Effects of clofutriben, a selective 11β-hydroxysteroid dehydrogenase type 1 inhibitor, on the efficacy and toxicity of prednisolone in patients with polymyalgia rheumatica: a single-blind controlled trial with sequential cohorts.

OBJECTIVES

Glucocorticoids effectively treat many diseases, but toxicity limits their utility. We aimed to learn whether, by reducing active intracellular glucocorticoid exposures, the 11β-hydroxysteroid dehydrogenase type 1 inhibitor clofutriben could selectively reduce glucocorticoid efficacy but reduce toxicity more strongly. We hypothesised that by increasing the prednisolone dose, it might be possible to restore efficacy back to the original level, thereby improving the benefit-risk profile.

METHODS

In sequential cohorts, adults with polymyalgia rheumatica received (single blind) prednisolone 10 mg/d with placebo for 2 weeks, then clofutriben with either prednisolone 10, 15, 20, or 30 mg/d for 2 weeks.

RESULTS

Forty-nine and 47 participants completed each trial period with evaluable data. Five who received prednisolone 10 mg/d with clofutriben experienced clinical relapse. No clinical relapses occurred during other treatments. Participants reported more severe symptoms and physical disability when prednisolone 10 mg/d or 15 mg/d, but not 20 mg/d or 30 mg/d, was given with clofutriben. Inflammatory biomarkers followed a similar pattern. Across all prednisolone doses, clofutriben coadministration mitigated glucocorticoid-related adverse effects on biomarkers of bone turnover, lipid metabolism, hypercoagulability, and cardiovascular and adrenal function.

CONCLUSIONS

Further trials to assess clofutriben's potential to improve the benefit-risk profile of prednisolone are warranted.