Q203 (6-chloro-2-ethyl-N-(4-(4-(4-(trifluoromethoxy)phenyl)piperidin-1-yl)benzyl)imidazo [1,2-a]pyridine-3-carboxamide) is an an imidazopyridine antitubercular compound. Q203 targets the cytochrome b subunit (QcrB) of the cytochrome bc1 complex. This complex is an essential component of the respiratory electron transport chain of ATP synthesis. Q203 inhibited the growth of multidrug-resistant (MDR) and extensively drug-resistant (XDR) M. tuberculosis clinical isolates in culture broth medium in the low nanomolar range and was efficacious in a mouse model of tuberculosis at a dose less than 1 mg per kg body weight, which highlights the potency of this compound. In addition, Q203 displays pharmacokinetic and safety profiles compatible with once-daily dosing. Q203 is a promising new clinical candidate for the treatment of tuberculosis.

Ravuconazole is a triazole with antifungal properties that inhibits cytochrome P450 sterol 14a-demethylase, an enzyme involved in sterol synthesis, resulting in lysis of the fungal cell wall and fungal cell death. It was investigated for the treatment of aspergillosis, candidiasis, and onychomycosis, but these studies were discontinued. Ravuconazole is now in phase II clinical trials to investigate efficacy in preventing fungal infections in patients undergoing chemotherapy and stem cell transplantation.

Thiorphan is the first potent synthetic inhibitor of enkephalinase. Thiorphan displays antinociceptive activity after systemic administration. Thiorphan also inhibits to a lesser extent the widely distributed angiotensin-converting enzyme, a carboxydipeptidase implicated in blood pressure regulation. Thiorphan failed to potentiate allergen-induced airway responses in asthma. Thiorphan significantly reduced the castor oil-induced diarrhea in rats when administered intravenously but not when administered intracerebroventricularly. Racecadotril, via its active metabolite thiorphan, was consistently effective in animal models and patients with various forms of acute diarrhea by inhibiting pathologic (but not basal) secretion from the gut without changing gastro-intestinal transit time or motility.

MK-2206 is an oral selective allosteric inhibitor of Akt that targets all three isoforms of human Akt (Akt-1, Akt-2 and Akt-3). In a phase I study of solid tumors, MK-2206 demonstrated evidence of target modulation and anti-proliferative activity as a single agent and in combination with other agents. Current ongoing trials of MK-2206 include monotherapy and combination therapy in breast cancer, colorectal cancer, haematological malignancies, non-small cell lung cancer and other. Detected treatment-related adverse event are: rash, fatigue, hyperglycemia.

Fozivudine tidoxil is a thioether lipid–Zidovudine (ZDV) conjugate. After intake it is split intracellularly into the lipid moiety and ZDV-monophosphate, which is subsequently phosphorylated to the active metabolite ZDV-triphosphate. The rationale behind the development of fozivudine (FZD) was to take advantage of the high cleavage activity in mononuclear cells and other organs resulting in increased amounts of intracellular ZDV available for phosphorylation to the active metabolite, and a very low activity in red blood and stem cells, which should result in reduced haematologic toxicity. It is member of the family of nucleoside reverse transcriptase (RT) inhibitors. Fozivudine tidoxil has been in Phase II clinical trials for the treatment of HIV infection. There were three adverse events possibly related to fozivudine: urine abnormality, gastrointestinal pain and abnormal dreams.

Bevirimat (3-O-(3',3'-dimethylsuccinyl) betulinic acid or MPC-4326 or PA-457) potently inhibits replication of both WT and drug-resistant HIV-1 isolates and demonstrate that the compound acts by disrupting a late step in Gag processing involving conversion of the capsid precursor (p25) to mature capsid protein (p24). Bevirimat inhibits replication of both wild-type and drug-resistant HIV-1 isolates in vitro, achieving similar 50% inhibitory concentration values with both categories. Serial drug passage studies have identified six single amino acid substitutions that independently confer bevirimat resistance. These resistance mutations occur at or near the CA-SP1 cleavage site, which is not a known target for resistance to other antiretroviral drugs. Bevirimat has been in phase 2 trial for the treatment of HIV infections. Bevirimat has demonstrated a consistent pharmacokinetic profile in healthy volunteers and HIV-infected patients. The demonstration of an antiviral effect following a single oral dose of bevirimat validates maturation inhibition as a potential target for antiretroviral therapeutics in humans.

Eprodisate (1,3-propanedisulfonate) is a negatively charged, sulfonated molecule of low molecular weight that has structural similarities to heparin sulfate; it is a glycosaminoglycan mimetic that binds to the glycosaminoglycan (GAG) binding site on serum A amyloid (AA) to prevent its interaction with glycosaminoglycan and arrest amyloidosis, or inhibit amyloid deposition. In nonclinical toxicity studies in two animal species (i.e., rat and dog), eprodisate was administered orally at doses of up to 2000 mg/kg/day for 39 weeks: eprodisate showed low toxicity potential at doses several fold higher than the anticipated clinical dose, was well tolerated upon chronic exposure and was found to be nonmutagenic and nonclastogenic. Furthermore, a series of safety pharmacology studies showed that eprodisate does not have any clinically significant effect on major organ function.

Hydroxytamoxifen (Afimoxifene) is an active metabolite of tamoxifen exerting estrogen receptor modulatory function. In addition, hydroxytamoxifen binds to regulates transcriptional activity of the estrogen-related receptor gamma. ASCEND Therapeutics, Inc. was developing TamoGel (4-hydroxytamoxifen gel) for a variety of estrogen-dependent conditions, including breast cancer, cyclic breast pain and gynecomastia.

R1479 (4′-azidocytidine) is a specific inhibitor of hepatitis C virus (HCV) replication. 4′-azidocytidine triphosphate is an inhibitor of native HCV replicase and recombinant HCV polymerase (NS5B). Balapiravir (R1626) is the tri-isobutyrate ester prodrug of R1479 under clinical development to improve exposure of R1479 upon oral administration.

R1479 (4′-azidocytidine) is a specific inhibitor of hepatitis C virus (HCV) replication. 4′-azidocytidine triphosphate is an inhibitor of native HCV replicase and recombinant HCV polymerase (NS5B). Balapiravir (R1626) is the tri-isobutyrate ester prodrug of R1479 under clinical development to improve exposure of R1479 upon oral administration.