番茄社区

There was no difference in drug persistence or other biomarkers among patients with inflammatory bowel disease (IBD) treated with an adalimumab (Humira) biosimilar, U.K. researchers found in an observational cohort study.

After a year of follow-up, patients who were switched to SB5 from adalimumab and patients started on SB5 saw no difference in drug persistence, C-reactive protein levels, clinical remission, fecal calprotectin levels, or trough level, reported Lauranne A.A.P. Derikx, MD, PhD, and colleagues at the Western General Hospital in Edinburgh, Scotland, writing in the .

Adalimumab, a monoclonal antibody targeting the tumor necrosis factor (TNF), is effective in treating moderate-to-severe IBD, but the treatment is costly.

"All our ADA [adalimumab] patients switched to an ADA biosimilar in a managed switch program to effectuate cost savings," Derikx told 番茄社区.

SB5 was , but is not scheduled to be available until 2023. It in August 2017 to treat Crohn's disease and ulcerative colitis, among other indications.

"These data are important as it demonstrates safety and general efficacy of biosimilar adalimumab with the observed rates of both primary non-response to new starts and secondary loss of response similar to those expected based on larger studies of originator-treated populations," said Dana J. Lukin, MD, PhD, of New York Presbyterian Hospital-Weill Cornell Medicine, who was not involved in the study.

Lukin added these data are also consistent with data from a recent .

Researchers used a prescription database to identify IBD patients treated with adalimumab from a tertiary center in Scotland. The authors attempted to discover the long-term outcomes of IBD patients switched to the biosimilar SB5 after taking adalimumab (SB5-switch cohort) or the effects of starting SB5 (SB5-start cohort).

Participants were adults with IBD, who were taking adalimumab as maintenance therapy as of February 1, 2019. If patients started adalimumab after December 2018, they were then started on SB5. Patients were excluded if they lacked follow-up data beyond 1 month after starting SB5. Most patients were given 40 mg of the drug every other week.

SB5 drug persistence among both cohorts was the primary outcome. The secondary endpoints included adverse events, immunogenicity (adalimumab drug/antibody levels), clinical remission, biochemical and fecal biomarkers.

There were 481 patients in this study, 256 in the "SB5-switch cohort" and 225 patients in the "SB5 start-cohort." Both groups had a slight majority of men. About 78%-89% had Crohn's disease.

Patients in the SB5-switch cohort had a median follow-up of 13.7 months and patients in the SB5 start-cohort had a median follow-up of 8.3 months. On average, patients were treated 32.5 months before switching.

After a year of follow-up, adalimumab persistence, a marker for real-world benefit, was 62.5% in patients in the start cohort and 83.1% in the switch cohort.

Trough levels were stable with detectable adalimumab antibodies in 10.5% of the SB5-switch group and 22% in the SB5-start group. There were no differences reported in C-reactive protein, clinical remission, and fecal calprotectin, the authors said.

The most commonly reported side effect was injection site pain, and the authors noted adalimumab trough levels were similar to baseline at week 26 and 52 after the treatment switch.

About 35% of start and switch cohorts discontinued SB5. In the switch cohort, the most common reason for discontinuation was adverse events, followed by secondary loss of response. In the start cohort, primary non-response, secondary loss of response and adverse events were equally common.

"The study provides also the first data about double ADA biosimilar switch -- from ADA originator, to SB5 and then ABP 501 with encouraging, although limited results," said Madalina Butnariu, MD, of the Ohio State University College of Medicine in Columbus, who was not involved with the research. "I would think the results can be used for our patients in the U.S."

Of those who discontinued, 35 patients, most from the switch cohort, had a double biosimilar switch from adalimumab to SB5 to yet another adalimumab biosimilar, ABP 501.

Double biosimilar switch patients had mostly Crohn's disease and only 17% of patients underwent dose intensification. None of the double-switch patients needed dose adjustment for ABP 501 or discontinued within the average follow-up (34 weeks).

"These data are essential since many patients are switched once already and currently clinicians face the question if a second switch is possible. The possibility of a second switch might reduce anti-TNF/ADA costs even further due to market forces, and this might further improve worldwide access to anti-TNF," Derikx told 番茄社区, adding that her group will report their experience with a double switch of another monoclonal antibody, infliximab, soon.

Limitations of this study include a lack of a control to assess the possible continued use of the adalimumab originator. Follow-up data was not extensive. There was also a lack of standardized care in adalimumab dosing, dose adjustments, and disease activity. However, the authors described the non-standardized clinical care as an additional strength of the study as well, reflecting real-world practices since different clinicians provide slight variations in clinical practices.

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