In vitrometabolism andin vivopharmacokinetics of quinoline 3-carboxamide derivatives in various species

Transcriptomic Impact of IMA-08401, a Novel AHR Agonist Resembling Laquinimod, on Rat Liver

IMA-08401 (C2) is a novel aryl hydrocarbon receptor (AHR) agonist and selective AHR modulator (SAHRM) that is structurally similar to laquinimod (LAQ). Both compounds are converted to the AHR-active metabolite DELAQ (IMA-06201) in vivo. SAHRMs have been proposed as therapeutic options for various autoimmune disorders. Clinical trials on LAQ have not reported any significant toxic outcomes and C2 has shown low toxicity in rats; however, their functional resemblance to the highly toxic AHR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) raises questions. Here, we characterize the hepatic transcriptomic changes induced by acute (single-dose) and subacute exposure (repeated dosing for 5 days followed by a 5-day recovery period) to C2 in Sprague-Dawley rats. Exposure to C2 leads to activation of the AHR, as shown by altered transcription of Cyp1a1. We identify a heightened response early after exposure that drops off by day 10. Acute exposure to C2 leads to changes to transcription of genes involved in antiviral and antibacterial responses, which highlights the immunomodulator effects of this AHR agonist. Subacute exposure causes an oxidative stress response in the liver, the consequences of which require further study on target tissues such as the CNS and immune system, both of which may be compromised in this patient population.

Laquinimod, a once-daily oral drug in development for the treatment of relapsing-remitting multiple sclerosis

Laquinimod is a novel, small, orally administered medication that has demonstrated efficacy in the treatment of multiple sclerosis, a chronic inflammatory demyelinating disease of the CNS. In preclinical testing, laquinimod inhibited the development of both acute and chronic paralysis in the multiple sclerosis model, experimental autoimmune encephalomyelitis. Furthermore, laquinimod reduced inflammation, demyelination and axonal damage in experimental autoimmune encephalomyelitis in mice treated at disease induction or at clinical disease onset. Recent findings from the clinical trials indicate that laquinimod has significant effects in reducing relapse rate and has more pronounced effects in reducing sustained disability progression as well as brain atrophy, with a good safety profile. In conclusion, preclinical studies show that laquinimod's unique mechanisms of action, including its immunomodulatory and CNS-protective effects, translate into clinical benefits in relapsing-remitting multiple sclerosis patients.

Development of laquinimod for relapsing–remitting multiple sclerosis

Laquinimod, a quinoline-3-carboxamide derivative, is a new, once-daily oral immunomodulatory therapy in development for the treatment of relapsing–remitting multiple sclerosis (MS). It has demonstrated efficacy in both acute and chronic experimental allergic encephalitis and in animal models of other inflammatory autoimmune diseases. It appears to act, in part, by shifting the immune response from a Th1 to a Th2 response and does not act through nonspecific immunosuppression. In Phase II studies in relapsing forms of MS, laquinimod brought about a 60% decrease in the cumulative number of gadolinium-enhancing lesions and a 33% decrease in relapse rates. In Phase II studies it was safe and well-tolerated. The most common laboratory abnormalities were a transient rise in alanine aminotransferase and C-reactive protein that returned to normal values despite continued therapy. There was no evidence of a proinflammatory effect. Phase III clinical trials for registration are in progress. Laquinimod may find use as a first-line agent in the treatment of relapsing forms of MS.

Inhibition of the development of chronic experimental autoimmune encephalomyelitis by laquinimod (ABR-215062) in IFN-beta k.o. and wild type mice

Laquinimod is a novel oral immunomodulatory substance, which is currently developed for the treatment of multiple sclerosis (MS). The ability of laquinimod to inhibit disease development was investigated in chronic experimental autoimmune encephalomyelitis (chEAE) in IFN-beta k.o. mice and wild type mice. Laquinimod was shown to inhibit both disease development and histopathological changes in the CNS. Furthermore, laquinimod was found to be independent of endogenous IFN-beta for its effect in chEAE. When laquinimod was combined with exogenous IFN-beta, a synergistic disease inhibitory effect was seen. These findings using laquinimod in preclinical disease models for MS emphasize the potential of laquinimod in the future treatment of MS also in patients that do not respond to IFN-beta monotherapy. Furthermore, the results indicate that laquinimod may favourably be combined with IFN-beta.