Early Impact of Expanding Generic Glatiramer Acetate Options Confined to Payer-Driven Conversion/Competition within Glatiramer Acetate Class

Background: Quarterly survey fielded by an independent market intelligence agency which specializes in tracking the US disease-modifying therapy (DMT) market, including benchmarking new launch metrics, in multiple sclerosis (MS).

Objectives: Characterize the impact of additional glatiramer acetate (GA) generics on the MS market in the United States.

Methods: Fielded in August (n=98) and November (n=103) 2017, US neurologists provided responses to an online survey.

Results: In August, use of the only available generic once-daily GA 20mg represented 14% of the GA class (3.4% of DMT-treated patients) driven by a 46% prescriber base. Following the early October launch of two additional GA generics, the generic share of the GA class increased to 21% (5.3% of DMT-treated patients), while the generic prescriber base remained steady at 46%. Compared to three months prior, shares of branded GA 40mg and the first-to-market generic GA 20mg decreased. However, reported use of the most recent GA generics, including the more preferred three-times-weekly GA 40mg dose, offsets those losses resulting in a GA class share of DMT-treated patients up 2 percentage points compared to one year ago. Two out of five neurologists report being pressured by managed care organizations to switch their branded GA patients to a GA generic. Indeed, 66% of generic GA 40mg initiations were due to managed care plan or pharmacy contacts advising a switch from branded GA 40mg. Over the next six months, neurologists anticipate that the GA class will begin to constrict due to a significant draw on branded GA share by non-GA DMTs that is not fully offset by the expected increase in generic GA 40mg share. Generic GA is projected to represent 31% of the GA class with a 56% prescriber base. Additional trending of generic GA metrics will be available at presentation.

Conclusions: The impact of expanding generic GA share, driven by managed care and pharmacy pressure, will be initially be restricted to conversion and competition within the GA class.  However, the anticipated decrease in GA share of DMT-treated patients, even with the increased number of GA agents, suggests that some neurologists anticipate choosing a non-GA DMT, such as teriflunomide, to use in the place of generic GA in treatment-naïve patients.