MANILA - The World Health Organization and drug regulators of different countries should not disregard positive results of trials conducted to test the efficacy of the anti-parasitic drug ivermectin on COVID-19, a Japanese professor said Thursday.

Morimasa Yagisawa, a visiting professor at the Kitasato University - Omura Satoshi Memorial Institute in Tokyo, said health authorities “should pay attention to such doctor-initiated small trials” on the ivermectin’s use for either prevention or treatment of COVID-19.

The WHO, as of March 31, does not recommend the use of ivermectin to treat COVID-19, citing “inconclusive” evidence, based on the findings of a guideline development group that reviewed pooled data from 16 randomized controlled trials.

• READ: WHO joins Europe, Merck in recommending against ivermectin for COVID-19

The drug, which is used in the treatment of onchocerciasis (river blindness), strongyloidiasis and other diseases caused by soil transmitted helminthiasis, as well as scabies, has been making headlines in the Philippines as some lawmakers and certain groups actively advocate for its use, distribution of which in a community in Quezon City were even held, despite repeated warnings by the country’s Food and Drug Administration.

• 2 lawmakers distribute ivermectin tablets despite warnings from health experts

Speaking from Tokyo, Yagisawa told Manila-based reporters in a virtual interview that 105 studies of ivermectin in COVID-19, in 32 countries, have been registered, of which, 24 have been completed and published.

And the results showed that "ivermectin is almighty for prophylaxis, for treatment of early and late stage, and also for long COVID (or) post-acute sequelae (of SARS-CoV-2),” he said.

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Yagisawa, 79, is among four authors of an article titled, “Global trends in clinical studies of ivermectin in COVID-19” that was published in March on The Japanese Journal of Antibiotics. His fellow author is Satoshi Omura, who, along with William Campbell, was awarded the 2015 Nobel Prize in Physiology or Medicine for discovering the drug, avermectin, a derivative of which is the ivermectin.

The article stated that as of Feb. 27 this year, “results of 42 clinical studies worldwide have undergone meta-analysis and concluded that ivermectin is effective in the treatment and prevention of COVID-19.”

During the interview, Yagisawa explained that ivermectin’s probable modes of action against SARS-CoV-2, the virus that causes COVID-19, include the following, among others:

• It will inhibit the entry of the virus in to the human cell.
• In case the virus enters the human cell, it prevents protein processing to happen.

Yagisawa said that the WHO and other relevant state drug regulators “neglected all of such small trials” of ivermectin in COVID-19, citing supposed “heavy bias” and the need for 3-phase studies, including placebo-controlled trial.

The independent group of experts, ethicist and patient-partners that the WHO convened to evaluate trials has “determined that the evidence on whether ivermectin reduces mortality, need for mechanical ventilation, need for hospital admission, and time to clinical improvement in COVID-19 patients is of ‘very low certainty’, due to the small sizes and methodological limitations of available trial data, including small number of events.”

They did not assess the preventive aspect as it was outside the scope of the guidelines then.

The European Medicines Agency also said in late March that latest published evidence it reviewed from laboratory studies, observational studies, clinical trials and meta-analyses are insufficient to approve the use of ivermectin in COVID-19 outside clinical trials.

“Laboratory studies found that ivermectin could block replication of SARS-CoV-2…, but at much higher ivermectin concentrations than those achieved with the currently authorized doses. Results from clinical trials were varied, with some studies showing no benefit and others reporting a potential benefit,” the EMA said.

“Although ivermectin is generally well tolerated at doses authorized for other indications, side effects could increase with the much higher doses that would be needed to obtain concentrations of ivermectin in the lungs that are effective against the virus,” it added.

The EMA also noted that the studies it reviewed “were small and had additional limitations, including different dosing regimens and use of concomitant medications.”

Meanwhile, Merck, an ivermectin manufacturer, said that as of early February, its company scientists found “no scientific basis for a potential therapeutic effect against COVID-19 from pre-clincal studies” of the drug.

“Frankly speaking, WHO, FDA, EMA (European Medicines Agency), and also Japanese MHW (Ministry of Health, Labor and Welfare) are very much wishing to develop vaccine to prevent COVID… But if you use, if we use ivermectin for prophylaxis, pharmaceutical companies will lose the market of vaccine throughout the world,” Yasigawa said when asked what could else be the reason for those organizations’ decision against the use of ivermectin in COVID-19 cases.

“For example, here in Japan, one shot of the vaccine, if we use Pfizer’s, one shot is 2,700 yen. Japan ordered more than 100 million shots. You can easily calculate how much Pfizer will get. So, they don’t wish to lose such big market,” he said.

ABS-CBN News reached out by email to WHO, which said it cannot comment on Yasigawa's remarks other than its March 31 statement on ivermectin.

Yagisawa said that aside from the results of the trials, ivermectin is also “very, very cheap.”

“I don’t know why they neglect such positive result throughout the world,” he said.

In the Philippines, ivermectin has been allowed for compassionate use in COVID-19 cases in six hospitals, said Eric Domingo, the country’s chief drug regulator.

In June, an 8-month clinical trial to determine the efficacy of ivermectin against COVID-19 will commence in the country.

The drug will be tested on 1,200 asymptomatic and non-severe coronavirus patients who are at least 18 years old, said Department of Science and Technology Secretary Fortunato dela Peña.

• DOST: Ivermectin clinical trials to begin in June; P22M committed to project

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