Epiroprim (Ro 11-8958) is a dihydrofolate reductase inhibitor. Epiroprim displayed activity against a broad range of bacteria including mycobacteria, staphylococci, enterococci, pneumococci, and streptococci as well as against Toxoplasma gondii. Epiroprim development has been discontinued.

Sulfiram (also known as monosulfiram) is a sulfide derivative patented by L. Givaudan & Cie. S. A. as effective anti-parasitic medicine used for the treatment and prevention of scabies and other skin related problems like itching, skin irritation, and inflammation. Sulfiram is a very weak inhibitor of aldehyde dehydrogenase. Sulfiram is usually sold as a solution or medicated soap, sometimes in combination with benzyl benzoate. Sulfiram is now rarely used, but, as of 2015, is still available in Brazil, India, and South Africa.

Piriprost (U-60, 257) is a structural analog of prostaglandin I2 (PGI2) with low IP receptor-mediated activity. It inhibits 5-LO (5-lipoxygenase). Piriprost inhibits the release of histamine and leukotrienes, implicating its role in inflammation and allergic responses. However, it was shown, that piriprost did not influence the airway responses after allergen in asthma. Nevertheless, even more, the drug was irritant to the respiratory tract than was placebo.

Safingol, the synthetic L-threo-stereoisomer of endogenous (D-erythro-) sphinganine, is an inhibitor of protein kinase C and sphingosine kinase in vitro, and in some cell types has been implicated in ceramide generation and induction of apoptosis. Safingol inhibits enzymatic activity and 3H-phorbol dibutyrate binding of purified rat brain PKC (IC50 = 37.5 uM and 31uM, respectively). Inhibits human PKCα, the major overexpressed isoenzyme in MCF-7 DOXR cells (IC50 = 40 uM). Safingol enhances the cytotoxic effect of the chemotherapeutic agent Mitomycin C (MMC) in gastric cancer cells by promoting drug-induced apoptosis. Safingol is an inhibitor of SphK (Sphingosine kinase). Safingol has been shown to act synergistically with other chemotherapeutic agents and may potentiate chemotherapy drug-induced apoptosis in vitro and in vivo.

Eprovafen is an anti-inflammatory compound.

Indisulam (also known as E7070) is a sulfonamide derivative patented by Japanese pharmaceutical company Eisai Co. as antitumor agent. Indisulam inhibits cyclin-dependent kinases (CDK), which regulate cell cycle progression and are usually over-expressed in cancerous cells. Inhibition of CDK results in G1/S phase arrest of the cell cycle, and may lead to induction of apoptosis and inhibition of tumor cell proliferation. Preclinical and clinical studies have established the synergy of indisulam with nucleoside analogs as well as topoisomerase inhibitors. These combinations were tolerated with acceptable toxicities, including diarrhea, vomiting, and myelosuppression. In Phase II clinical trials Combination of indisulam with DNA‐damaging agent (idarubicin) and nucleoside analog (cytarabine) in patients with relapsed and refractory AML is effective and largely well tolerated.

A second generation of HDACs, synthetic benzamide-containing HDACs such as Tacedinaline (CI-994), have reached phase I and II clinical trials. It has been investigated for its applications to the treatment of cancers such as Breast cancer and Colorectal cancer. Tacedinaline has been in phase III clinical trials by Pfizer for the treatment of advanced non-small cell lung cancer and pancreatic cancer combined with gemcitabine. However, this research has been discontinued. Mechanism of Action: Angiogenesis inhibitors; Histone deacetylase inhibitors. Pharmacokinetics showed that CI-994 absorption and disposition were unaffected by carboplatin and paclitaxel coadministration.

Forodesine hydrochloride is the salt of the synthetic high-affinity transition-state analog forodesine (BCX-1777, immucillin-H), a substrate designed to mimic the properties or the geometry of the transition state of reaction. It is an anticancer drug that has been developed for the treatment of different hematologic malignancies. In December 2006, orphan designation (EU/3/06/421) was granted by the European Commission to Napp Pharmaceuticals Research Limited, United Kingdom, for forodesine hydrochloride for the treatment of acute lymphoblastic leukemia. Forodesine hydrochloride has been evaluated in Phase I/Phase II clinical trials for several cancer types including chronic lymphocytic leukemia (CLL), B-Cell acute lymphoblastic leukemia and refractory cutaneous T-cell lymphoma (CTCL). Forodesine is a potent purine nucleoside phosphorylase (PNP) inhibitor that acts by elevating plasma 2'-deoxyguanosine (dGuo) and intracellular deoxyguanosine triphosphate, which in turn affects deoxynucleotide-triphosphate pools and induces cell death by apoptosis. Forodesine in the presence of dGuo inhibited the proliferation of CEM-SS (T-acute lymphoblastic leukemia) cells with an IC50 of 0.015 uM. This inhibition by forodesine and dGuo was accompanied by a 154-fold and 8-fold elevation of endogenous dGuo triphosphate (dGTP) and deoxyadenosine triphosphate (dATP) pools, respectively. Cytotoxic activity of forodesine in the presence of dGuo was selective to T lymphocytes. It is a 10- to 100-fold more potent inhibitor of human lymphocyte proliferation than other known PNP inhibitors such as PD141955 and BCX-34.8

Ascorbyl gamolenate, an aldehyde reductase inhibitor, participated in phase-I clinical trials for Diabetic neuropathies in the United Kingdom but these studies were discontinued.