ROS1-Positive Lung Cancer: Taletrectinib Receives FDA Approval for First- and Second-Line Treatment

On June 11, 2025, the US Food and Drug Administration (FDA) approved taletrectinib (Ibtrozi, Nuvation Bio) for patients with locally advanced or metastatic ROS1-positive non-small cell lung cancer (NSCLC) . This approval allows its use regardless of whether the patient has previously received a ROS1 tyrosine kinase inhibitor (TKI), both as first-line treatment and in subsequent lines .

To distinguish taletrectinib from the two first-generation medicines already available, crizotinib and entrectinib , it is considered a next-generation ROS1 TKI . Another ROS1 TKI approved in 2023, repotrectinib , is also regarded as a next-generation medicine. As with repotrectinib, the FDA granted taletrectinib breakthrough therapy designation. This indicates the drug's potential to provide substantial improvements in the treatment of a serious disease.

ROS1 gene rearrangements occur in approximately 1-2% of patients with non-small cell lung cancer (NSCLC) and are sensitive to targeted therapies. However, resistance to existing ROS1 inhibitors, particularly their limited effect on brain metastases, increases the need for new treatment options. This is where the next-generation ROS1 inhibitor taletrectinib stands out for both its efficacy and intracranial activity (activity within the brain).

🔬 Basis of the Approval: The TRUST-I and TRUST-II Phase 2 Studies

FDA approval was based on the results of two independent Phase 2 studies (TRUST-I – NCT04395677 and TRUST-II – NCT04919811). These results were also presented at the ASCO 2025 Congress .

1. Both studies are Phase 2 trials

• TRUST-I: NCT04395677
• TRUST-II: NCT04919811 → Both are single-arm, open-label, multicenter studies.

2. There was no control arm

• Both TRUST-I and TRUST-II are non-randomized, uncontrolled studies.
• In this type of design, efficacy is assessed through response rates and survival analyses within a single arm .
• FDA approval was granted on the basis of a strong efficacy signal and an acceptable safety profile in single-arm Phase 2 studies .

🌍 3. Study Scope and Geographic Distribution

🎯 Main Findings

1. Objective Response Rate (ORR)

• TKI-naive patients:
  • TRUST-I: 90% (CI: 83–95%)
  • TRUST-II: 85% (CI: 73–93%)
  • Response duration ≥6 months: 72% and 63%
• Previously treated patients:
  • TRUST-I: 52%
  • TRUST-II: 62%
  • Response duration ≥6 months: 74% and 83%

2. Overall Survival (OS) and Progression-Free Survival (PFS)

Median PFS and 12-month OS data were obtained from the pooled analysis:

• Median PFS: 45.6 months (CI: 29.0–not reached)
• 12-month PFS rate: 39.7%
• Median OS: Not yet reached
• 12-month OS rate: 77.5%

🧠 Activity in Brain Metastases

Objective Response Rate (ORR) in Brain Metastases:

• TKI-naive patients: 76.5% (CI: 50.1–93.2%)
• TKI-pretreated patients: 65.6%
• Median Duration of Response (DOR): 14.7 months and 11.9 months

🌍 Activity in Subgroups — Who Responds Better?

History of Chemotherapy:

• Patients who had received chemotherapy: 87.5% vs 89.1%
• Patients who had not: 91.6% vs 84.1%

Race and Geography:

• Asian patients (TKI-naive): 89.1%
• Western patients: 84.2%
• Non-Western regions: 89.7% vs 81.0% in Western patients

These data show similar efficacy regardless of race or region.

⚠️ Safety Profile

In both studies, Grade ≥3 adverse eventswere at a tolerable level:

• TRUST-I: 54.3%
• TRUST-II: 52.6%

The most common Grade 3+ adverse events:

• Elevated AST/ALT: 20.2% vs 18.1%
• Gastrointestinal adverse events: 5.8% vs 4.1%

🔎 What Will Change in Clinical Practice?

Taletrectinib may fill an important gap in ROS1-positive NSCLC in the following ways:

• First-line treatment now has an effective, approved next-generation option
• Patients resistant to crizotinib or entrectinib have a new option
• Activity in brain metastases is a distinguishing feature
• Long response durations and a survival advantage make it promising after adjuvant treatment or in advanced disease

📌 Conclusion

With FDA approval, taletrectinib (Ibtrozi) is a candidate for a new standard in patients with ROS1-positive NSCLC. TRUST-I and TRUST-II show a consistent efficacy and safety profile across global patient populations. In particular, intracranial activitymakes this medicine stand out within its class.