Tolvaptan: A Review in Autosomal Dominant Polycystic Kidney Disease

Tolvaptan [Jynarque^® (USA); Jinarc^® (EU, Canada); Samsca^® (Japan)] is a highly selective vasopressin V₂ receptor antagonist approved for the treatment of autosomal dominant polycystic kidney disease (ADPKD). In the phase III TEMPO 3:4 trial, 3 years’ treatment with tolvaptan slowed the increase in total kidney volume (TKV) and the decline in renal function relative to placebo. The composite secondary endpoint of time to investigator-assessed clinical progression also favoured tolvaptan over placebo. Although tolvaptan did not demonstrate a sustained disease-modifying effect on TKV over the longer term in the TEMPO 4:4 extension trial, the effect of tolvaptan in slowing renal function decline was maintained for a further 2 years. The phase III REPRISE trial confirmed the efficacy of tolvaptan in patients with later-stage ADPKD. Most of the adverse events commonly observed with tolvaptan (e.g. polyuria, nocturia, polydipsia, thirst) are consistent with its pharmacological activity. In the TEMPO trials, tolvaptan was also associated with idiosyncratic hepatotoxicity which was reversible on discontinuation of the drug. Although the use of tolvaptan requires careful consideration and balancing of benefits and risks, it provides a valuable treatment option to slow the progression of ADPKD in patients at risk of or with evidence of rapidly progressing disease.