Atrasentan (ABT-627, A-127722) is a selective endothelin A receptor antagonist. Atrasentan is being developed by AbbVie as an oral treatment for diabetic nephropathies.Abbott Laboratories was conducting clinical development of atrasentan for the treatment of certain cancers, including phase II trials for prostate cancer. However, no recent development has been reported for cancer indications and development is presumed to be discontinued.

Burapitant (SSR-240,600) is a drug developed by Sanofi-Aventis which was one of the first compounds developed that acts as a potent and selective antagonist for the NK1 receptor. Burapitant inhibited the binding of radioactive substance P to tachykinin NK1 receptors in human lymphoblastic IM9 cells, human astrocytoma U373MG cells, and human brain cortex. It also showed a subnanomolar affinity for guinea pig NK1 receptors but was less potent on rat and gerbil NK1 receptors. Burapitant inhibited [Sar(9),Met(O2)(11)]substance P-induced inositol monophosphate formation in human astrocytoma U373MG cells. Burapitant (0.1-10 mg/kg i.p. or p.o.) antagonized the excitatory effect of i.c.v. infusion of [Sar(9),Met(O2)(11)]substance P (SP) on the release of acetylcholine in the striatum of anesthetized and awake guinea pigs. This antagonistic action was still observed after repeated administration of Burapitant (5 days, 10 mg/kg p.o., once a day). Burapitant (10 mg/kg i.p.) inhibited the phosphorylation of the cAMP response element-binding protein in various brain regions induced by i.c.v. administration of [Sar9,Met(O2)(11)]SP. While burapitant itself did not proceed beyond early clinical trials and was never developed for clinical use in humans, promising animal results from this and related compounds have led to a number of novel drugs from this class that has now been introduced into medical use.

Ulodesine (BCX4208) is a new, orally active, highly potent inhibitor of purine nucleoside phosphorylase (PNP) for the treatment of hyperuricemia and gout. Inhibition of PNP reduces the substrates available for XO to form uric acid. The drug is currently under development for the management of hyperuricemia in chronic gout. Two Phase II clinical trials have shown promising results regarding urate-lowering effect in both as monotherapy and in combination with allopurinol. Ulodesine shows no interaction with CYP450 isoforms and has no hepatic metabolism; therefore, no drug interactions were expected. Following the successful outcome of the Phase IIb clinical trial, Phase III development of ulodesine is planned. One concern regarding the use of ulodesine is its impact on T cells. Lack of PNP is associated with immunodeficiency and autoimmune disorders.

LAGOCICLOVIR is a nucleoside reverse transcriptase inhibitor with activity against human immunodeficiency virus and hepatitis B virus.

Vapendavir (BTA-798) is an orally active capsid-binding inhibitor. It is a potent, orally bioavailable, broad spectrum inhibitor of the large group of HRVs. Vapendavir binds tightly to VP1s canyon and disrupts the ability of the capsid to bind to a specific cell surface receptor. This further inhibits the release of the viral RNA into the cell cytoplasm during the viral uncoating process (removing the lipid bilayer), thereby disrupting viral replication. Vapendavir is designed to be dosed orally. Vapendavir is in phase II clinical trials for the treatment of rhinovirus-induced aggravation of pre-existing asthma or COPD. Vapendavir has shown significant results in proof-of-concept studies. Thus far, from the Phase 1/2 studies conducted, vapendavir has demonstrated a desirable clinical pharmacology profile with high bioavailability, linear pharmacokinetic profile, remained unaffected by concomitant medications, and was not exclusively metabolized.

Vidofludimus (SC12267; 4SC-101) is a novel oral immunomodulator inhibiting dihydroorotate dehydrogenase (DHODH) and the expression of proinflammatory cytokines including interleukin-17 (IL17A and IL17F) and interferon-gamma. This drug is in the clinical trial for the treatment of inflammatory bowel diseases and Rheumatoid arthritis.