A study of biologic dose reduction in patients with stable psoriasis has found patients are not particularly worse off by increasing the interval between injections.
The Dutch study published in JAMA Dermatology, which randomised 120 patients to either dose reduction or usual care, found the mean difference in PASI scores at 12 months from baseline was 1.2.
Disease activity as measured by PASI score was significantly lower in the usual care group compared to the dose reduction group at both 9 and 12-month time points.
However the median Dermatology Life Quality Index (DLQI) at 12 month showed dose reduction was non-inferior to usual care.
No significant difference regarding persistent flares was found between the dose reduction and usual care groups during the study period however patients in the dose reduction group had a higher use of topical corticosteroids (73% v 35%).
About half of the patients (53%) successfully tapered their dose – 19% to two-thirds of their original dose and 34% to half their original dose.
General musculoskeletal concerns were more common in the dose reduction group (event rate 0.042 v 0.009 per month) however the rates of serious adverse events were similar in both groups (0.015 v 0.010 per month) and none were thought to be related to dose reduction.
The study said the dose reduction strategy could have an effect on health care expenditure.
However, “…physicians and patients need to be aware of the chance of an increase in PASI score when trying to reduce the dose. It is important to weigh the risk of a PASI score increase against the benefits of using a lower dose of the biologic.”
Commenting on the study, Sydney dermatologist Associate Professor Stephen Shumack said it was an interesting paper but with relatively small numbers and in patients using the older anti-TNF agents or ustekinumab.
He said most Australian clinicians would be pretty careful about sticking to dosing recommendations – for a number of reasons.
“The most important one is probably the worry that if people stop or reduce the dose, [then] trying to get them back on the normal dose is going to result in a reduced efficacy.”
“And we know that from a number of the studies where they have stopped and started … using a second agent or restarting an agent which may have been stopped for, say, pregnancy, it is often not quite as good as it was the first time.”
He said the stringent PBS requirements for assessment and repeat scripts also mitigated against dose changes.
“They are basically 6-monthly reviews and if you go outside that time significantly, you’ve got to write a reason why. You can’t suddenly stop it and then in 6 months time, after the event, re-prescribe.”
And finally, why go against the evidence?
“All of these agents have undergone phase 3 studies involving thousands of people and the dose schedule has been thought to be most appropriate to keep the psoriasis under control and to minimise the risk of adverse events.”
“We know the adverse event profile of these agents is actually pretty low – so it’s not as though we have a lot of adverse events that we need to try to minimise by reducing the dose as we would with drugs like methotrexate and cyclosporine.”
“Why would we need to do it? There are no safety issues, there is a lot of choice these days, and there is that worry about bringing a flare under control again despite the reassurance of this paper.”