FRI0380 Long-term safety of BCX4208 added to allopurinol in the chronic management of GOUT: Results of a phase 2 24-week blinded safety extension and vaccine challenge study

The landscape of pathophysiology guided therapeutic strategies for gout treatment

INTRODUCTION

Gout is a common autoinflammatory disease caused by hyperuricemia with acute and/or chronic inflammation as well as tissue damage. Currently, urate-lowering therapy (ULT) and anti-inflammatory therapy are used as first-line strategies for gout treatment. However, traditional drugs for gout treatment exhibit some unexpected side effects and are not suitable for certain patients due to their comorbidity with other chronic disease.

AREAS COVERED

In this review, we described the pathophysiology of hyperuricemia and monosodium urate (MSU) crystal induced inflammatory response during gout development in depth and comprehensively summarized the advances in the investigation of promising ULT drugs as well as anti-inflammatory drugs that might be safer and more effective for gout treatment.

EXPERT OPINION

New drugs that are developed based on these molecular mechanisms exhibited great efficacy on reduction of disease burden both in vitro and in vivo, implying their potential for clinical application. Moreover, hyperthermia also showed regulation effect on MSU crystals formation and the signaling pathways involved in inflammation.

Modulation of Urate Transport by Drugs

BACKGROUND

Serum urate (SU) levels in primates are extraordinarily high among mammals. Urate is a Janus-faced molecule that acts physiologically as a protective antioxidant but provokes inflammation and gout when it precipitates at high concentrations. Transporters play crucial roles in urate disposition, and drugs that interact with urate transporters either by intention or by accident may modulate SU levels. We examined whether in vitro transporter interaction studies may clarify and predict such effects.

METHODS

Transporter interaction profiles of clinically proven urate-lowering (uricosuric) and hyperuricemic drugs were compiled from the literature, and the predictive value of in vitro-derived cut-offs like C_max/IC₅₀ on the in vivo outcome (clinically relevant decrease or increase of SU) was assessed.

RESULTS

Interaction with the major reabsorptive urate transporter URAT1 appears to be dominant over interactions with secretory transporters in determining the net effect of a drug on SU levels. In vitro inhibition interpreted using the recommended cut-offs is useful at predicting the clinical outcome.

CONCLUSIONS

In vitro safety assessments regarding urate transport should be done early in drug development to identify candidates at risk of causing major imbalances. Attention should be paid both to the inhibition of secretory transporters and inhibition or trans-stimulation of reabsorptive transporters, especially URAT1.

Expert opinion on emerging urate-lowering therapies

INTRODUCTION

There has been a resurgence in gout therapeutics in the last decade, not only for the management of gout flares, but also for the treatment of hyperuricemia. This editorial summarizes new, emerging therapies for people with gout. Areas covered: We review several new therapies for gout, including those that are focused on lowering serum urate (levotofisopam, ulodesine, verinurad, merbarone, KUX-1151, UR-1102, FYU-981, SEL-212), or treating gout flares (canakinumab, bucillamine) or both (arhalofenate, diacerein). Expert opinion: Among therapies with both urate lowering and anti-inflammatory action, arhalofenate seems promising, but more data are needed. Examining therapies aimed at treating gout flares [anti-inflammatory action], bucillamine has some potential, but more data and Phase III studies are needed, to better understand its efficacy and safety. Among the urate-lowering therapies (ULTs), verinurad seems to be the most promising, while levotofisopam and ulodesine require more data. A uricase-replacement therapy with improved immune reaction (SLE-212) is in a Phase II trial. A number of ULTs including KUX-1151, UR-1102 and FYU-981 are in early development and more will be known once initial data and studies are published.

Treatment of hyperuricemia in gout: current therapeutic options, latest developments and clinical implications

Despite being the most common type of inflammatory arthritis, gout is often poorly managed. Except for febuxostat and pegloticase, research in new therapeutic agents for the management of hyperuricemia in gout remained insufficient for several decades. With emerging evidence of possible roles of hyperuricemia in cardiometabolic comorbidities, as well as more convincing evidence regarding poor outcomes (e.g. disability, recurrent hospital admissions) in patients with uncontrolled gout, several agents are current under development. Increasing knowledge regarding renal urate transporters has resulted in the development of new generation uricosurics such as lesinurad and arhalofenate. This review aims at discussing current therapeutic strategies for gout, as well as their limitations and the possible role of emerging agents in the chronic management of hyperuricemia in gout. Drugs in phases I and II of development will be discussed, along with new agents and therapeutic classes, such as purine nucleoside phosphorylase inhibitors and dual-action drugs. These new developments are encouraging, and will hopefully contribute to a more adequate management of hyperuricemia in gout.