ACR Meeting Abstracts

ACR Meeting Abstracts

Abstract Number: 560

Impact of Anti-Citrullinated Protein Antibody Status and Response to Abatacept

Leslie Harrold1,2, KK Gandhi3, H Litman4, S Kelly3, YF Li5, E Alemao3, S Deveikis4 and J Greenberg1,6, 1Corrona, LLC, Southborough, MA, 2Dept of Medicine, University of Massachusetts Medical School, Worcester, MA, 3Bristol-Myers Squibb, Princeton, NJ, 4Corrona, LLC., Southborough, MA, 5University of Massachusetts Medical School, Worcester, MA, 6NYU School of Medicine, New York, NY

Meeting: 2015 ACR/ARHP Annual Meeting

Date of first publication: September 29, 2015

Keywords: , ,

Session Information

Date: Sunday, November 8, 2015

Title: Rheumatoid Arthritis - Small Molecules, Biologics and Gene Therapy Poster I

Session Type: ACR Poster Session A

Session Time: 9:00AM-11:00AM

Background/Purpose:
Response to therapies may vary based on anti-citrullinated protein antibodies (ACPA)
status. We compared treatment response to abatacept in ACPA-positive versus -negative
RA patients (pts) in a US national observational
cohort. Methods: Using the Corrona RA registry, we identified new initiators of
abatacept between February 2006 and January 2014. ACPA testing (ELISA assay for
cyclic citrullinated peptide 2 seropositivity) was performed within 6 months of
initiation. Disease activity was assessed using CDAI at both initiation and at
a follow-up visit at 1 year (±3 months). The primary outcome was change in CDAI
from baseline, with a secondary outcome examining achievement of low disease
activity (LDA; CDAI ≤10) among those who initiated abatacept when in moderate
or high disease activity, and achievement of remission (CDAI ≤2.8) when
initiated with low, moderate or high disease activity. Multivariable linear and
logistic models were performed. Additionally, at 1 year we evaluated the
proportion of ACPA-positive and -negative pts who remained on abatacept,
switched to another biologic, or discontinued abatacept without initiating
another biologic.   Results: We identified 149 abatacept initiators who met inclusion criteria
(64 with ACPA <20 units/mL [considered negative] and 85 with ACPA ≥20 units/mL
[considered positive]). Most pts were female, Caucasian, aged 55.9–57.5 years,
with moderate disease activity and a median disease duration of 4–6 yrs (Table
1). The majority (77.9%) of pts had prior exposure to at least 1 biologic or
small molecule. Treatment with abatacept was associated with a mean change (95%
CI) in CDAI of –5.24 (–8.42, –2.06) in the ACPA-negative group compared with –7.99
(–10.71, –5.27) in the ACPA-positive group (Table 2). Achievement of LDA
occurred in 24.5% (95% CI 12.9, 36.1) of ACPA-negative patients vs 35.2% (24.1,
46.3) in the ACPA-positive group. Similarly, achievement of CDAI-defined remission
occurred in 3.2% (95% CI 0, 7.5) of ACPA-negative patients vs 17.1% (8.9, 25.2)
in the ACPA-positive group. Among the respective ACPA-negative and
ACPA-positive pts, at 1 year 54.5% vs 72.9% remained on abatacept, 28.1% vs
16.5% switched to another biologic and 17.2% vs 10.6% discontinued the drug
without initiating another biologic.

Conclusion: There was a suggestion of a greater response in ACPA-positive
abatacept users compared with ACPA-negative users although not significant. The
analyses were limited by sample size, warranting further evaluation.  

Table 1. Baseline characteristics
  Population comparisons
Baseline characteristics ACPA negative n=64 ACPA positive n=85 p-value
Mean age (SD), yrs 57.5 (13.1) 55.9 (12.6) 0.40
Female, n (%) 56 (87.5) 69 (81.2) 0.30
Caucasian, n (%) 56 (87.5) 61 (71.8) 0.10
Median disease duration (IQR), yrs 4 (10) 6 (11) 0.24
Mean CDAI score (SD) 22.9 (12.6) 22.2 (12.1) 0.84
Mean number of prior cDMARDs (SD) 1.8 (1.0) 1.9 (1.2) 0.90
Number of prior biologics/small molecules, n (%)      
0                       12 (18.8) 21 (24.7) 0.80
1 25 (39.1) 30 (35.3)  
2 20 (31.3) 27 (31.8)  
3+ 7 (10.9) 7 (8.2)  
ACPA=anti-citrullinated protein antibodies; cDMARD=conventional DMARD; IQR=interquartile range
   

Table 2. Outcomes

 

ACPA negative

n=64

ACPA positive

n=85

Unadjusted estimate

Multivariable

Adjusted estimate*

Primary outcome

Mean (SE)

Mean (SE)

p-value

Βeta coefficient (SE)

p-value

Change in CDAI

–5.24 (1.62)

–7.99 (1.39)

0.20

–2.03 (1.87)

0.28

Secondary outcome

%

%

p-value

OR (95% CI)

p-value

Overall achievement of LDA

24.5

35.2

0.20

2.00

(0.73, 5.5)

0.18

Overall achievement of remission

3.2

17.1

0.008

N/A†

N/A†

*Adjusted for age, sex, BMI, co-morbidities, disease duration, morning stiffness, baseline disease activity, and prior biologic/targeted synthetic DMARD use

†Owing to the small number of patients who achieved remission, the ability to adjust for more than one covariate in the model at one time was limited

ACPA=anti-citrullinated protein antibodies; LDA=low disease activity (CDAI ≤10); OR=odds ratio; remission (CDAI ≤2.8)

   
Disclosure: L. Harrold, Pfizer, AstraZeneca, 2,Pfizer, Genentech, 5,Corrona LLC, 3; K. Gandhi, Bristol-Myers Squibb, 1,Bristol-Myers Squibb, 3; H. Litman, Corrona LLC, 3; S. Kelly, Bristol-Myers Squibb, 1,Bristol-Myers Squibb, 3; Y. Li, None; E. Alemao, Bristol-Myers Squibb, 3,Bristol-Myers Squibb, 1; S. Deveikis, Corrona LLC, 3; J. Greenberg, Corrona LLC, 3,Corrona LLC, 1,AstraZeneca, Celgene, Genentech, Janssen, Novartis and Pfizer, 5.

To cite this abstract in AMA style:

Harrold L, Gandhi K, Litman H, Kelly S, Li Y, Alemao E, Deveikis S, Greenberg J. Impact of Anti-Citrullinated Protein Antibody Status and Response to Abatacept [abstract]. Arthritis Rheumatol. 2015; 67 (suppl 10). https://acrabstracts.org/abstract/impact-of-anti-citrullinated-protein-antibody-status-and-response-to-abatacept/. Accessed .

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