Publications by authors named "Grant R Whitman"

Article Synopsis
  • Researchers have identified calcium-dependent protein kinase 1 (CDPK1) in the protozoan responsible for cryptosporidiosis as a promising target for new therapies.
  • A specific compound, a pyridopyrimidinone, was found to effectively inhibit CdPK1 and prevent the growth of various strains of the parasite in host cells.
  • Although the compound showed low systemic exposure after oral dosing, it achieved high concentrations in the gastrointestinal tract and demonstrated some effectiveness in animal models of the disease.
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  • Metastatic castration-resistant prostate cancer is still incurable, despite recent treatments, and tumors show increased glycolysis as they progress.
  • The study introduces BKIDC-1553, a new small-molecule compound that inhibits glycolysis specifically in prostate cancer cells without causing severe toxicity, and demonstrates promising results in preclinical models.
  • BKIDC-1553 shows effective growth inhibition in various prostate cancer models and has safety and pharmacokinetic properties that suggest it’s ready for clinical trials to treat advanced prostate cancer.
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  • Metastatic castration-resistant prostate cancer remains largely untreatable, but this study focuses on a new small molecule, BKIDC-1553, that inhibits glycolysis in cancer cells without significant toxicity.
  • Researchers tested BKIDC-1553 across various prostate cancer models and found it effectively inhibits cell proliferation and shows promising results in preclinical trials, comparable to existing treatments like enzalutamide.
  • The findings suggest that BKIDC-1553 has the potential for safe use in human clinical trials, paving the way for new treatment options for advanced prostate cancer patients.
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Recent advances on the development of bumped kinase inhibitors for treatment of cryptosporidiosis have focused on the 5-aminopyrazole-4-carboxamide scaffold, due to analogs that have less hERG inhibition, superior efficacy, and strong safety profiles. Three compounds, BKI-1770, -1841, and -1708, showed strong efficacy in C. parvum infected mice.

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Testing for mycobacterial lipoarabinomannan (LAM) in urine is a practical but insensitive alternative to sputum testing to diagnose tuberculosis (TB) in people with HIV (PWH). Here, we evaluated urine LAM testing alongside PCR-based tests for Mycobacterium tuberculosis (MTB) DNA in tongue swabs. We hypothesized that the two nonsputum samples would deliver complementary, not redundant, results.

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Article Synopsis
  • - A phenotypic screen of the ReFRAME compound library pinpointed 85 cell-active compounds for treating giardiasis, yielding a hit rate of 0.72% from Giardia lamblia, GS clone H7.
  • - Mavelertinib, a third-generation EGFR tyrosine kinase inhibitor, was identified as a promising therapeutic agent due to its effectiveness against metronidazole-resistant strains and a unique binding mechanism distinct from traditional EGFR-TKIs.
  • - In murine infection models, mavelertinib showed significant efficacy at doses ranging from 5 to 50 mg/kg, prompting consideration for its repurposing in giardiasis clinical trials while further development of its analogues continues.
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The Neospora caninum Calcium-dependent protein kinase 1 (NcCDPK1) inhibitor BKI-1294 had demonstrated excellent efficacy in a pregnant mouse model of neosporosis, and was also highly efficacious in a pregnant sheep model of toxoplasmosis. In this work, we present the efficacy of BKI-1294 treatment (dosed 5 times orally every 48 h) starting 48 h after intravenous infection of sheep with 10 Nc-Spain7 tachyzoites at mid-pregnancy. In the dams, BKI-1294 plasma concentrations were above the IC for N.

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The apicomplexan parasite Neospora caninum is an important causative agent of congenital neosporosis, resulting in abortion, birth of weak offspring and neuromuscular disorders in cattle, sheep, and many other species. Among several compound classes that are currently being developed, two have been reported to limit the effects of congenital neosporosis: (i) bumped kinase inhibitors (BKIs) target calcium dependent protein kinase 1 (CDPK1), an enzyme that is encoded by an apicoplast-derived gene and found only in apicomplexans and plants. CDPK1 is essential for host cell invasion and egress; (ii) endochin-like quinolones (ELQs) are inhibitors of the cytochrome bc complex of the mitochondrial electron transport chain and thus inhibit oxidative phosphorylation.

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Article Synopsis
  • - Bumped kinase inhibitors (BKIs), specifically BKI-1748, effectively inhibit the growth of apicomplexan parasites like Neospora caninum and Toxoplasma gondii, showing significant activity at low concentrations (ECs of 165 nM and 43 nM, respectively) when tested on fibroblast cells.
  • - Treatment with BKI-1748 led to the formation of multinucleated schizont-like complexes in infected cells, preventing the parasites from becoming infectious and egressing, and displayed no detrimental effects on zebrafish embryos or pregnant mice.
  • - In mouse models, BKI-1748 improved pup survival and reduced the transmission of N. caninum and T. gond
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Article Synopsis
  • New drugs are urgently needed to treat infections in malnourished children under 2 and individuals with weakened immune systems in developing countries.
  • Researchers screened bioactive compounds from the Tres-Cantos GSK library, identifying 19 compounds and narrowing them down to four clusters for further testing in a mouse infection model.
  • Only one compound, an imidazole-pyrimidine, showed significant effectiveness in clearing the infection, demonstrating good safety and activity at low doses, and it targets calcium-dependent protein kinase 1, suggesting potential for future therapeutic development.
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Article Synopsis
  • * The new compound BKI-1649, featuring a unique pyrrolopyrimidine scaffold, has demonstrated better effectiveness in mouse models at lower doses than earlier pyrazolopyrimidine variants.
  • * Two derivatives, BKI-1812 and BKI-1814, were tested and showed enhanced potency compared to previous BKIs, while maintaining similar levels of toxicity and efficacy as their pyrazolopyrimidine counterparts.
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This is a review of the development of bumped-kinase inhibitors (BKIs) for the therapy of One Health parasitic apicomplexan diseases. Many apicomplexan infections are shared between humans and livestock, such as cryptosporidiosis and toxoplasmosis, as well as livestock only diseases such as neosporosis. We have demonstrated proof-of-concept for BKI therapy in livestock models of cryptosporidiosis (newborn calves infected with Cryptosporidium parvum), toxoplasmosis (pregnant sheep infected with Toxoplasma gondii), and neosporosis (pregnant sheep infected with Neospora caninum).

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Article Synopsis
  • Bumped kinase inhibitors (BKIs), specifically BKI 1369, effectively target calcium-dependent protein kinase 1 (CDPK1) to combat Cystoisospora suis, which causes coccidiosis in piglets.
  • The study tested the effectiveness of BKI 1369 with less frequent dosing, finding that a single treatment two days post-infection significantly reduced the replication of the parasite and oocyst excretion in infected piglets.
  • Treated piglets showed marked health improvements, including increased weight gain and fewer days of diarrhea, suggesting that less frequent use of BKI 1369 is a viable treatment option without adverse effects.
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Bumped kinase inhibitors (BKIs) are effective against a variety of apicomplexan parasites. Fifteen BKIs with promising in vitro efficacy against Neospora caninum tachyzoites, low cytotoxicity in mammalian cells, and no toxic effects in non-pregnant BALB/c mice were assessed in pregnant mice. Drugs were emulsified in corn oil and were applied by gavage for 5 days.

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Bumped Kinase Inhibitors, targeting Calcium-dependent Protein Kinase 1 in apicomplexan parasites with a glycine gatekeeper, are promising new therapeutics for apicomplexan diseases. Here we will review advances, as well as challenges and lessons learned regarding efficacy, safety, and pharmacology that have shaped our selection of pre-clinical candidates.

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Recent studies have illustrated the burden Cryptosporidium infection places on the lives of malnourished children and immunocompromised individuals. Treatment options remain limited, and efforts to develop a new therapeutic are currently underway. However, there are unresolved questions about the ideal pharmacokinetic characteristics of new anti-Cryptosporidium therapeutics.

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Previous studies on drug efficacy showed low protection against abortion and vertical transmission of in pregnant sheep. Bumped kinase inhibitors (BKIs), which are ATP-competitive inhibitors of calcium-dependent protein kinase 1 (CDPK1), were shown to be highly efficacious against several apicomplexan parasites and in laboratory animal models. Here, we present the safety and efficacy of BKI-1294 treatment (dosed orally at 100 mg/kg of body weight 5 times every 48 h) initiated 48 h after oral infection of sheep at midpregnancy with 1,000 TgShSp1 oocysts.

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Article Synopsis
  • Cystoisosporosis significantly impacts suckling piglets, and with resistance to the current treatment toltrazuril, there's a pressing need for new therapies.
  • Bumped kinase inhibitor (BKI) 1369 has shown promise in laboratory studies, effectively suppressing parasite growth and reducing symptoms in infected piglets without causing harmful side effects.
  • The study indicates that BKI 1369 accumulates in the piglet's system, suggesting it could be a viable alternative treatment for cystoisosporosis in pigs, although further research is needed for practical use.
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Cryptosporidium is a leading cause of pediatric diarrhea worldwide. Currently, there is neither a vaccine nor a consistently effective drug available for this disease. Selective 5-aminopyrazole-4-carboxamide-based bumped-kinase inhibitors (BKIs) are effective in both in vitro and in vivo models of Cryptosporidium parvum.

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Article Synopsis
  • Bumped kinase inhibitors (BKIs) effectively inhibit Toxoplasma gondii calcium-dependent protein kinase 1, showing potential in treating toxoplasmosis.
  • Pyrazolopyrimidine and 5-aminopyrazole-4-carboxamide scaffolds have been tested in both acute and chronic models, with recent discoveries of new scaffolds like pyrrolopyrimidine enhancing potency against acute toxoplasmosis.
  • Structural modifications in the BKIs lead to varying plasma concentrations while ensuring low toxicity in human cell assays and mice, marking them as promising candidates for advanced anti-Toxoplasma therapies.
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There is need for a more efficient cell-based assay amenable to high-throughput drug screening against Giardia lamblia. Here, we report the development of a screening method utilizing G. lamblia engineered to express red-shifted firefly luciferase.

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Recent reports highlighting the global significance of cryptosporidiosis among children have renewed efforts to develop control measures. We evaluated the efficacy of bumped kinase inhibitor (BKI) 1369 in the gnotobiotic piglet model of acute diarrhea caused by , the species responsible for most human cases. Five-day treatment with BKI 1369 reduced signs of disease early during treatment compared to those of untreated animals.

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Selective inhibitors of Cryptosporidium calcium-dependent protein kinase 1 ( CpCDPK1) based on the 1 H-pyrazolo[3,4- d]pyrimidin-4-amine (pyrazolopyrimidine, PP) scaffold are effective in both in vitro and in vivo models of cryptosporidiosis. However, the search for distinct safety and pharmacokinetic (PK) properties has motivated our exploration of alternative scaffolds. Here, we describe a series of 7 H-pyrrolo[2,3- d]pyrimidin-4-amine (pyrrolopyrimidine, PrP)-based analogs of PP CpCDPK1 inhibitors.

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Neospora caninum is one of the main causes of abortion in cattle, and recent studies have highlighted its relevance as an abortifacient in small ruminants. Vaccines or drugs for the control of neosporosis are lacking. Bumped kinase inhibitors (BKIs), which are ATP-competitive inhibitors of calcium dependent protein kinase 1 (CDPK1), were shown to be highly efficacious against several apicomplexan parasites in vitro and in laboratory animal models.

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Improvements have been made to the safety and efficacy of bumped kinase inhibitors, and they are advancing toward human and animal use for treatment of cryptosporidiosis. As the understanding of bumped kinase inhibitor pharmacodynamics for cryptosporidiosis therapy has increased, it has become clear that better compounds for efficacy do not necessarily require substantial systemic exposure. We now have a bumped kinase inhibitor with reduced systemic exposure, acceptable safety parameters, and efficacy in both the mouse and newborn calf models of cryptosporidiosis.

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