UK Hospital Reports Slightly Uneven Results of Rituximab Switch

The experience of one hospital in the United Kingdom of switching patients to a rituximab biosimilar was described in a recent conference abstract, with the process of switching not going as well as it had previously for patients using infliximab and etanercept.

The abstract was presented at The European League Against Rheumatism (EULAR) European Congress of Rheumatology 2019, held last month in Madrid, Spain.

The Luton and Dunstable University Hospital, in Luton, United Kingdom, said it was one of the first to use a Commissioning for Quality and Innovation (CQUIN) framework, which seeks service quality improvement and new ways of providing care. The CQUIN required biosimilar adoption within 3 months for new patients and 1 year for existing patients already on the originator product.

In the United Kingdom, as in other parts of Europe, biosimilars are used as a way to conserve healthcare expenditures while achieving similar outcomes.

Patients with rheumatoid arthritis (RA) in this study were switched to Truxima, the biosimilar rituximab made by Celltrion. The drug has been extensively studied in Europe.

The hospital sent a “switch” letter to all patients taking the reference product; the mailing included information about Truxima. Patients had the opportunity to contact a nurse helpline for more information, if adverse events developed, or if their disease worsened.

Researchers collected data on any adverse events and disease outcome on either side of the switch. At the start, they identified 44 patients with RA using the reference. Four had stopped treatment prior to switching; the remaining 40 agreed to switch to Truxima.

Prior to the switch, median disease activity score in a count of 28 joints (DAS28) with C-reactive protein was 3.0 (range 0.6-5.1). Following the switch, it was 2.95 (range 1.5-5.7).

Eight patients (20%) reported adverse effects; 4 had serum sickness reactions within the first week of the second dose with a loss of efficacy. One patient went to an emergency department for fewer than 24 hours for further management.

All 8 patients decided against further treatment with the biosimilar; 3 were transitioned back to the originator with no further concerns. In 1 case, the provider changed the treatment to an biologic with a different method of action.

Three patients had mild intolerance, but agreed to continue Truxima and had no additional issues. One patient developed miliary tuberculosis and was taken off biologic therapy.

The researchers reported that annual cost savings of nearly £140,000 (US $174,588) were achieved by switching, and that all patients were willing to switch. There were no major differences in disease outcomes when looking at the entire group, they noted, but 10% had severe serum sickness reaction with loss of efficacy and a loss of confidence in the drug.

“Our experience of switching rituximab patients is certainly not as smooth as it was for infliximab and etanercept,” the researchers wrote, adding that they still support switching patients, although they said close supervision is required.

Reference

Nisar MK. Rituximab biosimilar non-medical switch—does it work? Presented at: The European League Against Rheumatism European Congress of Rheumatology 2019, June 12-15, 2019; Madrid, Spain. Abstract FRI0110.