ABSTRACT
PI3Kδ plays a critical role in adaptive immune cell activation and function. Suppression of PI3Kδ has been shown to counter excessive triggering of immune responses which has led to delineating the role of this isoform in the pathophysiology of autoimmune disorders. In the current study, we have described preclinical characterization of PI3Kδ specific inhibitor LL-00071210 in various rheumatoid arthritis models. LL-00071210 displayed excellent in vitro potency in biochemical and cellular assay against PI3Kδ with IC50 values of 24.6 nM and 9.4 nM, respectively. LL-00071210 showed higher selectivity over PI3Kγ and PI3Kß as compared to available PI3K inhibitors. LL-00071210 had good stability in liver microsomes and plasma across species and showed low clearance, low-to-moderate Vss, with bioavailability of >50% in preclinical species. LL-00071210 demonstrated excellent in vivo efficacy in adjuvant-induced and collagen-induced arthritis models. Co-administration of LL-00071210 and methotrexate at subtherapeutic dose regimen in collagen induced arthritis model led to additive effects, indicating the combination potential of LL-00071210 along with available disease modifying anti-rheumatic drugs (DMARD). In conclusion, we have described a specific PI3Kδ inhibitor with â¼100-fold selectivity over other PI3K isoforms. LL-00071210 has good drug-like properties and thus warrants testing in the clinic for the treatment of autoimmune diseases.
Subject(s)
Arthritis, Rheumatoid , Phosphatidylinositol 3-Kinases , Arthritis, Rheumatoid/drug therapy , Humans , Phosphatidylinositol 3-Kinases/metabolism , Phosphoinositide-3 Kinase Inhibitors , Structure-Activity RelationshipABSTRACT
The role of calcium release-activated calcium (CRAC) channels is well characterized and is of particular importance in T-cell function. CRAC channels are involved in the pathogenesis of several autoimmune diseases, making it an attractive therapeutic target for treating inflammatory diseases, like rheumatoid arthritis (RA). A systematic structure-activity relationship study with the goal of optimizing lipophilicity successfully yielded two lead compounds, 36 and 37. Both compounds showed decent potency and selectivity and a remarkable pharmacokinetic profile. Further characterization in in vivo RA models and subsequent histopathological evaluation of tissues led to the identification of 36 as a clinical candidate. Compound 36 displayed an excellent safety profile and had a sufficient safety margin to qualify it for use in human testing. Oral administration of 36 in Phase 1 clinical study in healthy volunteers established favorable safety, tolerability, and good target engagement as measured by levels of IL-2 and TNF-α.
Subject(s)
Calcium Channel Blockers/pharmacology , Calcium Release Activated Calcium Channels/antagonists & inhibitors , Calcium/metabolism , Drug Discovery , Administration, Oral , Animals , Area Under Curve , Arthritis, Rheumatoid/drug therapy , Calcium Channel Blockers/pharmacokinetics , Clinical Trials, Phase I as Topic , Humans , Jurkat Cells , Male , Mice , Mice, Inbred BALB C , Rats , Rats, Inbred Lew , Structure-Activity RelationshipABSTRACT
A purified Arabinogalactan-Protein composition (LL-4218) was prepared from the leaves of Argemone mexicana to treat psoriasis. The effect of (LL-4218) was evaluated on reproductive (male and female fertility) and developmental toxicity in rats. LL-4218 was administered orally at the doses of 250, 500 and 1000 mg kg(-1). The results showed that LL-4218 did not produce any significant dose related changes in reproductive and developmental toxicity studies. Therefore, it is concluded that LL-4218 did not produce any significant toxic effect on reproduction and developmental parameters of rats and NOAEL for reproductive and developmental toxicity studies in rats was 1000 mg kg(-1).
Subject(s)
Argemone/chemistry , Fertility/drug effects , Fetal Development/drug effects , Galactans/toxicity , Plant Extracts/toxicity , Plant Proteins/toxicity , Animals , Female , Galactans/isolation & purification , Male , Plant Extracts/chemistry , Plant Proteins/isolation & purification , Pregnancy , Rats , Rats, WistarABSTRACT
Desoris (LLL 3348), a lyophilized aqueous extract prepared from the leaves of Argemone mexicana to treat chronic stable plaque-type psoriasis, was evaluated for reproductive (male and female fertility) and developmental toxicity in rats. Lrrp: Wistar rats were administered orally with LLL 3348 at dose levels of 0 (distilled water), 250, 500, and 1000 mg/kg b.wt, and the effects on reproductive parameters were assessed. Sperm parameters (motility, epididymal sperm concentration, testicular sperm head count, and sperm morphology), organ weight, and histology of the male reproductive system were evaluated in the male fertility study. Estrus cyclicity, corpora lutea, implantation sites, litter size at birth, fetal growth, development parameters up to weaning, and organ weight and histology of male and female reproductive systems were assessed in the female fertility study. There were no overt signs of toxicity noted in male and female reproduction parameters in rats up to 1000 mg/kg of LLL 3348 administration. There were no alterations in the male reproductive organ/system, sperm parameters, male and female fertility indices, embryonic development, and pre-wean developmental landmarks of pups. No gross and histological changes were observed in these studies. In a develop mental toxicity study, the test article was administered to pregnant females during gestation (5-19 days) and the fetuses were examined for external, visceral, and skeletal abnormalities. No toxic manifestation was revealed on caesarian section parameters, and no fetus anomalies/abnormalities were found. Therefore, it is concluded that LLL 3348 at the given dose did not produce any significant toxic effect in rats. The No Observed Adverse Effect Level (NOAEL) for male fertility, female fertility, and developmental toxicity studies was established as 1000 mg/kg in rats.
