Zai Lab and Novocure’s TTFields therapy shows survival benefit in pancreatic cancer: PANOVA-3 results unveiled at ASCO 2025

In a potentially paradigm-shifting announcement at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting, Zai Lab Limited (NASDAQ: ZLAB; HKEX: 9688) and Novocure (NASDAQ: NVCR) reported that Tumor Treating Fields (TTFields) therapy has demonstrated a statistically significant improvement in overall survival for patients with unresectable, locally advanced pancreatic adenocarcinoma. The results came from the pivotal Phase 3 PANOVA-3 trial, which was simultaneously published in the Journal of Clinical Oncology, and now positions TTFields as a compelling candidate for regulatory approval in one of oncology’s most treatment-resistant indications.

Why Is TTFields Therapy Generating Buzz Among Oncologists and Investors?

For decades, pancreatic cancer has remained one of the most formidable challenges in oncology, characterized by late diagnosis, poor prognosis, and limited treatment success. As of 2022, median survival for locally advanced, unresectable pancreatic cancer hovered around 9 to 12 months globally, and the five-year survival rate stood at just 7.2% in China. With over 134,000 new pancreatic cancer cases reported annually in China, the need for innovation is dire.

TTFields therapy—already approved for glioblastoma and mesothelioma—introduces a novel, non-invasive modality that uses alternating electric fields to disrupt mitosis in cancer cells. By combining TTFields with chemotherapy agents gemcitabine and nab-paclitaxel, Zai Lab and Novocure sought to test whether this adjunct could enhance overall outcomes without adding systemic toxicity.

What Did the PANOVA-3 Trial Show in Terms of Survival and Patient Benefit?

The PANOVA-3 trial, a randomized Phase 3 study involving 571 patients, assessed the efficacy of Tumor Treating Fields (TTFields) therapy combined with gemcitabine and nab-paclitaxel versus chemotherapy alone in patients with unresectable, locally advanced pancreatic adenocarcinoma. The final analysis showed that median overall survival (mOS) for patients receiving TTFields alongside chemotherapy reached 16.2 months, compared to 14.2 months in the control group. This 2.0-month survival extension was statistically significant, with a hazard ratio (HR) of 0.82 and a p-value of 0.039, signaling a meaningful clinical benefit.

In terms of one-year survival, the TTFields cohort achieved a rate of 68.1%, notably higher than the 60.2% observed in the chemotherapy-alone group, with a p-value of 0.029, further reinforcing the treatment’s impact on patient outcomes. Moreover, median pain-free survival was extended to 15.2 months in the TTFields arm, compared to 9.1 months in the control arm—representing a statistically significant 6.1-month improvement (p = 0.027). This secondary endpoint, which captures the duration before clinically meaningful worsening of patient-reported pain or death, is especially relevant in pancreatic cancer, where pain management remains a persistent therapeutic challenge.

These improvements were reinforced by quality-of-life analyses using EORTC QLQ-C30 and the PAN26 pancreatic module. Patients on the TTFields protocol experienced reduced deterioration in global health status, less digestive discomfort, and extended time before significant pain escalations were reported. Importantly, TTFields therapy was well tolerated with no new safety concerns. The most common device-related adverse events were mild-to-moderate skin reactions.

How Are Markets and Analysts Responding to the PANOVA-3 Milestone?

Initial market reaction has been cautiously optimistic. Novocure (NASDAQ: NVCR) shares rose modestly in pre-market trading following the ASCO 2025 presentation, as institutional investors factored in the medium-term potential for premarket approval (PMA) submission to the U.S. FDA in H2 2025. For Zai Lab (NASDAQ: ZLAB; HKEX: 9688), analysts suggested the data adds meaningful pipeline credibility amid growing scrutiny of clinical-stage biopharma valuations in both the U.S. and Chinese markets.

While the absolute survival improvement of two months may appear modest, in pancreatic oncology any statistically significant survival gain is viewed as clinically impactful—especially when achieved without additional toxicity. Analysts from investment firms including Jefferies and Bernstein have indicated that PANOVA-3 de-risks TTFields’ pancreatic indication, particularly if PANOVA-4—currently assessing the therapy in metastatic settings—can replicate the benefit in a more aggressive disease stage.

What Is TTFields Therapy and Why Is It Unique in Oncology?

TTFields therapy uses low-intensity, intermediate-frequency alternating electric fields to disrupt cancer cell mitosis. Delivered via wearable transducer arrays, the therapy does not rely on pharmacokinetics or systemic exposure, allowing for combinatorial use with chemotherapy, immunotherapy, and targeted agents without overlapping toxicity.

The mechanism of action is multi-faceted. TTFields disrupt microtubule polymerization, impair organelle function, and create physical forces that interfere with DNA segregation—all processes crucial to cell division in malignant cells. Due to differing morphology and electrical properties, healthy cells remain largely unaffected.

Novocure has built a platform around TTFields, with approvals already secured in glioblastoma, non-small cell lung cancer, and malignant pleural mesothelioma. The PANOVA-3 success potentially adds locally advanced pancreatic cancer to this list, significantly expanding TTFields’ clinical and commercial footprint.

How Is Zai Lab Positioning Itself in the Chinese Oncology Market?

For Zai Lab, the PANOVA-3 collaboration with Novocure enhances its profile as a leading Chinese-American biotech that brings global innovations to Chinese patients. The company has already established strategic partnerships with major pharmaceutical companies across oncology, immunology, and neuroscience. This TTFields milestone provides a crucial anchor in a market where pancreatic cancer is rapidly rising due to aging populations, smoking, obesity, and diabetes.

Zai Lab’s President of R&D, Dr. Rafael Amado, emphasized the urgent unmet need and affirmed the company’s commitment to filing regulatory submissions in China once PMA is secured in the U.S. Analysts expect that Zai Lab may pursue National Medical Products Administration (NMPA) pathways for conditional approval or fast-track designation, depending on local patient outcomes.

What Are the Next Steps for Regulatory Approval and Further Trials?

Novocure confirmed that a premarket approval submission to the FDA is planned for the second half of 2025, targeting the unresectable, locally advanced pancreatic cancer population. Parallel regulatory strategies are also being developed for the European Union, Japan, and emerging markets.

Meanwhile, the PANOVA-4 trial, a Phase 2 international study, is evaluating TTFields therapy in combination with atezolizumab (an immune checkpoint inhibitor), gemcitabine, and nab-paclitaxel for metastatic pancreatic cancer. Enrollment has been completed, and interim results are expected by mid-2026.

If PANOVA-4 data also show survival and quality-of-life improvements, the use case for TTFields could extend from locally advanced to metastatic settings, dramatically increasing the addressable market. Industry experts believe this could further validate the broader “device-plus-chemo” paradigm across other hard-to-treat solid tumors.

What Are the Broader Implications for Cancer Treatment Modalities?

TTFields therapy’s growing acceptance represents a shift toward physics-based cancer treatments that complement existing pharmacological approaches. Unlike immunotherapies, which can fail due to immune evasion, or targeted therapies, which suffer from resistance mutations, TTFields exerts mechanical and electro-physical forces, offering a unique mechanism unlikely to be influenced by genetic mutations alone.

In this respect, TTFields is creating a new category in oncology that could be synergistically applied in multimodal settings. As payers and regulators increasingly favor tolerable, value-driven innovations, TTFields may find a strong positioning, especially if its delivery model—wearable, home-based, and minimally invasive—aligns with evolving telehealth and patient convenience trends.

What Are Analysts Watching Moving Forward?

While the clinical efficacy and safety profile of TTFields therapy has been substantiated through the PANOVA-3 trial, institutional investors and biopharma analysts are closely monitoring three pivotal catalysts that could influence the near-term commercial trajectory for Novocure (NASDAQ: NVCR) and its regional partner Zai Lab Limited (NASDAQ: ZLAB; HKEX: 9688).

The first is the timeline for regulatory submissions and premarket approval (PMA) by the U.S. Food and Drug Administration, including acceptance milestones and the potential for an FDA Oncologic Drugs Advisory Committee (ODAC) review. Any delay or request for additional data could impact projected commercialization windows.

Secondly, attention is turning to reimbursement strategy and pricing negotiations in the United States and China—two of the largest oncology markets globally. Analysts emphasize that payer coverage decisions and health technology assessments will be critical in determining TTFields’ adoption curve, particularly given the device-based delivery model and need for long-term patient compliance.

The third and broader consideration is the pipeline momentum across additional indications. Investors are awaiting Phase 2 data from PANOVA-4, which is evaluating TTFields in combination with atezolizumab, gemcitabine, and nab-paclitaxel in metastatic pancreatic cancer. Simultaneously, ongoing glioblastoma re-treatment protocols and exploratory endpoints in non-small cell lung cancer (NSCLC) could open up expanded clinical applications, further solidifying TTFields therapy as a scalable, multimodal oncology platform.

For Novocure, success in pancreatic cancer adds a third commercial oncology pillar beyond brain and lung tumors. For Zai Lab, it reinforces its ability to deliver breakthrough therapies from global R&D into the Chinese market.

If TTFields therapy secures FDA approval in 2026 as anticipated, it could be the first new adjunctive modality in pancreatic cancer in over a decade, offering new hope for a patient population long underserved by existing therapies.