Switching from a branded biologic drug to a cheaper “biosimilar” makes no meaningful difference to patients suffering from a series of chronic inflammatory conditions, according to a major study published this week.

However the pharmaceutical industry is urging patients and doctors not to read too much into the landmark study.

The Nor-Switch survey by the Norwegian government looked specifically at the impact of switching patients from Johnson & Johnson's blockbuster Remicade to a rival version of the drug infliximab, called Remsima produced by Korean group Celltrion.

The two-year study found that switching from the Remicade to Remsima “was not inferior to continued treatment” with Remicade.

The outcome is being seen as a boost for the fast-growing biosimilars sector. Pfizer, the world's largest drug company, was quick to assert that the study proved the case for its Remicade alternative Inflectra, which is also produced by Celltrion, which is currently available in Europe.

Johnson & Johnson is currently appealing a decision to allow Pfizer market Inflectra in the US.

Three drugs

The three drugs are used to treat a range of inflammatory conditions – rheumatoid arthritis, Crohn’s disease, ulcerative colitis, psoriatic arthritis , spondyloarthritis and chronic plaque psoriasis.

With annual US sales of about $5 billion, Remicade is J&J’s biggest product. Sales jumped 9.4 per cent in the most recent quarter.

The Irish Pharmaceutical Healthcare Association (Ipha) has warned that too much should not be read into the study and that it did not provide support for interchangeability of biologic drugs in general.

Ipha, which represents drug manufacturers in Ireland, said it "noted with interest" the results of the Nor-Switch study. It said it welcomed the development of biosimilars which provide savings for hard-pressed healthcare budgets.

But it added: "The decision to switch to a biosimilar should always be a clinical decision made by the treating physician, on an individual patient basis, supported by scientific evidence, and with patient awareness."

Circumstances

Ipha chief executive Oliver O’Connor, said: “As biosimilar medicines are neither identical to the originator nor to other biosimilars, the results of the Nor-Switch study pertain only to the set of circumstances set out in the study. They are not applicable more generally to biologic and biosimilar medicines other than the two products concerned.”

Where a generic medicine is a cheaper identical “copy” of a branded traditional small molecule drug, biosimilar are “me-too” versions of modern, large molecule complex biologic medicines. The nature of biologics means biosimilars cannot be identical to them but to be licensed they must show no meaningful difference in safety, purity or potency from the original drug.