Treatment for life for severe haemophilia A- A cost-utility model for prophylaxis vs. on-demand treatment.

Prophylaxis has been established as the treatment of choice in children with haemophilia and its continuation into the adult years has been shown to decrease morbidity throughout life. The cost of factor therapy has made the option questionable in cost-effectiveness studies. The role of prophylaxis in pharmacokinetic dosage and tolerization against inhibitor formation were used to model the cost utility of prophylaxis vs. on-demand (OD) therapy over a lifetime horizon in severe haemophilia A. The model was applied to a single provider national health system exemplified by the United Kingdom's National Health Service and a third party provider in the United States. The incremental cost-effectiveness ratio (ICER) was estimated and compared to threshold values used by payer agencies to guide reimbursement decisions. A cost per quality-adjusted life year (QALY) was also estimated for Sweden. Prophylaxis was dominant over OD treatment in the UK. The model resulted in an ICER - $68 000 - within the range of treatments reimbursed in the USA. In Sweden, a cost/QALY of SEK 1.1 million was also within the range of reimbursed treatments in that country. Dosage- and treatment-induced inhibitor incidence were the most important variables in the model. Subject to continuing clinical evidence of the effectiveness of pharmacokinetic dosage and the role of prophylaxis in decreasing inhibitor incidence, treatment for life with prophylaxis is a cost-effective therapy, using current criteria for the reimbursement of health care technologies in a number of countries.

Synthesis of functionalized chiral carbocyclic cleft molecules complementary to Tröger's base derivatives.

The synthesis of optically pure functionalized cleft molecules derived from dibenzobicyclo[b,f][3.3.1]nona-5a,6a-diene-6,12-dione is reported. These clefts are reminiscent of Tröger's base but contain clefts with different dimensions and additional carbonyl (or alcohol) groups that may be utilized in molecular recognition studies. The 2,8-dimethyl and 2,8-dibromo derivatives were synthesized via an intramolecular Friedel-Crafts acylation and were resolved by chiral HPLC. The 2,8-dinitro derivative was prepared by regiospecific nitration of dibenzobicyclo[b,f][3.3.1]nona-5a, 6a-diene-6,12-dione. The dibromo and dinitro derivatives allow direct access to a range of functionalized molecular clefts. Palladium-catalyzed coupling of the dibromo derivative afforded the disubstituted phenyl, anisole, and acetylene derivatives, while reduction of the dinitro derivative and acetylation provided amino-dione and amide-hydroxyl derivatives. X-ray crystal structures of the dimethyl 12, dibromo 13, di(p-methoxyphenyl) 16, dinitro 18, and dimethyl dinitro 22 derivatives show cleft angles between the planes between the aromatic rings of 84-104 degrees. The synthetic route, structural features, and potential for molecular recognition studies of this class of clefts are compared with those of the more widely studied Tröger's base cleft molecules.

The synthesis and fluorescent properties of analogues of the zinc(II) specific fluorophore zinquin ester.

The synthesis and fluorescent properties in the absence and presence of zinc(II) of a range of 2-substituted derivatives of N-(6-methoxy-2-methyl-8-quinolyl)-4-methylbenzenesulfonamide are described. These analogues formed complexes with zinc(II) as indicated by a bathochromic shift in their UV/vis spectra. Analogues with isobutenyl and isobutyl side chains at the 2-position formed fluorescent complexes whose fluorescence was stronger than that of the 2-methyl-containing parent. These derivatives were converted, via conversion to the phenol with boron tribromide and reaction with ethyl bromoacetate, to systems with ester-containing side chains analogous to zinquin ester, a specific cellular fluorophore for zinc(II). All of these ester derivatives formed complexes with zinc(II) resulting in a bathochomic shift in their UV/vis spectra. Compounds with isobutyl, isobutenyl, and styryl side chains exhibited increased fluorescence compared to that of zinquin ester in the presence of zinc(II). The compound with the 2-isobutyl side chain was more selective in its fluorescence for zinc(II) over cadmium(II) compared to zinquin ester.