Cracking Prostate Cancer Resistance: The 1 mL Liquid Biopsy Breakthrough

BOSTON, MA – October 23, 2026 – During my tenure as a market analyst, I evaluated countless diagnostic platforms that promised to revolutionize oncology. Most offered incremental improvements—a slightly faster turnaround time here, a marginally broader gene panel there. But occasionally, a technology emerges that fundamentally shifts how we understand disease dynamics. In the high-stakes economics of oncology drug development, the true value of a therapeutic isn’t just in its initial success rate; it is in understanding why it eventually stops working.

Radioligand therapies, most notably 177Lu-PSMA-617, have undeniably transformed the treatment landscape for metastatic castration-resistant prostate cancer (mCRPC). But behind the encouraging survival curves and enthusiastic market uptake lies a complex, shifting biological battlefield. Tumors are master adapters, and acquired resistance remains the multi-billion-dollar hurdle in precision oncology.

Today, at the European Society for Medical Oncology (ESMO) Congress 2026 in Madrid, Precede Biosciences presented compelling new data that peers directly into this clinical blind spot. Using their proprietary functional liquid biopsy platform, Precede Bio Insight, the Boston-based diagnostics firm demonstrated that the transcriptional biology driving both response and resistance to PSMA-directed radioligand therapy can be accurately profiled from a mere 1 mL of blood.

Cracking the Radioligand Resistance Code

For patients with advanced mCRPC, 177Lu-PSMA-617 acts as a radioactive homing missile, seeking out the Prostate-Specific Membrane Antigen (PSMA) on the surface of cancer cells. It is an elegant mechanism of action, provided the target remains present. But what happens when the target vanishes?

The study presented at ESMO analyzed plasma samples from 57 mCRPC patients treated with this specific radioligand therapy. The most striking and clinically actionable findings emerged from the 17 patients who provided paired blood samples at both the baseline of treatment and at the point of disease progression. In 11 of those 17 patients, the liquid biopsy platform predicted a significant decline in PSMA expression.

This dynamic target loss perfectly encapsulates the frustration of managing advanced prostate cancer. When subjected to intense therapeutic pressure, prostate tumors often undergo lineage plasticity. Some cancer cells shed their PSMA receptors entirely or undergo neuroendocrine differentiation, effectively turning invisible to the radioligand therapy while adopting a more aggressive, stem-like state. It is a brilliant, albeit devastating, survival mechanism.

"While 177Lu-PSMA-617 has been a welcome addition, we still need to better identify patients most likely to benefit, to develop alternatives for those unlikely to respond, and to determine how best to sequence therapies after progression," noted Jacob E. Berchuck, MD, of the Winship Cancer Institute of Emory University, who presented the data. "These data build on prior observations and support new hypotheses for rational combination and sequencing of therapies in mCRPC."

From 1 mL of Blood: A Functional Epigenomic Breakthrough

To fully appreciate the gravity of this presentation, one must look closely at the underlying technology. Traditional liquid biopsies, which currently dominate the diagnostic market, primarily scan circulating tumor DNA (ctDNA) for static genetic mutations. While invaluable for matching patients to specific targeted therapies, these mutation panels offer a flat, two-dimensional view of the disease. They tell you what the genetic hardware looks like, but not what software the tumor is currently running.

The technology behind Precede Bio Insight takes a fundamentally different approach. Rather than hunting for mutations, the platform relies on comprehensive epigenomic profiling. By analyzing DNA methylation and other epigenomic modifications on cell-free DNA, their advanced machine-learning algorithms can infer genome-wide transcriptional biology. In simpler terms: they are not just looking for broken genes; they are reading the real-time gene expression and pathway activity of the tumor.

"The depth of biology recovered in a cohort of this size illustrates what becomes possible when tumor transcriptional biology can be profiled from just 1 mL of plasma," said Rehan Verjee, CEO of Precede Biosciences. "A higher-resolution view of disease biology has repeatedly improved how medicines are developed and how patients are treated in practice. This is what motivates us at Precede Biosciences."

Achieving this level of molecular resolution from a single milliliter of plasma is a logistical triumph that cannot be overstated. Traditional tissue biopsies are invasive, painful, and often fail to capture the full heterogeneity of metastatic disease—a single needle core might miss a resistant subclone entirely. A 1 mL blood draw, conversely, can be performed routinely, allowing oncologists to track the tumor's evolving phenotype in near real-time without subjecting the patient to repeated surgical procedures.

Phenotypic Tracking: The Next Era of Precision Oncology

The ESMO 2026 data also highlighted the predictive power of baseline profiling. Before treatment even began, the epigenomic platform categorized patients into three distinct molecular states previously only identifiable through invasive tissue biopsies: androgen receptor (AR)-high/metabolic, stem/epithelial-mesenchymal transition (EMT), and AR-low/proliferative.

The clinical outcomes aligned closely with these phenotypes. Patients harboring the AR-high/metabolic signature exhibited the most favorable responses to the radioligand therapy. Furthermore, analysis of published gene sets revealed that elevated AR signaling and luminal A activity correlated with a longer time to the next required treatment.

Conversely, the presence of stem-like characteristics and elevated WNT signaling activity served as a critical red flag, associating strongly with a shorter time to next treatment. The WNT pathway is notoriously involved in cell proliferation and migration, and its activation is a known driver of the EMT process—a state where cancer cells become more aggressive, mobile, and resistant to standard therapies. By identifying these high-risk phenotypes upfront, clinicians could theoretically pivot to combination therapies earlier in the treatment paradigm, rather than waiting for inevitable progression.

Mapping the Next Line of Defense

Perhaps the most commercially and clinically significant aspect of this presentation is what happens after progression. If a tumor sheds its PSMA targets, how do oncologists know what to aim at next?

At the point of disease progression, the epigenomic platform didn’t just note the absence of PSMA; it actively evaluated the predicted expression of alternative therapeutic targets, including TROP2, SEZ6, CEACAM5, and DLL3.

This is where the broader oncology drug pipeline comes into sharp focus. The biopharmaceutical industry is currently pouring billions of dollars into the development of Antibody-Drug Conjugates (ADCs) and next-generation bispecific T-cell engagers. TROP2 is already a heavily validated target in breast and urothelial cancers, with agents making significant clinical inroads. DLL3 is emerging as a highly relevant target in neuroendocrine tumors, perfectly aligning with the neuroendocrine differentiation often seen in post-PSMA prostate cancer. SEZ6 and CEACAM5 represent additional promising avenues for targeted intervention.

However, these next-generation therapies are incredibly potent and carry distinct toxicity profiles. You do not want to expose a patient to the systemic toxicity of a TROP2-directed ADC if their tumor isn't actively expressing TROP2. Precede's liquid biopsy effectively acts as the critical biological traffic cop in this scenario.

For a treating oncologist, the ability to draw a milliliter of blood from a progressing patient and definitively say, "PSMA is down, but DLL3 is up," is nothing short of revolutionary. It transitions the post-progression strategy from an educated guessing game into a rational, data-driven sequencing protocol.

As the precision medicine landscape continues to mature, the focus is rapidly shifting from merely identifying the presence of cancer to understanding its dynamic, real-time behavior. Platforms capable of non-invasively tracking these phenotypic shifts are poised to become the new standard of care, ensuring that the next generation of targeted therapies hits the right mark, at exactly the right time.