New Cancer Scan Enters Phase 3, Offering Hope for GI Cancers

DULLES, VA – December 29, 2025 – In a significant step forward for oncology diagnostics, SOFIE Biosciences has dosed the first patient in a pivotal Phase 3 clinical trial for its novel imaging agent, [18F]FAPI-74. The trial, named FAPI-GO, marks a critical milestone in the development of a new class of radiopharmaceuticals designed to more accurately detect aggressive gastroesophageal cancers, with a second trial for pancreatic cancer also launching this month.

This advancement moves beyond traditional imaging methods by targeting the very structure that supports tumor growth, offering the potential to transform how clinicians diagnose, stage, and manage some of the most challenging malignancies. The first dose was administered at a RadNet facility in Los Angeles, in a collaborative effort with Helios Clinical and The Oncology Institute of Hope and Innovation.

"We are proud of this milestone in the continuing clinical development of FAPI," said Patrick Phelps, President and CEO of SOFIE Biosciences, in a statement. "FAPI provides a different way to image and identify disease, by targeting cancer-associated fibroblasts in the tumor microenvironment. Dosing the first patient with [18F]FAPI-74 brings us one step closer to addressing vital areas of unmet need in gastric and esophageal cancers and realizing the promise of FAPI PET in precision medicine."

The Science of Seeing Cancer Differently

For decades, the workhorse of cancer imaging has been [18F]FDG PET/CT, a scan that detects cells with high metabolic activity, a hallmark of many cancers. While revolutionary, FDG-PET has known limitations. Its effectiveness can vary, and high background glucose uptake in healthy organs like the brain and liver can sometimes obscure or mimic tumors, leading to diagnostic ambiguity.

SOFIE's [18F]FAPI-74 represents a paradigm shift. Instead of tracking metabolic activity, it targets Fibroblast Activation Protein (FAP), a protein that is highly expressed on the surface of cancer-associated fibroblasts (CAFs). These fibroblasts are a key component of the tumor microenvironment, or stroma, creating a supportive scaffold that helps tumors grow, invade surrounding tissue, and evade the immune system. Since FAP is largely absent in healthy adult tissues, FAPI-based tracers can generate exceptionally clear images with high tumor-to-background contrast.

Early-stage research on FAPI agents has demonstrated significant advantages over FDG-PET in certain cancers. Studies have shown FAPI tracers can detect primary tumors and metastatic lesions with greater sensitivity and specificity, particularly in cancers rich with stromal tissue like those in the gastrointestinal tract. This ability to precisely visualize the tumor's supportive structure could enable the detection of smaller lesions and provide a more accurate picture of the disease's true extent.

"FAPI-74 is an exciting new advanced PET tracer," noted Judith Rose, MD, RadNet's Director of PET/CT and Research. "It is an honor to be in the position to have enrolled and imaged, in Los Angeles, the first patient in this important Phase 3 trial."

A New Front Against Aggressive Cancers

The initiation of two separate Phase 3 trials underscores the urgent need for better diagnostic tools for gastrointestinal cancers. Gastroesophageal and pancreatic cancers are notoriously aggressive and are often diagnosed at late stages, contributing to poor prognoses. Accurate staging is critical to determining the most effective treatment plan, but current imaging techniques can fail to identify the full spread of the disease.

The FAPI-GO trial is a multi-site, open-label study designed to evaluate how well [¹⁸F]FAPI-74 PET/CT can detect metastatic disease in adults with gastroesophageal cancer. The study plans to enroll 200 subjects across 18 sites over a 24-month period. Its primary goals are to establish the sensitivity and specificity of the scan for detecting distant metastases, a crucial factor in treatment planning and patient outcomes.

Simultaneously, SOFIE has launched a second Phase 3 study, FAPI-PRO, which began in December 2025. This trial will focus on the utility of [¹⁸F]FAPI-74 PET/CT for detecting metastatic disease in patients with Pancreatic Ductal Adenocarcinoma (PDAC), one of the deadliest forms of cancer. The ability to more accurately stage PDAC could spare patients from futile surgeries and guide them toward more appropriate systemic therapies sooner.

Strategic Alliances and Market Ambitions

Bringing a novel radiopharmaceutical to market is a complex undertaking that requires scientific innovation, clinical validation, and a robust logistical framework. SOFIE's strategy reflects this reality, built upon key partnerships to ensure the successful execution of its ambitious clinical program.

The collaboration with RadNet provides access to a vast national network of advanced imaging centers, essential for a multi-site trial. Helios Clinical brings expertise in clinical trial management, while The Oncology Institute of Hope and Innovation offers deep experience in community-based oncology care and patient recruitment.

This effort is set against the backdrop of a rapidly expanding radiopharmaceuticals market. Valued at over USD 8 billion in 2024, the global market is projected to exceed USD 20 billion by 2029, driven by the push for precision medicine. The FAPI PET imaging segment alone is forecast to grow exponentially, potentially reaching nearly USD 2 billion by 2033. SOFIE's investment in [18F]FAPI-74 positions the company to capture a significant share of this burgeoning field.

Furthermore, the choice of Fluorine-18 as the radioisotope for FAPI-74 is a key strategic advantage. With a longer half-life than other commonly used isotopes like Gallium-68, Fluorine-18 allows for centralized manufacturing and broader distribution, making the diagnostic agent more accessible to hospitals and imaging centers without their own on-site production capabilities. This logistical benefit is critical for achieving widespread market adoption following potential regulatory approval.

As these Phase 3 trials progress, the medical community will be watching closely. A successful outcome for [18F]FAPI-74 would not only validate a new diagnostic standard for challenging GI cancers but also reinforce the immense potential of targeting the tumor microenvironment. This approach could unlock a new wave of theranostics, where the same targeting molecule used for diagnosis is paired with a therapeutic payload to deliver radiation directly to the tumor's support system, opening yet another frontier in the fight against cancer.