Press Release

ANTI-TNF THERAPIES FOR RHEUMATOID ARTHRITIS
APPARENTLY NOT ASSOCIATED WITH INCREASED CANCER RISK

SAN FRANCISCO – Therapies commonly used to treat rheumatoid arthritis do not seem to cause cancer, according to research presented this week at the American College of Rheumatology Annual Scientific Meeting in San Francisco, Calif.

Rheumatoid arthritis is a chronic disease that causes pain, stiffness, swelling, and limitation in the motion and function of multiple joints. Though joints are the principal body parts affected by RA, inflammation can develop in other organs as well. An estimated 1.3 million Americans have RA, and the disease typically affects women twice as often as men.

TNF-antagonists (also called biologics) are a class of drugs that have been used since 1998; overall, they have been given to more than 600,000 people worldwide. These drugs are given to lessen inflammation by interfering with biologic substances that cause or worsen inflammation.

It has been unclear whether blocking tumor necrosis factor is associated with an increased risk of developing cancer in patients with RA. Some studies have shown an association between RA itself and certain types of cancer – namely lung cancer and, above all, hematological malignancies – though the reasons for this increased risk are uncertain.

Researchers in Spain recently looked to BIOBADASER, a drug registry established in 2001 for the active long-term follow up of the safety of biological therapies in rheumatology patients. As of December 2007, the registry included 4,529 patients with RA who had been treated with TNF antagonists.  Information includes medical records information about the patients (e.g., gender, date of birth, diagnosis, date of diagnosis), treatment information (e.g., type, dates of initiation and discontinuation) and occurrence of adverse events.

Researchers looked at this group of patients, and a second control group of patients with RA not included in the BIOBADASER registry that were followed from 1999 to 2005, to estimate the incidence of cancer in patients with RA who were treated with TNF antagonists versus those not treated with TNF antagonists.

After a total follow up of 14,001 person years, (11,758 from the BIOBADASER group and 2,243 from the second group), researchers found 29 cases of cancer in the control group and 70 in the TNF-treated group
After adjusting for age, sex, disease duration, and disease activity, they found that the incidence of developing cancer in the TNF group was very close to that of the non-TNF treated control group (0.92), leading them to conclude that TNF use did not confer an increased risk for developing cancer.

 “Despite foreseen fears, blocking the tumor necrosis factor does not make patients more prone to develop cancer,” explains Loreto Carmona, MD, PhD; director of research unit, Fundación Española de Reumatología (Spanish Foundation of Rheumatology), Madrid, Spain. “All on the contrary, blocking the inflammation cascade may help diminish the overall risk of cancer in these patients.”

Patients should talk to their rheumatologists to determine their best course of treatment.
The ACR is an organization of and for physicians, health professionals, and scientists that advances rheumatology through programs of education, research, advocacy and practice support that foster excellence in the care of people with or at risk for arthritis and rheumatic and musculoskeletal diseases. For more information on the ACR’s annual meeting, see www.rheumatology.org/annual.

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Editor’s Notes: Dr. Carmona will present this research during the ACR Annual Scientific Meeting at the Moscone Center from 5:30 – 5:45 pm on Monday, October 27, in Room 307. Dr. Carmona will be available for media questions and briefing at 8:30 am on Monday, October 27 in the on-site press conference room, 114.

Presentation Number: 1266

Is The Exposure To TNF Antagonists A Risk Factor For Cancer In Rheumatoid Arthritis?

Lydia Abásolo1, Loreto Carmona2, Juan J. Gómez-Reino3, BIOBADASER Study Group. 1Hospital Clínico San Carlos, Madrid, Spain; 2Fundacion Espanola de Reumatologia, Madrid, Spain; 3Complejo Hospitalario Universitario de Santiago, Santiago, Spain

Previous studies have shown a strong association between rheumatoid arthritis (RA) and certain cancer types, namely lung cancer and, above all, hematological malignancies. Blocking tumor necrosis factor (TNF) remains a controversial therapeutic strategy in patients at risk of developing cancer.

Purpose: To assess whether RA patients treated with TNF antagonists are at higher risk of cancer than RA patients not exposed to these therapies.

Methods: BIOBADASER is a national drug registry established in 2001 for the active long-term safety follow-up of safety of biological therapies in rheumatic patients. Until December 2007 it includes 4,529 RA patients treated with TNF antagonists. Data from patients (gender, date of birth, diagnosis, date of diagnosis), treatment (type, dates of initiation and discontinuation), and adverse events are systematically recorded. EMECAR is an external RA cohort (n=789) followed-up from 1999 to 2005 to estimate the incidence of comorbidity in RA. We estimated the incidence rate (IR) per 10,000 patient-years of cancer in RA patients in both cohorts. Patients in the control group who had been treated with biologics were censored as of the initiation of exposure. The annual relative rate of incident cancer in exposed versus non-exposed was analyzed by Poisson multivariate models. The models were adjusted for baseline disease activity, sex, age, and disease duration. Results are expressed as incidence risk ratio (IRR) and 95% confidence intervals (CI).

Results: The total follow-up was 14,001 person-years (11,758 from BIOBADASER and 2,243 in EMECAR). We found 99 incident cases of cancer, 29 in the control and 70 in the TNF group (IR exposed = 60 per 10,000 patient-years (95% CI: 47 - 75); IR non-exposed = 129 (95% CI: 90 - 186). Patients on biologics were slightly younger than those unexposed (54±13 vs 61±12), and had a higher DAS28 at baseline (5.5±1.3 vs 4.0±1.4), whereas the duration of RA was similar between groups (10±8 years in exposed and 9±8 in non-exposed). The crude IRR of cancer was 0.46 (95% CI: 0.29 - 0.70). After adjusting for age, sex, disease duration, and disease activity, the IRR was modified to 0.92 (95% CI: 0.41-2.04), loosing statistical significance.

Conclusions: TNF antagonist exposure does not seem to be associated with a higher risk for developing malignancy in RA patients.

Disclosure Block: L. Abásolo, None; L. Carmona, None; J.J. Gómez-Reino, Schering Plough, 6; Wyeth, 6; Abbott, 8; Schering, 8; Wyeth, 8.