lfm-a13 and Leukemia

The present study documents the chemosensitizing anti-leukemic activity of the leflunomide metabolite (LFM) analog, LFM-A13, a dual-function inhibitor of Bruton's tyrosine kinase (BTK) and Polo-like kinases (PLK), against human leukemic B-cell precursors. The results in 135 xenografted NOD/SCID mice regarding the anti-leukemic activity of GMP-grade LFM-A13, obtained with only 4-days of LFM-A13 therapy at nontoxic dose levels corresponding to 1-20% of its NOAEL (no observable advserse effect level), alone or in combination with the standard chemotherapy drug vincristine, demonstrate the potential of LFM-A13 as a new anti-leukemic drug candidate. All 82 LFM-A13-treated mice, including those receiving a combination of vincristine + LFM-A13 at the highest dose level of LFM-A13, tolerated their treatments well without weight loss, diarrhea, lethargy/ paralysis, other signs of morbidity, or mortality. The present study provides preclinical proof-of-principle for the development of LFM-A13 as a new chemosensitizing and apoptosis-promoting anti-leukemic agent and lends support to the hypothesis that the chemoresistance of relapsed B-cell precursor acute lymphoblastic leukemia (BCP-ALL) can be overcome by using LFM-A13 in combination with chemotherapy. Also presented are the results of a comprehensive meta-analysis of the overexpression of genes for LFM-A13 targeted kinases and their downstream effector molecules in B-lineage lymphoid malignancies utilizing the Oncomine database.

Topics: Adjuvants, Pharmaceutic; Agammaglobulinaemia Tyrosine Kinase; Amides; Animals; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Lineage; Drug Resistance, Neoplasm; Humans; Leukemia; Mice; Mice, Inbred NOD; Mice, SCID; Nitriles; Precursor Cells, B-Lymphoid; Protein Serine-Threonine Kinases; Protein-Tyrosine Kinases; Substrate Specificity

Targeting Bruton's tyrosine kinase (BTK) with a small molecule inhibitor may be useful in treatment of BTK-expressing malignancies because of the anti-apoptotic function of BTK in cancer cells. Furthermore, BTK inhibitors also exhibit anti-thrombotic properties that may be desirable in the context of the increased risk of thromboembolic complications in cancer patients. This review will focus on the role of BTK in drug resistance in cancer, thromboembolism, and various pathologic immune responses, such as graft versus host disease. The therapeutic potential of targeting BTK is illustrated by discussion of the biologic activity profile of the rationally designed BTK inhibitor LFM-A13.

Topics: Agammaglobulinaemia Tyrosine Kinase; Amides; Antineoplastic Agents; Apoptosis; Drug Design; Humans; Leukemia; Nitriles; Protein-Tyrosine Kinases; Thromboembolism

Topics: Adenocarcinoma; Amides; Aniline Compounds; Animals; Antineoplastic Agents; Breast Neoplasms; Drug Design; Enzyme Inhibitors; Epidermal Growth Factor; ErbB Receptors; Female; Genistein; Humans; Leukemia; Macaca fascicularis; Mice; Mice, Inbred BALB C; Mice, SCID; Models, Molecular; Molecular Structure; Neoplasm Proteins; Neoplasms; Nitriles; Protein Conformation; Protein Structure, Tertiary; Quinazolines; Recombinant Fusion Proteins; Sequence Alignment; Species Specificity; Structure-Activity Relationship; Tumor Cells, Cultured; Tumor Stem Cell Assay; Xenograft Model Antitumor Assays

The leflunomide (CAS 75706-12-6) metabolite (LFM) analog alpha-cyano-beta-hydroxy-beta-methyl-N-(2,5-dibromophenyl)-propenamide (LFM-A13, DDE-28, CAS 244240-24-2) is a rationally-designed specific inhibitor of the TEC family protein tyrosine kinase, Bruton's tyrosine kinase (BTK). LFM-A13 exhibited favorable pharmacokinetics in CD-1 mice, BALB/c mice, rats, and dogs. The intraperitoneal bioavailability was estimated to be -100%, while the oral bioavailability was -30%. LFM-A13 enters, but does not bind to multiple tissues followed by a rapid elimination from most of the tissues. Limited distribution of LFM-A13 to extravascular tissues and its corresponding low volume of distribution could be attributed to its plasma protein binding. LFM-A13 was not toxic to mice, rats, or dogs at daily dose levels as high as 100 mg/kg. LFM-A13 formulated as a suspension and hard gelatin capsules for oral administration showed a rapid absorption and favorable pharmacokinetic features. These preclinical research studies provide the basis for future pre-IND studies and clinicaldevelopment of LFM-A13 as an intravenously or orally administered new anti-leukemia agent targeting BTK.

Topics: Agammaglobulinaemia Tyrosine Kinase; Amides; Animals; Antineoplastic Agents; Capsules; Chromatography, High Pressure Liquid; Dogs; Excipients; Female; Gelatin; Injections, Intravenous; Intestinal Absorption; Leukemia; Male; Mice; Mice, Inbred BALB C; Nitriles; Protein-Tyrosine Kinases; Rats; Rats, Inbred Lew; Suspensions; Tissue Distribution

Here we report that treatment with the anti-leukemic compound, LFM-A13 resulted in SYK kinase activation and caused distinct shape changes in platelets. Also provided is electron microscopic evidence that similar shape changes are observed in platelets from XID mice. We propose that LFM-A13 induces a conformational change in the PH domain of BTK and causes BTK to associate with PIP2 which effects actin bundling and shape change.

Topics: Agammaglobulinaemia Tyrosine Kinase; Amides; Antineoplastic Agents; Enzyme Inhibitors; Enzyme Precursors; Fibrinolytic Agents; Humans; Intracellular Signaling Peptides and Proteins; Leukemia; Nitriles; Phosphorylation; Protein-Tyrosine Kinases; Syk Kinase