Pfizer Korea halted the supply of Vyndaqel Cap. 20 mg (Ingredient: Tafamidis), a transthyretin amyloid polyneuropathy (ATTR-PN) treatment, due to quality issues.

The drug, which delays peripheral nerve damage in adult patients with stage 1 symptomatic polyneuropathy, has no substitute drug with the same or similar efficacy. While Pfizer Korea still markets Vyndaqel Cap. 61mg in Korea, the drug has a different indication and cannot treat ATTR-PN.

The drug posted 1.3 billion won ($1.1 million) in sales last year, based on data from IQVIA, a pharmaceutical market research firm.

According to industry insiders, Pfizer Korea reported a supply shortage of Vyndaqel to the Korea Orphan and Essential Drug Center because the company had to discard some of the product due to a quality issue arising from one of its manufacturing plants.

“There was a problem with some of the product manufactured at our overseas plant,” a Pfizer Korea spokesperson said to Korea Biomedical Review on Monday. “Therefore, we had to dispose of the products.”

She added that the company is doing its best to resume the supply of Vyndaqel to Korean ATTR-PN patients.

However, the official did not disclose where the defective products were manufactured or what quality defects caused them to discard the products.

Pfizer Korea receives its Vyndaqel supply from its plants in Belgium, the U.S., and the U.K.

“We don’t have all the information about what kind of quality issue led to the company discarding the products,” the official said.