New gout drug may help severely affected: Study

By Dr. Ananya Mandal, MDAug 17 2011

A new drug for gout could help very sick gout patients who don't get better with usual treatment, according to a new study. The research was designed and funded by the pharmaceutical company Savient, which markets the drug, called Krystexxa (pegloticase).

The clinical trial results show that patients taking the drug had fewer gout symptoms a few months after starting treatment than those who got a sham treatment. The researchers say most gout patients don't have very severe disease and should not be using the drug because the drug still has some side effects.

Study author Dr. Michael Becker, from the University of Chicago said, “The progression in these individuals is extreme.” The patients in the study had “gone on to have really severe -- on average disabling -- (gout), poor quality of life (and) lots of pain.” “This is not a medication to be undertaken in a much larger group of patients,” he added.

Of 5 or 6 million people in the U.S. with gout, about three percent do not get better with typical gout drugs, such as Lopurin and Zyloprim, or they can't take the medication for another reason, Becker and colleagues note in the Journal of the American Medical Association. Gout is a form of arthritis that occurs when uric acid -- generally passed out of the body in the urine -- accumulates in joints and forms crystals, causing swelling and pain.

Last year, the U.S. Food and Drug Administration approved Krystexxa -- given by injection every other week -- for use in those patients. Krystexxa works by breaking that uric acid down into a form that's more easily passed through the body.

The current report combines data from two drug trials involving 212 patients with chronic gout. Study participants who got the drug injection every two weeks for six months were compared to a group that received injections once a month and a group that got only drug-free placebo injections. The majority of patients were men -- in their fifties, on average.

Krystexxa caused uric acid levels to fall quickly - but that response didn't always last. Forty-two percent of patients in the biweekly group and 35 percent in the monthly group still had lowered uric acid six months after starting treatment.

On average, patients who received the drug had a bigger improvement in their general physical function and quality of life compared to those who only got the drug-free injections. And those who got the most frequent drug injections also reported the least pain.

However, more than nine out of ten patients reported at least one “adverse event” - including painful gout flare-ups or reactions to the injections, including a few cases of breathing problems. Those reactions were more common in patients taking Krystexxa. Some patients also reported headaches and nausea.

All told, there were seven deaths - a patient randomized to placebo who died before the first infusion, three patients assigned to pegloticase who died during the treatment period, and three patients (one taking pegloticase and two on placebo) who died after the treatment period. Becker and colleagues reported that the three deaths during the treatment period included two involving cardiac adverse events (a cardiac arrest and an arrhythmia) and one renal failure. There was also a nonfatal heart attack, also in a pegloticase patient. No cardiovascular events were seen among placebo patients.

Krystexxa costs about $5,000 per month. Becker said patients whose symptoms improved with the injections could probably go back on cheaper medications - but it's not clear yet how long most patients would have to get the injections first.

Becker said, “When you have seriously ill people who have no options, 40 percent (of patients getting better) is pretty good…Gout can be a really serious and disabling disease. With this and other (drugs) that are coming into line for treatment, we can do a good job in virtually all these people, including the sickest.”