Ripasudil as a Potential Therapeutic Agent in Treating Secondary Glaucoma in HTLV-1-Uveitis: An In Vitro Analysis.

Human T-cell leukemia virus type 1 (HTLV-1), a virus that affects 5-10 million people globally, causes several diseases, including adult T-cell leukemia-lymphoma and HTLV-1-associated uveitis (HU). HU is prevalent in Japan and often leads to secondary glaucoma, which is a serious complication. We investigated the efficacy of ripasudil, a Rho-associated coiled coil-forming protein kinase inhibitor, in alleviating changes in human trabecular meshwork cells (hTM cells) infected with HTLV-1. HTLV-1-infected hTM cells were modeled in vitro using MT-2 cells, followed by treatment with varying concentrations of ripasudil. We assessed changes in cell morphology, viability, and inflammatory cytokine levels, as well as NF-κB activation. The results showed that ripasudil treatment changed the cell morphology, reduced the distribution of F-actin and fibronectin, and decreased the levels of certain inflammatory cytokines, such as interleukin (IL)-6, IL-8, and IL-12. However, ripasudil did not significantly affect NF-κB activation or overall cell viability. These findings suggest that ripasudil has the potential to treat secondary glaucoma in patients with HU by modulating cytoskeletal organization and alleviating inflammation in HTLV-1-infected hTM cells. This study lays the foundation for further clinical studies exploring the effectiveness of ripasudil for the treatment of secondary glaucoma associated with HU.

Brigatinib in Japanese patients with ALK-positive non-small-cell lung cancer: Final results of the phase 2 J-ALTA trial.

The phase 2, single-arm, multicenter, open-label J-ALTA study evaluated the efficacy and safety of brigatinib in Japanese patients with advanced ALK+ non-small-cell lung cancer (NSCLC). One expansion cohort of J-ALTA enrolled patients previously treated with ALK tyrosine kinase inhibitors (TKIs); the main cohort included patients with prior alectinib ± crizotinib. The second expansion cohort enrolled patients with TKI-naive ALK+ NSCLC. All patients received brigatinib 180 mg once daily (7-day lead-in at 90 mg daily). Among 47 patients in the main cohort, 5 (11%) remained on brigatinib at the study end (median follow-up: 23 months). In this cohort, the independent review committee (IRC)-assessed objective response rate (ORR) was 34% (95% CI, 21%-49%); median duration of response was 14.8 months (95% CI, 5.5-19.4); median IRC-assessed progression-free survival (PFS) was 7.3 months (95% CI, 3.7-12.9). Among 32 patients in the TKI-naive cohort, 25 (78%) remained on brigatinib (median follow-up: 22 months); 2-year IRC-assessed PFS was 73% (90% CI, 55%-85%); IRC-assessed ORR was 97% (95% CI, 84%-100%); the median duration of response was not reached (95% CI, 19.4-not reached); 2-year duration of response was 70%. Grade ≥3 adverse events occurred in 68% and 91% of TKI-pretreated and TKI-naive patients, respectively. Exploratory analyses of baseline circulating tumor DNA in ALK TKI-pretreated NSCLC showed associations between poor PFS and EML4-ALK fusion variant 3 and TP53. Brigatinib is an important treatment option for Japanese patients with ALK+ NSCLC, including patients previously treated with alectinib.

Bioluminescent immunoassay for serine/threonine protein kinase activity using an aequorin-labeled monoclonal antibody and a synthetic peptide as a substrate.

A bioluminescent immunoassay system was developed to determine serine/threonine protein kinase activity using an aequorin-labeled monoclonal antibody and a synthetic peptide as the substrate. A monoclonal antibody against the synthetic phosphorylated serine peptide (K9P peptide) of histone H3 (19 amino acid residues), referred to as the H3S10P antibody, was chemically conjugated to maleimide-activated aequorin to prepare aequorin-labeled H3S10P (AQ-S-H3S10P). For the serine/threonine kinase assay, a non-phosphorylated serine peptide (K9C peptide) coated on a microplate was incubated with serine/threonine protein kinase in the presence of ATP and Mg2+. The resulting phosphorylated K9C peptides (K9P peptide) were identified using AQ-S-H3S10P. Thus, after the removal of unbound AQ-S-H3S10P though washing, the serine/threonine kinase activity was determined by the luminescence activity of aequorin from AQ-S-H3S10P bound to the K9P peptide. This assay system, in combination with the K9C peptide and AQ-S-H3S10P, could be used to screen inhibitors of various serine/threonine protein kinases in general.

Edmond Fischer's kinase legacy: History of the protein kinase inhibitor and protein kinase A.

Although Fischer's extraordinary career came to focus mostly on the protein phosphatases, after his co-discovery of Phosphorylase Kinase with Ed Krebs he was clearly intrigued not only by cAMP-dependent protein kinase (PKA), but also by the heat-stable, high-affinity protein kinase inhibitor (PKI). PKI is an intrinsically disordered protein that contains at its N-terminus a pseudo-substrate motif that binds synergistically and with high-affinity to the PKA catalytic (C) subunit. The sequencing and characterization of this inhibitor peptide (IP20) were validated by the structure of the PKA C-subunit solved first as a binary complex with IP20 and then as a ternary complex with ATP and two magnesium ions. A second motif, nuclear export signal (NES), was later discovered in PKI. Both motifs correspond to amphipathic helices that convey high-affinity binding. The dynamic features of full-length PKI, recently captured by NMR, confirmed that the IP20 motif becomes dynamically and sequentially ordered only in the presence of the C-subunit. The type I PKA regulatory (R) subunits also contain a pseudo-substrate ATPMg2-dependent high-affinity inhibitor sequence. PKI and PKA, especially the Cß subunit, are highly expressed in the brain, and PKI expression is also cell cycle-dependent. In addition, PKI is now linked to several cancers. The full biological importance of PKI and PKA signaling in the brain, and their importance in cancer thus remains to be elucidated.

Properties of FDA-approved small molecule protein kinase inhibitors: A 2023 update.

Owing to the dysregulation of protein kinase activity in many diseases including cancer, this enzyme family has become one of the most important drug targets in the 21st century. There are 72 FDA-approved therapeutic agents that target about two dozen different protein kinases and three of these drugs were approved in 2022. Of the approved drugs, twelve target protein-serine/threonine protein kinases, four are directed against dual specificity protein kinases (MEK1/2), sixteen block nonreceptor protein-tyrosine kinases, and 40 target receptor protein-tyrosine kinases. The data indicate that 62 of these drugs are prescribed for the treatment of neoplasms (57 against solid tumors including breast, lung, and colon, ten against nonsolid tumors such as leukemia, and four against both solid and nonsolid tumors: acalabrutinib, ibrutinib, imatinib, and midostaurin). Four drugs (abrocitinib, baricitinib, tofacitinib, upadacitinib) are used for the treatment of inflammatory diseases (atopic dermatitis, psoriatic arthritis, rheumatoid arthritis, Crohn disease, and ulcerative colitis). Of the 72 approved drugs, eighteen are used in the treatment of multiple diseases. The following three drugs received FDA approval in 2022 for the treatment of these specified diseases: abrocitinib (atopic dermatitis), futibatinib (cholangiocarcinomas), pacritinib (myelofibrosis). All of the FDA-approved drugs are orally effective with the exception of netarsudil, temsirolimus, and trilaciclib. This review summarizes the physicochemical properties of all 72 FDA-approved small molecule protein kinase inhibitors including lipophilic efficiency and ligand efficiency.

Deucravacitinib is an allosteric TYK2 protein kinase inhibitor FDA-approved for the treatment of psoriasis.

Psoriasis is a heterogeneous, inflammatory, autoimmune skin disease that affects up to 2% of the world's population. There are many treatment modalities including topical medicines, ultraviolet light therapy, monoclonal antibodies, and several oral medications. Cytokines play a central role in the pathogenesis of this disorder including TNF-α, (tumor necrosis factor-α) IL-17A (interleukin-17A), IL-17F, IL-22, and IL-23. Cytokine signaling involves transduction mediated by the JAK-STAT pathway. There are four JAKS (JAK1/2/3 and TYK2) and six STATS (signal transducer and activators of transcription). Janus kinases contain an inactive JH2 domain that is aminoterminal to the active JH1 domain. Under basal conditions, the JH2 domain inhibits the activity of the JH1 domain. Deucravacitinib is an orally effective N-trideuteromethyl-pyridazine derivative that targets and stabilizes the TYK2 JH2 domain and thereby blocks TYK2 JH1 activity. Seven other JAK inhibitors, which target the JAK family JH1 domain, are prescribed for the treatment of neoplastic and other inflammatory diseases. The use of deuterium in the trimethylamide decreases the rate of demethylation and slows the production of a metabolite that is active against a variety of targets in addition to TYK2. A second unique aspect in the development of deucravacitinib is the targeting of a pseudokinase domain. Deucravacitinib is rather specific for TYK2 and its toxic effects are much less than those of the other FDA-approved JAK inhibitors. The successful development of deucravacitinib may stimulate the development of additional pseudokinase ligands for the JAK family and for other kinase families as well.

Incidence of heart failure following exposure to a protein kinase inhibitor, a French population-based study.

AIMS: Pharmacovigilance signals of heart failure (HF) following exposure to protein kinase inhibitors (PKIs) have been detected in recent years. Our aim was to identify the PKIs most frequently associated with the development of HF. METHODS: Using the French National Healthcare Database, all patients newly exposed to a PKI between January 2011 and June 2014 were followed up for 18 months. Specific hospitalization diagnosis and long-term HF-related disease codes were used to identify HF patients. HF incidence rate ratios (IRRs) were measured and adjusted hazard ratios (aHRs) were estimated using a Cox model. Sensitivity analyses were performed to limit the potential indication and competitive risk bias. RESULTS: Thirteen PKIs were studied. Among the 49 714 new PKI users registered during the study period, the mean IRR of HF was 3.38 per 100 person-years, with a median time to onset of 155 days. We found a significant increase in the incidence of HF for six medicinal products: pazopanib (aHR = 2.42, 95% confidence interval [CI] 1.67-3.52), dasatinib (aHR = 2.22, 95% CI 1.42-3.44), ruxolitinib (aHR = 2.11, 95% CI 1.69-2.64), crizotinib (aHR = 1.71, 95% CI 1.07-2.72), everolimus (aHR = 1.45, 95% CI 1.26-1.67) and vemurafenib (aHR = 1.37, 95% CI 1.01-1.86). Sensitivity analyses were consistent with our primary analysis. CONCLUSIONS: The current study provides knowledge on HF following exposure to a PKI. Additional studies could confirm these results for dasatinib, everolimus, pazopanib and ruxolitinib, and particularly for the two medicinal products with results slightly above the significance threshold, namely, crizotinib and vemurafenib, in our sensitivity analyses.

Cabozantinib in Japanese patients with advanced hepatocellular carcinoma: Final results of a multicenter phase II study.

AIM: Cabozantinib showed a favorable benefit-risk profile in Japanese patients with advanced hepatocellular carcinoma (HCC) in an open-label, phase II study (NCT03586973). This analysis presents cumulative data to final database lock. METHODS: Patients with previously treated, advanced HCC received cabozantinib 60 mg/day. Progression-free survival (PFS) and tumor response rates in prior-sorafenib and sorafenib-naïve cohorts were assessed by independent radiology committee (IRC) and an investigator. Liver function was evaluated by albumin-bilirubin (ALBI) score. RESULTS: Median cabozantinib exposure was 5.6 months. In the prior-sorafenib cohort (n = 20), median PFS was 7.4 months per IRC assessment and 5.6 months per investigator assessment. In the sorafenib-naïve cohort (n = 14), median PFS was 3.6 and 4.4 months per IRC and investigator assessment, respectively. Six-month PFS rate per IRC and investigator assessment in the prior-sorafenib cohort was 59.8% and 49.5%, respectively, and in the sorafenib-naïve cohort was 16.7% and 35.7%, respectively. Disease control rate by both IRC and investigator assessment was 85.0% in the prior-sorafenib cohort and 64.3% in the sorafenib-naïve cohort. Median overall survival (Kaplan-Meier estimate) was 19.3 and 9.9 months in the prior-sorafenib and sorafenib-naïve cohort, respectively. Mean ALBI score remained relatively constant in patients able to continue treatment. The most frequent adverse events were palmar-plantar erythrodysesthesia syndrome, diarrhea, hypertension, and decreased appetite. No new safety concerns were identified. CONCLUSIONS: Cabozantinib showed efficacy and a manageable safety profile in Japanese patients with advanced HCC.

Novel 7-Deazapurine Incorporating Isatin Hybrid Compounds as Protein Kinase Inhibitors: Design, Synthesis, In Silico Studies, and Antiproliferative Evaluation.

Cancer is a multifactorial disorder with extremely complex genetics and progression. The major challenge in cancer therapy is the development of cancer resistance and relapse. Conventional anticancer drugs directly target the DNA of the cell, while modern chemotherapeutic drugs include molecular-targeted therapy, such as targeting the abnormal cell signaling inside the cancer cells. Targeted chemotherapy is effective in several malignancies; however, the success has always been limited by drug resistance and/or side effects. Anticancer with multi-targeted actions simultaneously modulates multiple cancer cell signaling pathways and, therefore, may ease the chance of effective anticancer drug development. In this research, a series of 7-deazapurine incorporating isatin hybrid compounds was designed and successfully synthesized. Among those hybrids, compound 5 demonstrated a very potent cytotoxic effect compared to the reference anticancer drug against four cancer cell lines. Likewise, compound 5 inhibited the activity of four protein kinase enzymes in nanomolar ranges. Further analysis of the biological evaluation of compound 5 revealed the capability of compound 5 to arrest cell cycle progression and induce programmed cell death. Moreover, molecular simulation studies were performed to investigate the possible types of interactions between compound 5 and the investigated protein kinases. Finally, taking into consideration all the abovementioned findings, compound 5 could be a good candidate for further investigations.

Quinazolinones, the Winning Horse in Drug Discovery.

Quinazolines are nitrogen-containing heterocycles that consist of a benzene ring fused with a pyrimidine ring. Quinazolinones, oxidized quinazolines, are promising compounds with a wide range of biological activities. In the pharmaceutical field, quinazolinones are the building blocks of more than 150 naturally occurring alkaloids isolated from different plants, microorganisms, and animals. Scientists give a continuous interest in this moiety due to their stability and relatively easy methods for preparation. Their lipophilicity is another reason for this interest as it helps quinazolinones in penetration through the blood-brain barrier which makes them suitable for targeting different central nervous system diseases. Various modifications to the substitutions around the quinazolinone system changed their biological activity significantly due to changes in their physicochemical properties. Structure-activity relationship (SAR) studies of quinazolinone revealed that positions 2, 6, and 8 of the ring systems are significant for different pharmacological activities. In addition, it has been suggested that the addition of different heterocyclic moieties at position 3 could increase activity. In this review, we will highlight the chemical properties of quinazolinones, including their chemical reactions and different methods for their preparation. Moreover, we will try to modify some of the old SAR studies according to their updated biological activities in the last twelve years.

Design, synthesis, antitumor evaluation, and molecular docking of novel pyrrolo[2,3-d]pyrimidine as multi-kinase inhibitors.

In the last twenty years, protein kinases have been identified as important targets for cancer therapy. In order to prevent unexpected toxicity, medicinal chemists have always focused on discovering selective protein kinase inhibitors. However, cancer is a multifactorial process and its formation and progression depend on different stimuli. Therefore, it is imperative to develop anticancer therapy that targets multiple kinases associated cancer progression. In this research a series of hybrid compounds was designed and synthesized successfully with the aim of producing anticancer activity through the induction of multiple protein kinase inhibition. The designed derivatives comprise isatin and pyrrolo[2,3-d]pyrimidine scaffolds in their structures with a hydrazine linking the two pharmacophores. Antiproliferative and kinase inhibition assays revealed promising anticancer and multi-kinase inhibitory effects of compound 7 with comparable results with the reference standards. Moreover, compound 7 suppressed cell cycle progression and induced apoptosis in HepG2 cells. Finally, molecular docking simulation was performed to investigate the potential types of interactions between the protein kinase enzymes and the designed hybrid compounds. The results of this research indicated the promising anticancer effect of compound 7 through the inhibition of a number of protein kinase receptors and the suppression of cell cycle and the induction of apoptosis.

Antitumor activity of the protein kinase inhibitor 1-(ß-D-2'-deoxyribofuranosyl)-4,5,6,7-tetrabromo- 1H-benzimidazole in breast cancer cell lines.

BACKGROUND: The protein kinases CK2 and PIM-1 are involved in cell proliferation and survival, the cell cycle, and drug resistance, and they are found overexpressed in virtually all types of human cancer, including breast cancer. In this study, we investigated the antitumor activity of a deoxynucleoside derivative, the protein kinase inhibitor compound 1-(ß-D-2'-deoxyribofuranosyl)-4,5,6,7-tetrabromo-1H-benzimidazole (K164, also termed TDB), inter alia CK2 and PIM-1, on breast cancer cell lines (MDA-MB-231, MCF-7, and SK-BR-3). METHODS: An evaluation of the cytotoxic and proapoptotic effects, mitochondrial membrane potential (ΔΨm), and cell cycle progression was performed using an MTT assay, flow cytometry, and microscopic analysis. The Western blotting method was used to analyze the level of proteins important for the survival of breast cancer cells and proteins phosphorylated by the CK2 and PIM-1 kinases. RESULTS: The examined compound demonstrated the inhibition of cell viability in all the tested cell lines and apoptotic activity, especially in the MCF-7 and SK-BR-3 cells. Changes in the mitochondrial membrane potential (ΔΨm), cell cycle progression, and the level of the proteins studied were also observed. CONCLUSIONS: The investigated CK2 and PIM-1 kinase inhibitor K164 is a promising compound that can be considered a potential agent in targeted therapy in selected types of breast cancer; therefore, further research is necessary.

Properties of FDA-approved small molecule protein kinase inhibitors: A 2022 update.

Owing to the dysregulation of protein kinase activity in many diseases including cancer, this enzyme family has become one of the most important drug targets in the 21st century. There are 68 FDA-approved therapeutic agents that target about two dozen different protein kinases and six of these drugs were approved in 2021. Of the approved drugs, twelve target protein-serine/threonine protein kinases, four are directed against dual specificity protein kinases (MEK1/2), thirteen block nonreceptor protein-tyrosine kinases, and 39 target receptor protein-tyrosine kinases. The data indicate that 58 of these drugs are prescribed for the treatment of neoplasms (49 against solid tumors including breast, lung, and colon, five against nonsolid tumors such as leukemias, and four against both solid and nonsolid tumors: acalabrutinib, ibrutinib, imatinib, and midostaurin). Three drugs (baricitinib, tofacitinib, upadacitinib) are used for the treatment of inflammatory diseases including rheumatoid arthritis. Of the 68 approved drugs, eighteen are used in the treatment of multiple diseases. The following six drugs received FDA approval in 2021 for the treatment of these specified diseases: belumosudil (graft vs. host disease), infigratinib (cholangiocarcinomas), mobocertinib and tepotinib (specific forms of non-small cell lung cancer), tivozanib (renal cell carcinoma), and trilaciclib (to decrease chemotherapy-induced myelosuppression). All of the FDA-approved drugs are orally effective with the exception of netarsudil, temsirolimus, and the newly approved trilaciclib. This review summarizes the physicochemical properties of all 68 FDA-approved small molecule protein kinase inhibitors including lipophilic efficiency and ligand efficiency.

Targeting BCR-Abl in the treatment of Philadelphia-chromosome positive chronic myelogenous leukemia.

Chronic myelogenous leukemia (CML) is an indolent malignant hematological disease that accounts for about 15% of all cases of leukemia. This disorder results from the formation of the Philadelphia chromosome that involves a reciprocal translocation that produces a lengthened chromosome 9 and shortened chromosome 22 - the Philadelphia chromosome. As a consequence of the translocation, the dysregulated BCR-Abl fusion oncoprotein is formed and it produces the abnormal proliferation of white blood cells. The treatment of CML with imatinib revolutionized the treatment of this disorder and led to the discovery and development of dozens of effective targeted protein kinase inhibitors. Imatinib (first generation), dasatinib, nilotinib, and bosutinib (second generation) have been FDA-approved for frontline therapy, and ponatinib (third generation) is approved for resistant disease with a T315I mutation. Each of these drugs is orally bioavailable. The BCR-Abl fusion protein lacks the physiological N-terminal myristoyl group that binds to a hydrophobic pocket in the large protein kinase lobe and inhibits enzyme activity. The absence of the myristoyl group leads to enhanced protein kinase catalytic activity. Asciminib was designed to bind to this binding pocket to reduce Abl kinase activity. Asciminib is orally effective and was FDA-approved as a third-line treatment for CML and a first-line treatment in patients with the T315I mutation. It blocks the activity of BCR-Abl by interacting with the myristate-binding site located 23 Å from the ATP-binding site and is the prototype of a type IV inhibitor. Asciminib is a so-called STAMP inhibitor that Specifically Targets the Abl Myristoyl Pocket.

Tofacitinib Appears Well Tolerated and Effective for the Treatment of Patients with Refractory Crohn's Disease.

BACKGROUND: Active Crohn's disease increases the risk of strictures, fistulas, and abscesses. Less than 30% of patients with Crohn's disease achieve endoscopic remission on any therapy. Tofacitinib may be a therapeutic option for patients with refractory Crohn's disease. AIMS: We aimed to evaluate the safety and effectiveness of off-label tofacitinib for refractory Crohn's disease. METHODS: We retrospectively assessed adverse events and clinical/endoscopic response after therapy. RESULTS: Forty-four patients were included in the safety analysis and 35 were included in the clinical and/or endoscopic assessments. The mean age was 41.8 years and the mean disease duration was 17.4 years. All patients had prior biologic exposure. Adverse events were reported in 52.3% of patients; 13.6% had ≥ 1 serious adverse event after a median 54.6 weeks of treatment. Seventy percent achieved clinical response after a mean 29.4 (SD 15.1) weeks, and 33.3% achieved clinical remission after a mean 33.4 (SD 17.6) weeks of therapy. Endoscopic improvement occurred in 25.0%, endoscopic remission in 12.5%, and endoscopic healing in 4.2% of patients after a mean 52.0 (SD 15.0) weeks of therapy. The mean Simple Endoscopic Score in Crohn's disease significantly improved from 23.1 ± 3.7 to 18.0 ± 13.7 after treatment (P = .02). CONCLUSIONS: In the short term, tofacitinib appears well tolerated. The most common adverse event was minor infection. One serious infection and one colorectal cancer occurred. While half of patients reported adverse events, this likely reflects the severe refractory disease in this population and no new safety events were observed. Tofacitinib achieved clinical and endoscopic improvement in some patients with refractory Crohn's disease. Further research is needed to understand the long-term safety and efficacy of tofacitinib in Crohn's disease.

Effect of the rho-kinase inhibitor ripasudil in needling with mitomycin C for the failure of filtering bleb after trabeculectomy: a cross-sectional study.

BACKGROUND: Rho-kinase inhibitors can inhibit fibrosis after glaucoma surgery. This study aimed to evaluate the effect of rho-kinase inhibitor after needling procedure with mitomycin C for the failure of filtering bleb with trabeculectomy. METHODS: This retrospective single-center study examined the effects of rho-kinase inhibitor after the needling procedure. We included 27 eyes of 27 patients with glaucoma who underwent needling procedure using mitomycin C and were subsequently treated with ripasudil-a rho-associated protein kinase inhibitor (ripasudil group)-or without ripasudil (control group). The ripasudil and control groups were compared in terms of intraocular pressure (IOP) and the number of antiglaucoma medications. Success at 12 months after the needling procedure was defined as a > 20% decrease in IOP from the preoperative period without surgical reintervention. RESULTS: At 12 months after the needling procedure, the mean IOP decreased from 16.9 ± 4.5 to 12.6 ± 1.1 mmHg in the control group and from 16.0 ± 5.3 to 12.2 ± 1.2 mmHg in the ripasudil group (p = 0.77). The 12-month success rates were 60.00% and 56.25% in the control and ripasudil groups (p = 0.98), respectively. In the preoperative period, the numbers of antiglaucoma drugs were 0.27 ± 0.46 and 0.92 ± 0.91 in the control and ripasudil groups (p = 0.022), respectively, and at 12 months after the needling procedure, they were 1.07 ± 1.44 and 0.73 ± 1.10 (p = 0.52), respectively. CONCLUSIONS: Treatment with ripasudil (a rho-associated protein kinase inhibitor) after the needling procedure with mitomycin C did not show better results than treatment with the mitomycin C needling procedure alone at 12 months after the procedure.

Protein Kinase Inhibitors as a New Target for Immune System Modulation and Brain Cancer Management.

High-grade brain tumors are malignant tumors with poor survival and remain the most difficult tumors to treat. An important contributing factor to the development and progression of brain tumors is their ability to evade the immune system. Several immunotherapeutic strategies including vaccines and checkpoint inhibitors have been studied to improve the effectiveness of the immune system in destroying cancer cells. Recent studies have shown that kinase inhibitors, capable of inhibiting signal transduction cascades that affect cell proliferation, migration, and angiogenesis, have additional immunological effects. In this review, we explain the beneficial therapeutic effects of novel small-molecule kinase inhibitors and explore how, through different mechanisms, they increase the protective antitumor immune response in high-grade brain tumors.

Five-Year Follow-up of First 11 Patients Undergoing Injection of Cultured Corneal Endothelial Cells for Corneal Endothelial Failure.

PURPOSE: To report the safety and efficacy of a novel cell injection therapy using cultured human corneal endothelial cells (hCECs) for endothelial failure conditions via the report of the long-term 5-year postoperative clinical data from a first-in-humans clinical trial group. DESIGN: Prospective observational study. PARTICIPANTS: This study involved 11 eyes of 11 patients with pseudophakic endothelial failure conditions who underwent hCEC injection therapy between December 2013 and December 2014. METHODS: All patients underwent follow-up examinations at 1 week, 4 weeks, 12 weeks, and 24 weeks and 1 year, 2 years, 3 years, 4 years, and 5 years after surgery. Specific corneal endothelial cell parameters (i.e., corneal endothelial cell density [ECD], coefficient of variation of area, and percentage of hexagonal cells) and central corneal thickness, best-corrected visual acuity (BCVA) on a Landolt C eye chart, and intraocular pressure (IOP) were recorded. MAIN OUTCOME MEASURES: The primary outcome was the change in central ECD after cell injection therapy, and the secondary outcome was corneal thickness, BCVA, and IOP during the 5-year-postoperative follow-up period. RESULTS: At 5 years after surgery, normal corneal endothelial function was restored in 10 of the 11 eyes, the mean ± standard deviation central corneal ECD was 1257 ± 467 cells/mm2 (range, 601-2067 cells/mm2), BCVA improved significantly in 10 treated eyes, the mean visual acuity changed from 0.876 logarithm of the minimum angle of resolution before surgery to 0.046 logarithm of the minimum angle of resolution after surgery, and no major adverse reactions directly related to the hCEC injection therapy were observed. CONCLUSIONS: The findings in this study confirmed the safety and efficacy of cultured hCEC injection therapy for up to 5 years after surgery.

Hydrophobic and polar interactions of FDA-approved small molecule protein kinase inhibitors with their target enzymes.

Dysregulation and mutations of protein kinases play causal roles in many diseases including cancer. The KLIFS (kinase-ligand interaction fingerprint and structure) catalog includes 85 ligand binding-site residues occurring in both the small and large protein kinase lobes. Except for allosteric inhibitors, all FDA-approved drug-target enzyme complexes display hydrophobic interactions involving catalytic spine residue-6 (KLIFS-77), catalytic spine residue-7 (KLIFS-11), and catalytic spine residue-8 (KLIFS-15) within the small lobe and residues within the hinge-linker region (KLIFS-46-52). Except for allosteric antagonists, the approved drugs form hydrogen bonds with the third hinge residue (KLIFS-48) of their target. Most of the approved drugs, including the allosteric inhibitors, interact with the small lobe gatekeeper residue (KLIFS-45). The type IIA inhibitors have the most hydrophobic interactions with their target enzymes. These include interactions with KLIFS-27/31/35/61/66 residues of the back pocket within both the small and large lobes. There is also interaction with KLIFS-68 (regulatory spine residue-1), the conserved histidine of the catalytic loop that is found in the back pocket of type II antagonists, but within the front pocket of the other types of inhibitors. Owing to the participation of protein kinase signaling cascades in a wide variety of physiological and pathological processes, one can foresee the increasing use of targeted inhibitors both as primary and secondary treatments for many illnesses. Further studies of protein kinase signal transduction pathways promise to yield new and actionable information that will serve as a basis for fundamental and applied biomedical breakthroughs.

Properties of FDA-approved small molecule protein kinase inhibitors: A 2021 update.

Owing to the dysregulation of protein kinase activity in many diseases including cancer, the protein kinase enzyme family has become one of the most important drug targets in the 21st century. There are 62 FDA-approved therapeutic agents that target about two dozen different protein kinases and eight of these were approved in 2020. All of the FDA-approved drugs are orally effective with the exception of netarsudil (a ROCK1/2 non-receptor protein-serine/threonine kinase antagonist given as an eye drop for the treatment of glaucoma) and temsirolimus (an indirect mTOR inhibitor given intravenously for the treatment of renal cell carcinoma). Of the approved drugs, ten target protein-serine/threonine protein kinases, four are directed against dual specificity protein kinases (MEK1/2), thirteen block non-receptor protein-tyrosine kinases, and 35 target receptor protein-tyrosine kinases. The data indicate that 55 of these drugs are prescribed for the treatment of neoplasms (52 against solid tumors including breast, lung, and colon, nine against non-solid tumors such as leukemias, and four against both solid and non-solid tumors: acalabrutinib, ibrutinib, imatinib, and midostaurin). A total of three drugs (baricitinib, tofacitinib, upadacitinib) is used for the treatment of inflammatory diseases including rheumatoid arthritis. Seven of the approved drugs form covalent bonds with their target enzymes and are classified as TCIs (targeted covalent inhibitors). Of the 62 approved drugs, eighteen are used in the treatment of multiple diseases. Imatinib, for example, is approved for the treatment of eight different disorders. The most common drug targets of the approved pharmaceuticals include BCR-Abl, B-Raf, vascular endothelial growth factor receptors (VEGFR), epidermal growth factor receptors (EGFR), and ALK. The following eight drugs received FDA approval in 2020 for the treatment of the specified diseases: avapritinib and ripretinib (gastrointestinal stromal tumors), capmatinib (non-small cell lung cancer), pemigatinib (cholangiocarcinoma), pralsetinib and selpercatinib (non-small cell lung cancer, medullary thyroid cancer, differentiated thyroid cancer), selumetinib (neurofibromatosis type I), and tucatinib (HER2-positive breast cancer). All of the eight drugs approved in 2020 fulfill Lipinski's rule of five criteria for an orally effective medicine (MW of 500 Da or less, five or fewer hydrogen bond donors, 10 or fewer hydrogen bond acceptors, calculated log10 of the partition coefficient of five or less) with the exception of three drugs with a molecular weight greater that 500 Da: pralsetinib (534), selpercatinib (526) and ripretinib (510). This review summarizes the physicochemical properties of all 62 FDA-approved small molecule protein kinase inhibitors.