Switching From Reference Adalimumab to Biosimilar ABP 501 Does Not Cause Immunogenicity

Transitioning from reference adalimumab (Humira) to Amgen’s FDA- and EU-approved adalimumab biosimilar ABP 501 (Amgevita) was not associated with increased immunogenicity over an observation period of 72 weeks in patients with rheumatoid arthritis (RA), according to the results of an open-label extension (OLE) trial of a randomized 26-week phase 3 study.

The results of the OLE were presented by Eswar Krishnan, MD, and colleagues at the annual European Congress of Rheumatology, held June 13-16, 2018, in Amsterdam.

A total of 494 patients from the phase 3 trial completed the OLE trial (243 were taking ABP 501; 251 were using reference adalimumab). The researchers studied the incidence of binding anti-drug antibodies (bADAs) and neutralizing anti-drug antibodies (nADAs) after the patients were transitioned from reference adalimumab to ABP 501. Patients who had been randomized to ABP 501 in the original phase 3 study continued on ABP 501, while patients originally randomized to reference adalimumab were switched to ABP 501, so that all patients received ABP 501.

The researchers tracked the incidence of new ADAs in patients who were ADA-negative at the time of entry into the OLE study as well as the incidence after excluding transiently elevated ADAs. At baseline in the OLE study, there were 147 patients with negative bADA (-bADA) in the group that was using ABP 501 in both phases of the study and in 149 patients switched from reference adalimumab to ABP 501.

The number of new cases of positive bADA (+bADA) post-OLE were as follows:¹

Original Randomization Arm ABP 501/ABP 501 Reference adalimumab/

ABP 501

New cases +bADA post-OLE baseline

50

35

New cases of +nADA post-OLE baseline

20

12

Transient cases of +bADA

33

13

Transient cases of +nADA

8

2

Overall incidence of new cases +bADA

34.0%

23.5%

Overall incidence of new cases of +nADA

13.6%

8.1%

Incidence of non-transient cases of +bADA

11.6%

14.8%

Incidence of non-transient cases of +nADA

8.2%

6.7%

The researchers conclude that transitioning from reference adalimumab to biosimilar ABP 501 was not associated with an increase in immunogenicity in patients with RA who were followed for 72 weeks.

Reference

1. Krishnan E, Mytych D, Zhang N, Wang H, Kaliyaperumal A. Immunogenicity associated with a transition from adalimumab reference product to ABP 501 in patients with rheumatoid arthritis. Presented at the European League Against Rheumatism’s Annual European Congress of Rheumatology, June 13-16, 2018; Amsterdam, Netherlands. Abstract THU0198. doi: 10.1136/annrheumdis-2018-eular.7225.