Why ustekinumab dosing differs in Crohn’s disease

Safety profile

So what does all the preclinical evidence suggest about safety of ustekinumab? The UNITI trials combined included more than 1,000 patients, and there were no deaths, Dr. Sanborn said. “Usually with TNF blockers in 1,000 patients you would see a few deaths.”

Patient withdrawals from the preclinical studies were also relatively low, Dr. Sanborn reported. “With ustekinumab monotherapy, drug withdrawal is only 3% or 4%, so it seems to be different from TNF blockers in that sense [too].”

In addition, the rates of adverse events were similar between placebo (83.5%) and ustekinumab’s combined every 8 week and every 12 week dosing groups through 44 weeks (81.0%), Dr. Sanborn said. The rates of serious adverse events were likewise similar, 15.0% and 11.0%, respectively. Reported malignancy included two cases of basal cell skin cancers, one in the placebo group and one in the every-8-week dosing group, he added.

“So all those black box warnings you’re used to worrying about with TNF blockers – serious infections, about opportunistic infections, malignancy – there is no black box warning with this agent around that.”

Dr. Sanborn noted that the FDA labeling reports infections. “We know Crohn’s disease patients are [also] getting azathioprine, steroids, methotrexate, so you will see some infections, but there wasn’t a consistent opportunistic infection signal.”

One case of reversible posterior leukoencephalopathy syndrome is included on the labeling. Dr. Sanborn also put this in perspective: “With all the experience in psoriasis and psoriatic arthritis, and the clinical trials [in IBD], there is just one case. So the relationship is not very clear.”

“The safety signals with ustekinumab are really very good. It seems to be an extremely safe agent – we really don’t see much in terms of infections,” Brian Feagan, MD, an internist and gastroenterologist at the University of Western Ontario in London, said in a separate presentation at the conference. “We don’t have a lot of long-term experience with ustekinumab in Crohn’s disease, but we have a lot of experience in psoriasis, and it’s a safe drug.”

“Ustekinumab may be our first really valid monotherapy, with less immunogenicity,” Dr. Feagan said.