Starpharma lifts Petalion stake to 66% and takes control of FAP-targeted DEP® program
Starpharma (ASX: SPL) has increased its equity interest in Petalion Therapeutics from 22.5% to 66%, securing majority ownership, governance control and operational leadership of the FAP-targeted DEP® oncology program. The announcement was dated 20 October 2026.
Medicxi will remain a strategic partner and substantial shareholder, retaining a 30% interest. According to the company, majority ownership allows Starpharma to align development priorities, capital allocation and partnering decisions with its broader DEP® strategy.
Starpharma will host an online CEO briefing and Q&A session at 12.00 noon (AEDT) on Wednesday, 21 October 2026.
Ownership and governance structure
Petalion was established in 2024 as an asset-centric company focused on a single FAP-targeted oncology program using Starpharma’s proprietary DEP® dendrimer platform. Following completion of the initial R&D stage, Starpharma elected to increase its ownership before the program enters its next phase.
| Holder | Stake | Board role |
|---|---|---|
| Starpharma | 66% | Two directors; CEO Cheryl Maley to serve as Chair |
| Medicxi | 30% | One Board position |
| Petalion advisers | 4% | Not specified |
Under the revised structure:
- Petalion will become a UK-incorporated subsidiary of Starpharma Holdings Limited.
- Starpharma will lead operations and provide its DEP® platform, dendrimer, conjugation and development capabilities.
- Medicxi will continue to provide strategic, oncology-development, investment and asset-centric expertise.
How the investment is funded
Starpharma will contribute up to AUD $5.0 million to Petalion, made up of AUD $3.0 million in cash and up to AUD $2.0 million in R&D services. The services component is not a cash contribution.
The cash portion will be funded from the allocation for new R&D pipeline opportunities outlined in Starpharma’s recent capital raise. Sufficient funds remain within that allocation for Starpharma to progress other early-stage targeted oncology assets.
The allocation for new R&D pipeline opportunities sits within the recent capital raise, a fully underwritten entitlement offer that also funds the DEP® HER2-Lu Phase 1 study and extends the cash runway into FY28.
The company describes the transaction as a disciplined use of the capital allocated to new R&D pipeline opportunities. The announcement does not disclose a purchase price or valuation.
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Why FAP is a strong fit for the DEP® platform
Fibroblast activation protein (FAP) is a protein that is highly expressed in the tumour microenvironment (the area surrounding a tumour) across many solid tumours, with relatively limited expression in healthy tissue. This makes it a compelling pan-cancer target, with potential relevance across solid cancers including pancreatic, lung and breast cancers.
Starpharma’s tuneable DEP® dendrimer platform is designed to optimise tumour localisation, penetration, retention and payload delivery while limiting unnecessary exposure to healthy tissue. Petalion applies this approach in a FAP-targeted dendrimer-drug conjugate.
Cheryl Maley, Chief Executive Officer
“Petalion is strongly aligned with our strategy to build a focused portfolio of differentiated targeted-oncology therapies…”
Maley said the conjugate demonstrates the versatility of the DEP® platform across therapeutic payloads.
Next phase and what investors should watch
The next phase will focus on generating the evidence required for lead candidate selection and defining the program’s development and partnering pathway, with the aim of bringing an asset into the clinic. Initial research has supported progression into further optimisation and lead candidate selection.
The milestones outlined in the announcement are:
- Lead candidate selection
- Definition of the development pathway
- Partnering decision
The company identifies lead candidate selection, and definition of the subsequent development and partnering pathway, as the next value-inflection point. No timelines are disclosed.
Partnering is already a live theme for the platform, with the Radiopharm Theranostics option delivering a $0.5 million fee and a potential pathway to up to AUD $91 million plus royalties if exercised.
Medicxi’s retained ownership, Board representation and strategic input, together with Starpharma’s research capability and capital deployment, are described by the company as a balanced structure for advancing the program and evaluating future investment decisions.
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