South Korean biotech firm Genexine faced regulatory and ethical scrutiny regarding its handling of safety data for its drug candidate ES16001, according to investigative reporting published by Maeil Shinmun on September 15, 2026. Preclinical trials for the compound revealed severe adverse effects in animal subjects, yet human trials for COVID-19 and shingles proceeded shortly afterward.
Timeline of ES16001 Development and Preclinical Safety Signals
ES16001 originated as a treatment candidate for shingles derived from an extract of Daphniphyllum macropodum (known domestically as dampalsu), according to Maeil Shinmun.
As the COVID-19 pandemic spread, the company expanded the scope of ES16001 to include a viral infection treatment. In September 2020, Genexine launched a Phase 2 trial in India involving 60 COVID-19 patients split evenly between a treatment group and a placebo group.
According to subsequent judicial findings cited by Maeil Shinmun, preclinical animal tests conducted on hamsters in 2021 revealed severe safety issues. Several test subjects died, while others exhibited clinical signs including drug reflux, hematemesis (vomiting blood), and severe lung hypertrophy. Court records indicated that these adverse findings were omitted from the final preclinical report submitted to the Ministry of Food and Drug Safety (MFDS).
Advancement of Shingles and COVID-19 Human Trials
Despite the adverse animal data, development across multiple indications continued. However, actual patient recruitment for the shingles study did not begin immediately.
On September 23, 2021, Genexine applied for domestic Phase 2 and 3 clinical trials for ES16001 as a COVID-19 treatment. On September 30, 2021, regulatory regulators issued a request for supplements covering 14 specific items. Internal MFDS reviews later showed that agency staff harbored concerns over whether the Indian Phase 2 trial data alone sufficiently demonstrated safety.
Representatives for the Democratic Party stated that the contact involved checking on progress after receiving documentation, and did not constitute a request for expedited approval or preferential handling. The MFDS ultimately approved the domestic COVID-19 Phase 2 and 3 trials on October 26, 2021.
Patient Administration and Regulatory Scrutiny
While some industry defenders argued that preclinical toxicity in one indication does not automatically invalidate research into another—due to differences in dosage, duration, administration routes, and animal models—international regulatory frameworks dictate caution. Under ICH M3(R2) guidelines, severe toxicity observed in nonclinical studies directly influences clinical trial continuity and often mandates supplementary nonclinical evaluation. An anonymous official at a domestic biotech firm told Maeil Shinmun that proceeding with human trials while cognizant of severe animal mortality presents ethical concerns, particularly if trial data is omitted or altered.
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