Roche's Divarasib Just Beat the First-Generation KRAS Drugs. Here's Why That Changes the Lung Cancer Landscape.
For five years, the KRAS G12C inhibitor market in lung cancer has been a story of scientific triumph and commercial disappointment. Amgen's Lumakras and Bristol Myers Squibb's Krazati were genuine breakthroughs when they launched in 2021 and 2022, respectively. They proved that KRAS, long considered undruggable, could be targeted with a small molecule. They gave patients with a specific genetic subtype of non-small cell lung cancer a new option. And then, by most commercial measures, they underperformed. Lumakras generated $363 million in sales last year. Krazati brought in $205 million. For drugs targeting one of the most common oncogenic mutations in lung cancer, those numbers tell a story of unmet potential.
On July 2, 2026, Roche announced results from the Phase 3 Krascendo 1 trial that may explain why those numbers have stayed modest, and what comes next. Roche's investigational KRAS G12C inhibitor divarasib beat both Lumakras and Krazati in a direct head-to-head comparison, achieving statistically significant improvements in both progression-free survival and overall survival in patients with previously treated KRAS G12C-mutated NSCLC. It is the first time any KRAS inhibitor has been tested directly against its approved competitors in a randomized Phase 3 trial, and the result was unambiguous.
What the Science Says About Why Divarasib Is Different
The Krascendo 1 trial enrolled 338 adults who had already received prior treatment for KRAS G12C-mutated advanced or metastatic NSCLC. Patients were randomized to receive divarasib once daily, Lumakras once daily, or Krazati twice daily. The primary endpoint was progression-free survival as assessed by blinded independent central review. The key secondary endpoint was overall survival. Roche has not yet released the numerical data, which will be presented at an upcoming medical meeting, but the company confirmed that both endpoints were met with statistical significance and that no new safety signals were observed.
The scientific rationale for expecting divarasib to outperform its predecessors was established before the trial began. In preclinical studies, divarasib demonstrated greater potency and selectivity than both sotorasib and adagrasib in binding to the KRAS G12C protein and locking it in its inactive state. The KRAS G12C mutation works by keeping the KRAS protein permanently switched on, driving continuous, unregulated cell growth. All three drugs target the same mechanism, but the molecular engineering behind divarasib was designed to address the limitations that have constrained the first-generation compounds. Cross-trial comparisons had suggested a clinical edge, but cross-trial comparisons are notoriously unreliable. The Krascendo 1 data provide the randomized, controlled evidence that those comparisons could not.
The Commercial Stakes and What They Actually Are
Roche's chief medical officer Levi Garraway said the results "should establish divarasib as a new standard of care for previously treated lung cancer patients with this genetically defined tumor subtype." That framing is commercially significant, but it is also worth reading carefully. The second-line NSCLC market, where Krascendo 1 was conducted, is the smaller of the two opportunities Roche is pursuing. The company forecasts peak divarasib sales of 1 to 2 billion Swiss francs in the second-line setting. That is a meaningful number, but it is not the number that has analysts most interested.
The larger opportunity is in first-line treatment, where patients have not yet received any therapy for their advanced disease. Roche is testing divarasib in combination with Merck's pembrolizumab against pembrolizumab plus chemotherapy in the Krascendo 2 trial. Jefferies analyst Michael Leuchten has estimated that success in first-line could open a revenue opportunity of up to 5 billion Swiss francs, roughly $6.2 billion at current exchange rates. That is a different order of magnitude than the second-line market, and it is the reason Roche made the strategic decision to run a head-to-head trial rather than simply comparing divarasib to chemotherapy. Winning against the standard of care in second-line is a prerequisite for credibility in first-line. Krascendo 1 provides that credibility.
What the First-Generation Drugs Got Wrong
The underwhelming commercial performance of Lumakras and Krazati is worth examining, because it shapes the context in which divarasib will launch. Both drugs were approved on the basis of single-arm trials showing objective response rates and progression-free survival improvements over historical benchmarks. Neither was tested head-to-head against the other, and neither was tested against a chemotherapy comparator in a randomized trial at the time of approval. The result was a market where prescribers had limited evidence to guide treatment selection, payers had limited evidence to justify premium pricing, and patients had limited data to understand what they were choosing between.
Divarasib's regulatory path is different. The Krascendo 1 data provide a direct comparison that the first-generation approvals lacked. When Roche submits to health authorities, which it has indicated it plans to do with a 2027 filing target, the application will include randomized evidence of superiority over approved alternatives. That is a stronger evidentiary foundation than either Lumakras or Krazati had at launch, and it may translate into a more compelling reimbursement argument with payers who have been cautious about the class.
The Broader Implications for Targeted Oncology
The Krascendo 1 result is also a data point in a larger story about how targeted oncology is evolving. The first generation of drugs against any validated target tends to establish proof of concept and capture early adopters. The second generation, designed with the benefit of understanding what the first generation's limitations were, often delivers the clinical performance that the market was expecting all along. This pattern has played out in EGFR inhibitors, ALK inhibitors, and now, it appears, in KRAS G12C inhibitors.
KRAS G12C is found in approximately 14% of NSCLC cases, which translates to a substantial patient population given that lung cancer remains the leading cause of cancer-related deaths worldwide, claiming approximately 1.8 million lives annually. NSCLC accounts for roughly 85% of those cases. The mutation is also present in colorectal cancer and other solid tumors, and Roche's development program extends beyond lung cancer. The full scope of divarasib's potential will depend on how the data evolve across indications, but the Krascendo 1 result establishes the foundation.
What Comes Next
The detailed data from Krascendo 1 will be presented at an upcoming medical meeting, at which point the oncology community will be able to evaluate the magnitude of the survival benefit and the safety profile in full. The numbers matter. A statistically significant improvement in overall survival that translates into a few weeks of additional life carries different clinical weight than one that translates into months. The market will be watching closely when those figures are disclosed.
For Amgen and Bristol Myers Squibb, the Krascendo 1 result is a competitive challenge that will require a strategic response. Amgen has been investing in combination strategies for Lumakras, and BMS has been exploring Krazati in earlier lines of therapy. Whether either company can find a clinical niche that divarasib does not occupy will depend on data that have not yet been generated. For now, Roche has done something that the KRAS G12C field has needed for years: it has run the trial that tells prescribers, payers, and patients which drug actually works better. The answer, at least in second-line NSCLC, is divarasib.
