FDA approves Ironwood's gout combination drug

The FDA has approved Ironwood Pharmaceuticals’ gout drug, Duzallo, although the regulator has required a black box warning highlighting risk of kidney failure.

A once-daily drug, Duzallo combines the standard of care treatment, allopurinol, with Ironwood’s lesinurad.

Ironwood said the drug offers a dual mechanism of action treating inefficient excretion and overproduction of uric acid in gout patients.

Gout is a painful form of inflammatory arthritis caused by elevated levels of uric acid in the blood.

The black box on the label, the FDA’s most serious side-effect warning, regards the risk of acute renal failure.

Ironwood bought rights to lesinurad from AstraZeneca last year, as the Anglo-Swedish firm is selling off certain pipeline drugs in order to raise cash to boost R&D in core areas such as cancer.

Massachusetts-based Ironwood expects its portfolio of gout drugs to generate around $300 million in peak annual US sales.

Approval of Duzallo was based on the clinical programme supporting Ironwood’s Zurampic (lesinurad) monotherapy and a pharmacokinetic study that evaluated the bioequivalence of the fixed-dose combination of lesinurad and allopurinol compared to co-administration of separate lesinurad and allopurinol tablets.

The efficacy and safety of lesinurad plus allopurinol were demonstrated in two pivotal phase 3 clinical trials, CLEAR 1 and CLEAR 2, which supported the Zurampic filing.

In clinical trials of adult patients with gout who failed to achieve target serum uric acid (sUA) levels on allopurinol alone, lesinurad in combination with allopurinol nearly doubled the number of patients who achieved sUA target below 6 mg/dL at month 6, reduced the mean sUA level to less than 6 mg/dL by month one and maintained that level through month 12.

Tom McCourt, senior vice president of marketing and sales and chief commercial officer at Ironwood, said: “With Duzallo, nearly twice as many patients with uncontrolled gout may be able to achieve target serum uric acid levels compared to those patients taking allopurinol alone, which is important, considering the significant unmet need among uncontrolled gout patients.”