Femoxetine is a selective serotonin re-uptake inhibitor. It was being studied in the treatment of narcolepsy, migraine, depressive states and eating disorder. Femoxetine development has been discontinued.

Bufrolin is xanthine derivative and mast cell stabilizer with antiallergic activity. In recent studies, Bufrolin was found to be high potency agonists of human GPR35.

Pafuramidine or DB289, [2,5-bis-(4-amidinophenyl)furan bis-O-methylamidoxime] is a pro-drug of DB75, [2,5-bis(4-amidinophenyl)furan] also known as furamidine. The biotransformation process of DB289 to DB75 in the human liver consists of three O-demethylation reactions catalyzed by the Cyp4F enzyme subfamily and three N-dehydroxylation reactions catalyzed by cytrochrome b5 and NADH-cytochrome b5 reductase. DB289 was studied for therapeutic treatment against human African trypanosomiasis, Pneumocystis pneumonia and malaria. In November 2006, Immtech Pharmaceuticals, Inc. announced that the U.S. Food and Drug Administration (FDA) had granted orphan drug designation for pafuramidine (DB289) to treat Pneumocystis jiroveci pneumonia (PCP), a common life-threatening opportunistic infection in HIV/AIDS and other immunosuppressed patients. Despite the high efficacy of DB289 in patients, the mechanism of action of DB75 is unknown. The mechanism of antimicrobial activity of diamidine compounds is incompletely understood. They undergo active uptake by purine transporter systems in trypanosomes and their mechanism of action may involve interference with DNA-associated enzymes inhibition of heme crystallization11 or/and collapse of the transmitochondrial membrane potential.

Tallimustine (also known as FCE 24517), an alkylating benzoyl mustard derivative of distamycin A that was studied as an anti-tumor agent. Tallimustine participated in phase I clinical trial in patients with advanced cancer. As a result, the was obtained the recommended Phase II dosage for tallimustine. However, the further development of this drug was discontinued.

Filanesib is a highly selective, targeted KSP inhibitor with a mechanism of action distinct from currently available myeloma therapies such as immunomodulatory drugs (IMiDs®) and proteasome inhibitors. Across multiple studies, filanesib has demonstrated activity in heavily pretreated multiple myeloma patients, with a consistent safety profile including no drug-induced peripheral neuropathy and limited non-hematologic toxicity. Adverse events are generally limited to transient, non-cumulative and predominantly asymptomatic myelosuppression (decreases in blood counts) when supportive measures are used. Alpha 1-acid glycoprotein (AAG), a plasma protein, is a potential patient selection marker for filanesib. AAG is undergoing further investigation in clinical trials and could represent the first patient selection marker for a myeloma therapy. Filanesib is in Phase II for Multiple myeloma treatment.

Azamethonium (known in Europe as pendiomid), a substance with the ganglia-blocking effect that was used in Europe to treat patients with acute pulmonary embolism. Information about the nowadays application of this drug is not available.

Otamixaban is a synthetically derived parenteral fXa inhibitor currently in late stage clinical development at Sanofi-Aventis for the management of acute coronary syndrome. Otamixaban is a potent (Ki = 0.5 nM), selective, rapid acting, competitive and reversible fXa inhibitor that effectively inhibits both free and prothrombinase-bound fXa. Factor Xa (fXa) is a critical serine protease situated at the confluence of the intrinsic and extrinsic pathways of the blood coagulation cascade. FXa catalyzes the conversion of prothrombin to thrombin via the prothrombinase complex. Its singular role in thrombin generation, coupled with its potentiating effects on clot formation render it an attractive target for therapeutic intervention. In vivo experiments have demonstrated that Otamixaban is highly efficacious in rodent, canine and porcine models of thrombosis. In addition, recent clinical findings indicate that Otamixaban is efficacious, safe and well tolerated in humans and therefore has considerable potential for the treatment of acute coronary syndrome. Following the results of the Treatment of non-ST elevation Acute coronary syndrome with otamixaban, Sanofi has decided to discontinue the investigational programme with otamixaban, due to efficacy lower than expected. Otamixaban did not show superior benefit/risk to the combination of unfractionated heparin.

Nitroarginine (LNNA), an analog of L-arginine, is a competitive inhibitor of nitric oxide synthase which has been shown to prevent glutamate toxicity. Nitroarginine has been experimentally tested for its ability to prevent ammonia toxicity and ammonia-induced alterations in brain energy and ammonia metabolites. The Kd value (k(off)/k(on)) of bovine brain cNOS for LNNA was 15 nM. In contrast to the potent and slow onset of LNNA inhibition of brain cNOS, LNNA inhibition of inducible mouse macrophage NOS (iNOS) was weaker (Ki = 4.4 uM) and rapidly reversible. Thus, LNNA was a 300-fold more potent inhibitor of bovine brain cNOS than mouse macrophage iNOS. By inhibiting nitric oxide synthase LNNA causes the selective reduction of blood flow to tumor cells. Despite the potential of LNNA to function as an adjuvant in cancer therapies, its poor solubility and stability have hindered the development of an injectable formulation of LNNA that is suitable for human administration.

Etoloxamine is an antihistamine.

Elacridar is an oral bioenhancer that targets multiple drug resistance in tumors. Elacridar is a strong and relatively specific inhibitor of P-gp and BCRP, two main efflux transporters. Development of elacridar is assumed to have been discontinued.