Pfizer taps company coming off FDA ban for Paxlovid production in China

In building its COVID-19 pandemic products empire, Pfizer has steered relatively clear of controversy as it has developed vaccines and treatments quickly and manufactured them with remarkable efficiency.

But the company has perhaps opened itself up to scrutiny with its selection of a manufacturing partner in China for its COVID oral antiviral Paxlovid.

Pfizer will team with Zhejiang Huahai for five years. The Chinese firm will produce and sell Paxlovid exclusively in China. The company drew the ire of the FDA in 2018 when the agency investigated the company for the presence of a suspected carcinogen in a blood pressure medicine it produced.

In a scathing warning letter, the FDA blasted Huahai for altering its manufacturing process in 2011 to include a solvent suspected of producing the impurity.

“You failed to adequately assess the potential formation of mutagenic impurities when you implemented the new process,” the warning letter read.

The FDA also admonished the company for failing to act on a customer complaint in 2016 about the suspected carcinogen.

After a global recall of blood pressure medicines produced by Huahai and several other companies, the FDA banned drugs produced at Huahai’s factory in Chuannan. Last year, after Huahai addressed the compliance issues, the FDA lifted its ban.

Questioned about potential scrutiny it might be under, Pfizer offered only a bare-bones statement, confirming the manufacturing agreement. While Huahai announced the partnership on Aug. 17, Pfizer did not reciprocate.

Pfizer will provide the ingredients for Paxlovid, which is a combination of two drugs—nirmatrelvir and ritonavir—and Huahai will handle the manufacture, packaging and sale.  

Paxlovid will become the first oral antiviral COVID treatment available in China. Pfizer sold $8.1 billion of the drug in the second quarter and expects its sales for 2022 to be near $22 billion.