# Unnatural Products

> Santa Cruz biotech engineering macrocyclic peptides; argenx agreed November 9, 2026 to acquire its remaining shares for $550M upfront plus up to $595M in milestones.

## Why it is interesting

The proposed argenx acquisition is a platform-company exit with a conditional price ceiling, not a fully paid $1.15B takeover. It builds on argenx's existing minority stake and research collaboration. The buyer is seeking an internal macrocyclic peptide-discovery capability for potential oral and long-acting immunology medicines, while Unnatural Products retains science, team and its Santa Cruz site subject to transaction closing. Original publicly disclosed equity includes more than $6M seed (2019), $32M Series A (2023) and $45M Series B (2026), totaling more than $83M. The acquisition consideration is separate. Partnership headline values (e.g. Novartis) are not recognized revenue.

## Profile

- **Latest funding:** Series B — $45M (March 16, 2026)
- **Latest known valuation:** Not publicly disclosed
- **Total disclosed equity funding:** $83M
- **Stage:** series-b
- **Status:** private
- **Industries:** N/A
- **Coverage:** full
- **Last updated:** 2026-11-14
- **Latest funding investors:** The Venture Collective, argenx, Droia Ventures, Merck Global Health Innovation Fund, ARTIS Ventures, First Spark Ventures

## Key facts

- Nov 9 2026: argenx signed definitive agreement to acquire remaining UNP equity. $550M cash on closing plus up to $595M contingent milestones; up to ~$1.15B possible, not realized price. Buyer already owns a minority stake. Expected year-end close, not yet completed.
- The Santa Cruz discovery team is to become argenx's peptide discovery hub after closing; a two-plus-year prior collaboration preceded the acquisition announcement.
- Mar 16 2026: UNP closed $45M Series B led by The Venture Collective, with argenx, Droia Ventures and continuing investors. This is venture equity, not the acquisition payment.
- Dec 19 2023: $32M Series A co-led by Merck Global Health Innovation Fund and ARTIS Ventures. Other earlier seed investment is known from secondary sources but exact cash total isn't independently reconciled in this update. An earlier September 2019 seed was MORE THAN $6M led by ARTIS; together the three announcements disclose MORE THAN $83M of startup equity, not an exact $83M.
- Feb 18 2026: Novartis licensing includes up to $100M IN upfront and pre-IND milestone payments plus up to $1.7B in downstream milestones, with conditional royalties—not guaranteed cash, new equity, nor UNP's acquisition price.
- Research-stage platform; oral availability, target selectivity and clinical benefits require compound-specific preclinical and clinical validation. Company has not disclosed a marketed medicine.

## Funding history

- Series B · $45M · March 16, 2026
  Source: https://www.globenewswire.com/news-release/2026/03/16/3256110/0/en/unnatural-products-raises-45-million-series-b-financing-to-advance-macrocyclic-peptide-therapeutics.html
- Series A · $32M · December 19, 2023
  Source: https://www.globenewswire.com/news-release/2023/12/19/2798607/0/en/Unnatural-Products-Inc-Announces-32-Million-in-Series-A-Funding-Led-by-Merck-Global-Health-Innovation-Fund-and-ARTIS-Ventures.html
- Seed · More than $6M · September 17, 2019
  Source: https://www.globenewswire.com/news-release/2019/09/17/1916801/0/en/Drug-Discovery-Startup-Unnatural-Products-Inc-Receives-6-Million-in-Seed-Funding-led-by-ARTIS-Ventures.html

**By:** [Venture Capital Tracker](https://venturecapitaltracker.com/editorial-policy)
**Last updated:** November 14, 2026

**Editorial note:** AI tools assisted with research, structure, or drafting. Venture Capital Tracker retains human editorial responsibility for factual accuracy, relevance, and source quality before publication.

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Source: https://venturecapitaltracker.com/startup/unnatural-products