Injection of Etanercept into Arthritis Joints: Dose-Response and Efficacy

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Injection of Etanercept into Arthritis Joints: Dose-Response and Efficacy

Category:  17 RA‹treatment

Henning Bliddal, Etienne Qvistgaard, Lene Terslev, Anette Savnik, Christian

C Holm, Bente Danneskiold-Samsøe, Søren Torp-Pedersen

Institute, Frederiksberg Hospital, Copenhagen F, Denmark

Presentation Number: 1386

Poster Board Number: 341

Keywords: Ultrasound, Intra-articular, etanercept

Background: Patients with rheumatoid arthritis are often treated with

injections of steroid into

particularly active joints. Etanercept (ET) is proposed as an alternative

medication for intra-articular

use.

Objectives: To test the dose-response and localized efficacy of ET injected

into joints

with active arthritis as compared to a control joint to test for a systemic

effect.

Methods: Design. Randomized, controlled, double-blind (dosage) and observer

blind study.

Patients with active synovitis were eligible

for therapy with injection of ET if intra-articular steroid was

considered. Two joints were chosen in each patient; one joint received an

injection of ET and the other acted as control. In the first part of the

study the injected dose of ET was randomized to 2, 4 and 8 mg per joint

(double-blind). In the second part all

patients received 8 mg. 26 patients (mean age 58.6 y, range 25-82,

seropositive n=16) were injected

with ET: 16 wrists, 6 MCP, PIP, DIP, or MTP joints, 2 elbows, and 2 ankles.

Methods. Disease activity before the injection was evaluated clinically and

by MRI and Doppler ultrasonography (DUS). On US, the pixels on the color

DUS images were calculated as a fraction of the total synovial area. All

invasive

procedures were carried out by the guidance of ultrasound verifying the

correct placement of the

needle and injection. Treatment failure was defined as no subjective effect

at any follow-up

visit including a demand of a steroid injection, an option the patient could

choose at any

time point consulting the blinded observer. Follow-up lasted 3 months after

the injection.

Results: DOSE-RESPONSE STUDY: Not all patients had a satisfactory effect of

2 or 4 mg

ET, while no systemic effect was obtained on any of the doses in these

patients. Accordingly, 8 mg was

chosen for the rest of the study. STEROID INJECTIONS: 3 patients were

regarded as treatment failures and received steroid injections shortly

afterwards: Two in the 2 mg group

(PIP joint after 2 weeks and wrist after 2 months) and one after 8 mg (ankle

after 1

month). EFFICACY(all patients): VAS decreased after one week in 23/25 and

after one month in 14/25 (two-way ANOVA p<0.05). The DUS pixels decreased

after one week in 18/25 and after one

month in 21/25 patients (two-way ANOVA p<0.05), but not in the control

joints. Several joints went into long-lasting remission after

the injection and in one DIP after 2 mg and one wrist after 4 mg the DUS

activity

was extinguished. A more localized effect within the joint was obtained in

some of the large joints. Only one patient reported relief in other joints

than the wrist injected after a dose

of 8 mg.

Conclusion: ET given as intra-articular injection has a definite effect on

the synovitis

and may be used as an alternative to steroids for intra-articular therapy in

arthritis. An

increase of the dosage chosen in this study must be considered for use in

large joints.

Ref: Euro Radiol .2000; 10(10):1655, Ann Rheum Dis. 2001 Jul;60(7):690