Chinese biotech firm Kintor Pharmaceutical Limited saw its stock price jump by more than 20 percent the day after it announced on April 25 that it had “completed the first patient enrollment and dosing” in a late-stage U.S. clinical trial of its experimental COVID-19 treatment.

It was the company’s latest announcement about the progress of the drug, Proxalutamide. The Hong Kong-listed company’s stock price has nearly quadrupled since March 1 as some analysts wrote about the big sales potential for a COVID-19 treatment. Kintor has seen its market capitalization soar to HK$23.4 billion ($3 billion) from HK$6.6 billion on March 1.

But the company had not dosed any patients as of early May, according to the doctor Kintor identified as its principal clinical trial investigator in documents it posted on a U.S. trials website. The doctor--California-based gastroenterologist Zeid Kayali--also told Reuters he was “not in charge” of the trial, contradicting what the company had said in the documents describing the study. Kayali declined further comment, referring questions to Kintor.

Told of Kayali’s comments, Kintor Chief Financial Officer Lucy Lu said Kayali was merely one of its trial investigators. She declined further comment on the firm’s announcement on patient dosing. Lu declined as well to name a different principal investigator, or the institution overseeing the trial, calling that information “confidential.”

Companies are not obliged to release such information. But many pharmaceutical firms routinely provide details about who is leading their clinical trial and which research organization or medical institution is responsible for ensuring patient safety and scientific validity.

Kintor’s lack of transparency, along with inconsistencies in the company’s statements, raise a “red flag” about the company’s claims, said Stephen Ostroff, a former U.S. Food and Drug Administration (FDA) chief scientist and two-time acting FDA commissioner.

Another red flag: Kintor has repeatedly touted a Brazilian study of Proxalutamide that claimed an effectiveness rate so high that Ostroff and other pharmaceutical specialists say it is hard to believe.

The Brazil study said Proxalutamide showed a 92 percent reduction in mortality risk among hospitalized COVID-19 patients, which Ostroff said would be “breathtakingly extraordinary” if true.

Alexandre Cavalcanti, director of Sao Paulo’s HCor Research Institute, called a presentation of the study’s findings by its authors “amateur” and said its claimed reduction of mortality risk is too high to be credible in light of a global struggle to find effective COVID-19 treatments.

Kintor stock turned briefly negative in morning trade in Hong Kong but was trading up more than 4 percent at 0303 GMT, putting it on course to its third straight session of gains.

STOCK GETS A BOOST

Proxalutamide does not have regulatory approvals and is not available for sale. The Brazil study of the drug has not been peer-reviewed or published, but the authors released a short presentation of its results during a March news conference. Kintor promoted their findings.

“Based on the positive results... we expect Proxalutamide could become an important tool in the global fight against COVID-19,” Kintor’s Chief Executive Tong Youzhi said in a statement announcing the Brazilian results on March 11.

That same day, Kintor’s stock price jumped by nearly 9 percent.

Lu, Kintor’s CFO, did not answer detailed questions from Reuters about the criticisms of the Brazil study and Kintor’s claims about its U.S. trial.

One of the study’s authors, Brown University dermatology professor Carlos Wambier, dismissed its critics and called its results “very encouraging.”

In an April 2 client note, analysts from Beijing-based brokerage China Renaissance cited Kintor’s progress reports as evidence of the “potentially wider application of Proxalutamide.” They gave the stock a “buy” recommendation and set a target price of HK$50.75. Kintor’s stock now trades at about HK$66, having reached a record high HK$82 in late April.

“The stock price is majorly driven by the COVID-19-related clinical progress,” said Sam Hu, analyst at CMB International in Hong Kong.

One of the study’s authors is a consultant hired by a Brazilian Health Ministry official who is an ally of the country’s President Jair Bolsonaro. The president is a vaccine skeptic and a critic of masks and lockdowns who has promoted discredited COVID-19 remedies such hydroxychloroquine. The health official, Helio Angotti, assigned a team of consultants to find evidence to support Bolsonaro’s unfounded medical claims.

Angotti declined to comment. Bolsonaro’s office did not respond to written questions from Reuters. The consultant who co-authored the Proxalutamide study, Ricardo Zimerman, did not respond to requests for comment.

RESEARCH AND POLITICS

Lu said Kintor is in talks with Brazilian federal health regulator Anvisa about conducting its own clinical trial. Anvisa said in a statement that Kintor had not filed any formal request to conduct a trial, but did not comment on any talks between the regulator and the company.

Two Anvisa staffers, speaking on condition of anonymity, questioned the results of the Brazilian Proxalutamide study, saying the authors’ results presentation contained no detailed data or evidence. One of the Anvisa staffers characterized the presentation as more marketing than science. Brazil’s Health Ministry, in a March technical note, concluded that “the available evidence for the drug is still incipient,” with limited information on safety and outcomes.

Kintor originally conceived of Proxalutamide as a cancer treatment, before pivoting to COVID-19. Lu told Reuters that the FDA had allowed the firm to progress to a Phase III trial, skipping Phases I and II, after evaluating its previous oncology studies and the Brazil research. She declined to share any documentation from the FDA outlining that permission.

The FDA declined to comment on Kintor or its COVID-19 drug. Ostroff said it was concerning and atypical that Kintor used earlier-stage oncology trials, along with the questionable Brazil study, as shortcuts to a Phase III COVID-19 trial. The company’s answers to basic questions about its clinical trial, he added, were evasive.

“Most pharmaceutical companies, especially related to COVID-19, will be quite open about what sorts of trials they’re doing,” he said.