Another placebo-controlled trial (FIXTURE), involving 1306 patients, studied the same regimens, but included subcutaneous etanercept as an active control. These patients were also followed up for 52 weeks and efficacy was assessed at week 12. The response to secukinumab was significantly greater than the response to placebo and etanercept whether assessed by the PASI or the investigator (see Table). There was a 100% reduction in the PASI score in 24.1% of the secukinumab 300 mg group and 14.4% of the 150 mg group, compared with 4.3% of the etanercept group and none of the placebo group.1
In both trials response to therapy was sustained in most (72–84%) patients treated for up to 52 weeks. The statistically significant advantage over etanercept was also maintained.1
Two trials have studied the feasibility of patients injecting themselves using prefilled devices. A total of 359 patients were randomised. They injected themselves with secukinumab 150 mg or 300 mg, or a placebo weekly for five weeks and then monthly, with efficacy assessed at 12 weeks. In the trial of prefilled syringes, a reduction of 75% on the PASI score was achieved by 75.9% of patients injecting 300 mg, 69.5% of those injecting 150 mg and none of the placebo group.2 The corresponding responses in the trial of an autoinjector pen were 86.7%, 71.7% and 3.3%.3 All the patients were able to use the devices.
The main adverse effects reported in the trials were nasopharyngitis and other upper respiratory symptoms. Patients taking secukinumab were also more prone to develop diarrhoea than those taking placebo. Neutropenia developed in 1% of patients.1 As secukinumab affects the immune system, there is an increased risk of infections such as candidiasis and oral herpes. Patients should be tested for tuberculosis before treatment. Live vaccines should not be given. Patients can have hypersensitivity reactions to secukinumab, but only 1% of patients developed antibodies to the drug during a year of treatment. There are no studies of drug interactions and secukinumab has not been assessed in pregnant or breastfeeding women.
Secukinumab has been shown to be effective for the treatment of plaque psoriasis for at least 52 weeks. Longer term studies will report on the efficacy and safety of continued treatment. While secukinumab appears to have an advantage over etanercept, the full results of a comparison with ustekinumab in 676 patients were not published at the time of writing. Results at 16 weeks showed a 90% improvement in the PASI score for 79% of the secukinumab group and 57.6% of the ustekinumab group.4 Other drugs acting on interleukin 17A are also likely to emerge in the future.