Surotomycin is a benzenebutanoic acid derivative patented by Cubist Pharmaceuticals, Inc. as antibacterial agents for the treatment of Gram-positive infections. Surotomycin has a fourfold greater in vitro potency than vancomycin against C. Difficile and other Gram-positive bacteria with minimal impact on the Gram-negative organisms of the intestinal microbiota. Surotomycin, given orally, has been shown to be highly effective against both initial and relapsing hamster Clostridium difficile-associated diarrhea, with a potency similar to vancomycin. Surotomycin is non-inferior to vancomycin and offers a promising alternative for the treatment and prevention of C. diff infection.

Fialuridine, or 1-(2-deoxy-2-fluoro-1-D-arabinofuranosyl)-5-iodouracil (FIAU) is a thymidine nucleoside analog with activity against various herpesviruses and hepatitis B virus (HBV) in vitro and in vivo. Herpes virus thymidine kinase considered to be a target of FIAU. In a Phase II study, fialuridine induced a severe toxic reaction in chronic hepatitis B patients characterized by hepatic failure, lactic acidosis, pancreatitis, neuropathy, and myopathy. These clinical manifestations led to the hypothesis that the toxicity of FIAU was mediated through mitochondrial dysfunction, possibly as a result of the inhibition of mitochondrial DNA polymerase gamma and/or incorporation of FIAU into mitochondrial DNA.

Radalbuvir (also known as GS-9669 ) is a Hepatitis C virus NS 5 protein inhibitor for the treatment of hepatitis C virus (HCV) infection developed by Gilead Sciences. Radalbuvir is a highly optimized thumb site II nonnucleoside inhibitor, with a binding affinity of 1.35 nM for the genotype (GT) 1b protein. It is a selective inhibitor of HCV RNA replication, with a mean 50% effective concentration of ≤ 11 nM in genotype 1 and 5 replicon assays, but lacks useful activity against genotypes 2 to 4. In preclinical Radalbuvir exhibited at least additive activity in combination with agents encompassing four other direct modes of action (NS3 protease, NS5A, NS5B via an alternative allosteric binding site, and NS5B nucleotide) as well as with alpha interferon or ribavirin in replicon assays. It exhibited high metabolic stability in vitro human liver microsomal assays, which, in combination with its pharmacokinetic profiles in rat, dog, and two monkey species, is predictive of good human pharmacokinetics. In clinical trials, Radalbuvir shows highly effective inhibition of wild-type HCV.

Scopafungin (also known as GE4800) is an inhibitor of oxidative phosphorylation in mitochondria. Scopafungin also inhibits, in vitro, a variety of pathogenic fungi, yeasts, and gram-positive bacteria.

Ruzasvir (previously known as MK-8408) was developed as a nonstructural protein 5A (NS5A) inhibitor for the treatment of hepatitis C and hepatitis C infection. Ruzasvir successfully completed phase II clinical trial for combination therapy. The obtained results have shown that ruzasvir in combination with uprifosbuvir was highly effective and well-tolerated in participants infected with hepatitis C virus genotypes GT1, GT2, GT4, GT5, and GT6, with a lower efficacy in GT3-infected persons.