Preclinical Pharmacologic Evaluation of MST-997, an Orally Active Taxane with Superior In vitro and In vivo Efficacy in Paclitaxel- and Docetaxel-Resistant Tumor Models

Background: Death receptor 5 (DR5) is a member of the tumor necrosis factor (TNF) receptor superfamily that multimerizes when bound to its ligand, TNF-related apoptosis inducing ligand (TRAIL), to activate the extrinsic apoptotic pathway. DR5 is broadly expressed on solid and hematologic cancers and has been targeted with both recombinant TRAIL and agonistic antibodies in the clinic. However, these therapeutics have been unsuccessful due to lack of efficacy or hepatotoxicity. We have developed IGM-8444, a pentameric IgM with 10 binding sites specific for DR5, that multimerizes DR5 to selectively and potently induce tumor cell apoptosis while maintaining tolerability. We have previously presented the in vitro and in vivo efficacy of IGM-8444 in solid tumor models, demonstrating low picomolar potency across multiple tumor cell lines, strong tumor regressions in cell line and patient derived xenograft mouse tumor models, and dose-dependent increases in apoptotic biomarkers. Here, we evaluate the activity of IGM-8444 in hematologic malignancies in combination with chemotherapy or targeted agents including Bcl-2 inhibitors targeting the intrinsic apoptotic pathway. Methods: Human hematologic cancer cell lines and primary human hepatocytes were evaluated in vitro for dose-dependent IGM-8444-induced cytotoxicity. Cell lines were further evaluated using IGM-8444 in combination with chemotherapy or targeted agents including Bcl-2 inhibitor ABT-199. In vivo efficacy was evaluated using IGM-8444 in combination with ABT-199 in cell line-derived xenograft mouse tumor models. Results: In a previous cancer cell line screen profiling single agent IGM-8444 cytotoxicity across 190 solid and hematologic cell lines, 25 (13%) were classified as highly responsive and 75 (39%) as moderately responsive to IGM-8444 induced cell death. Here the in vitro activity of IGM-8444 was evaluated across a subset of 32 NHL and AML cell lines. 5/21 (24%) of NHL cell lines and 5/11 (45%) of AML cell lines tested were classified as highly responsive or moderately responsive to IGM-8444-induced cytotoxicity. The DOHH-2 and JEKO1 NHL cell lines were amongst the most sensitive, with growth-normalized EC50 values as low as 0.03 ng/mL (0.03 pM) for JEKO1. Combinations with chemotherapy including cytarabine and doxorubicin or targeted agents such as Bcl-2 inhibitor ABT-199 resulted in synergistic in vitro cytotoxicity in multiple cell lines, as determined by Bliss synergy scores. IGM-8444 demonstrated minimal to no in vitro cytotoxicity to primary human hepatocytes at doses several log-fold higher than efficacious doses, and this favorable in vitro safety profile was maintained in combination with chemotherapeutic agents and ABT-199. Combination of IGM-8444 with ABT-199 also resulted in synergistic in vivo efficacy. In a DOHH-2 NHL model, IGM-8444 and ABT-199 showed modest tumor growth inhibition as single agents. However the combined treatment regimen led to tumor regressions during the first 2 weeks of treatment, with 3 of 10 animals showing a partial response and 2 of 10 animals achieving a complete response. The combined treatment also extended median overall survival compared to the control group, which was a significant improvement compared to either agent alone. Collectively, these results provide a strong rationale for simultaneously targeting the extrinsic and intrinsic apoptotic pathways to achieve enhanced efficacy. Conclusions: These data support the clinical development of IGM-8444 in hematological malignancies as a single agent, in combination with standard of care chemotherapy, and in combination with targeted agents that impact the intrinsic signaling pathway such as Bcl-2 inhibitor ABT-199. Initiation of a Phase I clinical study evaluating the safety of IGM-8444 is anticipated in 2020. Disclosures Wang: IGM Biosciences Inc: Current Employment, Current equity holder in publicly-traded company. Matthew:IGM Biosciences Inc: Current Employment, Current equity holder in publicly-traded company. Wang:IGM Biosciences Inc: Current Employment, Current equity holder in publicly-traded company. Kothambawala:IGM Biosciences Inc: Current Employment, Current equity holder in publicly-traded company. Calhoun:IGM Biosciences Inc: Current Employment, Current equity holder in publicly-traded company. Humke:IGM Biosciences Inc: Current Employment, Current equity holder in publicly-traded company. Sinclair:IGM Biosciences Inc: Current Employment, Current equity holder in publicly-traded company. Keyt:IGM Biosciences Inc: Current Employment, Current equity holder in publicly-traded company.

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Faculty Opinions recommendation of The in vitro mechanisms and in vivo efficacy of intravenous lidocaine on the neuroinflammatory response in acute and chronic pain.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.726025441.793523751 ◽

2016 ◽

Author(s):

Jan Jakobsson

Keyword(s):

Chronic Pain ◽

Intravenous Lidocaine ◽

Neuroinflammatory Response ◽

In Vivo Efficacy

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Intracellular localisation of Mycobacterium tuberculosis affects efficacy of the antibiotic pyrazinamide

Nature Communications ◽

10.1038/s41467-021-24127-3 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Pierre Santucci ◽

Daniel J. Greenwood ◽

Antony Fearns ◽

Kai Chen ◽

Haibo Jiang ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Host Cell ◽

Combination Chemotherapy ◽

In Vitro Activity ◽

In Vivo Efficacy ◽

Human Macrophages ◽

Ion Microscopy ◽

Intracellular Localisation

AbstractTo be effective, chemotherapy against tuberculosis (TB) must kill the intracellular population of the pathogen, Mycobacterium tuberculosis. However, how host cell microenvironments affect antibiotic accumulation and efficacy remains unclear. Here, we use correlative light, electron, and ion microscopy to investigate how various microenvironments within human macrophages affect the activity of pyrazinamide (PZA), a key antibiotic against TB. We show that PZA accumulates heterogeneously among individual bacteria in multiple host cell environments. Crucially, PZA accumulation and efficacy is maximal within acidified phagosomes. Bedaquiline, another antibiotic commonly used in combined TB therapy, enhances PZA accumulation via a host cell-mediated mechanism. Thus, intracellular localisation and specific microenvironments affect PZA accumulation and efficacy. Our results may explain the potent in vivo efficacy of PZA, compared to its modest in vitro activity, and its critical contribution to TB combination chemotherapy.

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P074 In vitro and in vivo efficacy of linezolid on Treponema pallidum, the syphilis agent

10.1136/sextrans-2021-sti.208 ◽

2021 ◽

Author(s):

L Giacani ◽

A Haynes ◽

M Vall Mayans ◽

M Ubals Cazorla ◽

C Nieto ◽

...

Keyword(s):

Treponema Pallidum ◽

In Vivo Efficacy

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Efficacy of a novel lantibiotic, CMB001, against MRSA

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkab040 ◽

2021 ◽

Author(s):

Jerzy Karczewski ◽

Christine M Brown ◽

Yukari Maezato ◽

Stephen P Krasucki ◽

Stephen J Streatfield

Keyword(s):

Antibacterial Activity ◽

Pharmacokinetic Analysis ◽

Maximum Tolerable Dose ◽

In Vivo Efficacy ◽

Clostridioides Difficile ◽

Alternative Treatment Option ◽

Significant Damage ◽

Tolerable Dose

Abstract Objectives To evaluate the efficacy of a novel lantibiotic, CMB001, against MRSA biofilms in vitro and in an in vivo experimental model of bacterial infection. Methods Antibacterial activity of CMB001 was measured in vitro after its exposure to whole blood or to platelet-poor plasma. In vitro efficacy of CMB001 against a Staphylococcus aureus biofilm was studied using scanning electron microscopy. The maximum tolerable dose in mice was determined and a preliminary pharmacokinetic analysis for CMB001 was performed in mice. In vivo efficacy was evaluated in a neutropenic mouse thigh model of infection. Results CMB001 maintained its antibacterial activity in the presence of blood or plasma for up to 24 h at 37°C. CMB001 efficiently killed S. aureus within the biofilm by causing significant damage to the bacterial cell wall. The maximum tolerable dose in mice was established to be 10 mg/kg and could be increased to 30 mg/kg in mice pretreated with antihistamines. In neutropenic mice infected with MRSA, treatment with CMB001 reduced the bacterial burden with an efficacy equivalent to that of vancomycin. Conclusions CMB001 offers potential as an alternative treatment option to combat MRSA. It will be of interest to evaluate the in vivo efficacy of CMB001 against infections caused by other pathogens, including Clostridioides difficile and Acinetobacter baumannii, and to expand its pharmacokinetic/pharmacodynamic parameters and safety profile.

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Therapeutic Application of Brain-Specific Angiogenesis Inhibitor 1 for Cancer Therapy

Cancers ◽

10.3390/cancers13143562 ◽

2021 ◽

Vol 13 (14) ◽

pp. 3562

Author(s):

Mitra Nair ◽

Chelsea Bolyard ◽

Tae Jin Lee ◽

Balveen Kaur ◽

Ji Young Yoo

Keyword(s):

Angiogenesis Inhibitor ◽

Suppressor Gene ◽

Chemotherapeutic Agents ◽

Tumor Models ◽

In Vivo Models ◽

Herpes Simplex Viruses ◽

Multiple Tumor ◽

And Function

Brain-specific angiogenesis inhibitor 1 (BAI1/ADGRB1) is an adhesion G protein-coupled receptor that has been found to play key roles in phagocytosis, inflammation, synaptogenesis, the inhibition of angiogenesis, and myoblast fusion. As the name suggests, it is primarily expressed in the brain, with a high expression in the normal adult and developing brain. Additionally, its expression is reduced in brain cancers, such as glioblastoma (GBM) and peripheral cancers, suggesting that BAI1 is a tumor suppressor gene. Several investigators have demonstrated that the restoration of BAI1 expression in cancer cells results in reduced tumor growth and angiogenesis. Its expression has also been shown to be inversely correlated with tumor progression, neovascularization, and peri-tumoral brain edema. One method of restoring BAI1 expression is by using oncolytic virus (OV) therapy, a strategy which has been tested in various tumor models. Oncolytic herpes simplex viruses engineered to express the secreted fragment of BAI1, called Vasculostatin (Vstat120), have shown potent anti-tumor and anti-angiogenic effects in multiple tumor models. Combining Vstat120-expressing oHSVs with other chemotherapeutic agents has also shown to increase the overall anti-tumor efficacy in both in vitro and in vivo models. In the current review, we describe the structure and function of BAI1 and summarize its application in the context of cancer treatment.

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