Session Information
Session Type: Abstract Submissions (ACR)
Background/Purpose:
Risks of hospitalized infections for newer biologic agents have not been well characterized compared to risks for anti-TNF therapy. Purpose: To compare the risk of hospitalized bacterial infections among RA patients starting rituximab (RTX), abatacept (ABA) or a new anti-TNF after failure of at least one previous anti-TNF
Methods:
Using data from 1998-2011 from the U.S. Veteran’s Health Administration, we identified 3872 patients who started RTX, ABA, or anti-TNF therapy after prior exposure to another anti-TNF agent. To minimize confounding from channeling of cancer patients to certain biologics, the 720 patients with a history of cancer between 1998 and 2011 were excluded, leaving a final sample of 3152 patients. . Baseline characteristics were defined in the year prior to treatment initiation. For each subject, exposure episodes were defined based upon days supply (injections) or usual dosing intervals (infusions), with 9 months assumed for RTX exposure. Current exposure was extended by 90 days for all biologics. The outcome was hospitalization with a primary diagnosis of bacterial infection. The hazard ratio (HR, 95% CI) for hospitalized infection for RTX and ABA vs. anti-TNFs was calculated, adjusting for confounders as in the Table.
Results: A total of 596 RTX, 451 ABA and 3111 anti-TNF(61% adalimumab) switcher treatment episodes (first initiation of the biologic),were identified among the eligible patients. Mean age was 60.2 +10.6 years, 87% were male; 25% had diabetes, 14% had COPD, and 44% used oral glucocorticoids. Two- thirds of anti-TNF exposure episodes were adalimumab. The mean ± SD follow-up time for each treatment episode was 11± 12 months. The most common types of hospitalized infections were pneumonia (37%), skin/soft tissue infections (22%), urinary tract infections (9%), and bacteremia/sepsis (7%).
Crude hospitalized infection rates/100 person years (95% CI) were: RTX=4.4 (3.1, 6.4), ABA=2.8 (1.7, 4.7), anti-TNF=3.0 (2.8, 3.9). Results were similar for a less restrictive cohort of RA patients excluding only hematologic cancer in the prior 12 months (4927 episodes, 3727 RA patients).
Conclusion:
In older, predominantly male US veterans with RA and a high comorbidity burden, risk of hospitalized bacterial infections for patients treated with RTX or ABA were comparable to patients switching to a different anti-TNF therapy (mostly adalimumab).
Table 1: Multivariable Adjusted* Hazard Ratios for Risks of Hospitalized infections Among RA Patients Switching to Abatacept or Rituximab Compared to Patients Switching to Another Anti-TNF (Analysis Restricted to Patients Without Prior Cancer)
|
Infection-Related Risk Factor |
Hazard Ratio (95% CI) |
|
Medication Exposure (referent to anti-TNF therapy) |
|
|
Abatacept |
0.72 (0.41-1.26) |
|
Rituximab |
1.14 (0.70-1.87) |
|
Age Group (years) (referent to <50) |
|
|
50-60 |
1.82 (0.86-3.86) |
|
60-70 |
1.78 (0.82-3.86) |
|
70-80 |
2.11 (0.92-4.80) |
|
≥ 80 |
2.40 (0.80-7.15) |
|
Comorbidities |
|
|
COPD |
1.77 (1.20-2.59) |
|
Diabetes |
1.06 (0.75-1.51) |
|
Prednisone-equivalent steroid dose (referent to no use) |
|
|
1 – 7 mg/day |
1.33 (0.88-2.02) |
|
7 – 10mg/day |
1.31 (0.83-2.08) |
|
> 10mg/day |
1.71 (1.10-2.68) |
* adjusted for variables included in the table and additionally for heart failure, recent biologic switch in last 90 days, number of biologic switches and calendar year; none were significantly associated with the outcome
Disclosure:
J. R. Curtis,
Roche/Genetech, UCB< Centocor, Corrona,Amgen, Pfizer, BMS, Crescendo, Abbott,
2,
Roche/Genetech,UCB, Centocor, CORRONA, Amgen, Pfizer, BMS, Crescendo, Abbott,
5;
S. Yang,
None;
N. M. Patkar,
None;
L. Chen,
None;
J. A. Singh,
research and travel grants from Takeda, Savient, Wyeth and Amgen,
2,
J.A.S. has received speaker honoraria from Abbott,
,
; aConsultant fees from URL pharmaceuticals, Savient, Takeda, Ardea, Allergan and Novartis.,
5;
G. W. Cannon,
None;
T. R. Mikuls,
Amgen; Genentech ,
2;
E. S. Delzell,
Amgen,
2;
K. G. Saag,
AHRQ, NIH/NIAMS,
2,
Amgen;Abbott;Ardea:Lilly:Merck:Novartis:Regeneron:Savient:URL,
5,
NOF;ACR,
6;
M. M. Safford,
None;
S. DuVall,
Anolinx LLC,
2,
Genentech Inc.,
2,
F. Hoffmann-La Roche Ltd,
2,
Amgen Inc,
2,
Shire PLC,
2,
Mylan Specialty PLC,
2;
K. Alexander,
Roche Pharmaceuticals,
1,
Roche/Genetech,
3;
P. Napalkov,
Roche Pharmaceuticals,
1,
Roche Pharmaceuticals,
2;
A. Kamauu,
Anolinx LLC,
4,
Genetech Inc, Roche, Shire, Dey Pharma,
2;
J. Baddley,
Merck Pharmaceuticals,
5.
ACR Meeting Abstracts - https://acrabstracts.org/abstract/hospitalized-bacterial-infections-among-u-s-veterans-with-rheumatoid-arthritis-initiating-tnf-antagonist-and-newer-biologic-agents/