Gout tophi may be cleared up with pegloticase, if its approved.

Pegloticase, previously called PEG/Uricase, is a gout tophi treatment whose developers will apply to the US FDA for approval later in 2008. It has completed its phase 3 trials and is currently in extension trials (OLE trials). The decision will probably come in the first six months of 2009. If positive, expect its developers to move quickly for approval in other countries, beginning with those that are members of the European Union.

Pegloticase is not a xanthine oxidase inhibitor, unlike febuxostat or allopurinol. It works by converting uric acid into a substance called allantoin which is more soluble than uric acid and better excreted. Hence uric acid levels fall.

TRIAL RESULTS OF PEGLOTICASE ON TOPHI

The company developing pegloticase have not yet publicly revealed everything they have learnt about it and its effects on tophaceous gout. The amount of data that is available for febuxostat is not currently available for pegloticase. More will be learnt later in 2008.

What they have said so far is very encouraging.

In December 2007 the company said:

"We believe that the most clinically important of the secondary efficacy outcomes assessed in these studies was the effect of pegloticase on gout tophi. The every two week dose arm ( i.e. the group of patients taking pegloticase every two weeks) attained statistical significance in the pre-specified pooled analysis for the elimination of gout tophi (complete elimination of at least one tophus and no new tophi), whereas the every four week dose group did not attain statistical significance."

In May 2008 the company said:

"31% of the patients who were non-responders for the resolution of gout tophi at the end of Phase 3 showed a complete response in the OLE, with additional patients showing a partial response for tophus resolution."

There appears to be a similar pattern to febuxostat. The longer you take it, the more likely it is that you will clear tophi gout up. And you'll probably need to be on a two week course.

In June 2008 the CEO of its developing company made a presentation about pegloticase's progress to financial analysts, which was also web cast. In his remarks about pegloticase and tophi, there was a definite delight in his voice when he described one case of how a multi-tophi sufferer, after 25 weeks of pegloticase treatment during the phase three trials, had cleared them up. And some of the tophi had been "weeping." i.e. exuding pus, which makes their disappearance even more welcome and necessary.

But pegloticase is for certain categories of gout sufferers among whom are treatment failure gout sufferers i.e. if other drugs simply don't work, pegloticase (if it's approved) may be prescribed. For most gout sufferers it won't be the first drug prescribed.