Fifteen percent is the equity Xenetic Biosciences (NASDAQ: XBIO) shareholders are expected to hold in the post-merger company under a definitive all-stock share exchange agreement signed September 16 with privately held Santersus AG. Santersus shareholders take the remaining 85%, calculated on a fully diluted, as-converted basis. The two figures sum to 100 before adjustments tied to Xenetic's net cash position at closing, so the final split is not locked.
The combined company would be renamed Santersus Bio, Inc. and trade on Nasdaq under the proposed ticker SNTS, following a Xenetic strategic review. Santersus chief executive James Ladtkow would lead the combined organization, backed by the existing Santersus management team. A proposed board of eight directors would include six Santersus nominees and two Xenetic nominees. Specified shareholders, directors, and officers would be subject to 180-day post-closing lock-up agreements.
The announcement discloses no transaction valuation, combined cash figure, or projected operating expenses. Investors will need forthcoming SEC filings, including a resale registration statement on Form S-1, to assess the combined company's funding position. Net cash adjustments at closing could shift the final equity percentages beyond the stated 85-15 baseline.
The combined pipeline
Four programs, two NET-targeting technologies. Neutrophil extracellular traps, or NETs, are structures implicated in multiple disease processes. Santersus contributes NucleoCapture, a blood purification platform that physically removes NETs from circulation. Xenetic contributes DNase technology designed to degrade NETs enzymatically in tissue. The two mechanisms address the same target through different points of intervention.
| Program | Technology | Stage | FDA designation |
|---|---|---|---|
| Sepsis | NucleoCapture | Late-stage study, ongoing | Breakthrough Device |
| Systemic lupus erythematosus | NucleoCapture | Advancing to late stage | Breakthrough Device |
| Liver transplantation | NucleoCapture | Ready for late-stage study | None disclosed |
| B-cell lymphoma (Israel) | DNase | Phase 1b alongside anti-CD19 CAR-T | None disclosed |
Breakthrough Device Designation does not constitute marketing approval, and progress in one indication does not establish effectiveness in the others.
The Q4 2026 target closing is contingent on Xenetic shareholder approval, Nasdaq listing requirements, and effectiveness of the Form S-1. Until those conditions are met, Xenetic and Santersus remain separate companies.