Pharmacy Benefits Company Predicts Significant Cost Hike in MG Therapy Soliris

Expanded use of the U.S. Food and Drug Administration-approved therapy Soliris (eculizumab) to treat myasthenia gravis (MG) could lead to a significant wholesale cost increase in 2018 and beyond, according to a new study by Prime Therapeutics.

Prime manages pharmacy benefits for health plans, employers, and government programs, including Medicare and Medicaid.

The study’s findings were presented at the AMCP Managed Care & Specialty Pharmacy 30th Annual Meeting, held April 23-26 in Boston.

Soliris, manufactured by Alexion, was approved as an expanded indication by the FDA in October 2017 for adults with generalized MG who were positive for anti-acetylcholine receptor (AchR) antibodies.

Before its approval to treat MG, Soliris was approved as a therapy for the rare conditions atypical hemolytic uremic syndrome (aHUS) and paroxysmal nocturnal hemoglobinuria (PNH).

The wholesale acquisition cost (WAC) is an estimate of the manufacturer’s list price for a drug to wholesalers or direct purchasers, without including discounts.

Because Soliris has an expensive WAC of more than $700,000 for the first year of therapy, Prime researchers assembled a forecast of medical and pharmacy claims data to prepare health plans for the potential impact of Soliris expenses, as well as to analyze overall trends.

Prime analyzed pharmacy and medical claims data from 2016 for more than 15 million commercially insured adults. They identified 1,574 members with a diagnosis of myasthenia gravis, of whom 511 (32%) had either a medical or pharmacy claim for an immunosuppressant or immune globulin.

Researchers assumed 10% of the 511 members would be anti-AchR positive and refractory (nonresponsive) to other therapies. These patients would likely be eligible for treatment with Soliris, according to data from the Soliris Phase 3 clinical trial (NCT01997229).

To help with their cost forecast, the study’s researchers used the $704,000 wholesale acquisition cost for the first year of therapy and assumed that patients would be 100% adherent to the medication. They calculated cost in a per member per month (PMPM) unit.

Results indicates that before the Soloris label expansion to include MG, there was a 53% increase in the PMPM expenditures of Soliris. The WAC went from $0.38 PMPM in the first quarter of 2016 to $0.58 PMPM in the third quarter of 2017.

By predicting the upward trend of this forecast (before MG), Prime researchers expect the per member per month cost expenditures to reach $0.74 in the third quarter of 2018.

But with the label expansion including new MG members, this would add an additional $0.20 to PMPM expenditures, leading to a PMPM of $0.94 in the third quarter of 2018.

Regardless of disease severity, Soliris is likely to be used in up to 74% of patients with MG who are positive for anti-AchR. Among those patients, researchers assume that 30% will begin taking Soliris, leading to an additional potential PMPM of $1.37, leading to a total per member per month expenditure of $2.11 in the third quarter of 2018.

“Given the high cost of Soliris and its approval for use by the majority of MG patients, forecasting this drug’s potential utilization and cost is crucial to helping our health plan clients understand the impact of the new, broader FDA-approved use,” Catherine Starner, PharmD, Prime’s health outcomes consultant senior principal, said in a press release.

Starner said the study demonstrates the importance of integrated medical and pharmacy claims data to perform drug utilization forecasting, especially for rare conditions that are treated with an expensive specialty drug.