Ponesimod is an experimental drug for the treatment of multiple sclerosis (MS) graft-versus-host disease and psoriasis. It acts on certain types of white blood cells (lymphocytes) which are involved in the autoimmune attack on myelin seen in multiple sclerosis (MS). Ponesimod is an orally active, reversible, and selective sphingosine-1-phosphate receptor (S1PR1) modulator. The drug is in phase II clinical trial for the treatment of graft-versus-host disease. In addition, the phase III clinical trial comparing ponesimod to teriflunomide in relapsing-remitting MS is ongoing.

Maribavir (previously known as 1263W94) is a novel benzimidazole riboside compound. This drug was in phase III of clinical trial for the prevention of cytomegalovirus (CMV) infections in transplant patients, sponsored by ViroPharma. However, drug failed to demonstrate a higher efficacy rate than the placebo. Maribavir has activity against cytomegalovirus and Epstein-Barr virus (EBV), but not against other human herpesviruses. Maribavir’s mechanism of action is unique and is complex compared to the currently approved antivirals for CMV. Maribavir inhibits the viral UL97 kinase rather than the viral DNA polymerase. The UL97 kinase is important for viral DNA elongation, DNA packaging, and nuclear egress of encapsidated viral DNA. In addition, maribavir inhibits the EBV DNA polymerase processivity factor (BMRF1), reduces the level of certain EBV glycoproteins, and inhibits viral transcription. However, future work will be designed to address the interaction of MBV and BGLF4 and to evaluate the mechanisms through which maribavir downregulates viral transcripts. BGLF4 belongs to the family of conserved herpesvirus PKs, which includes HCMV UL97, HSV UL13, and HSV US3. Maribavir does need to be phosphorylated for its activity.

A-4250 (odevixibat) is a selective inhibitor of the ileal bile acid transporter (IBAT) that acts locally in the gut. Ileum absorbs glyco-and taurine-conjugated forms of the bile salts. IBAT is the first step in absorption at the brush-border membrane. A-4250 works by decreasing the re-absorption of bile acids from the small intestine to the liver, whichreduces the toxic levels of bile acids during the progression of the disease. It exhibits therapeutic intervention by checking the transport of bile acids. Studies show that A-4250 has the potential to decrease the damage in the liver cells and the development of fibrosis/cirrhosis of the liver known to occur in progressive familial intrahepatic cholestasis. A-4250 is a designated orphan drug in the USA for October 2012. A-4250 is a designated orphan drug in the EU for October 2016. A-4250 was awarded PRIME status for PFIC by EMA in October 2016. A-4250 is in phase II clinical trials by Albireo for the treatment of primary biliary cirrhosis (PBC) and cholestatic pruritus. In an open label Phase 2 study in children with cholestatic liver disease and pruritus, odevixibat showed reductions in serum bile acids and pruritus in most patients and exhibited a favorable overall tolerability profile.

Estetrol is the natural human fetal selective estrogen receptor modulator. It is synthesized exclusively by the human fetal liver during pregnancy. Estetrol has a moderate affinity for human estrogen A receptor (ERa) and estrogen B receptor (ERb). Estetrol may be suitable as a potential drug for human use in applications such as hormone replacement therapy (vaginal atrophy, hot flushes), contraception and osteoporosis. The most common drug-related adverse events were lower abdominal pain, nausea, headache, dysmenorrhoea, breast enlargement and acne. Estetrol had been in clinical trials for the treatment of breast and prostate cancers.

Tivozanib (formerly AV-951, KRN-951) is a potent and selective VEGFR tyrosine kinase inhibitor and inhibits angiogenesis and vascular permeability in tumor tissues. It completed phase III a trial investigation for the treatment of renal cell carcinomas, but has not been still approved. In addition, this drug is in the phase II of clinical trial for the investigation it in patients with glioblastoma and colorectal carcinoma.

Avacopan (CCX-168) an orally administered selective and potent complement 5a receptor inhibitor. Avacopan blocked the C5a binding, C5a-mediated migration, calcium mobilization, and CD11b upregulation in U937 cells as well as in freshly isolated human neutrophils. Avacopan is being developed for inflammatory and autoimmune diseases.

Difelikefalin is an orally bioavailable second-generation peptide. It is an investigational peripheral kappa opioid receptor agonist. Difelikefalin significantly reduced moderate to severe chronic itching while achieving across-the-board clinically meaningful improvements in quality of life measures in patients with hemodialysis-associated pruritus in a phase 2 study. In a phase 2 clinical investigation, difelikefalin was safe, well tolerated and showed robust analgesic activity for postoperative pain in female patients undergoing laparoscopy, with a significant reduction in post-operative morphine consumption and opioid-related side effects. Now difelikefalin is in phase III clinical trials for the treatment of post-operative pain and pruritus.