Avacta Therapeutics (AIM: AVCT) has reported encouraging clinical results from its ongoing Phase 1a/1b trial of faridoxorubicin (AVA6000), with median progression-free survival reaching 11.4 months in a selected group of salivary gland cancer patients, compared with published historical benchmarks of six to 6.7 months.
The oncology drug developer presented the findings at the European Society for Medical Oncology (ESMO) Congress in Madrid, highlighting the potential of its proprietary pre|CISION technology to deliver chemotherapy selectively within tumours.
The analysis involved 32 patients with salivary gland cancer treated with AVA6000 at doses of 310mg/m² or higher, excluding certain rare cancer subtypes and patients who had received more extensive previous treatment.
The reported median progression-free survival of 11.4 months is nearly double historical treatment benchmarks, although the results come from a non-randomised early-stage trial and do not establish superiority over existing treatments.
The analysis, based on data collected up to 5 October 2026, reported a 95% confidence interval extending from seven months to an upper limit that had not yet been reached.
Three patients achieved partial tumour responses, while a further six experienced minor responses, with reported response durations ranging from 18.7 to 72 weeks.
Median overall survival had not been reached at the time of the analysis, indicating that longer follow-up is required to assess survival outcomes.
AVA6000 is designed to deliver the chemotherapy drug doxorubicin directly to tumours, using fibroblast activation protein (FAP) to trigger drug release within the tumour microenvironment.
The technology aims to concentrate chemotherapy where it is needed while reducing exposure to healthy tissues, potentially improving tolerability and widening the therapeutic window.
Tumour biopsy analysis showed a 100-to-one concentration ratio of released doxorubicin in tumour tissue compared with plasma, supporting the drug’s intended targeted delivery mechanism.
Importantly, FAPI-PET imaging demonstrated that FAP expression remained detectable over prolonged treatment periods, including in patients experiencing substantial tumour shrinkage.
Pharmacokinetic studies extending to 12 treatment cycles also indicated continued cleavage of AVA6000 and sustained release of doxorubicin over time.
The findings suggest that the treatment’s activation mechanism may remain functional during repeated dosing, potentially supporting longer-lasting anticancer activity.
Avacta believes persistent FAP activity may be linked to the recruitment of additional FAP-positive fibroblasts into treated tumours, a mechanism also observed in recent preclinical research involving its next-generation drug candidate AVA6103.
Those preclinical findings, presented separately at ESMO, suggested that treatment-related fibroblast recruitment could help maintain drug activation even as tumours shrink.
Chief Executive Christina Coughlin said the latest AVA6000 and AVA6103 datasets supported the ability of the pre|CISION platform to deliver potent chemotherapy payloads over prolonged periods.
She highlighted the observed progression-free survival, tumour responses and sustained drug release as encouraging evidence of the platform’s potential to improve treatment outcomes.
Dr Alan Ho of Memorial Sloan Kettering Cancer Center, senior author of the ESMO presentation, described the findings as promising for patients with salivary gland cancers, a group of rare diseases with limited effective treatment options.
He also highlighted the FAPI-PET findings as valuable evidence of the biological activity underlying AVA6000’s treatment mechanism.
The AVA6000 Phase 1a/1b programme has enrolled 51 patients with salivary gland cancer across its various doses and cohorts, with expansion studies also evaluating the treatment in soft tissue sarcoma and triple-negative breast cancer.
Data from the latter two cancer groups continue to mature, providing potential opportunities to assess the platform across additional tumour types.
Meanwhile, Avacta’s next-generation candidate AVA6103 is progressing through the FOCUS-01 Phase 1 trial, with tumour pharmacokinetic findings anticipated in late 2026 or early 2027 and initial efficacy data expected during the first half of 2027.
For investors, the 11.4-month median progression-free survival result represents an important clinical development milestone, supported by evidence of tumour responses, targeted drug delivery and sustained FAP activity during treatment.
However, the comparison with historical benchmarks should be interpreted cautiously because the study lacks a randomised control group, and differences in patient selection and previous treatments can influence outcomes.
Attention will now turn to longer-term survival data, maturing results from other AVA6000 tumour cohorts and the forthcoming AVA6103 clinical findings, which will help determine whether Avacta’s pre|CISION platform can translate its early clinical promise into reproducible benefits for cancer patients.
Details of the ESMO presentation
A Phase 1a/1b trial of FAP-Dox (AVA6000), a Fibroblast Activation Protein (FAP)-released and tumor microenvironment (TME)-targeted doxorubicin peptide drug conjugate in patients with salivary gland cancers
Authors: Renata Ferrarotto, Robert Metcalf, Steph A. Pang, William D. Tap, et. al, Alan L. Ho
Poster number: 1549P
Time: Monday October 26, 12:00-12:45pm CET
The poster can be found on Avacta’s website here.
