Research Documents Real-World Experience With Biosimilar Infliximab, Etanercept

Three presentations at the 2017 American College of Rheumatology’s Annual Meeting in San Diego, California, covered research on the real-world treatment of rheumatology patients with originator infliximab therapy and biosimilar infliximab (CT-P13; Inflectra and Remsima) and etanercept (Benepali) therapy.

Patients Maintained on Originator Infliximab Showed Greater Adherence

Patients with rheumatologic diseases maintained on originator infliximab had greater adherence to therapy than those who initiated the originator and switched to biosimilar infliximab CT-P13, according to a Turkish study conducted by Lorie A. Ellis, PhD, and colleagues.¹ Additionally, the researchers reported, CT-P13 discontinuation resulted in originator re-initiation in the majority of patients. The reasons for discontinuation in this study are unknown, but regional differences in practice patterns were observed.

A total of 697 adult patients with 1 or more rheumatoid arthritis (RA) diagnosis code who were taking reference infliximab were identified in a Turkish national healthcare database. Eligible patients initiated and continued the reference in the continuer cohort (CC) (n = 605) or initiated the reference and switched to CT-P13 in the switch cohort (SC) (n = 92) during the study period. Mean duration of originator infliximab therapy during the baseline period was 422 days (CC) and 438 days (SC). Average duration of follow-up was 16 months (CC) and 15 months (SC).

During the combined baseline and post-index periods, median time on any infliximab therapy was 1080 days (CC) and 540 days (SC). Discontinuation occurred in 19% (CC) and 87% (SC); mean time from index to originator discontinuation was 276 days (CC), while mean time from index to CT-P13 discontinuation was 132 days. Switching from originator infliximab to CT-P13 occurred in 13% of all originator initiators on the index date, and an additional 10% of the CC switched to a non-infliximab anti-TNF medication post-index. The majority of SC (82%) switched again post-index (away from CT-P13) and 88% of those re-initiated originator infliximab therapy.

Regional variation in switching was noted: switching from originator infliximab to CT-P13 occurred most frequently in Central Anatolia. Switching from CT-P13 occurred in more than 75% of SC patients in all regions, except for the Aegean.

US Biosimilar Infliximab Not Significantly Impacting Reference Infliximab

The US adoption of biosimilar infliximab (Inflectra) so far has been low and has not yet significantly impacted reference infliximab (IFX), according to an analysis by Janna Radtchenko, MBA, and colleagues.²

Longitudinal prescription and medical claims from Symphony Health were used to evaluate the uptake of biosimilar infliximab relative to reference infliximab from the FDA’s approval of biosimilar infliximab in April 2016 through the first quarter of 2017. The database contains claims records for 279 million patients representing an estimated 63% of specialty prescriptions, 58% of medical claims, and 25% of hospital claims in the United States.

Of the 78,481 patients who initiated a biologic or biosimilar therapy for RA since the approval of biosimilar infliximab, 0.1% were treated with the biosimilar and 6.6% were treated with reference infliximab, the analysis found. The first patient began the biosimilar in May 2016 and 78 patients started the biosimilar during the first quarter of 2017. Claims records show the following for patients treated with the biosimilar:

• 73.3% were female
• 64.4% were 65 or older
• 1 patient was commercially insured, the rest had unknown insurance status
• 34.4% were previously treated with reference infliximab
• 62.2% received the biosimilar as their first biologic
• Mean age for patients receiving the biosimilar was 65.9 compared with 55.0 for reference infliximab-receiving patients (P <0.0001)
• Mean number of prior biologics was 0.5 for patients receiving the biosimilar and 0.5 for patients receiving reference infliximab
• Median (mean) duration was 1.0 (4.5) days for the biosimilar and 60.0 (101.2) for reference infliximab due to late biosimlar adoption.

The researchers conclude that there has been no significant impact of the infliximab biosimilar on the use of the reference biologic. “Duration of therapy on [the biosimilar] is relatively short due to its delayed launch,” they note. The majority of [biosimilar infliximab] patients received it as their first biologic, but a third switched from [the reference]. Future monitoring of [biosimilar infliximab] uptake is warranted, especially as other approved biosimilars prepare for launch.

Biosimilar Use in Children and Young People with Juvenile Idiopathic Arthritis in a Real-World Setting

A study of biosimilar use in children and young people (CYP) with juvenile idiopathic arthritis (JIA) in the United Kingdom shows that these drugs are used as both first-line and subsequent-line biologic therapies, despite these indications having not been approved for such a use, according to Diederik De Cock, MD, and colleagues.³

Unlike the situation with RA, in which a majority of patients receiving biosimilars to date have switched from originator biologics, this initial finding in JIA suggests that biosimilars are being considered front-line therapy (as alternatives to the originator drugs) as a cost-savings measure, the researchers hypothesize. “Further follow-up of these children will assess the safety and effectiveness of biosimilars in pediatric use,” they conclude.

The Biologics for Children with Rheumatic Diseases (BCRD) study was launched in 2010 as an ongoing, prospective UK study of children with JIA who started biologic therapies other than etanercept. Follow-up data are collected at 6 months, 1 year, and annually thereafter. Since September 2015, data have been captured on 3 biosimilars available in the United Kingdom: 2 infliximabs (Inflectra and Remsima) and 1 etanercept (Benepali).

As of May 2017, 26 patients have been identified as having started a biosimilar:

• 81% Remsima
• 12% Inflectra
• 8% Benepali

Of these, 35% started a biosimilar as their first biologic therapy. Only 1 patient starting Remsima switched directly from the originator product, Remicade; 62% switched from an alternative, non-originator biologic.

Reasons for switching from alternative biologics were efficacy-related (50%), safety-related (31%), combined efficacy-and-safety-related (13%), and needle-phobia-related (6%).

No serious adverse events have been reported to date, and all of the CYP studied continue on their biosimilar drugs.

References

1. Ellis LA, Simsek I, Xie L, et al. Analysis of real-world treatment patterns in a matched sample of rheumatology patients with continuous infliximab therapy or switched to biosimilar infliximab. Presented at the American College of Rheumatology 2017 meeting, November 7, 2017; San Diego, California. Abstract 455. http://acrabstracts.org/abstract/analysis-of-real-world-treatment-patterns-in-a-matched-sample-of-rheumatology-patients-with-continuous-infliximab-therapy-or-switched-to-biosimilar-infliximab/

2. Radtchenko J, Smith Y, Kish J, Feinberg B. Real-world utilization of biosimilars for management of rheumatoid arthritis (RA) in the US. Presented at the American College of Rheumatology 2017 meeting, November 7, 2017; San Diego, California. Abstract 1041. http://acrabstracts.org/abstract/real-world-utilization-of-biosimilars-for-management-of-rheumatoid-arthritis-ra-in-the-us/

3. De Cock D, Kearsley-Fleet L, Baildam E, et al. Biosimilar use in children and young people with juvenile idiopathic arthritis in a real-world setting in the United Kingdom. Presented at the American College of Rheumatology 2017 meeting, November 7, 2017; San Diego, California. Abstract 2287. http://acrabstracts.org/abstract/biosimilar-use-in-children-and-young-people-with-juvenile-idiopathic-arthritis-in-a-real-world-setting-in-the-united-kingdom/