The Pharmacist’s Authority to Substitute Biologic Medications Expands with the Inclusion of a New Ustekinumab Biosimilar Group

The landscape of pharmaceutical dispensing in France has seen a significant evolution with the recent authorization for pharmacists to substitute prescribed biologic medications with authorized biosimilars. This expansion now encompasses an eleventh group of biologic drugs, specifically focusing on ustekinumab, a widely used biologic agent. This development, effective from April 14, 2026, signifies a crucial step towards increasing patient access to more affordable biologic therapies while maintaining therapeutic equivalence. The inclusion of the ustekinumab group is subject to specific conditions, building upon the general framework already established for biosimilar substitution.

Understanding Biologics and Biosimilars

Biologic medications, derived from living organisms, are complex protein-based drugs used to treat a wide range of chronic and serious conditions, including autoimmune diseases, cancer, and inflammatory disorders. Unlike conventional small-molecule drugs, biologics are larger and more intricate, making it challenging to produce exact replicas. Biosimilars are highly similar versions of approved biologic medicines, demonstrating no clinically meaningful differences in terms of safety, purity, and potency. The development and approval process for biosimilars involve rigorous scientific evaluation to ensure they offer the same clinical benefits as the reference biologic.

The French healthcare system, like many others globally, has been actively promoting the use of biosimilars to foster competition, drive down healthcare costs, and improve patient access to innovative treatments. The ability for pharmacists to directly substitute biosimilars at the point of dispensing is a key strategy to achieve these objectives. This empowers pharmacists to make informed decisions based on therapeutic equivalence, thereby streamlining the treatment pathway for patients.

The Ustekinumab Group: A New Frontier for Substitution

The newly added ustekinumab group represents a significant therapeutic area where biosimilar substitution will now be permitted. Ustekinumab, marketed under the brand name Stelara, is a monoclonal antibody that targets specific proteins involved in inflammatory processes. It is primarily used to treat conditions such as moderate to severe plaque psoriasis, psoriatic arthritis, Crohn’s disease, and ulcerative colitis. These are often long-term, debilitating conditions requiring sustained treatment, making the cost of medication a considerable factor for both patients and healthcare systems.

The original press release indicates that Stelara 130 mg solution for dilution for infusion is not included in this substitution group, as this specific formulation is exclusively administered in a hospital setting. This distinction is important, as pharmacist-led substitution typically applies to medications dispensed in community pharmacies. The focus of this new authorization is on the Stelara formulations available for outpatient use.

Within the ustekinumab group, eight biosimilar medications have been identified and are now eligible for substitution. This offers a substantial array of choices for healthcare providers and patients, potentially leading to significant cost savings. The authorization, effective April 14, 2026, provides a clear timeline for the implementation of this new substitution policy.

Conditions for Substitution within the Ustekinumab Group

The authorization for pharmacists to substitute biosimilars within the ustekinumab group is not unconditional. In addition to the general requirements applicable to all biosimilar substitutions, specific criteria must be met. These conditions are designed to ensure patient safety, preserve therapeutic continuity, and maintain the integrity of the prescriber’s intent.

While the detailed conditions are referenced in "Encadré 2" (Box 2), a general understanding of biosimilar substitution principles in France is crucial. Typically, these include:

• Therapeutic Equivalence: The biosimilar must have demonstrated no clinically significant differences in efficacy and safety compared to the reference biologic.
• Prescriber’s Consent (Implicit or Explicit): Depending on the regulatory framework and specific drug class, prescribers may have the option to prohibit substitution. In many cases, implicit consent is assumed unless explicitly stated otherwise, but open communication between healthcare professionals is encouraged.
• Information to the Patient: Patients must be informed about the substitution and the specific biosimilar being dispensed. They have the right to refuse the substitution.
• Pharmacist’s Professional Judgement: The pharmacist must exercise their professional judgment to ensure the substitution is appropriate for the individual patient, considering factors like prior treatment history and potential contraindications.
• Traceability: Robust systems must be in place to track which biologic and biosimilar has been dispensed to ensure accurate patient records and pharmacovigilance.

The specific conditions for the ustekinumab group will likely emphasize these core principles, potentially including requirements related to patient monitoring for specific side effects or the need for close collaboration with the prescribing physician, especially given the complex nature of the conditions treated by ustekinumab.

Therapeutic Indications of Stelara

To fully appreciate the impact of this new substitution authorization, it is essential to understand the broad therapeutic applications of ustekinumab (Stelara). As outlined in "Encadré 3" (Box 3), Stelara 45 mg and 90 mg formulations (available in vials and pre-filled syringes and pens) are indicated for the treatment of several significant chronic inflammatory diseases:

• Plaque Psoriasis: For adults and children (depending on age and weight) with moderate to severe plaque psoriasis who have failed or are intolerant to other systemic therapies.
• Psoriatic Arthritis: For adults with active psoriatic arthritis who have had an inadequate response or are intolerant to disease-modifying antirheumatic drugs (DMARDs).
• Crohn’s Disease: For adults with moderately to severely active Crohn’s disease who have had an inadequate response, lost response, or were intolerant to conventional therapy or a TNF-alpha inhibitor.
• Ulcerative Colitis: For adults with moderately to severely active ulcerative colitis who have had an inadequate response, lost response, or were intolerant to conventional therapy or a TNF-alpha inhibitor.

The inclusion of ustekinumab in the biosimilar substitution program is therefore highly significant, impacting a considerable number of patients suffering from these chronic and often life-altering conditions. The availability of more affordable biosimilars could potentially broaden access to these treatments, especially for patients facing financial constraints or for healthcare systems aiming to optimize resource allocation.

Broader Implications and Future Outlook

The expansion of pharmacist-led biosimilar substitution to include the ustekinumab group is a clear indication of the French government’s commitment to leveraging biosimilars for cost containment and improved patient access. This policy is expected to have several key implications:

• Increased Competition and Cost Savings: The introduction of multiple biosimilars in the ustekinumab market is likely to drive down prices, benefiting both public healthcare budgets and individual patients through reduced co-payments.
• Enhanced Patient Access: By making these advanced biologic therapies more affordable, biosimilar substitution can help ensure that more patients receive the treatments they need, particularly those who might otherwise be unable to access them.
• Pharmacist Empowerment: This policy further empowers pharmacists as key stakeholders in patient care, entrusting them with the responsibility to make informed decisions about medication selection within approved therapeutic classes.
• Stimulation of Biosimilar Development: A robust biosimilar market encourages further investment in the development and manufacturing of biosimilars, fostering innovation and competition.

However, the successful implementation of this policy relies on several factors. Continued education for healthcare professionals and patients about biosimilars is crucial to address any lingering concerns or misconceptions. Robust pharmacovigilance systems are essential to monitor the safety and effectiveness of biosimilars post-authorization. Furthermore, clear communication channels between physicians, pharmacists, and patients will be paramount to ensure seamless transitions and optimal patient outcomes.

The inclusion of the ustekinumab group marks a significant milestone in the ongoing integration of biosimilars into mainstream medical practice. As the biosimilar market continues to mature, it is anticipated that similar expansions to other biologic drug classes will follow, further solidifying the role of biosimilars in providing accessible, high-quality, and cost-effective treatments for a growing number of patients. The French healthcare system’s proactive approach in this area serves as a potential model for other countries seeking to harness the benefits of biosimilar medicines. The ultimate goal remains to ensure that patients receive the most appropriate and effective treatment, regardless of whether it is the originator biologic or a biosimilar, within a framework that prioritizes safety, efficacy, and affordability.