BackgroundDrug discovery has undergone major transformations in the last century, progressing from the recognition and refinement of natural products with therapeutic benefit, to the systematic screening of molecular libraries on whole organisms or cell lines and more recently to a more target-based approach driven by greater knowledge of the physiological and pathological pathways involved. Despite this evolution increasing challenges within the drug discovery industry are causing escalating rates of failure of development pipelines.DiscussionWe review the challenges facing the drug discovery industry, and discuss what attempts are being made to increase the productivity of drug development, including a refocusing on the study of the basic biology of the disease, and an embracing of the concept of ‘translational research’. We consider what ophthalmic drug discovery can learn from the sector in general and discuss strategies to overcome the present limitations. This includes advances in the understanding of the pathogenesis of disease; improvements in animal models of human disease; improvements in ophthalmic drug delivery and attempts at patient stratification within clinical trials.SummaryAs we look to the future, we argue that investment in ophthalmic drug development must continue to cover the whole translational spectrum (from ‘bench to bedside and back again’) with recognition that both biological discovery and clinical understanding will drive drug discovery, providing safe and effective therapies for ocular disease.

No abstract

Sir, Reply to 'Patient experience of the transition from Xalatan to generic latanoprost' I congratulate the authors of this study. 1 It is, to my knowledge, the first published study on the real world experience of patients receiving generic versions of latanoprost available in the UK. The results relating to patient preference and desire to recommence branded medication are as expected. Patients in the study, as many patients with ocular hypertension and primary open angle glaucoma, are subject to variables associated with non-acceptance of generic medication, namely, being elderly and having had their medicine originally prescribed by a hospital specialist. 2 Patients concerned about wasting of resources can be reassured. The cost of using generic latanoprost at the April 2014 price of d1.77 per 2.5 ml (Department of Health Drug Tariff, available at http:// www.ppa.org.uk/ppa/edt_intro.htm), is substantially less than that of using Xalatan at d12.48 per 2.5 ml (http://www.mims.co.uk/Drugs/eye/glaucoma/ xalatan/) even if the patients need more than one bottle per month. Patients who are supported in the changefor example, by counselling and the provision of suitable dispensing aids-are more likely to adjust successfully. I note that the study was undertaken before the introduction of the new formulation of Xalatan in March 2013 (http://www.medicines.org.uk/emc/medicine/ 9043/SPC/). The lower pH of the Xalatan available since that date may alter the results relating to comfort in the eye as Xalatan is now the most acidic latanoprost eye drop on the UK market. It would be of interest to know whether loss of control of IOP in individuals using generic latanoprost was associated with non-compliance due to problems in administration of the medication or with the use of specific generics. Patients and those involved in their care should be encouraged to report problems with generic latanoprost to the MHRA via the Yellow Card scheme giving details of the generic concerned.