Avacta's Targeted Cancer Drug Shows Major Promise in Tough-to-Treat Disease

LONDON and PHILADELPHIA – December 17, 2025

Biopharmaceutical firm Avacta Therapeutics has unveiled compelling new clinical data for its lead cancer drug, faridoxorubicin (AVA6000), offering a significant ray of hope for patients with advanced salivary gland cancers—a rare and aggressive disease with notoriously limited treatment options. The preliminary results from the company's Phase 1b study demonstrated clinically meaningful tumor shrinkage and an impressive 90% disease control rate, reinforcing the potential of its novel precision-guided therapy.

The announcement provides a crucial boost not only for the drug itself but also for Avacta's underlying pre|CISION® delivery platform, a technology designed to unleash potent chemotherapy directly within tumors while sparing healthy tissue. The positive data has been met with cautious optimism from the oncology community, which has long sought more effective treatments for this challenging form of head and neck cancer.

A Breakthrough for a Neglected Cancer

Salivary gland cancers (SGC) represent a small but devastating fraction of head and neck malignancies, with approximately 2,500 cases diagnosed annually in the United States. While early-stage disease can often be managed with surgery and radiation, the prognosis darkens considerably once the cancer metastasizes. For these patients, there is no established standard of care, and conventional chemotherapy often yields poor responses and significant toxicity. The five-year survival rate for advanced SGC hovers around a grim 42%.

It is against this backdrop of high unmet medical need that Avacta's latest results are so significant. The combined data from its Phase 1a and Phase 1b trials included 30 patients with SGC treated at or above the therapeutic dose of 250 mg/m². Of these, an impressive 27 patients (90%) saw their disease either shrink or stabilize, a metric known as the disease control rate (DCR).

More specifically, nine patients experienced clinically meaningful tumor shrinkage. This included two confirmed partial responses, defined by RECIST criteria as a tumor reduction of at least 30%, and seven confirmed minor responses, where tumors shrank by 10-30%. These results were observed in patients who were treatment-naïve as well as those who had already failed other therapies, highlighting the drug's potential broad utility in this patient population.

"For a rare cancer like SGC where we have struggled to make progress, seeing a 90% disease control rate in a Phase 1 study is highly encouraging," commented one clinical oncologist not involved in the trial. "Tumor shrinkage and disease stability can translate into valuable time for patients and an improvement in quality of life. These are the kinds of early signals we hope to see for a disease with so few effective options."

The Science of a 'Smart Bomb' Therapy

At the heart of AVA6000's success is Avacta's proprietary pre|CISION® platform, a sophisticated drug delivery system that transforms a well-known chemotherapy agent, doxorubicin, into a targeted therapy. Doxorubicin has been a cornerstone of cancer treatment for decades, but its use is limited by severe side effects, including heart damage and immune system suppression, because it attacks healthy and cancerous cells alike.

The pre|CISION® technology cleverly circumvents this problem. It attaches doxorubicin to a special peptide that renders it inactive as it circulates through the body. This peptide is designed to be a specific substrate for an enzyme called fibroblast activation protein-alpha (FAP), which is heavily over-expressed in the microenvironment of most solid tumors but largely absent in healthy tissue. When AVA6000 reaches the tumor, the abundant FAP acts like a molecular scissor, cleaving the peptide and releasing the full, potent dose of doxorubicin precisely where it is needed most. This mechanism aims to maximize the drug's tumor-killing power while minimizing collateral damage to the rest of the body.

Dr. Christina Coughlin, CEO of Avacta, commented on the significance of the findings in the company's official press release. "These data continue to reinforce our belief in the transformative potential of our pre|CISION® peptide drug conjugates to expand the therapeutic index and increase the efficacy of highly potent therapeutics," she stated. "The clinically meaningful tumor shrinkage and prolonged progression free survival we have observed in the study highlight faridoxorubicin’s potential as an important new treatment option for patients with SGC and other solid tumors."

Importantly, translational data from the study showed that the drug's payload was effectively released even in tumors with the lowest levels of FAP expression, supporting a broad market opportunity for the platform.

Validating a Platform and Boosting a Pipeline

The positive results for AVA6000 do more than just advance a single drug candidate; they provide powerful clinical validation for the entire pre|CISION® platform. For a clinical-stage biotech company like Avacta, such proof-of-concept is a pivotal milestone that can attract significant investor interest and potential partnerships with larger pharmaceutical firms. By successfully demonstrating that its FAP-targeting mechanism works as designed in humans, Avacta has de-risked its technology and opened the door to a broader pipeline of precision medicines.

The platform's modular design means that other highly potent cancer drugs could be conjugated to the same FAP-activated peptide, creating a portfolio of targeted therapies for a wide array of FAP-positive solid tumors. This positions the London and Philadelphia-based company as a key innovator in the competitive field of precision oncology. While the competitive landscape for SGC is evolving with other targeted agents and immunotherapies in development, Avacta's unique approach to reactivating a classic chemotherapy agent within the tumor itself offers a distinct and potentially complementary strategy.

The Path Forward

The trial data, while still early, is characterized by its consistency and durability. The safety profile of faridoxorubicin in the Phase 1b cohort was in line with previous observations from Phase 1a, continuing to demonstrate a favorable safety profile compared to standard doxorubicin.

Perhaps one of the most promising indicators of the drug's long-term potential is that the median progression-free survival (PFS)—the length of time patients live without their disease worsening—has not yet been reached for the Phase 1b cohort. At the time of the data cutoff, 13 of the 19 evaluable patients in this group were still on therapy, with a median follow-up already exceeding 15 weeks. This suggests that the clinical benefits are not fleeting and that patients are able to remain on treatment for a prolonged period.

Based on the favorable efficacy and safety signals, Avacta will continue enrollment in the SGC cohort of the trial. The company expects to provide further updates on the maturing data, including survival outcomes, in the first half of 2026. As researchers continue to collect and analyze this crucial information, patients and physicians alike will be watching closely, hopeful that this innovative approach may soon redefine the standard of care for a cancer that has been left behind for far too long.