# Ansun Biopharma
Ansun Biopharma, Inc. is a San Diego, California biotechnology company, formerly named NexBio, Inc., that develops the host-directed antiviral drug candidate DAS181 (fludase) for respiratory virus infections, and it appears to have remained an independent, privately held, Phase 3-stage company through mid-2026.[9](http://biobase.whitefordresearch.com/companies/ansun-biopharma) • [8](https://vivoseq.com/company/ansun-biopharma-inc) Founded in California in 2003, it has raised $195,138,386 across seven SEC Form D offerings between 2010 and 2019.[3](https://cdek.pharmacy.purdue.edu/org/1479/) • [4](https://www.dealdata.net/company-profile/0001534671/)
| Fact | Detail |
| --- | --- |
| Founded | 2003, California[3](https://cdek.pharmacy.purdue.edu/org/1479/) |
| Headquarters | 3030 Callan Road, Suite 200, San Diego, CA 92121 (incorporated in California)[1](https://www.sec.gov/cgi-bin/browse-edgar?CIK=&action=getcompany&company=Ansun+Biopharma%2C+Inc.&count=10&dateb=&owner=include&search_text=&type=) |
| Former name | NexBio, Inc. (SEC filings under that name through May 29, 2013)[1](https://www.sec.gov/cgi-bin/browse-edgar?CIK=&action=getcompany&company=Ansun+Biopharma%2C+Inc.&count=10&dateb=&owner=include&search_text=&type=) |
| Leadership | CEO and Chairperson Dr. Nancy Chang (since 2017); board member Dr. Allen Chao; Mikael Havluciyan listed as executive officer on Form D filings[5](https://www.ansunbiopharma.com/about/who-we-are/) • [4](https://www.dealdata.net/company-profile/0001534671/) |
| Total Form D funding | $195,138,386 across 7 rounds, 2010-2019 (last amendment November 24, 2020)[4](https://www.dealdata.net/company-profile/0001534671/) • [6](https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&filenum=021-348287) |
| Lead asset | DAS181 (fludase), Phase 3 in the STOP-PIV trial (NCT03808922)[7](https://www.ansunbiopharma.com/clinical-trials/) |
| Status through 2026 | Trial listings active through June 24, 2026; one tracker records "Left NME R&D (2025)"[8](https://vivoseq.com/company/ansun-biopharma-inc) • [3](https://cdek.pharmacy.purdue.edu/org/1479/) |
## What Ansun Biopharma does
Ansun develops DAS181 (fludase), a host-directed recombinant sialidase fusion protein derived from [Actinomyces viscosus](https://www.edgepedia.org/actinomyces-viscosus). Instead of attacking the virus, the drug removes sialic acids from the surfaces of respiratory epithelial cells; because influenza, parainfluenza, and related viruses use those sialic-acid molecules as entry receptors, stripping them away blocks viral entry. A peer-reviewed description notes that the protein's catalytic domain cleaves host respiratory epithelial receptors while an amphiregulin glycosaminoglycan-binding sequence retains the drug on cell surfaces.[9](http://biobase.whitefordresearch.com/companies/ansun-biopharma) The company says this mechanism could potentially block entry of all sialic acid-dependent viruses, including influenza, parainfluenza, metapneumovirus, and enterovirus 68.[5](https://www.ansunbiopharma.com/about/who-we-are/)
The company self-reports a team of approximately 25 scientists, doctors, and staff in San Diego.[5](https://www.ansunbiopharma.com/about/who-we-are/)
## History, people, and the NexBio years
The company operated as NexBio, Inc. before renaming itself Ansun Biopharma; SEC records show filings under the NexBio name through May 29, 2013 under CIK 0001534671.[1](https://www.sec.gov/cgi-bin/browse-edgar?CIK=&action=getcompany&company=Ansun+Biopharma%2C+Inc.&count=10&dateb=&owner=include&search_text=&type=) From 2004 through 2011 the company received several NIH research grants, including one for "Development of Fludase as an Anti-Influenza Agent," and in September 2006 a $50 million NIH contract to develop an influenza drug, known as the Fludase Contract.[2](https://www.justice.gov/usao-sdca/pr/ansun-biopharma-pay-more-2-million-overbilling-us)
Mikael Havluciyan is listed as an executive officer on the Form D filings of NexBio, Inc. and Ansun Biopharma, Inc.[4](https://www.dealdata.net/company-profile/0001534671/) According to the company, Dr. Nancy Chang, an internationally recognized biochemist who co-founded Tanox (acquired by [Genentech](https://www.edgepedia.org/genentech) in 2007 for just under $1 billion), has led Ansun since 2017 as CEO and Chairperson, and board member Dr. [Allen Chao](https://www.edgepedia.org/allen-chao) founded Watson Pharmaceuticals.[5](https://www.ansunbiopharma.com/about/who-we-are/) No source in the record independently names a founder or founding date; Purdue's Center for Drug Evaluation gives 2003 as the founding year.[3](https://cdek.pharmacy.purdue.edu/org/1479/) No source explains why the company renamed itself from NexBio to Ansun.
## DAS181 in the clinic
DAS181 reached Phase 2 in immunocompromised patients with severe lower respiratory tract parainfluenza infection; a randomized, placebo-controlled Phase 2 study was published in Clinical Infectious Diseases, and both the published report and the company say the data suggested benefit for patients receiving supplemental oxygen.[9](http://biobase.whitefordresearch.com/companies/ansun-biopharma) • [7](https://www.ansunbiopharma.com/clinical-trials/)
The lead program is STOP-PIV (DAS181-3-01, NCT03808922), a Phase 3 multi-center trial of DAS181 for lower respiratory tract parainfluenza infection in immunocompromised patients, with Ansun BioPharma as lead sponsor and listed as recruiting; the trial also included a severe COVID-19 sub-study, evaluating the drug against sialic-acid dependent respiratory viruses such as parainfluenza or influenza.[7](https://www.ansunbiopharma.com/clinical-trials/) • [9](http://biobase.whitefordresearch.com/companies/ansun-biopharma) Purdue's tracker records 11 trials in total with a highest phase of Phase 3.[3](https://cdek.pharmacy.purdue.edu/org/1479/)
## Funding and investors (by the numbers)
Ansun's SEC Form D record totals $195,138,386 across seven offerings between 2010 and 2019, amended November 24, 2020.[4](https://www.dealdata.net/company-profile/0001534671/) • [6](https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&filenum=021-348287) Round by round (amounts sold as filed):
- **2010:** $9,900,000 of a $16,000,000 round opened November 28, 2010
- **2013:** $5,000,000 of a $24,275,430 round opened April 25, 2013
- **2014:** $7,500,000 of a $17,900,000 round opened May 13, 2014
- **2015:** $4,000,000 of a $10,000,000 round opened November 18, 2015
- **2017:** $1,650,000 in debt, opened February 24, 2017
- **2018:** $67,088,386 in equity, first sale April 19, 2018
- **2019:** $100,000,000 in equity, first sale July 17, 2019 (Form D filed September 9, 2019, amended 2020)
The two large financings drew institutional investors. Press-release-based records describe a $85,000,000 Series A closed May 14, 2018 with Sinopharm Healthcare Fund, Lilly Asia Ventures, Lyfe Capital, Yuanming Capital, Matrix Partners China, 3e Bioventures Capital, Oceanpine Capital, VI Ventures, and Joincap Investment, and an $80,000,000 Series B closed October 1, 2019 with Oceanpine Capital, Greater Bay Area Development Fund Management, Junson Capital, Korean Investment Partners, Yuanming Capital, Lilly Asia Ventures, Matrix China, 3E Bioventures, and Lyfe Capital; no valuations were disclosed.[9](http://biobase.whitefordresearch.com/companies/ansun-biopharma) The press labels and dates do not map one-to-one onto the Form D rounds: the filed 2018 amount is $67,088,386 while the press Series A is $85 million, and the press Series B date (October 1, 2019) differs from the Form D first-sale date of July 17, 2019. The Form D figures are the SEC-filed ones; the discrepancy is unresolved in the record.[4](https://www.dealdata.net/company-profile/0001534671/) • [9](http://biobase.whitefordresearch.com/companies/ansun-biopharma)
## Controversies and disputes
The most significant event on record is a US Department of Justice settlement over billing on the NIH grants and the Fludase Contract. According to the DOJ, former Chief Executive Officer Mang Yu directed then-Vice [President](https://www.edgepedia.org/president-corporate-title) of Finance and Administration Dongmei Wang to fabricate employee timesheets to maximize billing on the NIH grants and the Fludase Contract, with the conduct occurring from 2004 to 2011.[2](https://www.justice.gov/usao-sdca/pr/ansun-biopharma-pay-more-2-million-overbilling-us) The company agreed to pay the NIH $1,654,600 in a criminal settlement (charging under 18 U.S.C. § 1031, federal program fraud) and $495,000 to settle civil False Claims Act allegations covering false claims submitted from September 1, 2006 through June 30, 2011, for a total of more than $2 million.[2](https://www.justice.gov/usao-sdca/pr/ansun-biopharma-pay-more-2-million-overbilling-us)
## Status and recent developments
The record through 2026 indicates a company still operating: its website is live, its pipeline page was updated in 2025, and the Phase 3 NCT03808922 trial was listed as recruiting, with a Phase III DAS181 trial record dated June 24, 2026. No reliable evidence of an acquisition, IPO, or shutdown was found.[9](http://biobase.whitefordresearch.com/companies/ansun-biopharma) • [8](https://vivoseq.com/company/ansun-biopharma-inc) One signal runs against this: Purdue's Center for Drug Evaluation records Ansun's status as "Left NME R&D (2025)" (NME meaning new molecular entity), which conflicts with the continued trial listings and is unresolved.[3](https://cdek.pharmacy.purdue.edu/org/1479/) The last SEC filing on record is the November 24, 2020 Form D/A.[6](https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&filenum=021-348287)
## References
1. [SEC EDGAR company search results for Ansun Biopharma, Inc.](https://www.sec.gov/cgi-bin/browse-edgar?CIK=&action=getcompany&company=Ansun+Biopharma%2C+Inc.&count=10&dateb=&owner=include&search_text=&type=)
2. [Ansun Biopharma To Pay More Than $2 Million For Overbilling The U.S. (DOJ)](https://www.justice.gov/usao-sdca/pr/ansun-biopharma-pay-more-2-million-overbilling-us)
3. [Organization: Ansun Biopharma, Inc. (Purdue CDEK)](https://cdek.pharmacy.purdue.edu/org/1479/)
4. [ANSUN BIOPHARMA, INC. — Form D offering history (DealData, from SEC EDGAR)](https://www.dealdata.net/company-profile/0001534671/)
5. [Who We Are – Ansun Biopharma](https://www.ansunbiopharma.com/about/who-we-are/)
6. [SEC EDGAR filings under File Number 021-348287 (Ansun Biopharma, Inc.)](https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&filenum=021-348287)
7. [Clinical Trials – Ansun Biopharma](https://www.ansunbiopharma.com/clinical-trials/)
8. [Ansun Biopharma, Inc. — VivoSeq](https://vivoseq.com/company/ansun-biopharma-inc)
9. [Ansun Biopharma — Whiteford Research Biobase](http://biobase.whitefordresearch.com/companies/ansun-biopharma)
---
*Topic: Encyclopedia › Society and history › Economics and business › Business and work › Business and work overview › Companies and corporations › Venture-backed startups and growth companies › Health, biotech, and medtech startups › Biologics and antibody developers*
*Initially written Sep 17, 2026 · Edited: Oct 11, 2026; Oct 15, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license