THE KEY PROVISIONS: A COMPARISON
Table 1. A comparison of key provisions of the biosimilars bills and the Hatch-Waxman Act
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The Waxman and Eshoo bills are a study in contrasts, differing in many key provisions that are important to the constituencies
interested in coming up with an appropriate and effective regulatory scheme for biosimilars. Several of these key differences
between these bills, and a comparison of their provisions to those in the Hatch-Waxman Act under which generic small-molecule
therapeutics are regulated, are highlighted in Table 1.
Market Exclusivity
The provision that is receiving the most attention is the exclusivity period that each bill would provide. This provision
mandates the length of time after initial introduction of a new biologic product, a new formulation containing the biologic
product, or a new indication for the biologic product, during which the FDA could not approve a biosimilar drug for marketing
in the US if it contained the same biologic, was contained in the same or a similar formulation, or was indicated for the
same medical or therapeutic use. As shown in Table 1, the Hatch-Waxman Act has similar provisions prohibiting approval of
generic pharmaceuticals by the FDA during the first five years after approval of a new small-molecule drug (commonly referred
to as a new chemical entity), and during the first three years after approval of either a new formulation containing a previously
approved and marketed small-molecule drug or a new medical or therapeutic use for a previously approved and marketed small-molecule
drug. The Act also provides for a six-month additional period of market exclusivity if the approval-holder undertakes pediatric
studies to determine the safety and efficacy of the approved drug in pediatric populations. Under the Hatch-Waxman rubric,
these periods of market exclusivity were intended to provide brand-name pharmaceutical companies with incentives to research
and develop new pharmaceutical products and methods for using such products, providing them with a head-start in the marketplace
before any competitor could enter the market with a generic version of the approved drug for the approved indication.
The Waxman biosimilars bill largely tracks the exclusivity periods seen in the Hatch-Waxman Act, providing the same five-year
and three-year exclusivity periods seen in the small-molecule regime and the same six-month pediatric extension. In contrast,
the Eshoo bill goes far beyond the Waxman bill, providing for 12 years of market exclusivity for a new biologic product, and
up to 14 years for a previously approved biologic product if, during the first eight years after its approval, the biologic
is approved for a new indication (although that term of exclusivity is measured from the date on which the biologic was first
approved for any indication). Thus, under the Waxman bill, a new biologic product could receive a maximum of 5.5 years of
market exclusivity before a biosimilar could be approved, whereas the Eshoo bill would provide for up to 14.5 years of market
exclusivity for a new biologic product.
Comparative Effectiveness
Another key difference between the bills is the requirement for new clinical trials on the part of the biosimilar applicant.
Under the Eshoo bill, biosimilar applicants would have to conduct clinical trials comparing the immunogenicity of the biosimilar
product to that of the reference (previously approved) biologic product, and those data would have to be included in the biosimilar
application submitted to the FDA. The FDA would be permitted to waive the requirement for such trials, but only after it published
regulatory guidance regarding the conditions under which such a waiver would be provided. In contrast, the Waxman bill would
not require new clinical trials for a biosimilar drug, and would permit the biosimilar applicant to rely on the safety and
efficacy data provided to the FDA by the reference drug manufacturer in its application for first approval of the reference
biologic, provided that the biosimilar application contains information demonstrating that: (a) the biosimilar product and
the reference biologic product have highly similar molecular structural features; (b) no clinically meaningful differences
would be expected between the biosimilar and the reference product in terms of safety, purity, and potency; (c) the biosimilar
and the reference biologic product have the same mechanism or mechanisms of action; and (d) the biosimilar and the reference
biologic product are used and administered in the same way, and the dosage form and strength of the biosimilar are the same
as those of the reference product. This scenario is similar to that used for the review and licensing of small-molecule generic
therapeutic pharmaceutical products under the Hatch-Waxman Act, which permits the generic applicant to rely on safety and
efficacy data provided to the FDA by the brand name applicant in support of a new drug application.
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