REG - Avacta Group PLC - Avacta Presents Phase 1a Data for Faridoxorubicin

AvactaAnnouncement

Today 07:00

For best results when printing this announcement, please click on link below:
https://newsfile.refinitiv.com/getnewsfile/v1/story?guid=urn:newsml:reuters.com:20251020:nRST9980Da&default-theme=true

RNS Number : 9980D  Avacta Group PLC  20 October 2025

 

 

Avacta Therapeutics presents compelling Phase 1a data for faridoxorubicin and
the pre|CISION(®) platform at the European Society of Medical Oncology Annual
Congress

 

Median progression free survival (PFS) has not been reached in the cohort of
patients with salivary gland cancer with PFS follow up suggesting a more than
doubling of the benchmark PFS and a disease control rate of 91%

 

No maximum tolerated dose reached despite dosing up to 385 mg/m²
(approximately 4x conventional doxorubicin dose) with no severe cardiac
toxicity observed even at cumulative doses up to 550 mg/m²

 

 

LONDON and PHILADELPHIA - October 20, 2025 - Avacta Therapeutics (AIM: AVCT,
'Avacta', 'the Company'), a clinical stage biopharmaceutical company
developing pre|CISION(®), a unique oncology delivery platform, today
announces further development updates in the Phase 1a clinical trial with its
lead program, faridoxorubicin (FAP-Dox, AVA6000) were presented at the 2025
European Society of Medical Oncology Annual Congress in Berlin, Germany on
October 19, 2025.

 

Faridoxorubicin treatment data demonstrate favorable safety and tolerability
across both the every three weeks and every two weeks dosing regimens. The
trial data also demonstrate a robust reduction in toxicities associated with
conventional doxorubicin therapy, with preliminary efficacy in patients with
salivary gland cancers and soft tissue sarcomas. Cardiac safety data in
patients treated above the standard cumulative dose demonstrate no severe
toxicity observed either in treatment stage or in follow up and no severe
cardiac adverse events were reported in the trial, regardless of the
cumulative dose level.

 

Median progression-free survival (PFS) has not been reached in the
previously-reported cohort of patients with salivary gland cancers, indicating
a durable response. The follow up data to-date suggest a duration of PFS that
is more than double the duration of that reported in benchmark data in this
patient population of pretreated patients in Phase 1a (median duration of PFS
follow-up of 41 weeks).

 

 

Christina Coughlin, CEO Avacta commented:

 

"We are delighted to confirm the observations first published in April of this
year with exciting efficacy in patients with salivary gland cancers. These
data continue to demonstrate the power of pre|CISION(®) to generate
meaningful PFS data in a patient population with limited therapeutic options
and importantly with no FAP on the tumor cells.

"Given the extension of PFS, we are excited to be moving this program forward.
The very strong cardiac safety data out to the cumulative maximum dose of 550
mg/m(2) validates the safety implications of the platform and has the
potential to open up a new avenue of treatment options for patients.

"These data highlight three important findings for the pre|CISION(®)
platform: first, the elimination of the cardiac signal even at higher
cumulative doses demonstrates that pre|CISION(®) is capable of protecting
normal tissues from toxicity. Second, the activity in a tumor type without FAP
on the tumor cells confirms the bystander effect of pre|CISION(®) and third,
the tumor concentration data even at low FAP expression opens up an even
greater number of cancer types to the platform.

"This development, combined with the recent update on our first dual payload
peptide drug conjugate, underscores the tremendous potential of our
proprietary pre|CISION(®) technology pipeline to deliver meaningful benefits
for patients."

 

Faridoxorubicin (AVA6000, FAP-Dox) Clinical Highlights (ESMO Developmental
Therapeutics Poster Session, October 19, 2025)

Faridoxorubicin is a FAP-activated form of doxorubicin designed to reduce the
systemic side effects of conventional chemotherapy and concentrate the active
payload in the tumor microenvironment. Prior reports (AACR Annual Meeting,
April 2025
(https://avacta.com/new-response-in-the-fap-dox-ava6000-phase-1b-trial/) )
have demonstrated favorable preliminary safety and early efficacy data in a
subset of patients with salivary gland cancers.

Clinical data with faridoxorubicin

In the Phase 1a dose-escalation study, faridoxorubicin was well-tolerated
across both every-three-week (Q3W) and every-two-week (Q2W) dosing regimens
(N-63 patients). No maximum tolerated dose (MTD) was reached despite dosing up
to 385 mg/m² every three weeks. In addition, no events of severe cardiac
toxicity were observed even to maximum cumulative exposure consistent with the
anthracycline dose of 550 mg/m(2), further supporting a markedly improved
safety profile over conventional doxorubicin.

In patients with salivary gland cancers (SGC, n=11) treated at or above the
dose level of 250 mg/m(2), faridoxorubicin demonstrated multiple confirmed
partial and minor responses with a disease control rate of 91%. Median
progression-free survival (PFS) has not yet been reached, with an absolute
median PFS follow-up of approximately 41 weeks (range 8 to 76 weeks). Multiple
patients demonstrate durable disease stabilization despite discontinuing the
therapy once reaching the cumulative maximum dose. The Kaplan Meier estimated
median follow-up is 51 weeks. Kaplan Meier modeling functions by calculating
the probability of overall survival at each event time and multiplying these
probabilities to estimate the median follow up based on observed data. The
faridoxorubicin observations compare favorably to recent benchmarking data in
this patient population presented at ESMO 2024, with a reported PFS of 3.5-4
months in a large cohort (n=54) published by the EORTC in a similar setting of
pretreated patients with SGC. In addition to the comparison to the pretreated
patient cohort,, the data with faridoxorubicin compare well to the first line
cohort in this EORTC study, with a PFS reported at 4-6.5 months (Licitra et
al. ESMO Annual Congress 2024).

In patients with soft tissue sarcomas (n=17 evaluable), multiple tumor
responses are observed, even at lower doses including one responder at the 160
mg/m(2) Q3W dose level. The stabilization of disease despite the removal of
the drug is observed in this indication as well, suggesting a highly-effective
and durable treatment in this cancer indication. The key difference between
the biology of many subsets of soft tissue sarcoma and other epithelial
malignancies is that many sarcoma subsets demonstrate direct tumor cell
expression of FAP, which could enhance efficacy. The vast majority of
epithelial malignancies do not demonstrate expression of FAP on tumor cells,
only on the cancer associated fibroblasts.

Cardiac safety data demonstrate that despite dosing of faridoxorubicin with a
cumulative exposure up to 550 mg/m(2) of conventional doxorubicin, no severe
cardiac events were reported, either during the dosing timing or in the
follow-up period. Echocardiogram (ECHO) data were analyzed similar to the
liposomal doxorubicin label in the full cohort of patients and these data
presented based on the cumulative dose received of released doxorubicin. These
data reveal that only two patients demonstrated ECHO changes consistent with
adverse findings, one patient treated below the maximum of 450mg/m(2) and one
patient treated to 500 mg/m(2). This includes a patient reported previously
experiencing the early dose limiting toxicity due to ECHO changes in the 120
mg/m2 Q3W cohort (grade 2 cardiac failure). None of the patients treated to
the cumulative dose of 550 mg/m(2) demonstrated observed ECHO changes. The
cardiac safety data compare favorably to that reported with both the
doxorubicin and liposomal doxorubicin respective drug labels.

Clinical pharmacology data with faridoxorubicin

Despite dosing up to approximately 4x the dose of conventional doxorubicin,
the data demonstrate exposure of released doxorubicin in plasma and normal
tissues is generally lower than that observed with conventional dose
doxorubicin (75 mg/m(2) Q3W) and the median tumor to plasma ratio is 100:1.
The lack of toxicity is explained by the limited tissue distribution as well
as limited first pass effect exposure of released doxorubicin (reported in
Lahu et al. AACR 2025).

Biopsy and plasma data collected during the trial at 24 hours after the first
dose demonstrate two key factors relevant to the pre|CISION(®) platform: (1)
intratumoral concentration of the active payload is dose-dependent, indicating
that the higher doses lead to higher absolute values of released doxorubicin
in the tumor and (2) efficient cleavage of the PDC is observed in all tumors,
even those with limited 1+ expression, suggesting the lower level of
expression required for cleavage of the peptide is quite low, demonstrating
the potential of pre|CISION(®) medicines in a number of other malignancies
with lower expression of FAP.

Avacta continues to enroll patients in the Phase 1b expansion cohorts with
data in salivary gland cancer anticipated by the end of 2025.

Title: A Phase I trial of FAP-Dox (AVA6000), a Fibroblast Activation Protein
(FAP)-released and tumor microenvironment (TME)-targeted doxorubicin peptide
drug conjugate in patients with FAP-positive solid tumors

Session Title: Developmental Therapeutics

Session Date and Time: 17 October, 19:40 - 20:00

Location: Berlin Auditorium - Hub 27

Abstract Presentation Number: 964P

Speaker: William D. Tap

 

 

Avacta will present an Investor Meet conference to review the published data
on Tuesday October 21, 2025.  Details for the webinar will be posted on the
Avacta home page.

Lahu G., et al. (2025). Comparative Pharmacokinetics and Tumor Activation of
Fibroblast Activation Protein (FAP)-enabled pre|CISION® Peptide Drug
Conjugates.  AACR Annual Meeting, abstract CT15.

Licitra et al. (2024). A randomised phase I study to evaluate the efficacy and
safety of androgen deprivation therapy (ADT) vs chemotherapy (CT) in patients
with recurrent and/or metastatic, androgen receptor (AR) expressing, salivary
gland cancers. ESMO Annual Congress, abstract LBA36.

 

-Ends-

 

 

For further information from Avacta, please contact:

 

 Avacta Group plc                                           https://avacta.com (https://avacta.com/) / (https://avacta.com/)

 Christina Coughlin (CEO), Brian Hahn (CFO)

 Peel Hunt (Nomad and Broker)

 James Steel / Chris Golden                                 www.peelhunt.com (http://www.peelhunt.com/)

 Panmure Liberum (Joint Broker)                             www.panmureliberum.com (http://www.panmureliberum.com)

 Emma Earl / Will Goode / Mark Rogers

 Zeus (Joint Broker)                                        www.zeuscapital.co.uk (http://www.zeuscapital.co.uk/)

 James Hornigold / George Duxberry

 Dominic King

 ICR Healthcare

 Mary-Jane Elliott / Jessica Hodgson / Stephanie Cuthbert   avacta@icrhealthcare.com (mailto:avacta@icrhealthcare.com)

 Investor Contact

 Renee Leck                                                 renee@thrustsc.com (mailto:renee@thrustsc.com)

 THRUST Strategic Communications

 Media Contact                                               carly@thrustsc.com (mailto:carly@thrustsc.com)

 Carly Scaduto

 THRUST Strategic Communications

 

 

About Avacta - www.avacta.com
(https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.avacta.com%2F&data=05%7C02%7CChris.Coughlin%40avacta.com%7Ce5faa8dfbe3d49fc56f808dd35799958%7C64d2165ff9e04869bc73bfe4fc4fa9ab%7C0%7C0%7C638725518576703790%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=qWTC74zmTzjVQqwaFiKeiHUwMY5RUlsvb7C%2BkLRahGU%3D&reserved=0)

Avacta is a clinical stage life sciences company developing an innovative
proprietary drug delivery peptide drug conjugate (PDC) platform,
pre|CISION(®). The pre|CISION(®) platform uniquely enables the repurposing
of a range of oncology drugs as PDC payloads with the goal to significantly
reduce toxicity and side effects for patients by concentrating the drug
directly in the tumor.

 

About pre|CISION(®)

 

The key aspect of pre|CISION(®) is its peptide drug conjugates (PDC)
technology. The combination of the cancer drug and the proprietary cleavable
peptide (the PDC) is inert and incapable of entering cells and killing them
until the peptide is specifically released within the tumor. The active
payload in the pre|CISION(®) PDC is released when the PDC comes into contact
with the common tumor-associated protein, known as fibroblast activation
protein (FAP), in the tumor. The release of the payload from the
pre|CISION(®) product directly in the tumor results in higher concentration
of the drug at the tumor and lower blood and healthy tissue levels than
standard systemic administration, offering the potential to improve efficacy
and patient tolerability.

 

This information is provided by RNS, the news service of the London Stock Exchange. RNS is approved by the Financial Conduct Authority to act as a Primary Information Provider in the United Kingdom. Terms and conditions relating to the use and distribution of this information may apply. For further information, please contact
rns@lseg.com (mailto:rns@lseg.com)
 or visit
www.rns.com (http://www.rns.com/)
.

RNS may use your IP address to confirm compliance with the terms and conditions, to analyse how you engage with the information contained in this communication, and to share such analysis on an anonymised basis with others as part of our commercial services. For further information about how RNS and the London Stock Exchange use the personal data you provide us, please see our
Privacy Policy (https://www.lseg.com/privacy-and-cookie-policy)
.   END  MSCKKLFFEBLXFBB



            Copyright 2019 Regulatory News Service, all rights reserved