Ten-Year Data Perjeta Regimen Cuts Death Risk by 17% in HER2+ Breast Cancer
In a significant milestone for the treatment of early-stage HER2-positive breast cancer, Genentech, a member of the Roche Group (SIX: RO, ROG; OTCQX: RHHBY), together with the Breast International Group (BIG), the Institut Jules Bordet Clinical Trials Support Unit, and the Frontier Science Foundation, has announced the final results from the Phase III APHINITY clinical trial. These final results, disclosed today, demonstrate a statistically significant overall survival (OS) benefit associated with the use of a Perjeta® (pertuzumab)-based regimen for patients with HER2-positive early breast cancer, even ten years following treatment.
The APHINITY study, which enrolled patients with early-stage HER2-positive breast cancer who had undergone surgery, was designed to evaluate the efficacy of adding Perjeta to the established standard regimen of Herceptin® (trastuzumab) and chemotherapy in the adjuvant setting. The study’s findings provide a compelling narrative of enduring benefit, particularly among individuals with lymph node-positive disease—those considered at higher risk for recurrence.
A Decade of Progress: Statistically Significant Survival Gains
According to the final OS analysis conducted after ten years of follow-up, treatment with the Perjeta-based regimen led to a 17% reduction in the risk of death compared with the standard treatment of Herceptin and chemotherapy with a placebo. Specifically, 91.6% of patients treated with Perjeta, Herceptin, and chemotherapy were alive at ten years, compared with 89.8% in the placebo group. This difference, while modest in absolute numbers, reached statistical significance with a hazard ratio (HR) of 0.83 (95% confidence interval [CI]: 0.69-1.00; p=0.044), validating the long-term impact of adding Perjeta to the therapeutic regimen.
The survival benefit was even more pronounced in a prespecified subgroup analysis of patients with lymph node-positive disease. These individuals experienced a 21% reduction in the risk of death (HR=0.79; 95% CI: 0.64-0.97), emphasizing the therapeutic importance of Perjeta for patients with a greater likelihood of disease recurrence due to nodal involvement.
Reinforcing a Standard of Care
Commenting on the significance of the results, Dr. Levi Garraway, M.D., Ph.D., chief medical officer and head of Global Product Development at Genentech, emphasized the durable value of early and targeted intervention in breast cancer. “Early treatment of breast cancer can provide substantial patient benefit and also increases the chance for cure. For people with early-stage HER2-positive disease, the APHINITY results validate the sustained benefits of the Perjeta-based regimen,” Garraway said. “These long-term data reinforce the regimen’s value as a well-established standard-of-care treatment in the curative setting.”
Professor Sibylle Loibl, chair of the APHINITY study and head of the German Breast Group (GBG), echoed these sentiments. “After ten years, the APHINITY trial clearly shows a statistically significant and clinically meaningful improvement of the overall survival,” she stated. “Adding Perjeta to standard adjuvant treatment is most beneficial for people with HER2-positive breast cancer with lymph node-positive disease who are at high risk of recurrence.”
Sustained Invasive Disease-Free Survival and Favorable Safety Profile
While overall survival data represents the most critical endpoint in cancer research, previously reported benefits in invasive disease-free survival (IDFS)—the primary endpoint of the APHINITY trial—were also confirmed and maintained in this final analysis. Patients in the Perjeta group continued to show reduced risk of cancer recurrence or metastasis (HR=0.79; 95% CI: 0.68-0.92), reinforcing earlier reports from interim and mid-term analyses. However, this benefit was limited to patients with lymph node-positive disease; those with node-negative disease did not experience a measurable IDFS advantage.
Importantly, the ten-year follow-up also confirmed that the safety profile of the Perjeta-based regimen remained consistent with previous observations, and no new or unexpected safety concerns emerged. The regimen was generally well tolerated, and cardiac safety, a known concern with HER2-targeted therapies, remained within acceptable thresholds throughout the decade-long observation period.
Upcoming Presentation at ESMO Breast Cancer Congress
The full findings of the APHINITY trial’s final analysis will be presented as a late-breaking abstract on Thursday, May 15, 2025, at the European Society for Medical Oncology (ESMO) Breast Cancer Congress. The results are expected to stimulate renewed dialogue among oncologists, researchers, and patient advocates regarding the evolving landscape of early-stage HER2-positive breast cancer treatment.
Collaborative Research Driving Decades of Progress
The success of the APHINITY trial is a testament to the strength and vision of global scientific collaboration. Developed through a close partnership among Genentech, Breast International Group (BIG), and other international research entities, the APHINITY trial builds on earlier landmark studies such as HERA (HERceptin Adjuvant), which helped define the role of Herceptin in early-stage HER2-positive breast cancer more than a decade ago.
These foundational studies have established Perjeta and Herceptin as cornerstone therapies for this patient population, and their impact continues to resonate across oncology practices worldwide.
Liz Frank, an independent research advocate who has been involved with APHINITY, highlighted the broader importance of such collaborative research initiatives. “The international collaborations in APHINITY have facilitated important insights about HER2-positive breast cancer and are continuing to yield promising findings,” Frank noted. “Scientists and clinicians are working together with the broader goal of improving our understanding of HER2-positive breast cancer, improving the quality of life for people living with the disease and ultimately, helping them to live longer with no disease occurring.”
Building on the HER2-Positive Treatment Landscape
The APHINITY trial represents one of the longest-running and most impactful adjuvant studies in breast cancer, and its decade-long follow-up offers not only reassurance but also forward-looking guidance for clinicians and patients. As new HER2-targeted agents—including antibody-drug conjugates and novel bispecifics—enter clinical use, the foundational role of agents like Perjeta and Herceptin remains deeply relevant.
This is especially true in the context of individualized cancer care, where treatment regimens are increasingly tailored to a patient’s recurrence risk, molecular subtype, and comorbidities. The enduring efficacy and safety of the Perjeta-based regimen in high-risk, node-positive patients supports its continued use as a key component of curative-intent treatment strategies.
The APHINITY results also remind the oncology community of the importance of long-term follow-up in adjuvant clinical trials. While early signals of efficacy may lead to accelerated regulatory approvals and guideline inclusion, it is only through comprehensive, longitudinal observation that the full magnitude of treatment benefit—and risk—can be fully understood.
With the release of its final ten-year results, the APHINITY trial has delivered critical evidence confirming the durable survival benefit of adding Perjeta to adjuvant therapy in HER2-positive early breast cancer. The findings not only strengthen the case for Perjeta as a standard-of-care component in high-risk patients but also highlight the remarkable progress that collaborative international oncology research can achieve.
As clinicians worldwide prepare to review the full data at the upcoming ESMO Breast Cancer Congress, the APHINITY study serves as both a scientific triumph and a beacon of hope for individuals diagnosed with HER2-positive early breast cancer—affirming that with the right combination of innovation, collaboration, and persistence, even the most aggressive forms of cancer can be confronted with curative intent.
