Bayer version of COVID-19 antimalarial hopeful may come with quality concerns: report

Bayer Headquarters site Leverkusen, Germany
Bayer is one in a suite of drugmakers to pledge free doses of hydroxychloroquine to the U.S. (Bayer)

Drugmakers are rushing to supply millions of doses of chloroquine phosphate, a cheap generic in testing as a possible treatment for COVID-19, after public interest sent demand through the roof.

But donated batches of the antimalarial drug from Bayer—which haven't been approved by the FDA—are drawing quality concerns. 

The U.S. government has grown worried that millions of doses of chloroquine phosphate donated to the U.S. by Bayer for emergency use may have been produced at facilities that didn't meet the FDA's quality standards, sources told Reuters. 

Bayer has donated about 3 million doses of its version of the generic antimalarial, marketed as Resochin, sourced from plants in India and in Karachi, Pakistan. Unlike other versions of chloroquine phosphate that have FDA approvals, Bayer's version has no FDA green light as an antimalarial, and its production facilities haven't been inspected by the agency despite some troubling manufacturing knocks in the past, Reuters reported. 

In an email Monday, a Bayer spokesman said the FDA had previously tested and cleared the Resochin donated to the U.S. for the national's Strategic National Stockpile, alleviating perceived quality concerns. 

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Hydroxychloroquine, a more tolerable form of chloroquine phosphate, has been touted by President Donald J. Trump and others as a possible therapy for COVID-19 in combination with the antibiotic azithromycin, sending demand for the drug skyrocketing in recent weeks. Drugmakers like Bayer, Mylan and Novartis have pledged millions of doses of both cheap generic antimalarials for emergency use and to supply a range of ongoing clinical trials. 

After a 2015 inspection of Bayer's own Karachi plant, Pakistani regulators cited the facility for "gross failure" in its manufacturing processes for the drug, Reuters said.

Another Resochin plant in India, run by Ipca Laboratories, has not been evaluated by the FDA, but the drugmaker has run afoul of the agency in inspections of other Indian plants that turn out chloroquine, hydroxychloroquine and their active ingredients. 

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In late March, the FDA said it would lift a five-year ban on products from Ipca's Indian plants so the drugmaker could ship hydroxychloroquine sulphate and chloroquine phosphate APls along with hydroxychloroquine sulphate tablets to the U.S.

That 2015 ban covered products from three Ipca manufacturing facilities because of rampant data manipulation. The FDA also cited a “cascade of failure” at one of the three plants, in Silvassa, India.

Ipsa said a shortage of the malaria drugs led the FDA to grant its import alert exception. 

While there are a number of approved generics of hydroxychloroquine, both finished doses and API are growing scarce in the U.S.  According to a note from Jefferies analysts in March, Ipca and Indian compatriots Natco are the only U.S. suppliers for chloroquine. Ipca, which still provides both drugs to the Indian market, has one of the largest supplies, and both produce APIs for both drugs in-house. 

As Jefferies said, the situation “could be positive” for Ipca, particularly because as recently as September, the FDA ravaged the company’s Silvassa plant where it makes its hydroxychloroquine sulphate tablets. Its failures were detailed (PDF) in an FDA Form 483 that had only three observations but a list of issues that stretches to 10 pages. 

Editor's Note: This story has been updated to correct an error and add a statement from Bayer. Bayer donated millions of doses of chloroquine phosphate to the U.S.