The 2026 American Society of Clinical Oncology (ASCO) Annual Meeting, held from 29 May to 2 June in Chicago, drew more than 44,000 oncology professionals and delivered what many clinicians described as some of the most consequential trial data seen at the conference in years. Across five plenary late-breaking abstracts spanning pancreatic cancer, prostate cancer, lung cancer, sarcoma, and breast cancer, the ASCO 2026 results signalled a genuine shift in what is clinically possible for patients who have long had limited options.
A New Standard in Pancreatic Cancer
Of all the ASCO 2026 results presented at the plenary session, it was the data from the phase 3 RASolute 302 trial that drew the loudest response from the audience. Daraxonrasib, a first-in-class oral RAS(ON) multi-selective inhibitor developed for patients with previously treated metastatic pancreatic ductal adenocarcinoma (mPDAC), reduced the risk of death by 60% compared with investigator’s choice chemotherapy. Median overall survival improved from 6.7 months in the chemotherapy arm to 13.2 months with daraxonrasib, while median progression-free survival extended from 3.5 months to 7.3 months.
The drug produced a response rate of 33.2% versus 11.8% with chemotherapy and also delayed deterioration in pain and global health status by a statistically significant margin. Treatment-related grade 3 or higher adverse events occurred in 43.6% of daraxonrasib patients compared with 57.5% in the chemotherapy group, and treatment discontinuation rates due to those adverse events were substantially lower at 1.2% versus 11.2%.
Pancreatic cancer has long been among the most treatment-resistant malignancies, with second-line options offering limited benefit and poor tolerability. The RASolute 302 results, published simultaneously in the New England Journal of Medicine, were described by oncologists as landscape-changing.
Brian Wolpin, MD, MPH, of Dana-Farber Cancer Institute, stated:
“The results support daraxonrasib as the new standard of care for patients with previously treated metastatic PDAC.”
Perioperative Apalutamide Transforms High-Risk Prostate Cancer
The PROTEUS trial examined whether adding apalutamide (Erleada) to androgen deprivation therapy around the time of radical prostatectomy could improve outcomes in men with high-risk localised or locally advanced prostate cancer. The final analysis, presented as abstract LBA1 and simultaneously published in the New England Journal of Medicine, showed that perioperative apalutamide plus androgen deprivation therapy made patients approximately nine times more likely to have little or no cancer remaining in the prostate after surgery, with a pathological complete response or minimal residual disease rate of 8.9% versus 1.0% on hormone therapy alone. The regimen also reduced the risk of metastasis or death by 20%, improving five-year metastasis-free survival from 73.5% to 78.2%.
Mary-Ellen Taplin, MD, of Dana-Farber Cancer Institute, who led the study, stated:
“These results have the potential to be practice changing and support perioperative apalutamide plus ADT as a new standard of care for patients with high-risk localized prostate cancer who are candidates for radical prostatectomy.”
The trial enrolled 2,109 patients across 118 centres in 18 countries. Rash was the most common adverse event of special interest, occurring in 33.0% of the apalutamide group versus 15.3% with placebo, and was the leading cause of treatment discontinuation in the apalutamide arm.
Selpercatinib Rewrites the Rules for Early-Stage Lung Cancer
The LIBRETTO-432 trial demonstrated that adjuvant selpercatinib reduced the risk of disease recurrence or death by 83% in patients with resected stage IB to IIIA RET fusion-positive non-small cell lung cancer (NSCLC). Among 151 patients randomised across 65 sites in 22 countries, the two-year event-free survival rate was 92% with selpercatinib compared with 61% with placebo, while median event-free survival was not reached in the treatment arm versus 31.8 months with placebo. Results were simultaneously published in the New England Journal of Medicine.
RET fusions occur in approximately 1% to 2% of NSCLC cases, yet until now no targeted adjuvant therapy had been approved for patients with early-stage disease who remain at high risk for recurrence after surgery. Selpercatinib, marketed as Retevmo by Eli Lilly, was already approved for advanced RET-positive NSCLC, but the LIBRETTO-432 trial marks its first randomised phase 3 demonstration of benefit in the earlier-stage setting.
David R. Spigel, MD, President and Chief Medical Officer at Sarah Cannon Research Institute and an ASCO Expert in lung cancer, commented:
“These compelling results establish a new standard of care for a rare subset of lung cancer and are immediately practice-changing. LIBRETTO-432 reinforces the need for comprehensive biomarker testing across all stages of non-small cell lung cancer.”
The First Positive Phase 3 Trial in Liposarcoma
For patients with advanced dedifferentiated liposarcoma, a rare and aggressive soft tissue sarcoma with historically very limited treatment options, the phase 3 SARC041 trial delivered a landmark result. Abemaciclib, a CDK4/6 inhibitor already approved in breast cancer, reduced the risk of progression or death by 62% compared with placebo in 108 patients with recurrent or metastatic disease. Median progression-free survival extended from just 1.5 months in the placebo arm to 9.7 months with abemaciclib.
Mark A. Dickson, MD, of Memorial Sloan Kettering Cancer Center, who presented the findings, stated:
“This is the first positive phase 3 clinical trial in dedifferentiated liposarcoma.”
CDK4 amplification is a near-universal molecular feature of this sarcoma subtype, making it one of the most clearly defined oncogenic drivers in any solid tumour, and the SARC041 result validates that biological rationale at the highest level of clinical evidence.
Ivonescimab Challenges the Lung Cancer Immunotherapy Standard
The phase 3 HARMONi-6 trial tested ivonescimab, a first-in-class bispecific antibody simultaneously targeting PD-1 and VEGF, against tislelizumab plus chemotherapy in 532 patients with previously untreated advanced squamous NSCLC. At a prespecified interim analysis after a median follow-up of 21.4 months, ivonescimab plus chemotherapy reduced the risk of death by 34% compared with the control arm, with a hazard ratio of 0.66, and the results were simultaneously published in The Lancet.
The benefit of ivonescimab was not limited by PD-L1 expression levels, extending survival even in patients whose tumours had very low or absent PD-L1 protein. Earlier results had shown progression-free survival of approximately 11 months with ivonescimab versus approximately 9 months with tislelizumab. The HARMONi-6 presentation carried additional historical significance: it marked the first time a China-originated investigational oncology drug has been selected for the ASCO Plenary Session in the society’s 61-year history. The trial was conducted entirely across 50 sites in China, and clinicians in other regions have noted that questions of ethnic, dietary, and healthcare-setting variability will need to be addressed before the results can be fully extrapolated to Western populations.
Genomic Testing Spares Thousands from Unnecessary Chemotherapy
The fifth of the major ASCO 2026 results came not from a new drug but from a reassessment of who needs one. The phase 3 OPTIMA trial, led by Professor Rob Stein of the UCL Cancer Institute with Co-Chief Investigator Professor Iain MacPherson of the University of Glasgow, enrolled 4,429 patients aged 40 and over with early-stage estrogen receptor-positive, HER2-negative breast cancer and evaluated whether the Prosigna genomic test could safely guide de-escalation of chemotherapy in patients with clinical features that would traditionally qualify them for it.
Prosigna analyses the activity of 50 genes to assign a Risk of Recurrence score. The OPTIMA findings, presented on 30 May, showed that approximately 68% of enrolled patients had low genomic risk scores. In that low-risk group, hormone therapy alone produced five-year invasive breast cancer-free survival of 93.6%, compared with 94.8% among those who received chemotherapy: a difference of 1.2 percentage points with no clinical significance. Across the overall per-protocol population, the trial demonstrated non-inferiority for the test-directed approach, with a five-year invasive breast cancer-free survival of 90.3% in the test-directed arm versus 91.8% in the control arm. Researchers estimate Prosigna-guided decision-making could allow approximately 5,000 NHS breast cancer patients each year to avoid chemotherapy safely.
Professor Stein commented:
“Our findings show that many patients can safely avoid chemotherapy without compromising their outcomes. These results mark an important step toward more personalised treatment.”
What the ASCO 2026 Results Signal
Across five plenary abstracts, the ASCO 2026 data reinforced the direction oncology has been moving for over a decade: towards precision, towards biomarker selection, and towards recognising that more treatment is not always better. The OPTIMA trial’s de-escalation finding sits alongside the targeted efficacy results from LIBRETTO-432 and SARC041 as evidence that the field has moved meaningfully beyond the blunt application of cytotoxic therapy. The pancreatic cancer data from RASolute 302 disrupts a disease area that has resisted meaningful progress for generations. Whether the ASCO 2026 results translate quickly into regulatory approvals will depend on how agencies respond to the submissions that are expected to follow in the coming months.
