SUMMARY: The American Cancer Society estimates that for 2026, about 229,410 new cases of lung cancer will be diagnosed and 124,990 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Non-Small Cell Lung Cancer (NSCLC) accounts for approximately 85% of all lung cancers and adenocarcinoma is now the most frequent histologic subtype of lung cancer.
Approximately 10-15% of Caucasian patients and 35-50% of Asian patients with adenocarcinomas, harbor activating EGFR (Epidermal Growth Factor Receptor) mutations, and 90% of these mutations are either exon 19 deletions or L858R substitution mutation in exon 21. EGFR exon 20 insertion mutations are the third most common after L858R and exon 19 deletions and occur in about 2-3% of all patients with NSCLC and up to 12% of EGFR-mutated NSCLC . These mutations are also enriched in women, non-smokers, Asian populations, and those with adenocarcinoma.These highly heterogeneous group of mutations are typically associated with limited sensitivity to conventional EGFR Tyrosine Kinase Inhibitors (TKIs) due to an altered conformation of the kinase active site. Next-Generation sequencing provides an alternative to Polymerase Chain Reaction (PCR)-based tests, which fail to identify 50% or more of exon 20 insertion mutations. Patients with EGFR exon 20 insertion mutations have a 5-year Overall Survival (OS) of 8% in the frontline setting, compared to an OS of 19% for patients with EGFR exon 19 deletions or L858R mutations. Further, the use of immunotherapy is detrimental in this patient population and there is therefore a clinically unmet need for this patient group.
The treatment landscape for patients with advanced NSCLC harboring EGFR exon 20 insertion (ex20ins) mutations continues to evolve, with emerging targeted therapies offering new opportunities to improve outcomes in this historically challenging patient population.
Sunvozertinib (ZEGFROVY®), a novel oral, selective, and irreversible EGFR TKI specifically designed to target EGFR exon 20 insertion mutations, has already received regulatory approval in the United States and China for previously treated patients whose disease progressed following platinum-based chemotherapy. Building on encouraging efficacy observed in the pivotal WU-KONG1B and WU-KONG6 studies, the global Phase 3 WU-KONG28 trial evaluated whether Sunvozertinib could improve outcomes when used as first-line therapy.
WU-KONG28: Evaluating a Chemotherapy-Free First-Line Approach
WU-KONG28 (NCT05668988) is a multinational, randomized Phase 3 study, comparing Sunvozertinib with standard platinum-based chemotherapy, in treatment-naïve patients with advanced nonsquamous NSCLC harboring EGFR exon 20 insertion mutations.
A total of 324 patients were randomized 1:1 to receive either oral Sunvozertinib 300 mg once daily (N=163) until disease progression, or Carboplatin plus Pemetrexed chemotherapy (N=161) administered every three weeks for up to six cycles, followed by Pemetrexed maintenance. Patients assigned to chemotherapy were permitted to cross over to Sunvozertinib following centrally confirmed disease progression. The Primary endpoint was Progression-Free Survival (PFS) assessed by Blinded Independent Central Review (BICR), while key Secondary endpoints included Overall Survival (OS), Objective Response Rate (ORR), Duration of Response (DoR), and Safety.
Significant Improvement in Progression-Free Survival
At the January 16, 2026 data cutoff, Sunvozertinib demonstrated a statistically significant and clinically meaningful improvement in PFS compared with chemotherapy. Median PFS reached 10.3 months with Sunvozertinib versus 7.5 months with chemotherapy, corresponding to a 35% reduction in the risk of disease progression or death (HR 0.65; 95% CI, 0.50–0.85; P=0.0008).
Notably, separation of the PFS curves occurred early, suggesting rapid disease control with targeted therapy. At 12 months, 46.1% of patients receiving Sunvozertinib remained progression-free compared with 26.7% of patients treated with chemotherapy. The PFS advantage was generally consistent across analyzed patient subgroups.
Higher Response Rates and More Durable Tumor Control
Beyond prolonging PFS, Sunvozertinib achieved substantially deeper and more durable responses. The confirmed ORR was 58.9% with Sunvozertinib compared with 31.1% with chemotherapy. Patients receiving Sunvozertinib also experienced greater tumor shrinkage, with a median best percentage reduction in target lesions of 42.1% versus 24.7% in the chemotherapy arm.
Response durability further favored the targeted agent, with a median DoR of 11.2 months compared with 7.1 months for chemotherapy. These findings reinforce earlier clinical observations that Sunvozertinib provides robust antitumor activity across a broad spectrum of EGFR exon 20 insertion subtypes.
Overall Survival Data Still Maturing
Overall Survival analyses remain immature, with data maturity at 38.9% at the time of analysis. Interpretation of future OS results may be influenced by the study’s crossover design, as more than 90% of chemotherapy-treated patients with confirmed disease progression subsequently crossed over to receive Sunvozertinib.
While longer follow-up is needed to determine whether the PFS and response advantages translate into an Overall Survival benefit, the current efficacy results strongly support the clinical activity of Sunvozertinib in the frontline setting.
Manageable Safety Profile Supports Long-Term Use
The safety profile observed in WU-KONG28 was consistent with previous studies of Sunvozertinib. Grade 3 or higher adverse events occurred in 75.5% of patients receiving Sunvozertinib compared with 56.7% of patients receiving chemotherapy. The most frequently reported high-grade toxicities included elevated serum creatine kinase levels, diarrhea, and anemia.
Importantly, treatment discontinuation due to drug-related adverse events occurred in only 7.4% of patients, and no treatment-related deaths were reported. Severe rash was uncommon, and although grade 3 or higher diarrhea occurred in approximately 13.5% of patients, these events were generally manageable through proactive monitoring, supportive care, and dose modifications. The majority of patients were able to maintain treatment, reflected by a median relative dose intensity of 95%.
Implications for Clinical Practice
Historically, treatment options for EGFR exon 20 insertion-positive NSCLC have been limited, with platinum-based chemotherapy delivering modest response rates and relatively short progression-free survival. While the addition of targeted antibodies such as Amivantamab has improved outcomes, these approaches still rely on intravenous chemotherapy-based regimens.
The WU-KONG28 results position Sunvozertinib as a compelling chemotherapy-free alternative. As an oral targeted therapy, Sunvozertinib offers the potential for improved convenience and quality of life while delivering superior efficacy compared with standard platinum-doublet chemotherapy.
Looking Ahead
The WU-KONG28 trial represents a significant milestone in the treatment of EGFR exon 20 insertion-positive NSCLC. Sunvozertinib demonstrated superior Progression-Free Survival, higher response rates, greater tumor shrinkage, and longer response durability compared with standard chemotherapy, while maintaining a manageable and predictable safety profile.
As Overall Survival data continue to mature, these findings provide strong evidence supporting Sunvozertinib as a potential new first-line standard of care for patients with advanced NSCLC harboring EGFR exon 20 insertion mutations, further advancing the shift toward personalized, targeted treatment strategies in lung cancer.
First-Line Sunvozertinib in NSCLC with EGFR Exon 20 Insertion Mutations. Zhou C, Greillier L, Liu G, et al. or the WU-KONG28 Investigators. Published May 29, 2026. DOI: 10.1056/NEJMoa2604461
