Pain intensity is frequently measured on an 11-point pain intensity numerical rating scale (PI-NRS), where 0=no pain and 10=worst possible pain. However, it is difficult to interpret the clinical importance of changes from baseline on this scale (such as a 1- or 2-point change). To date, there are no data driven estimates for clinically important differences in pain intensity scales used for chronic pain studies. We have estimated a clinically important difference on this scale by relating it to global assessments of change in multiple studies of chronic pain. Data on 2724 subjects from 10 recently completed placebo-controlled clinical trials of pregabalin in diabetic neuropathy, postherpetic neuralgia, chronic low back pain, fibromyalgia, and osteoarthritis were used. The studies had similar designs and measurement instruments, including the PI-NRS, collected in a daily diary, and the standard seven-point patient global impression of change (PGIC), collected at the endpoint. The changes in the PI-NRS from baseline to the endpoint were compared to the PGIC for each subject. Categories of "much improved" and "very much improved" were used as determinants of a clinically important difference and the relationship to the PI-NRS was explored using graphs, box plots, and sensitivity/specificity analyses. A consistent relationship between the change in PI-NRS and the PGIC was demonstrated regardless of study, disease type, age, sex, study result, or treatment group. On average, a reduction of approximately two points or a reduction of approximately 30% in the PI-NRS represented a clinically important difference. The relationship between percent change and the PGIC was also consistent regardless of baseline pain, while higher baseline scores required larger raw changes to represent a clinically important difference. The application of these results to future studies may provide a standard definition of clinically important improvement in clinical trials of chronic pain therapies. Use of a standard outcome across chronic pain studies would greatly enhance the comparability, validity, and clinical applicability of these studies.

Treatment of PHN with pregabalin is safe, efficacious in relieving pain and sleep interference, and associated with greater global improvement than treatment with placebo.

In patients with diabetic peripheral neuropathy, pregabalin demonstrated early and sustained improvement in pain and a beneficial effect on sleep, which were confirmed by positive patient global impression. Pregabalin was well tolerated at all doses.

Belinostat [Beleodaq(®) (US)], a small-molecule hydroxamate-type inhibitor of class I, II and IV histone deacetylase (HDAC) enzymes, has been developed by TopoTarget and Spectrum Pharmaceuticals for the treatment of relapsed or refractory peripheral T-cell lymphoma (PTCL). Belinostat has received its first global approval as monotherapy for this indication in the US, under the Food and Drug Administration's accelerated approval program. This article summarizes the milestones in the development of belinostat leading to this first approval for the treatment of PTCL.

Ipragliflozin (Suglat® [Japan]), an orally active, next-generation sodium-glucose transporter 2 (SGLT2) inhibitor, has been developed by Astellas Pharma and Kotobuki Pharmaceutical for the treatment of type 2 diabetes mellitus. Ipragliflozin has received its first global approval in this indication in Japan, for use as monotherapy or in combination with another antihyperglycaemic agent (metformin, pioglitazone, a sulfonylurea, an α-glucosidase inhibitor, a dipeptidylpeptidase-4 inhibitor or nateglinide). Ipragliflozin is the first SGLT2 inhibitor to be approved in Japan. This article summarizes the milestones in the development of ipragliflozin leading to this first approval for the treatment of type 2 diabetes mellitus.