The US Food and Drug Administration (FDA) has approved boxed warning of higher blood clots and death risk with 10mg twice-daily dose of Pfizer’s Xeljanz (tofacitinib) drug in ulcerative colitis patients.

The regulator has also limited use of the drug to some patients who do not experience an effective response or have severe side effects with certain drugs.

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These changes have been recommended after the FDA examined interim results from an ongoing post-marketing safety clinical trial, Study A3921133, which assessed 5mg and 10mg Xeljanz in rheumatoid arthritis (RA).

As of January, 19 cases of blood clots in the lung were reported out of 3,884 patient-years of follow-up in the tofacitinib 10mg twice-daily group, versus three cases out of 3,982 patient-years in those on TNF blockers.

Furthermore, data showed 45 cases of death versus 25 cases respectively.

The 10mg twice-daily dose is yet to receive approval for RA or psoriatic arthritis (PsA), while the 5mg twice a day dose has been authorised for these conditions.

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However, the US regulatory agency has said that increased risks of blood clots and death with a higher dose in RA patients may also apply to ulcerative colitis patients.

Pfizer inflammation and immunology chief medical officer Tamas Koncz said: “Xeljanz is an important treatment option for rheumatoid arthritis, psoriatic arthritis and ulcerative colitis in appropriate patients who are suffering from these debilitating autoimmune conditions.

“Pfizer remains confident in the benefit / risk profile of Xeljanz, which has been studied in more than 50 clinical trials, including more than 20 trials in rheumatoid arthritis patients, and prescribed to over 208,000 adult patients worldwide in the last seven years.”

In March, the European Medicines Agency (EMA) advised against the use of a higher dose of tofacitinib, beyond the 5mg twice-daily recommendation, for rheumatoid arthritis patients.

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