhibitors, FMDP and ADGP previously used against enzyme of E.coli (PDBid: 1XFF), were used for docking studies of enzyme in R.oryzae by SchrödingerMaestro v9.1. To investigate binding between enzyme and inhibitors, Glide and Induced Fit docking were performed. IFD results of 1XFF with FMDP yielded C1, R73, W74, T76, G99 and D123 as the binding sites. C379 and Q427 appear to be vital for binding of R.oryzae enzymes to inhibitors. The comparison results of IFD scores of enzyme in R.oryzae and E.coli (PDBid: 2BPL) yield appreciable score, hinting at the probable effectiveness of inhibitors FMDP and ADGP against R.oryzae, with ADGP showing an improved enzyme affinity. Moreover, the two copies of gene G-6-P synthase due to extensive fungal gene duplication, in R. oryzae eliminating the problem of drug ineffectiveness could act as a potential antifungal drug target in R. oryzae with the application of peptide ligands.