The recent TGA approval of subcutaneous (SC) infliximab (Remsima SC) across all current infliximab indications expands the treatment options for adult patients with chronic inflammatory diseases, including inflammatory bowel disease.

The SC formulation was approved by the TGA in on 12th November 2020. The manufacturer, Celltrion, has applied for reimbursement, with hopes of PBS availability in 2021.

Speaking to the limbic, gastroenterologist Associate Professor Miles Sparrow from the Alfred Hospital in Melbourne described how the availability of the SC formulation is likely to bring a range of benefits.

“Many of our patients are young, so a self-administered treatment will suit a lot of people, including those who travel and don’t want to be tied down to having an intravenous infusion every two months,” he said. “Our infusion centres at the hospital are all way over-booked, so from the point of view of our workforce, the SC formulation is also helpful,” he added.

Professor Sparrow noted that the introduction of subcutaneous infliximab (Remsima) comes at a time when models of care are undergoing a revolution. “The pandemic has taught us that we can do a lot of things without bringing patients into the hospital – via telehealth, remote monitoring and other measures that have been put in place this year to limit risks to patients. “Subcutaneous therapies are another example of offering therapy while avoiding patients having to come into a hospital setting,” he said.

“Having patients come into the hospital every two months does give clinicians the ability to regularly monitor their patients. We try to maximise the time the patient comes into the hospital by doing other tests at the same time. The SC formulation means that we need to consider other ways to do this. Having said that, I think on balance the convenience factor of SC administration far outweighs this concern,” Professor Sparrow noted.

SC formulation efficacy and safety

The efficacy and safety of the SC formulation has been compared to the intravenous (IV) formulation in both active ulcerative colitis and active Crohn’s disease over a 12-month treatment period.¹ The efficacy following infliximab (Remsima SC) 120mg SC formulation was generally comparable to infliximab (CT-P13)  5 mg/kg IV formulation in terms of clinical response, clinical remission, and mucosal healing or endoscopy assessments, respectively, for active ulcerative colitis and active Crohn’s disease.¹

Potential serum benefits with SC versus IV infliximab formulations

The results of the pharmacokinetic studies in patients with active Crohn’s disease, active ulcerative colitis, and active rheumatoid arthritis suggest that trough concentrations are higher for the SC formulation given every two weeks compared to the IV formulation given every eight weeks.¹ The mean C_trough level at steady state was 20.0mcg/mL in patients with active Crohn’s disease and active ulcerative colitis.¹

Commenting on these results, Professor Sparrow noted, “We have learnt in recent years that serum levels do associate with treatment outcomes.” He also referred to the data showing no increase in immunogenicity with the SC formulation compared to the IV formulation,¹ which he considered was a positive sign.

The IV infusion is likely to continue to have a place in therapy

While the introduction of a SC formulation of infliximab is welcome news, Professor Sparrow noted that there’s likely to be a continued need for the IV infusion. “Some patients don’t like injections,” he said. “There are also patients who prefer the less frequent two-month scheduling where they can forget about the treatment in between times,” he added.

Injections administered in an infusion centre also provide assurance that the patient is receiving the drug. “There will be a group of patients where doctors will be hesitant to use the SC formulation where they’re concerned about adherence – these would be patients with a history of not taking recommended therapies. At least with an intravenous dose, you know that the patient has had the treatment,” he noted.

Initiating patients on subcutaneous infliximab (Remsima SC)

Subcutaneous infliximab (Remsima SC) is available as a 120 mg solution for injection in a single-use pre-filled auto-injector pen and also in a single-use pre-filled syringe.¹  The recommended dose is 120 mg once every two weeks.

When initiating new patients on infliximab, it is recommended to commence SC infliximab (Remsima SC) four weeks after the last of two IV induction infliximab infusions given two weeks apart.  The first SC dose should be administered under medical supervision. Subsequent doses may be self-administered by the patient where appropriate and after adequate training.

When switching patients from maintenance infliximab infusions, it is recommended to commence the SC formulation eight weeks after the last IV infliximab infusion.

For questions about Rensima SC contact Celltrion directly by clicking here.

References

1. Remsima Australian Approved Product Information