To examine how a new class of drug: vesicular monoamine transporter (VMAT-2) inhibitors disseminated the market since its FDA approval in 2017.

In 2017, Deutrabenazine (AUSTEDO) was approved for Tardive dyskinesia (TD) and chorea associated with Huntington’s disease (HD). Valbenazine (INGREZZA) was approved for TD.

There are multiple factors that influence diffusion of new medications into the market: patient’s medical need, prescriber’s adoption of new practice, and external environmental factors such as cost. We sought to analyze how the two VMAT-2 inhibitors disseminated into the market.

This cross-sectional study conducted a descriptive statistical analysis on the prescription records of deutrabenazine and valbenazine between 2017-2020 from Medicare Part D public use files. In addition, the prescribers from Medicare Part D dataset were linked to the Open Payment database to see if there was a correlation between prescribing pattern and industry payments.

A total of 3,706 deutrabenazine prescribers and 4,897 valbenazine prescribers were identified. For both drugs, prescription volume increased annually across specialties. The majority of early deutrabenazpine prescribers were neurologists (N=57, 83%), while the majority of early valbenazine prescriberswere psychiatrists (n=73, 50%). 1,217 (32.8%) deutrabenazine (AUSTEDO) prescribers received industry payments from TEVA pharmaceuticals and 1,509 (30.8%) of valbenazine (INGREZZA) prescribers received industry payments from Neurocrine Biosciences.

Approximately 73.4% (deutrabenazpine) and 81.1% (valbenazine) of the industry payment was utilized in non-consulting services: the mean value per physician for non-consulting services was about $17,488 for deutrabenazine (AUSTEDO) and $24,496 for valbenazine (INGREZZA).

These results demonstrate annual growth in prescription volume for both VMAT-2 inhibitors after FDA approval, with neurologists and psychiatrists the dominant prescribers for deutrabenazine and valbenazine, respectively. Further research exploring the causative factors of new medication uptake is needed to better understand how medications disseminate across the market.