Pimecrolimus, an ascomycin macrolactam derivative, is an inhibitor of T-cell and mast-cell activation, developed and launched by Novartis for the potential treatment of psoriasis and allergic, irritant and atopic dermatitis. The topical formulation had been launched in the US by February 2002 for mild-to-moderate atopic dermatitis in patients aged two years and older. Pimecrolimus is an immunomodulating agent. The mechanism of action of pimecrolimus in atopic dermatitis is not known. While the following have been observed, the clinical significance of these observations in atopic dermatitis is not known. It has been demonstrated that pimecrolimus binds with high affinity to macrophilin-12 (FKBP-12) and inhibits the calcium dependent phosphatase, calcineurin. Therefore, it inhibits T cell activation by blocking the transcription of early cytokines. In particular, pimecrolimus inhibits at nanomolar concentrations Interleukin-2 and interferon gamma (Th1-type) and Interleukin-4 and Interleukin-10 (Th2-type) cytokine synthesis in human T-cells. In addition, pimecrolimus prevents the release of inflammatory cytokines and mediators from mast cells in vitro after stimulation by antigen/IgE. Following the administration of a single oral radiolabeled dose of pimecrolimus numerous circulating O-demethylation metabolites were seen. Studies with human liver microsomes indicate that pimecrolimus is metabolized in vitro by the CYP3A sub-family of metabolizing enzymes. No evidence of skin mediated drug metabolism was identified in vivo using the minipig or in vitro using stripped human skin.

CMX157 is a lipid (1-0-hexadecyloxypropyl) conjugate of the acyclic nucleotide analog tenofovir (TFV) with activity against both wild-type and antiretroviral drug-resistant HIV strains, including multidrug nucleoside/nucleotide analog-resistant viruses. CMX157 was designed to mimic lysophosphatidylcholine to take advantage of natural lipid uptake pathways and to achieve high intracellular concentrations of the active antiviral, with the aim of increasing the effectiveness of TFV against wild-type and mutant HIV. CMX157 demonstrated potential to effectively suppress replication of multiNRTI-resistant (MNR) HIV that cannot be treated with any currently available NRTIs, including TDF. It is in phase II clinical trial for HIV infections in USA and phase Ib portion of the phase I/II trial for Hepatitis B in Thailand (PO).

Bosentan is a dual endothelin receptor antagonist important in the treatment of pulmonary artery hypertension (PAH). It is licensed in the United States, the European Union and other countries by Actelion Pharmaceuticals for the management of PAH under the trade name Tracleer®. Bosentan is used to treat pulmonary hypertension by blocking the action of endothelin molecules that would otherwise promote narrowing of the blood vessels and lead to high blood pressure. Bosentan competitively antagonizes the binding of 125I-labeled ET-1 to human vascular smooth muscle cells (predominantly ETA receptors) with an inhibition constant (Ki ) of 4.7 nM and to human placenta membranes (predominantly ETB receptors) with a Ki of 95 nM. Furthermore, bosentan is specific for endothelin receptors and does not interfere with the binding of a variety of peptides, neurotransmitters, growth factors, or eicosanoids to their receptors.

Zoledronic acid (Reclast, Aclasta, Zometa) is an intravenous, highly potent amino-bisphosphonate approved worldwide, including in the USA, EU and Japan for use in patients with primary or secondary osteoporosis or low bone mass (approved indications vary between countries). Its high affinity to and long half-life in bone, and long duration of action allow for once-yearly administration, which has the potential to improve adherence to therapy. Zoledronic acid once yearly for up to 3 years improved bone mineral density (BMD) at several skeletal sites, reduced fracture risk and bone turnover, and/or preserved bone structure and mass relative to placebo in clinical studies in patients with primary or secondary osteoporosis. While additional benefits were seen when treatment was continued for up to 6 years, as evidenced by a reduced risk of vertebral fractures and higher BMD relative to 3 years’ therapy, there was the minimal advantage of treatment beyond 6 years. Therefore, in patients with low fracture risk, treatment discontinuation should be considered after approximately 5 years’ therapy. Zoledronic acid administered annually or once in 2 years was also effective in preventing bone loss in patients with low bone mass. Zoledronic acid was generally well tolerated, with the most common adverse events (AEs) being transient, mild-to-moderate post-infusion symptoms, which decreased with subsequent infusions.

Imatinib (GLEEVEC®) is a tyrosine kinase inhibitor and antineoplastic agent that inhibits the BCR-ABL tyrosine kinase, the constitutive abnormal tyrosine kinase created by the Philadelphia chromosome abnormality in chronic myeloid leukaemia (CML). It inhibits proliferation and induces apoptosis in BCR-ABL positive cell lines as well as fresh leukemic cells from Philadelphia chromosome positive CML. Imatinib (GLEEVEC®) inhibits colony formation in assays using ex vivo peripheral blood and bone marrow samples from CML patients. It is also an inhibitor of the receptor tyrosine kinases for platelet-derived growth factor (PDGF) and stem cell factor (SCF), c-kit, and inhibits PDGF- and SCF-mediated cellular events. In vitro, imatinib (GLEEVEC®) inhibits proliferation and induces apoptosis in gastrointestinal stromal tumor (GIST) cells, which express an activating c-kit mutation.

Bimatoprost (marketed in the US, Canada and Europe by Allergan, under the trade name Lumigan) ophthalmic solution is a topical medication used for controlling the progression of glaucoma or ocular hypertension, by reducing intraocular pressure. It is a prostaglandin analogue that works by increasing the outflow of aqueous fluid from the eyes. It binds to the prostanoid FP receptor. It selectively mimics the effects of naturally occurring substances, prostamides. Bimatoprost is believed to lower intraocular pressure (IOP) in humans by increasing outflow of aqueous humor through both the trabecular meshwork and uveoscleral routes. Elevated IOP presents a major risk factor for glaucomatous field loss. The higher the level of IOP, the greater the likelihood of optic nerve damage and visual field loss. Bimatoprost is the major circulating species in the blood once it reaches the systemic circulation following ocular dosing. Bimatoprost then undergoes oxidation, N-deethylation and glucuronidation to form a diverse variety of metabolites. In human blood, bimatoprost resides mainly in the plasma. Approximately 12% of bimatoprost remains unbound in human plasma.

Dexmethylphenidate is the dextrorotary form of methylphenidate. Dexmethylphenidate is marketed under the trade name Focalin. Focalin (dexmethylphenidate hydrochloride) is the d-threo-enantiomer of racemic methylphenidate hydrochloride, which is a 50/50 mixture of the d-threo and l-threoenantiomers. Focalin is a central nervous system (CNS) stimulant, available in three tablet strengths. Each tablet contains dexmethylphenidate hydrochloride 2.5, 5, or 10 mg for oral administration. Dexmethylphenidate is used as a treatment for ADHD, ideally in conjunction with psychological, educational, behavioral or other forms of treatment. Methylphenidate blocks dopamine uptake in central adrenergic neurons by blocking dopamine transport or carrier proteins. Methylphenidate acts at the brain stem arousal system and the cerebral cortex and causes increased sympathomimetic activity in the central nervous system. Methylphenidate is a catecholamine reuptake inhibitor that indirectly increases catecholaminergic neurotransmission by inhibiting the dopamine transporter (DAT) and norepinephrine transporter (NET), which are responsible for clearing catecholamines from the synapse, particularly in the striatum and meso-limbic system.

Fondaparinux is a synthetic and specific inhibitor of activated Factor X (Xa). By selectively binding to antithrombin III (ATIII), fondaparinux sodium potentiates (about 300 times) the innate neutralization of Factor Xa by ATIII. Neutralization of Factor Xa interrupts the blood coagulation cascade and thus inhibits thrombin formation and thrombus development. Fondaparinux is indicated for the prophylaxis of deep vein thrombosis (DVT), which may lead to pulmonary embolism (PE): in patients undergoing hip fracture surgery, including extended prophylaxis; in patients undergoing hip replacement surgery; in patients undergoing knee replacement surgery; in patients undergoing abdominal surgery who are at risk for thromboembolic complications. The most serious adverse reactions reported with Fondaparinux are bleeding complications and thrombocytopenia. Agents that may enhance the risk of hemorrhage should be discontinued prior to initiation of therapy with Fondaparinux unless these agents are essential.

Almotriptan is a triptan drug for the treatment of migraine headaches. Almotriptan is marketed under the trade name Axert. Almotriptan is used for treating acute migraine headaches with or without aura (eg, dark spots, flashing lights, wavy lines). Almotriptan binds with high affinity to 5-HT1D, 5-HT1B, and 5-HT1F receptors. Almotriptan has weak affinity for 5-HT1A and 5-HT7 receptors, but has no significant affinity or pharmacological activity at 5-HT2, 5-HT3, 5-HT4, 5-HT6; alpha or beta adrenergic; adenosine (A1, A2); angiotensin (AT1, AT2); dopamine (D1, D2); endothelin (ETA, ETB); or tachykinin (NK1, NK2, NK3) binding sites.

Dutasteride is a synthetic 4-azasteroid compound that is a selective inhibitor of both the type 1 and type 2 isoforms of steroid 5 alpha-reductase (5AR), intracellular enzymes that convert testosterone to 5 alpha-dihydrotestosterone (DHT). Type I 5a-reductase is predominant in the sebaceous glands of most regions of skin, including scalp, and liver. Type I 5a-reductase is responsible for approximately one-third of circulating DHT. The Type II 5a-reductase isozyme is primarily found in prostate, seminal vesicles, epididymides, and hair follicles as well as liver, and is responsible for two-thirds of circulating DHT. Dutasteride inhibits the conversion of testosterone to 5 alpha-dihydrotestosterone (DHT), which is the androgen primarily responsible for the initial development and subsequent enlargement of the prostate gland. Testosterone is converted to DHT by the enzyme 5 alpha-reductase, which exists as 2 isoforms, type 1 and type 2. Dutasteride is a competitive and specific inhibitor of both type 1 and type 2 5 alpha-reductase isoenzymes, with which it forms a stable enzyme complex. Dissociation from this complex has been evaluated under in vitro and in vivo conditions and is extremely slow. Used for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate gland to improve symptoms, and reduce the risk of acute urinary retention and the need for surgery. Marketed under the brand name Avodart.