Fotretamine was developed as an immunosuppressant and antineoplastic agent. However, information about the further development of this drug is not available.

Fosmidomycin (3-(formylhydroxyamino)-propylphosphonic acid mono-sodium salt, 3-(N-formyl-N-hydroxyamino)-propylphosphonic acid mono-sodium salt, FR-31564) is a potent inhibitor of P. falciparum 1-deoxy-D-xylulose-5-phosphate reductoisomerase (PfDXR), developed by Albert Schweitzer Hospital for P. falciparum malaria treatment. Fosmidomycin was originally isolated as natural antibiotic from Streptomyces lavendulae. Fosmidomycin is active against a broad range of enterobacteria, but not against Gram-positive organisms or anaerobes. Fosmidomycin was developed as far as an early phase II study for the treatment of urinary tract infections by Fujisawa Pharmaceutical Company (Osaka, Japan) in the early eighties, but these trials have been discontinued. In recent clinical studies, it was shown that fosmidomycin is effective in curing uncomplicated Plasmodium falciparum malaria in humans. The treatment was well tolerated and resulted in a fast parasite and fever clearance. However, the high rate of recrudescence precludes the use of fosmidomycin as a monotherapy. In drug combination studies, the synergy of fosmidomycin with clindamycin was observed. Clinical studies with a fosmidomycin-clindamycin combination are currently ongoing.

Sumarotene (also known as Ro 14-9706) is a third-generation retinoid developed by Hoffmann-La Roche, F., und Co. A.-G., as a topical dermatologic agent for the repair of photodamage, antikeratinization, and antiproliferation. Sumarotene shows activity in standard preclinical and pharmacologic models of repair of photodamage, antikeratinization, and antiproliferation. In clinical trials, Sumarotene effectively decreases the number of actinic keratoses. Sumarotene is well-tolerated and most patients have only slight or absent local inflammation.

Lotifazole (F 1686) - 4-phenyl-2-(2',2',2-trichloroethoxycarboxamido) thiazole is an immunostimulant. It has a range of anti-inflammatory activities in animals that differs from the activities of classic non-steroidal drugs.

Sunagrel is a phenylethanolamine derivative patented by Maggioni Farmaceutici S.p.A. as platelet aggregation inhibitor and antilipidaemic agent.

Sabeluzole (previously known as R 58 735) was developed for the treatment of Alzheimer's disease. It reached phase II clinical trials in Canada and Belgium before its development was discontinued. This drug possibly acts as N-methyl-D-aspartate (NMDA) receptor antagonist. In addition, the effect of sabeluzole on sleep, breathing and daytime symptoms was investigated in 13 patients with obstructive sleep apnea. Besides, no beneficial effect of sabeluzole was shown on peripheral nerve function in patients at an early stage of diabetic polyneuropathy.

Alprenoxime is a prodrug to alprenolol. Alprenoxime is a β-blocker that was in phase II clinical trials with Pharmos in the USA as an antiglaucoma agent. Alprenoxime is a potent ocular antihypertensive agent. Alprenoxime was designed to undergo metabolic activation to the beta-blocker, alprenolol, specifically within the eye using hydrolase and reductase enzymes that reside in the iris-ciliary body. Previous studies in rabbits confirmed that intraocular pressure (IOP) significantly decreased after topically instilling ophthalmic drops of alprenoxime, while heart rates remained essentially unchanged after intravenous dosing. Alprenoxime has no significant cardiac activity at doses much greater than potential therapeutic levels, supporting that alprenoxime could be safely used in treating glaucoma. Alprenoxime was taken to clinical trials and has successfully passed Phase I studies, demonstrating complete lack of cardiovascular side effects, even in humans, including isoprenaline induced tachycardia.

Fialuridine I-124 is an isotope-labeled form of fialuridine, or 1-(2-deoxy-2-fluoro-1-D-arabinofuranosyl)-5-iodouracil (FIAU), a thymidine nucleoside analog with activity against various herpesviruses and hepatitis B virus (HBV) in vitro and in vivo. Bacterial or herpes virus thymidine kinase (TK) considered to be a target of FIAU. Fialuridine I-124 is a positron emission tomography/computed tomography (PET/CT) tracer that was developed for imaging of cells transfected with the herpes simplex virus 1 (HSV1) thymidine kinase reporter gene. This enzyme transfers a γ phosphate group fom ATP to the 5’ hydroxyl group of pyrimidine deoxynucleosides. The lipophilic tracer diffuses into the cell and is trapped in the cell with HSV1-TK activity, because the phosphorylated tracer cannot pass the plasma membrane. TK gene of bacteria was sufficiently similar to that of the viral TK of HSV1 and fialuridine I-124 could also be phosphorylated by the endogenous bacterial TK. Once phosphorylated by TK, fialuridine I-124 becomes trapped within bacteria and can be detected with positron emission tomography/computed tomography (PET/CT).

KRN-7000, a compound with an alpha-galactosylceramide structure, shows potent anti-tumor activity in animal models. It also has strong immunostimulating effect being a high-affinity CD1d antigen.