Category:Biologics: Difference between revisions

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The vaccines, although a long-established category of biologic medicine, deserve specific mention here. The traditional inactivated, attenuated, subunit, conjugate, and toxoid vaccines have been the foundation of public-health practice for over two centuries (Jenner's smallpox cowpox inoculation in 1796 being the conventional founding event). The contemporary additions of the recombinant subunit vaccines (the hepatitis B vaccine, 1986, the first FDA-approved recombinant vaccine; the human papillomavirus vaccines Gardasil and Cervarix), the conjugate polysaccharide vaccines (the ''Haemophilus influenzae'' type b vaccine, the pneumococcal conjugate vaccines, the meningococcal conjugate vaccines), the virus-like-particle vaccines (the HPV vaccines, Cervarix and Gardasil), the viral-vectored vaccines (the Ebola Ervebo, the COVID-19 AstraZeneca and Janssen vaccines), and the mRNA vaccines (the COVID-19 [[wikipedia:Pfizer-BioNTech COVID-19 vaccine|Pfizer-BioNTech]] and [[wikipedia:Moderna COVID-19 vaccine|Moderna]] vaccines, approved in late 2020) extend the platform.

The clinical-pharmacology challenges of the biologic category differ substantially from those of small-molecule medicines. Biologics are administered parenterally (subcutaneous, intramuscular, intravenous, intrathecal, intravitreal) because of their oral non-absorption; they are immunogenic to varying degrees (neutralising antibodies that reduce or abolish efficacy on continued exposure; immediate hypersensitivity reactions including anaphylaxis; the cytokine release syndrome characteristic of T-cell-engaging therapies); they have complex pharmacokinetics with non-linear clearance, target-mediated ~~drug~~ disposition, and substantially longer half-lives (weeks to months) than most small molecules; they are temperature-sensitive (the cold-chain requirement for many biologics has shaped both manufacturing and supply); and they are expensive, with annual treatment costs commonly in the tens of thousands of dollars. The introduction of biosimilars (the FDA Purple Book lists more than fifty approved biosimilars across major reference biologics including infliximab, adalimumab, trastuzumab, rituximab, pegfilgrastim, epoetin) has reduced costs but the substitution pattern remains substantially more conservative than that of small-molecule generics.

The clinical-pharmacology challenges of the biologic category differ substantially from those of small-molecule medicines. Biologics are administered parenterally (subcutaneous, intramuscular, intravenous, intrathecal, intravitreal) because of their oral non-absorption; they are immunogenic to varying degrees (neutralising antibodies that reduce or abolish efficacy on continued exposure; immediate hypersensitivity reactions including anaphylaxis; the cytokine release syndrome characteristic of T-cell-engaging therapies); they have complex pharmacokinetics with non-linear clearance, target-mediated disposition, and substantially longer half-lives (weeks to months) than most small molecules; they are temperature-sensitive (the cold-chain requirement for many biologics has shaped both manufacturing and supply); and they are expensive, with annual treatment costs commonly in the tens of thousands of dollars. The introduction of biosimilars (the FDA Purple Book lists more than fifty approved biosimilars across major reference biologics including infliximab, adalimumab, trastuzumab, rituximab, pegfilgrastim, epoetin) has reduced costs but the substitution pattern remains substantially more conservative than that of small-molecule generics.

== Classes indexed ==

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== Notes on scope ==

The boundary of this category is "medicine of biological origin or large-molecule complexity that cannot be characterised by routine chemical analysis." The peptide medicines synthesised by chemical synthesis (the small peptide hormones in their synthetic form: oxytocin, vasopressin, calcitonin, octreotide, leuprolide and other GnRH analogues) sit at the boundary; they are conventionally classified as biologics when their molecular weight and complexity make a chemistry-based regulatory pathway difficult, and as small-molecule medicines when the chemistry is straightforward. The category here uses the conventional regulatory boundary (FDA's Biologics License Application versus New Drug Application pathway) rather than a molecular-size cutoff. The recombinant proteins are biologics; the wholly synthetic peptides under a New Drug Application are not. The category extends to include the cellular and gene-therapy medicines, which the FDA regulates under its Center for Biologics Evaluation and Research (CBER) rather than under the small-molecule Center for Drug Evaluation and Research (CDER).

The boundary of this category is "medicine of biological origin or large-molecule complexity that cannot be characterised by routine chemical analysis." The peptide medicines synthesised by chemical synthesis (the small peptide hormones in their synthetic form: oxytocin, vasopressin, calcitonin, octreotide, leuprolide and other GnRH analogues) sit at the boundary; they are conventionally classified as biologics when their molecular weight and complexity make a chemistry-based regulatory pathway difficult, and as small-molecule medicines when the chemistry is straightforward. The category here uses the conventional regulatory boundary (FDA's Biologics License Application versus New Drug Application pathway) rather than a molecular-size cutoff. The recombinant proteins are biologics; the wholly synthetic peptides under a New Drug Application are not. The category extends to include the cellular and gene-therapy medicines, which the FDA regulates under its Center for Biologics Evaluation and Research (CBER) rather than under the small-molecule Center for Drug Evaluation and Research (the CDER name preserves the regulatory term).

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