Merck runs out of Parkinson’s disease drug Sinemet as manufacturing issues, forecasting miss lead to shortage

Merck & Co. is out of stock and dealing with back orders of some of its Sinemet Parkinson’s disease drug products that won't be resolved until next year. The issues have resulted from manufacturing problems at the CMO that produces the drug for Merck, and because the drugmaker badly missed its forecast for demand.

Merck recently let the FDA and other healthcare regulators around the globe know it expects the “constraint” for some Sinemet and Sinemet Plus products to continue into the first quarter of 2019. It suggested patients seek out levodopa products from other suppliers. Its controlled release version and other dose Sinemet products are unaffected at this time. 

But the “manufacturing-related delays” being experienced by CMO are not alone in causing the shortage, Merck explained in an emailed statement.

The drugmaker said it has only a small share of the levodopa market. But it explained that at the same time that supplies from generic makers have declined, and its own supplier ran into manufacturing issues,  “Merck has received an increase in orders for the product, far exceeding our forecast.”

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Merck did not respond to a question about whether a recently announced price cut may have contributed to that surge in orders. Sinemet was among six drugs whose prices the Kenilworth, New Jersey, drugmaker in July announced would be cut by 10%. Those cuts were part of several strategies Merck made as a “responsible pricing” pledge after President Trump called on drugmakers to be more reasonable in setting drug prices.

The move included slashing the price of its hepatitis C drug Zepatier by 60% and instituting price-hike controls across its entire portfolio. At the time, Evercore ISI analyst Umer Raffat said the moves were not that dramatic. He pointed out that Zepatier’s market share was small compared to competitors.

The market share of the other drugs named in its cuts, including prostate treatment Proscar and Sinemet, “are all TINY,” Raffat wrote. That’s because they’re off-patent and losing ground to generic competitors. Combined sales of the six products amounted to less than 0.1% of Merck’s total sales last year, Raffat said.

As for the Sinemet shortage, Merck said it is committed to doing its best “to ensure a reliable supply of Sinemet for patients and prescribers” and is working to resolve the situation as quickly as possible.