Trinity Delta FAP-Dox Phase Ib results confirm efficacy in SGC

FAP-Dox Phase Ib results confirm efficacy in SGC

Lighthouse | 18 December 2025

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Early data from the faridoxorubicin (FAP-Dox, AVA6000) Phase Ib SGC (salivary gland cancers) cohort (n=19) show durable tumour shrinkage and are consistent with results seen in the Phase Ia (n=11) cohort. DCR (disease control rate) remains high at 90%. The median PFS (progression free survival) has yet to be reached but, at over nine months, is already over double the benchmark 3.5-4.0 months seen for conventional therapy in pre-treated SGC, and 4.0-6.5 months in first-line SGC.
Across both cohorts 30 patients were treated with a dose of 250mg/m² or greater, with nine showing a clinically meaningful tumour shrinkage (two partial responses of 30% or more, seven minor responses of between 10% and 30%). A further 18 patients had stable disease. Enrolment is continuing into the Phase Ib cohort, which will increase the sample size, with data also is expected to mature further: 13 of the 19 patients currently in the Phase Ib cohort remain on treatment, with two in PFS follow up at the 15 October 2025, data cut off.
Faridoxorubicin safety data continue to impress, with a similar profile to that seen in other results. Importantly, no severe cardiac adverse events (typically 6-20%, which limits standard doxorubicin dosing) regardless of cumulative dose (the maximum reached was 550mg/m²). In addition, there is a favourable tolerability and side-effect profile across both two- and three-week dosing regimens.
Most patients (c 70%) had tumours with moderate to high FAP levels, however, an effective doxorubicin concentration was seen even in patients with low FAP tumour expression. This supports the view that modest levels of FAP on the surface of cancer associated fibroblasts (CAFs) in the tumour stroma are sufficient to activate cleavage and achieve the desired drug concentrations in the tumour.
Faridoxorubicin is the lead asset from Avacta’s proprietary pre|CISION platform, and its selective activation in the tumour microenvironment (TME) – with a 100-fold greater concentration of active doxorubicin than in plasma – underpins the whole tenet of minimising systemic toxicities and improving patient outcomes.
SGC is a rare cancer (three cases per 100,000), representing 6-8% of all head & neck cancers, but treatment is difficult with no recognised SoC (standard of care). Various treatments are employed, especially in advanced or metastatic disease, but are hampered by limited efficacy and toxicity issues. The encouraging data to date suggest faridoxorubicin could find a pivotal role in treating SGC.

Trinity Delta view: Updated SGC data in 30-patients confirm that the efficacy and safety signals seen in Phase Ia are consistent and meaningful. Maturing data from the Phase 1b cohort will guide design of the Phase II/III registration study in SGC. Whilst clearly important, we view the real significance of this encouraging data as providing the proof-of-concept for Avacta’s FAP-targeted pipeline. Although faridoxorubicin has a clear clinical, and commercial, role, the greater value of Avacta’s pre|CISION platform lies in the next-generation programmes that are being progressed through preclinical development. The ability to selectively activate highly potent drugs in the TME should lead to a valuable pipeline of novel, and highly relevant, targeted therapeutics.

Lighthouse

18 December 2025


Price	72.00p
Market Cap	312.24m
Primary exchange	AIM
Sector	Healthcare
Company Code	AVCT

Corporate client	Yes

Company description

Avacta is a clinical stage biotech focused on the novel pre|CISION platform to generate peptide-drug conjugates to target delivery of toxic payloads into the tumour microenvironment, which has the potential to expand the reach and reduce the systemic toxicities of highly potent cancer therapeutics. Lead programme faridoxorubicin is in Phase Ib, and multiple next generation candidates are in preclinical development.

Analysts

Lala Gregorek
lgregorek@trinitydelta.org
+44 (0) 20 3637 5043

Franc Gregori
fgregori@trinitydelta.org
+44 (0) 20 3637 5041

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