Abatacept Demonstrates Safety and Efficacy in RA, Regardless of Malignancy History

Abatacept (ABT) demonstrated comparable safety and efficacy among patients with and without a history of malignancy diagnosed with rheumatoid arthritis (RA), according to study results published in Therapeutic Advances in Musculoskeletal Disease.

Investigators conducted a multicenter retrospective study and reported on the safety and efficacy of ABT among patients with RA with and without a history of malignancy.

Patients with RA treated with ABT were recruited from 2 centers and divided into 2 groups based on the presence (previous malignancy, PM group) or absence (no previous malignancy, NP group) of a history of malignancy.

The Disease Activity Score-28 for RA with C-reactive protein and Simplified Disease Activity Index were utilized for the analysis of disease activity.

A total of 312 patients were included in the analysis: 73 in the PM group and 239 in the NP group. Among patients in the PM group, the most common types of previous malignancies were lymphoma (27 malignancies), breast cancer (16 malignancies), stomach cancer (12 malignancies), and lung cancer (5 malignancies).

There was an improvement in disease activity 3 months after initiating ABT therapy among both groups.

During the observation period, 11 patients were newly diagnosed with a malignancy and 1 experienced a recurrence after initiating ABT, corresponding to a malignancy incidence rate of 1080.3 per 100,000 person-years.

Among the PM vs NP groups, mean patient age at ABT initiation was higher (72.5 vs 69.2 years), methotrexate use was lower (24.7% vs 48.5%), and Steinbrocker stage was greater. After adjusting the analysis for patient differences among these 3 factors, 68 patients were selected from each group.

There were no significant differences between the PM and NP groups in 1-year (89.4% vs 85.8% per year) and 10-year (58.5% vs 53.5% per 10 years; P =.49) ABT continuation rates. Additionally, there were no differences in malignancy incidence following ABT initiation between the PM (779.0 per 100,000 patient years) vs NP (1183.1 per 100,000 patient years; P =.68) groups.

Analysis was further adjusted for patient differences among known malignancy risk factors, including smoking history, interstitial lung disease, disease duration, sex, and inflammatory status; 40 patients were selected from each group. When controlling for these factors, no significant differences in the 1- and 10-year continuation rates of ABT (P =.70) or the incidence of malignancy (P =1.0) were observed between the 2 groups following ABT initiation.

This study was limited by its retrospective design and focus on a specific geographic region and race, making it challenging to generalize the findings to different populations, cancer types, and age groups.

The study authors concluded, “[Abatacept] may also be effective in older patients with a history of malignancy and may not specifically increase the risk of developing malignancy or relapse.”

Disclosure: This research was partially supported by JSPS KAKENHI Grant Numbers JP20K17446 and the Japan Rheumatism Foundation. One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.