Certolizumab pegol: Has serious infection risk been overstated?

 

Contrary to prior reports, certolizumab pegol may not be associated with an increased risk of serious infections versus other biologics used in the treatment of rheumatoid arthritis, according to results of a recent U.K. registry study.

Certolizumab pegol (Cimzia) actually had a lower risk of serious infections, compared with etanercept in the primary analysis, according to a report on the study recently published in Annals of the Rheumatic Diseases.

In sensitivity analyses, though, the result in favor of certolizumab pegol was no longer significant, according to lead author Andrew I. Rutherford, MBBS, of King’s College London, and his coauthors.

“From these results, it would be wrong to conclude that certolizumab pegol has a lower rate of [serious infection] than other biologics,” Dr. Rutherford and his colleagues said in their report. “However, the risk does not appear to be significantly higher as has previously been suggested.”

The prospective, observational cohort study, based on data from the British Society for Rheumatology Biologics Register for Rheumatoid Arthritis (BSRBR-RA), represented 19,282 patients with 46,771 years of follow-up, according to the authors.

For the entire cohort, the incidence of serious infections was 5.51 cases per 100 patient-years (95% confidence interval, 5.29-5.71), and the 30-day mortality after serious infection was 10.4% (95% CI, 9.2%-11.6%), the report said. Compared with etanercept, the risk of serious infections was lower for certolizumab pegol (adjusted hazard ratio, 0.75; 95% CI, 0.58-0.97). Etanercept was used as the reference arm for comparison since it was the most widely prescribed drug in the registry.

That finding is in “direct contradiction” to a 2011 Cochrane review finding that certolizumab pegol was associated with an infection rate three to four times higher than other anti–tumor necrosis factor (anti-TNF) drugs (Cochrane Database Syst Rev. 2011;2:Cd008794), the authors noted.

 

“It would seem unusual for drugs acting on the same pathway with similar efficacy to have such drastically different infection risks,” Dr. Rutherford and his coauthors observed in their report.

However, investigators noticed that in the certolizumab pegol cohort, a large number of patients had not previously been on a biologic. When those biologic-naive patients were excluded from analysis, there was no longer a difference in infection rate favoring certolizumab pegol. “This suggests that unmeasured confounders may be responsible for the difference that was observed in the primary analysis,” the investigators said in their discussion of the results.

The Cochrane review showing an increased risk of serious infections with certolizumab pegol was a large network meta-analysis, which they said relies on indirect comparisons between drugs and could be prone to error if there are differences in study design.

“In contrast, national registers use the same methodology for detecting and reporting of adverse events for each drug,” they added.

Dr. Rutherford reported no disclosures. Study coauthors reported disclosures related to Pfizer, AbbVie, Bristol-Myers Squibb, UCB, and Celgene. The British Society for Rheumatology, which commissioned the study, receives income from AbbVie, Celltrion, Hospira, Pfizer, UCB, and Roche related to a different contract.

SOURCE: Rutherford AI et al. Ann Rheum Dis. 2018 Mar 28. doi: 10.1136/annrheumdis-2017-212825.

 

Contrary to prior reports, certolizumab pegol may not be associated with an increased risk of serious infections versus other biologics used in the treatment of rheumatoid arthritis, according to results of a recent U.K. registry study.

Certolizumab pegol (Cimzia) actually had a lower risk of serious infections, compared with etanercept in the primary analysis, according to a report on the study recently published in Annals of the Rheumatic Diseases.

In sensitivity analyses, though, the result in favor of certolizumab pegol was no longer significant, according to lead author Andrew I. Rutherford, MBBS, of King’s College London, and his coauthors.

“From these results, it would be wrong to conclude that certolizumab pegol has a lower rate of [serious infection] than other biologics,” Dr. Rutherford and his colleagues said in their report. “However, the risk does not appear to be significantly higher as has previously been suggested.”

The prospective, observational cohort study, based on data from the British Society for Rheumatology Biologics Register for Rheumatoid Arthritis (BSRBR-RA), represented 19,282 patients with 46,771 years of follow-up, according to the authors.

For the entire cohort, the incidence of serious infections was 5.51 cases per 100 patient-years (95% confidence interval, 5.29-5.71), and the 30-day mortality after serious infection was 10.4% (95% CI, 9.2%-11.6%), the report said. Compared with etanercept, the risk of serious infections was lower for certolizumab pegol (adjusted hazard ratio, 0.75; 95% CI, 0.58-0.97). Etanercept was used as the reference arm for comparison since it was the most widely prescribed drug in the registry.

That finding is in “direct contradiction” to a 2011 Cochrane review finding that certolizumab pegol was associated with an infection rate three to four times higher than other anti–tumor necrosis factor (anti-TNF) drugs (Cochrane Database Syst Rev. 2011;2:Cd008794), the authors noted.

 

“It would seem unusual for drugs acting on the same pathway with similar efficacy to have such drastically different infection risks,” Dr. Rutherford and his coauthors observed in their report.

However, investigators noticed that in the certolizumab pegol cohort, a large number of patients had not previously been on a biologic. When those biologic-naive patients were excluded from analysis, there was no longer a difference in infection rate favoring certolizumab pegol. “This suggests that unmeasured confounders may be responsible for the difference that was observed in the primary analysis,” the investigators said in their discussion of the results.

The Cochrane review showing an increased risk of serious infections with certolizumab pegol was a large network meta-analysis, which they said relies on indirect comparisons between drugs and could be prone to error if there are differences in study design.

“In contrast, national registers use the same methodology for detecting and reporting of adverse events for each drug,” they added.

Dr. Rutherford reported no disclosures. Study coauthors reported disclosures related to Pfizer, AbbVie, Bristol-Myers Squibb, UCB, and Celgene. The British Society for Rheumatology, which commissioned the study, receives income from AbbVie, Celltrion, Hospira, Pfizer, UCB, and Roche related to a different contract.

SOURCE: Rutherford AI et al. Ann Rheum Dis. 2018 Mar 28. doi: 10.1136/annrheumdis-2017-212825.

 

Contrary to prior reports, certolizumab pegol may not be associated with an increased risk of serious infections versus other biologics used in the treatment of rheumatoid arthritis, according to results of a recent U.K. registry study.

Certolizumab pegol (Cimzia) actually had a lower risk of serious infections, compared with etanercept in the primary analysis, according to a report on the study recently published in Annals of the Rheumatic Diseases.

In sensitivity analyses, though, the result in favor of certolizumab pegol was no longer significant, according to lead author Andrew I. Rutherford, MBBS, of King’s College London, and his coauthors.

“From these results, it would be wrong to conclude that certolizumab pegol has a lower rate of [serious infection] than other biologics,” Dr. Rutherford and his colleagues said in their report. “However, the risk does not appear to be significantly higher as has previously been suggested.”

The prospective, observational cohort study, based on data from the British Society for Rheumatology Biologics Register for Rheumatoid Arthritis (BSRBR-RA), represented 19,282 patients with 46,771 years of follow-up, according to the authors.

For the entire cohort, the incidence of serious infections was 5.51 cases per 100 patient-years (95% confidence interval, 5.29-5.71), and the 30-day mortality after serious infection was 10.4% (95% CI, 9.2%-11.6%), the report said. Compared with etanercept, the risk of serious infections was lower for certolizumab pegol (adjusted hazard ratio, 0.75; 95% CI, 0.58-0.97). Etanercept was used as the reference arm for comparison since it was the most widely prescribed drug in the registry.

That finding is in “direct contradiction” to a 2011 Cochrane review finding that certolizumab pegol was associated with an infection rate three to four times higher than other anti–tumor necrosis factor (anti-TNF) drugs (Cochrane Database Syst Rev. 2011;2:Cd008794), the authors noted.

 

“It would seem unusual for drugs acting on the same pathway with similar efficacy to have such drastically different infection risks,” Dr. Rutherford and his coauthors observed in their report.

However, investigators noticed that in the certolizumab pegol cohort, a large number of patients had not previously been on a biologic. When those biologic-naive patients were excluded from analysis, there was no longer a difference in infection rate favoring certolizumab pegol. “This suggests that unmeasured confounders may be responsible for the difference that was observed in the primary analysis,” the investigators said in their discussion of the results.

The Cochrane review showing an increased risk of serious infections with certolizumab pegol was a large network meta-analysis, which they said relies on indirect comparisons between drugs and could be prone to error if there are differences in study design.

“In contrast, national registers use the same methodology for detecting and reporting of adverse events for each drug,” they added.

Dr. Rutherford reported no disclosures. Study coauthors reported disclosures related to Pfizer, AbbVie, Bristol-Myers Squibb, UCB, and Celgene. The British Society for Rheumatology, which commissioned the study, receives income from AbbVie, Celltrion, Hospira, Pfizer, UCB, and Roche related to a different contract.

SOURCE: Rutherford AI et al. Ann Rheum Dis. 2018 Mar 28. doi: 10.1136/annrheumdis-2017-212825.