OBJECTIVES: Monoclonal antibodies (mAbs) used in oncology account for more than 70% of the French market share of the antineoplastic agents. The launch of intravenous (IV) biosimilar drugs (BS) promises cost savings, although development of subcutaneous (SC) forms may impede competition.

The study aims to evaluate how the SC forms challenge the BS penetration in Paris University Hospitals (AP-HP) and French hospitals.

METHODS: This analysis focuses on three mAbs (rituximab, trastuzumab, daratumumab) from January 2018 to December 2022. They are the only anti-cancer mAbs to have both an IV and a SC form. Among them, only daratumumab has no biosimilar. Data were collected from the Agency for Information on Hospital Care database.

RESULTS: The number of chemotherapy sessions involving the three mAbs administration has increased by 11% and 16% for French hospitals and AP-HP respectively. Similarly, spending has increased by 67% and 34% respectively.

In 2018, SC trastuzumab was used in 52% and 39% of sessions in France and AP-HP respectively. Since the BS launch (2019), the use of the SC form has plummeted at AP-HP, but it remains administered in 47% of stays at national level. The BS penetration rate in 2022 is 68% (France) and 93% (AP-HP).

Over the period, IV (more than 95% are BS) and SC rituximab chemotherapy sessions are constant: 17% (France) and 14% (AP-HP) for SC forms, which are not widely used due to restricted indications compared to IV form.

Since the SC launch of daratumumab in 2021, the SC form has taken more than 95% of the market share for both France and AP-HP, which will complicate the arrival of BS.

CONCLUSIONS: Overall, when IV BS are available, they are mostly administered. Nevertheless, SC forms offer some advantages such as patient comfort, which have an impact on the BS penetration, as in the case of trastuzumab.