New ROS1+ Lung Cancer Drug Shows Positive Results for Over Half of Patients

Nuvation Bio released updated efficacy data from a phase 2 study of their new drug Ibtrozi (taletrectinib) in adult patients with locally advanced or metastatic ROS1-positive (ROS1+) non-small cell lung cancer (NSCLC) which shows that over half of patients, regardless of treatment-naïvety, saw their tumors shrink on this drug.

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The updated results, which doctors discussed on Sept. 7 in a mini oral presentation at the International Association for the Study of Lung Cancer's (IASLC) 2025 World Conference on Lung Cancer (WCLC), remains partially incomplete still because the median progression-free survival (PFS) from the phase 1 study was 40.9 months, and that amount of time has not yet elapsed from the end of the phase 2 study. However, both the phase 1 and 2 studies show promising results for patients both for patients who had been treated with an ROS1 tyrosine kinase inhibitor (TKI) previously and for TKI-naïve patients, and for patients with and without brain metastases.

Another significant part of the drug profile is the relatively mild and low level of adverse effects for patients. Most common were nausea, dizziness, and diarrhea, which went away after a few days for most patients.

Nuvation Bio Founder, President and CEO David Hung, M.D., said the results "emphasize impressive PFS and durability of response, with a tolerable and manageable safety profile that helps patients stay on therapy so they can continue to benefit."

Results By The Numbers

The phase II study (TRUST-II) shows the most promising results in TKI-naïve patients, for whom a confirmed objective response rate (cORR) was 85.2% at a median follow-up time frame of 20.5 months. The longest observed PFS among these patients was ongoing at 31.6. months; the median PFS from the phase 1 (TRUST-I) study of 40.5 months has not yet been reached. Just over 66% of patients with brain metastases also saw an intracranial response of their tumors.

Most TKI-pre-treated patients also saw improvements, though not at the same rates as their TKI-naïve counterparts. At a median follow-up of 20.4 months, 61.7% of these patients showed a confirmed objective response and 56.3% of patients with brain metastases showed intracranial response to the drug. The median DOR and PFS were 19.4 and 11.8 months, respectively.

The median duration of response (DOR) from both the TRUST-I and TRUST-II studies has not yet been reached, so further updates will likely be released. Still, these promising results, when considered alongside the high level of tolerance most patients had with the drug (only one patient experienced adverse effects strong enough to stop treatment, and no patients stopped taking the drug because of the common side effects) are exciting for both medical practitioners and patients with ROS1+ lung cancer.

REFERENCES

1. Nuvation Bio Inc. Nuvation Bio announces new data from pivotal clinical studies of IBTROZI™ (taletrectinib) in advanced ROS1-positive non-small cell lung cancer at 2025 World Conference on Lung Cancer. Nuvation Bio Inc. Sept. 7, 2025. Accessed Sept. 12, 2025. https://investors.nuvationbio.com/news/news-details/2025/Nuvation-Bio-Announces-New-Data-from-Pivotal-Clinical-Studies-of-IBTROZI-taletrectinib-in-Advanced-ROS1-Positive-Non-Small-Cell-Lung-Cancer-at-2025-World-Conference-on-Lung-Cancer/default.aspx