A Novel Convergent Synthesis of the Potent Antiglaucoma Agent Tafluprost.
ABSTRACT: Tafluprost (AFP-168, 5) is a unique 15-deoxy-15,15-difluoro-16-phenoxy prostaglandin F2? (PGF2?) analog used as an efficacious ocular hypotensive agent in the treatment of glaucoma and ocular hypertension, as monotherapy, or as adjunctive therapy to ?-blockers. A novel convergent synthesis of 5 was developed employing Julia-Lythgoe olefination of the structurally advanced prostaglandin phenylsulfone 16, also successfully applied for manufacturing of pharmaceutical grade latanoprost (2), travoprost (3) and bimatoprost (4), with an aldehyde ?-chain synthon 17. The use of the same prostaglandin phenylsulfone 16, as a starting material in parallel syntheses of all commercially available antiglaucoma PGF2? analogs 2-5, significantly reduces manufacturing costs resulting from its synthesis on an industrial scale and development of technological documentation. Another key aspect of the route developed is deoxydifluorination of a trans-13,14-en-15-one 30 with Deoxo-Fluor. Subsequent hydrolysis of protecting groups and final esterification of acid 6 yielded tafluprost (5). The main advantages are the preparation of high purity tafluprost (5) and the application of comparatively cheap reagents. The preparation and identification of two other tafluprost acid derivatives, tafluprost methyl ester (32) and tafluprost ethyl amide (33), are also described.
Project description:Conjunctiva-associated lymphoid tissue (CALT) is closely associated with ocular surface immunity. This study investigated the effects of antiglaucoma prostaglandin analogs with or without benzalkonium chloride (BAK) preservative on organized CALT using an acute toxic model. A total of 48 albino rabbits were used and seven groups of treatments were constituted. Solutions (50 µl) of PBS, 0.02%BAK, (0.02%BAK+)latanoprost, (0.015%BAK+)travoprost, (0.005%BAK+)bimatoprost, (BAK-free)travoprost preserved with the SofZia® system or (BAK-free)tafluprost were instilled 15 times at 5-min intervals in both eyes. CALT changes were analyzed using in vivo confocal microscopy (IVCM), immunohistology in cryosections for detecting MUC-5AC+ mucocytes and CD45+ hematopoietic cells. Antiglaucoma eye drops stimulated inflammatory cell infiltration in the CALT, and seemed to be primarily related to the concentration of their BAK content. The CALT reaction after instillation of BAK-containing eye drops was characterized by inflammatory cell infiltration in the dome and intrafollicular layers and by cell circulation inside the lymph vessels. CD45 was strongly expressed in the CALT after instillation of all BAK-containing solutions at 4 h and decreased at 24 h. The number of MUC-5AC+ mucocytes around the CALT structure decreased dramatically after instillation of BAK-containing solutions. This study showed for the first time the in vivo aspect of rabbit CALT after toxic stimuli, confirming the concentration-dependent toxic effects of BAK. IVCM-CALT analysis could be a pertinent tool in the future for understanding the immunotoxicologic challenges in the ocular surface and would provide useful criteria for evaluating newly developed eye drops.
Project description:OBJECTIVES:Bimatoprost-timolol (bimatoprost 0.03%-timolol 0.5% fixed-dose combination [FDC]) and tafluprost-timolol (tafluprost 0.0015%-timolol 0.5% FDC) eye drops are currently the only topical intraocular pressure (IOP)-reducing therapies available as preservative-free (PF) prostaglandin and timolol FDC. The aim of this study was to investigate changes to ocular signs and symptoms when patients with ocular hypertension (OH) or open-angle glaucoma (OAG) switched from PF or benzalkonium chloride (BAK)-preserved bimatoprost-timolol to PF tafluprost-timolol eye drops. DESIGN:This was a 12-week, open-label, phase IV study. SETTING:Sixteen centres in Finland, Germany, Italy and the UK. PARTICIPANTS:Patients with OH or OAG (IOP on medication ?21?mm Hg), treated with PF or BAK-preserved bimatoprost-timolol for ?4 weeks before screening, and presenting with conjunctival hyperaemia and ?1?ocular symptom. INTERVENTIONS:Patients were switched to PF tafluprost-timolol once daily in the treated eye(s). PRIMARY AND SECONDARY OUTCOME MEASURES:The primary endpoints were change from screening to week 12 in conjunctival hyperaemia and worst ocular symptom. The secondary outcome measures were changes from screening in ocular signs (other than conjunctival hyperaemia) and symptoms at week 12. RESULTS:Of 123 enrolled patients, 121 were included in the intention-to-treat dataset, of which all were Caucasian and 54.5% were female; 76 patients used BAK-preserved bimatoprost-timolol and 45 used PF drops. Conjunctival hyperaemia and severity of worst ocular symptom following switch to PF tafluprost-timolol significantly reduced from screening to week 12 in all patients (p<0.001). The percentage of patients with ocular signs and symptoms was significantly reduced at week 12 compared with screening (p<0.001). IOP was not affected by the change of treatment. CONCLUSIONS:Switching from BAK-preserved or PF bimatoprost-timolol to tafluprost-timolol reduced both signs and symptoms of ocular surface disease with no clinically relevant effect on IOP. TRIAL REGISTRATION NUMBER:EudraCT2014-005273-37; Results.
Project description:For primary open angle glaucoma (POAG), laser treatment or surgery is used when the target intraocular pressure (IOP) cannot be achieved by pharmacological agents, such as prostaglandin (PG) analogs; these drugs also have varied effects. We retrospectively reviewed the medical records of 74 POAG patients (74 eyes) whose IOP was inadequately controlled by PG analogs (bimatoprost [13 eyes], latanoprost [34 eyes], tafluprost [11 eyes], and travoprost [16 eyes]) and underwent primary trabeculectomy. The proportion of patients with no recurrent IOP elevation within 24 months post-trabeculectomy was significantly (P < 0.001) lower in the bimatoprost group (31.3%) than in the latanoprost (83.2%), tafluprost (45.5%), or travoprost groups (65.6%). Deepening of the upper eyelid sulcus (DUES) was observed before trabeculectomy in 18 of 74 eyes (24.3%) treated with bimatoprost (9 eyes; 50.0%), latanoprost (3 eyes; 16.7%), tafluprost (1 eye; 5.5%) and travoprost (5 eyes; 27.8%). The proportion of patients with no recurrent IOP elevation up to 24 months post-trabeculectomy was significantly (P < 0.0001) lower in the DUES(+) group (34.7%) than in the DUES(-) group (74.3%). Multivariate stepwise logistic regression analysis, with no recurrent IOP elevation used as dependent variable, and bimatoprost, latanoprost, travoprost, tafluprost, β-blocker, carbonic anhydrase inhibitor, brimonidine, gender, age, preoperative IOP, mean deviation, duration of PG analog use before surgery, and the number of ophthalmic solutions used as independent variables, identified only bimatoprost as a significant independent factor (P = 0.0368). Thus, the outcome of trabeculectomy varied depending on the PG analog used preoperatively, and bimatoprost use was associated with a high risk of recurrent IOP elevation up to 2 years post-trabeculectomy. This may indicate that the incidence of DUES differed with the PG analog used. Patients with glaucoma who are treated with bimatoprost should be monitored for DUES, and when these patients undergo trabeculectomy, the postoperative course of IOP should be followed carefully.
Project description:The aim of the present study was to examine the effects of switching from Latanoprost ophthalmic solution containing a preservative to preservative-free Tafluprost ophthalmic solution or Tafluprost containing a preservative on ocular surfaces.Forty patients (40 eyes) with glaucoma (mean age: 62.0 ± 10.9 years) using Latanoprost with preservative for six months or longer were assigned either to a Tafluprost-containing-preservative group (20 eyes) or preservative-free-Tafluprost group (20 eyes). The intraocular pressure, corneal epithelial barrier function (fluorescein uptake concentration with fluorophotometer FL-500), superficial punctate keratopathy (AD classification), and tear film breakup time (TBUT) were assessed before switching and at 12 weeks after switching.No significant differences in intraocular pressure were noted after switching in either group. Corneal epithelial barrier function was improved significantly after switching in both the Tafluprost-containing-preservative and the preservative-free-Tafluprost groups. There were no significant differences in AD scores after switching in the Tafluprost-containing-preservative group, but significant improvements were noted in the preservative-free-Tafluprost group. No significant differences in TBUT were noted in the Tafluprost-containing-preservative or preservative-free-Tafluprost groups after switching.After switching from preservative Latanoprost to Tafluprost containing-preservative or preservative-free Tafluprost, corneal epithelial barrier function was improved while the intraocular pressure reduction was retained.
Project description:A new preservative-free fixed-dose combination of 0.0015% tafluprost, a prostaglandin F2? analog, and 0.5% timolol (TAF/TIM; Santen Oy, Tampere, Finland), a beta-adrenergic antagonist has recently been developed. The intraocular pressure (IOP) reduction with TAF/TIM in open-angle glaucoma and ocular hypertension is similar to that of other prostaglandin-timolol fixed-combination products. Patients with high IOP responded well to TAF/TIM with reductions of up to 40% (>13 mmHg) and beyond. Compared to previous controlled and double-masked clinical trials with DuoTrav(®) (Alcon, Fort Worth, USA) and Ganfort(®) (Allergan, Irvine, USA), TAF/TIM caused less superficial ocular side effects and less conjunctival hyperemia. Plausible explanations for the differences in side effects between the fixed-combination products are discussed.
Project description:Topical ophthalmic formulations of analogues of the endogenous arachidonic acid cyclooxygenase metabolite, PGF2? , are the standard of care treatment for the blinding disease glaucoma. These are the most potent and efficacious medical therapies for lowering intraocular pressure (IOP), the most important risk factor identified for disease progression. They have few side effects and offer the convenience of once-a-day dosing. It was initially believed that endogenous PGs raised IOP and caused substantial ocular surface adverse effects. However, carefully designed experiments demonstrated that esterification of the carboxylic acid afforded potent and efficacious topical ocular hypotensive activity. The final hurdle to be overcome was improvement of the side effect profile. A hypothesis was advanced that the IOP-lowering effect of PGF2? isopropyl ester was due to activation of its cognate PG-FP receptor, while side effects were largely due to promiscuous interaction with other PG receptors. This hypothesis was validated by modification of the ? chain (carbons 13-20) to a phenyl group. This provided the first marketed FP-class PG agonist analogue (FP-PGA) ocular hypotensive agent, latanoprost. Since the introduction of latanoprost into clinical medicine to lower and control IOP, a number of additional FP-PGAs have been discovered, characterized and marketed, including travoprost, tafluprost, unoprostone isopropyl ester and bimatoprost (an amide). LINKED ARTICLES: This article is part of a themed section on Eicosanoids 35 years from the 1982 Nobel: where are we now? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.8/issuetoc.
Project description:The efficacy, safety and tolerability of the preservative-free (PF) fixed combination (FC) of tafluprost 0.0015% and timolol 0.5% (once daily) were compared to those of the individual components (PF tafluprost 0.0015% once daily and PF timolol 0.5% twice daily) in patients with open-angle glaucoma or ocular hypertension inadequately controlled on prior timolol or prostaglandin monotherapy for 6 months.A stratified, double-masked, randomized, multicenter phase III study was conducted. A total of 189 prior timolol users were randomized within the timolol stratum (TS) to receive either FC (n = 95) or timolol 0.5% (TIM; n = 94). Furthermore, a total of 375 prior prostaglandin analog (PGA) users were randomized within the prostaglandin stratum (PS) to receive either FC (n = 188) or tafluprost 0.0015% (TAF; n = 187). To be eligible for participation in the study, the patients were required to have an intraocular pressure (IOP) of ?22 mmHg when on timolol (TIM) or of ?20 mmHg when on PGA in either treated eye at the screening and end-of-run-in visits. In addition to these, the study included visits at baseline, 2 and 6 weeks, 3 and 6 months and at a post-study visit. IOP was measured at 8 a.m., 10 a.m., 4 p.m., and 8 p.m.In the TS, a significant reduction from baseline IOP was seen with FC and TIM throughout the study. Average diurnal IOP change from baseline at month 3 was -8.55 mmHg (32%) for FC and -7.35 mmHg (28%) for TIM. The model-based treatment difference (FC-TIM) was -0.885 mmHg [95% confidence interval (CI) -1.745 to -0.024; p = 0.044] demonstrating the superiority of FC over TIM. In the PS, a significant reduction in IOP was seen with both FC and TAF throughout the study. The average diurnal IOP change from baseline at month 3 was -8.61 mmHg (33%) for FC and -7.23 mmHg (28%) for TAF. The model-based treatment difference (FC-TAF) was -1.516 mmHg (95% CI -2.044 to -0.988; p < 0.001) demonstrating the superiority of FC over TAF. In the TS, related ocular adverse events (AEs) were more frequent for patients treated with FC compared to TIM (16.8% versus 6.4%), whereas related non-ocular AEs were more frequent with TIM compared to FC (2.1% versus 0.0%). In the PS, AEs were similarly distributed between FC and TAF. The frequency of conjunctival hyperemia of FC was low (6.4%).The preservative-free fixed combination of tafluprost and timolol provided a substantial and significant IOP reduction in both strata. The IOP reduction was superior to both tafluprost 0.0015% and timolol 0.5% when given as monotherapies. Overall, the study treatments were safe and well tolerated.Santen Oy, Tampere, Finland.
Project description:Travoprost is a prostaglandin analogue widely used for reducing intraocular pressure (IOP) in patients affected with glaucoma and ocular hypertension. It exerts its ocular hypotensive effect through the prostaglandin FP receptors, located in the ciliary muscle and the trabecular meshwork. Several studies have shown that topical administration of travoprost induces a mean IOP reduction ranging from 25% to 32%, and sustained throughout the 24-hour cycle. When compared with timolol, travoprost is more effective at reducing IOP, while generally no difference has been found in the head-to-head comparison with other prostaglandin analogues. The fixed combination of travoprost and timolol has demonstrated a hypotensive efficacy comparable to the concomitant administration of the two drugs. Recently, a new preservative-free formulation of travoprost 0.004% has been marketed for reducing tolerability-related problems in subjects affected with ocular surface disease. Low rates of topical and systemic adverse reactions, strong ocular hypotensive efficacy, and once-a-day dosing make travoprost a first-line treatment for patients affected with elevated IOP.
Project description:To compare the safety and efficacy of fixed-dose tafluprost/timolol combination (Taf/T-FDC) with those of fixed-dose latanoprost/timolol combination (Lat/T-FDC) by measuring the intraocular pressure (IOP)-lowering effect, ocular pharmacokinetics, and ocular surface toxicity.The IOP-lowering effect of Taf/T-FDC and Lat/T-FDC in ocular normotensive monkeys was evaluated at 4 and 8 h after instillation in study A, at 12, 14, 16, and 18 h after instillation in study B, and at 24, 26, 28, and 30 h after instillation in study C. Drug penetration into the eye was evaluated by measuring the concentrations of timolol, tafluprost acid (active metabolic form of tafluprost), and latanoprost acid (active metabolic form of latanoprost) using liquid chromatography coupled with tandem mass spectrometry after single instillation of Taf/T-FDC or Lat/T-FDC to Sprague Dawley rats. Cytotoxicity following 1-30 min exposure of SV40-transformed human corneal epithelial cells to Taf/T-FDC or Lat/T-FDC was analyzed using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assays. Undiluted and 10-fold diluted solutions of each FDC were evaluated.The IOP-lowering effect of Taf/T-FDC was almost equivalent to that of Lat/T-FDC at 4-8 h after instillation. The peak IOP reduction of Taf/T-FDC and Lat/T-FDC was observed at 8 h after instillation, and there is no difference between the two. The difference between them was observed at 24-30 h after instillation, and Taf/T-FDC demonstrated a significantly greater IOP-lowering effect than Lat/T-FDC at 24-30 h after instillation. The IOP-lowering effect of Taf/T-FDC was sustained up to 30 h after instillation, while that of Lat/T-FDC had almost disappeared at 28 h after instillation. Timolol concentrations in aqueous humor after Taf/T-FDC instillation were higher than those after Lat/T-FDC instillation (Cmax, 3870 ng/mL vs 1330 ng/mL; AUCinf, 3970 ng·h/mL vs 1250 ng·h/mL). The concentrations of tafluprost acid and latanoprost acid in aqueous humor after instillation of Taf/T-FDC and Lat/T-FDC, respectively, were similar to those after instillation of mono-preparations of tafluprost and latanoprost, respectively. The cytotoxic effect of Taf/T-FDC to the human corneal epithelial cells was significantly lower than that of Lat/T-FDC at all evaluated time points in both undiluted and 10-fold diluted FDCs.Taf/T-FDC provides increased IOP-lowering effect duration and lower potential ocular surface toxicity than Lat/T-FDC.
Project description:Although ocular circulation at the retina and optic disc is known to be associated with the pathology of glaucoma, direct measurement of blood flow velocity has been difficult to obtain. This prospective observational study enrolled 11 consecutive patients with treatment-naïve primary open-angle glaucoma (POAG) and 11 healthy subjects, and the effects of topical tafluprost treatment on ocular circulation were examined at baseline and at 1, 4, and 12 weeks after initiating treatment with topical tafluprost on POAG patients using multiple modalities, which include adaptive optics scanning laser ophthalmoscopy (AOSLO). Baseline mean intraocular pressure (IOP) was significantly higher and mean parafoveal blood flow velocity (pBFV) was significantly lower in POAG eyes than in healthy eyes. Mean IOP was significantly decreased (1 week, -19.1%; 4 weeks, -17.7%; and 12 weeks, -23.5%; all P?<?0.001) and mean pBFV was significantly increased from the baseline at all follow-up periods after initiating treatment (1 week, 14.9%, P?=?0.007; 4 weeks, 21.3%, P?<?0.001; and 12 weeks, 14.3%, P?=?0.002). These results reveal that tafluprost may not only lower IOP but may also improve retinal circulation in POAG eyes and AOSLO may be useful to evaluate retinal circulatory change after treatment.