Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


TNF Switching in PsA Patients.

Chakravarty1,  Eliza F., Reed5,  George, Decktor3,  Dennis, Bolge3,  Susan, Bolce3,  Rebecca, Ingham3,  Michael, DeHoratius2,  Raphael J.

Mountain View, CA
Centocor Ortho-Biotech, Horsham, PA
Centocor Ortho-Biotech
Stanford University, Sunnyvale, CA
University of Massachusetts Medical School

Purpose:

To examine patterns of Anti-TNF switching in psoriatic arthritis (PsA) patients and patient factors associated with switching.

Methods:

We identified biologic naïve PsA patients cared for by US rheumatologists participating in the CORRONA registry that initiated their first anti-TNF (Etanercept, Infliximab, Adalimumab) and followed for 2 years. Maintainers were defined as patients with no change of anti-TNF over two years. Switchers were defined as patients who discontinued and started another biologic within 6 months of discontinuation. Discontinuers were defined as patients who discontinued and did not initiate another biologic within 6 months. We defined early switchers as patients who switched within the first year and late switchers as patients who switched between 12 and 24 months. Maintainers were compared to switchers at time of switch using a comparable follow-up time point. Multivariable logistic regression estimated associations of characteristics with switching in early and late switchers.

Results:

There were 139 biologic naive PsA patients who initiated an anti-TNF and had >=2 years of follow up. Of these, 91 (65%) were maintainers, 18 (13%) were discontinuers, and 30 (22%) were switchers. Distribution of maintainers and switchers were significantly different between IV anti-TNF and subcutaneous (SC) anti-TNF with 85% maintainers, 9% discontinuers, 6% switchers in IV vs. 59% maintainers, 14% discontinuers and 27% switchers in SC anti-TNF (p=0.012). Among those patients who switched from any of the anti-TNFs the proportion achieving a Modified ACR 20 at 6 and 12 months was 23%, and 29%.

Table 1 compares characteristics among the patient groups. At initiation, switchers and discontinuers had higher disease activity as measured by patient pain, patient global and physician globas assessments. Switchers were more likely to be female, younger, have higher BMI and a shorter duration of disease. At the time of the switch, switchers and discontinuers had higher disease activity compared to maintainers.

In the multivariable analyses, Physician Global Assessment (OR=1.6 95%CI:[1.05, 2.41]) and duration of disease (OR=0.81 [0.67, 0.98]) were the best predictors for early switchers. In late switchers, Patient Global Assessment (OR=1.54 [1.14, 2.09]), Age (OR=0.92 [0.85, 0.98]), and being female (OR=10.7 [2.2, 52.5]) were the best predictors of switching.

Conclusions:

Over a two year period the majority of patients started on a TNF inhibitor for PSA will remain on their original treatment. Fewer patients discontinued IV TNF inhibition (Infliximab) than SC TNF inhibition (Etanercept, Adalimumab), however the factors associated with this are unknown. In those who remained on initial therapy benefit appeared to be maintained, in those who switched there was a mild likelihood of improvement. A number of factors were associated with either early or late switch.

Table 1. Patient Characteristics (Mean ± SD)

 Maintainers n=91Discontinuers n=18Switchers n=30p-value
Female41%61%73%0.005
Age52 ± 10.652 ± 9.147 ± 14.20.095
BMI31.0 ± 5.533.2 ± 5.734.3 ± 8.20.029
Duration PsA10.5 ± 10.47.8 ± 7.76.3 ± 7.80.092
At Initiation    
        Pt pain (0–100)34.4 ± 2251.4 ± 22.047.7 ± 19.9<0.001
        MD global (0–100)25.3 ± 20.029.2 ± 22.334.1 ± 19.30.112
        Pt global (0–100)35.1 ± 25.046.3 ± 23.144.2 ± 17.80.068
At time of Switch Discontinuation*    
        Pt pain (0–100)27.8 ± 23.245.0 ± 29.040.1 ± 24.7<0.001
        MD global (0–100)13.5 ± 14.721.7 ± 19.622.9 ± 16.90.008
        Pt global (0–100)24.4 ± 2233.8 ± 27.744.4 ± 19.9<0.001
* use comparable time after initiation in Maintainers.

To cite this abstract, please use the following information:
Chakravarty, Eliza F., Reed, George, Decktor, Dennis, Bolge, Susan, Bolce, Rebecca, Ingham, Michael, et al; TNF Switching in PsA Patients. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :1960
DOI: 10.1002/art.29725

Abstract Supplement

Meeting Menu

2010 ACR/ARHP