Attributes Affect Share
Determining a brand's intrinsic potential for share retention is critical to forming that strategy. Brand managers must pinpoint
the key factors associated with share retention and figure out how to make the best estimates of a brand's potential.
Analysis Group research indicates there are several product and therapeutic class attributes that are most strongly associated
with share retention. They can be grouped into two categories: product and class. (See "Retention Attributes.")
Retention Attributes: Based on an analysis of 30 recent patent expiration, the following attributes were correlated with a
better prescription retention 12 months after generic entry.
Product attributes. Generally, products that are more difficult to manufacture have higher potential for share retention because there will be
fewer generic entrants. This phenomenon has historically applied to certain advanced delivery systems—the osmotic pump technology
in Procardia XL (nifedipine), for example—and it is likely to come into play more frequently during the next few years as
biologic injectables, such as Epogen/Procrit (erythropeitin), begin to lose exclusivity.
Another product attribute associated with share retention is the complexity or risk associated with administering the drug.
Physicians are more conservative, payers less demanding, and generic entrants less aggressive about products with high risks
or challenging titration (concentration) issues. The blood-thinning drug Coumadin (warfarin) has had few generic competitors
and has sustained high sales for many years, in part because of the risks associated with its narrow therapeutic index.
Attribute-Based Forecast: Forecast models that use product attributes to predict the number of generic competitors after patent
expiration (and their estimated price) can be highly accurate.
One circumstance meriting special attention is whether the manufacturer has developed or licensed a follow-on product in the
class. Follow-ons and OTC options are typically considered long before the patent expires and are crucial in determining the
brand's potential. In most cases, a brand's share erosion is accelerated by the introduction of a new brand by the same manufacturer,
for example, AstraZeneca's launch of Nexium (esomeprazole) to follow Prilosec (omeprazole).
Class attributes. The therapeutic class is also critical to the brand's potential for retaining share. For instance, if there has already been
a significant number of generic entrants to a class, companies can expect a weak effect from a new generic, both on the brand
and the class overall, because some degree of shifting to generics may have already occurred.
Category conditions, in which a new brand or therapeutic class is about to enter the market, can override product attributes
that might help retain share. The post-expiration share loss experienced by Pepcid (famotidine), a leading H2 agonist for
treating acid reflux disease, was accelerated in part by the entry of proton pump inhibitors into the category.
In addition, the prescribing environment—including managed-care benefit structures (patient copay, prior authorization, and
step edits), state Medicaid preferred drug lists (PDLs), and Medicare coverage/reimbursement—is constantly changing. Modeling
these dynamics is an essential step in defining a product's optimal postexpiration strategy.
Another Analysis Group finding is that the more "retention" attributes a product has, the more prescription share it retains
in the face of generic competition. (See "More Attributes=More Share.") The research also shows that brand managers can use
these attributes to create powerful multivariate models that estimate brand share and allow scenario analysis of the brand's
strategic options. Such models can be en- hanced if the brand team is able to approximate the number of generic entrants by
determining the number of abbreviated new drug applications that have been filed for the compound.