Imiglucerase biosimilar(ISU Abxis Co., Ltd.)

Approved in 1994 and assigned the International Nonproprietary Name (INN) imiglucerase by the World Health Organization, Cerezyme^® (Sanofi Genzyme) is an enzyme replacement therapy used to treat Gaucher disease in > 90 countries. At least two therapies approved outside the USA and the European Union, Abcertin^® and Asbroder^®, have adopted the identical INN imiglucerase. Both drugs were approved via regulatory pathways not aligned with World Health Organization Similar Biotherapeutic Product guidelines.

We analyzed whether the use of the identical INN "imiglucerase" for these drugs impacts adverse event (AE) reporting in the Sanofi Global Safety Database.

First, we reviewed all imiglucerase individual case safety reports (referred to as cases) including AE data reported between January 2012 and March 2018 that contained Abcertin or Asbroder in the narrative. In a second analysis, we examined cases from Mexico reported between May 2013 and March 2018 to assess changes in imiglucerase reporting following the 2015 approval of Asbroder in Mexico.

Fifty-six cases mentioning Asbroder and none mentioning Abcertin were retrieved in the first analysis. Upon close review, the AEs of 45 cases (80.4%) were attributed to Asbroder, one (1.8%) to Cerezyme; the specific drug attribution for the AEs of ten cases (17.9%) could not be determined. In the second analysis, a substantial increase in cases and AEs was observed in the period after Asbroder approval (73 cases with 150 AEs pre-approval vs 132 cases with 333 AEs post-approval). Twenty-three of 132 (17.4%) post-approval cases reported discontinuation of treatment (19 related to Asbroder AEs, and four related to Cerezyme AEs). Infusion-associated reactions occurred in 25/132 cases (17 Asbroder related, six Cerezyme related, two indeterminate).

This analysis demonstrates two potential consequences of identical INN use between Cerezyme and Asbroder: (1) an aggregate safety profile for Cerezyme that includes other products using the identical INN leading to inaccurate pharmacovigilance data and (2) healthcare providers switching, substituting, or potentially assuming interchangeability between the products. Identical INN use without the brand name differentiator may compromise pharmacovigilance data, potentially masking differences in safety profiles between products.