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: Drug immunogenicity is one of the main mechanisms behind therapeutic failure in rheumatoid arthritis (RA) patients. Our aim was to follow for 2 years RA patients treated with anti TNF agents and to analyze whether the duration of efficacious anti TNF treatment is correlated to their serum drug level at the moment of disease flare, immunogenicity and csDMARD association.
Methods: Ninety two RA patients already treated with anti TNF agents (infliximab, adalimumab, etanercept) were included in a prospective study for 2 years. The clinical activity was measured by DAS28-ESR and SDAI scores. Patient’s follow-ups were done every 2 months for infliximab (IFX) and every 3 months for etanercept (ETN) and adalimumab (ADL). At the moment of first sign of treatment failure, serum samples were obtained before anti TNF drug administration. Serum drug and anti-drug antibodies levels were measured by ELISA.
Results: Sixty five patients experienced signs of treatment failure and consequently they were tested for serum drug and anti-drug levels. Eighteen patients were excluded from final analysis due to changes in therapy that could affect serum drug level and immunogenicity, as increase in anti TNF agent dose and a new csDMARD association. Twenty patients treated with IFX experienced loss of response. Eleven patients had undetectable IFX serum level and 9 patients – detectable IFX serum level. The mean IFX treatment duration until the disease flare was not different in these 2 groups: 29.36±17.56 months vs. 40.66±36.96 months (P=0.379). Efficacious treatment duration did not correlate to IFX drug level (r=0.176, P=0.458) at the moment of disease flare, nor with combination therapy with csDMARD (r=-0.045, P=0.852). Nine patients had anti IFX antibodies, but their presence did not correlate to IFX efficacious time (r=0.302, P=196). Serum ETN drug and anti ETN antibodies levels were measured in 18 patients. Only 3 patients had undetectable ETN level. The mean ETN efficacious treatment duration was not significantly different between patients with detectable vs. undetectable ETN serum level (47.8±38.5 months vs. 57.67±23.75 months, P=0.679). Treatment duration did not correlate to ETN serum level(r=-0.244, P=0.328), nor to csDMARD association(r=-0.012, P=0.962). Nine patients treated with ADL for mean 45.56±23.88 months experienced first signs of loss of response. Only one patient had undetectable drug level being on efficacious treatment with ADL for 36 months. The mean efficacious treatment duration in patients with detectable ADL serum level was 46.7±25.2 months. Treatment duration did not correlate to ADL serum level (r=0.377, P=0.318), nor with csDMARD association (r=0.413, P=0.270).
Conclusion: The efficacious treatment duration of anti TNF agents in RA patients seems not to correlate to serum drug level at the moment of first signs of loss of response and may not be influenced by csDMARD association.
To cite this abstract in AMA style:
Mazilu D, Opris D, Iachim E, Deaconu C, Saulescu I, Borangiu A, Grosanu L, Constantinescu C, Balanescu A, Predeteanu D, Ionescu R. Time to First Signs of Loss of Response in Rheumatoid Arthritis Patients Treated with Anti TNF Agents: Correlations with Serum Drug Level, Immunogenicity and Csdmard Association [abstract]. Arthritis Rheumatol. 2015; 67 (suppl 10). https://acrabstracts.org/abstract/time-to-first-signs-of-loss-of-response-in-rheumatoid-arthritis-patients-treated-with-anti-tnf-agents-correlations-with-serum-drug-level-immunogenicity-and-csdmard-association/. Accessed .« Back to 2015 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/time-to-first-signs-of-loss-of-response-in-rheumatoid-arthritis-patients-treated-with-anti-tnf-agents-correlations-with-serum-drug-level-immunogenicity-and-csdmard-association/