His family confirmed to VnExpress his passing early Tuesday.
Nguyen Thi Son, his mother-in-law and founder of Son Kim Group, a family business with interests in property and retail, said on social media that he suffered from heart disease and frequently mentioned feeling "very tired" but remained committed to his work.
Nhan grew up in New York, the U.S., and got a Ph.D. in biotechnology from the University of Arizona.
After years of researching abroad, he returned to Vietnam and founded Nanogen Pharmaceutical Biotechnology Jsc in 1997.
He served as chairman and CEO of the firm until 2021, when he transferred the two roles to his wife, Nguyen Thi Hong Van.
But six months later he returned as CEO, and remained in the job until his passing.
In 2019 Nanogen was valued at over VND5 trillion (US$193 million). Nhan was its largest shareholder with a 59.6% stake, while Van owned 14.6% of the shares.
Nanogen was among three Vietnamese organizations researching Covid-19 vaccines, and became in late 2020 the first to conduct human trials for its vaccine, NanoCovax.
A year later the research team reported that a 25-microgram dose offered nearly 52% protective efficacy after 180 days.
Nanogen’s core achievements include producing pharmaceutical raw materials and injectable drugs using leading technologies.
Nhan also had a background in finance.
He served on the board of directors of Vina Securities Company from 2013 to 2016.
He was recognized for his expertise in mergers and acquisitions in the pharmaceutical, hospital and medical equipment sectors in the U.S. and Hong Kong.