denufosol-tetrasodium and diquafosol

Dinucleoside 5',5'-polyphosphates (DNPs) are endogenous substances that play important intra- and extracellular roles in various biological processes, such as cell proliferation, regulation of enzymes, neurotransmission, platelet disaggregation and modulation of vascular tone. Various methodologies have been developed over the past fifty years to access these compounds, involving enzymatic processes or chemical procedures based either on P(III) or P(V) chemistry. Both solution-phase and solid-support strategies have been developed and are reported here. Recently, green chemistry approaches have emerged, offering attracting alternatives. This review outlines the main synthetic pathways for the preparation of dinucleoside 5',5'-polyphosphates, focusing on pharmacologically relevant compounds, and highlighting recent advances.

Topics: Deoxycytosine Nucleotides; Dinucleoside Phosphates; Dry Eye Syndromes; Green Chemistry Technology; Humans; Ophthalmic Solutions; Phosphorylation; Polyphosphates; Purinergic P2Y Receptor Agonists; Receptors, Purinergic; Uracil Nucleotides; Uridine

Among the most promising of the new therapies being developed for the treatment of Cystic Fibrosis (CF) are those targeted at increasing mucosal hydration on the surface of the airways. One of these therapies, P2Y(2) receptor agonists, bypasses the defective CFTR chloride channel, and activates an alternative chloride channel. This activation results in an increase in airway surface epithelial hydration, and through these actions and effects on cilia beat frequency, increases mucociliary clearance. The pharmacology of P2Y(2) agonists has been confirmed in several preclinical and clinical studies. Denufosol tetrasodium is a novel second-generation, metabolically stable, selective P2Y(2) receptor agonist currently in Phase 3 clinical development. In radiolabelled deposition studies of P2Y(2) agonists in healthy non-smokers and smokers, approximately 7mg of a 40-mg nebulizer (PARI LC Star) load was deposited in the lungs. In a pharmacokinetic study in healthy volunteers, very limited systemic exposure was observed when doses of 200mg of denufosol were nebulized. Thus, it appears that high concentrations of denufosol can be achieved in the airways with very low systemic absorption. Denufosol has been generally well-tolerated in healthy volunteers and patients with CF. The most common adverse events were in the respiratory system, with cough having the highest frequency. Doses of 20-60mg have been evaluated in Phase 2 trials of up to 28 days duration, and superiority relative to placebo on FEV1 has been observed in patients with relatively normal lung function (FEV1 greater than or equal to 75% of predicted). The first Phase 3 trial is a comparison of denufosol 60mg and placebo in 350 patients with CF with FEV1 at study entry greater than or equal to 75% of predicted.

Topics: Administration, Inhalation; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Cystic Fibrosis; Deoxycytosine Nucleotides; Female; Forced Expiratory Volume; Humans; Male; Polyphosphates; Purinergic P2 Receptor Agonists; Receptors, Purinergic P2Y2; Uracil Nucleotides; Uridine

P2Y(2) receptor agonists are a new class of compounds that are being evaluated as a treatment for the pulmonary manifestations of Cystic Fibrosis (CF). Results of preclinical research suggest that these compounds inhibit sodium absorption, restore chloride conductance and rehydrate the CF airway surface. In addition, P2Y(2) receptor agonists have been shown to enhance ciliary beat frequency and increase mucociliary clearance in animals and subjects with impaired mucociliary clearance. The normalization of airway surface liquid and enhancement of lung clearance is expected to provide a clinical benefit to CF patients. A number of P2Y(2) agonist compounds have been evaluated in healthy subjects and patients with CF. Most recently, INS37217, a metabolically stable and potent P2Y(2) agonist has been developed and studies have shown it to be well-tolerated when given via inhalation. This compound is currently being evaluated in children and adults with CF lung disease.

Topics: Administration, Inhalation; Animals; Clinical Trials as Topic; Cystic Fibrosis; Deoxycytosine Nucleotides; Epithelium; Humans; Mucociliary Clearance; Ophthalmic Solutions; Polyphosphates; Purinergic P2 Receptor Agonists; Receptors, Purinergic P2Y2; Uracil Nucleotides; Uridine

INS37217 [P(1)-(uridine 5')-P(4)-(2'-deoxycytidine 5')tetraphosphate, tetrasodium salt] is a deoxycytidine-uridine dinucleotide with agonist activity at the P2Y(2) receptor. In primate lung tissues, the P2Y(2) receptor mRNA was located by in situ hybridization predominantly in epithelial cells and not in smooth muscle or stromal tissue. The pharmacologic profile of INS37217 parallels that of UTP, leading to increased chloride and water secretion, increased cilia beat frequency, and increased mucin release. The combined effect of these actions was confirmed in an animal model of tracheal mucus velocity that showed that a single administration of INS37217 significantly enhanced mucus transport for at least 8 h after dosing. This extended duration of action is consistent with the ability of INS37217 to resist metabolism by airway cells and sputum enzymes. The enhanced metabolic stability and resultant increased duration of improved mucociliary clearance may confer significant advantages to INS37217 over other P2Y(2) agonists in the treatment of diseases such as cystic fibrosis.

Topics: Animals; Astrocytoma; Brain Neoplasms; Calcium; Chlorides; Cilia; Cystic Fibrosis; Deoxycytosine Nucleotides; Epithelial Cells; Humans; In Situ Hybridization; In Vitro Techniques; Indicators and Reagents; Macaca mulatta; Mucins; Mucociliary Clearance; Ophthalmic Solutions; Polyphosphates; Purinergic P2 Receptor Agonists; Receptors, Purinergic P2; Receptors, Purinergic P2Y2; Reverse Transcriptase Polymerase Chain Reaction; Sheep; Tumor Cells, Cultured; Uracil Nucleotides; Uridine

Topics: Animals; Deoxycytosine Nucleotides; Eye; Male; Ophthalmic Solutions; Polyphosphates; Purinergic P2 Receptor Agonists; Rabbits; Tears; Uracil Nucleotides; Uridine