A new ROS1 lung cancer drug has reached patients in the US. What happens next in Europe?

25 Jul

On 22 July 2026, the US Food and Drug Administration (FDA) approved zidesamtinib (Jideytro), a new targeted therapy for people with ROS1-positive non-small cell lung cancer whose disease has progressed after an earlier ROS1 inhibitor.

The approval adds another treatment option for people living with ROS1-positive lung cancer in the United States. The medicine has not yet been submitted for approval to the European Medicines Agency (EMA), so it is not yet available in Europe.

The approval also highlights a wider issue. While targeted therapies continue to advance, access to those medicines still varies considerably across Europe.

The science continues to advance

ROS1 rearrangements drive around 2% of non-small cell lung cancer cases. People affected are often younger than the wider lung cancer population, are more likely to be women and many have never smoked. ROS1-positive lung cancer also has a higher likelihood of spreading to the brain, making treatments with good activity in the central nervous system particularly important.

Zidesamtinib was developed to address several challenges seen with earlier ROS1 inhibitors, including resistance mutations, disease progression in the brain and treatment tolerability.

In the study supporting approval, 117 people whose disease had progressed after previous ROS1-targeted therapy achieved an objective response rate of 44%. More than two thirds of those who responded were still responding after 12 months.

Responses were also seen in people who had previously received two or more ROS1 inhibitors, including lorlatinib, repotrectinib and taletrectinib.

Alexander Drilon, an investigator on the ARROS-1 study, said resistance mutations, disease progression in the brain and treatment-related side effects remain important challenges in ROS1-positive lung cancer. He described the responses seen with zidesamtinib, including in people who had already received multiple previous ROS1 inhibitors, as meaningful progress.

These findings suggest that some tumours continue to depend on the ROS1 pathway even after earlier targeted treatments stop working, allowing newer inhibitors to remain effective. As more medicines become available, treatment sequencing is becoming an increasingly important part of care for ROS1-positive lung cancer.

Zidesamtinib is the fifth ROS1 inhibitor to receive approval in the United States, following crizotinib, entrectinib, repotrectinib and taletrectinib.

Where Europe stands

Taletrectinib, another newer ROS1 inhibitor already approved in the United States, China and Japan, had its marketing authorisation application validated by the EMA earlier this year. Validation is an important step in the European regulatory process, but it is not the same as approval and no decision date has been announced.

Zidesamtinib has not yet entered the European regulatory process.

For people living with lung cancer in Europe, regulatory approval is only one part of the pathway. Medicines must also go through health technology assessment, pricing and reimbursement processes before they become routinely available, and these vary between countries.

EFPIA's latest Patients W.A.I.T. Indicator found that the average time between European marketing authorisation and patient availability is now 597 days. Availability also differs considerably across Europe, with some countries routinely providing access to new medicines much earlier than others.

Lung Cancer Europe's own work has identified similar differences in access to new medicines, biomarker testing and multidisciplinary care across Europe. The challenge is no longer simply developing new treatments, but ensuring that people can benefit from them regardless of where they live.

Access starts with testing

Targeted treatments can only be used if the relevant biomarker has been identified.

Access to biomarker testing continues to vary across Europe, meaning some people may not be tested for ROS1 rearrangements even when targeted treatment is available. Research from ESMO has highlighted substantial differences in access to molecular testing technologies between European countries.

Improving access to biomarker testing remains an essential part of improving access to precision medicine.

Other factors affecting access

The timing of regulatory submissions also contributes to differences between regions. Pharmaceutical companies often submit new medicines to the FDA before the EMA, meaning European regulatory review begins later.

Once approved at European level, additional national processes determine whether and when medicines become available. Smaller markets and lower-income countries can face further delays because of pricing negotiations and commercial decisions about launch priorities.

Continued progress

The approval of zidesamtinib is another example of continued progress in ROS1-positive lung cancer.

It provides another treatment option for people whose cancer has progressed after earlier ROS1-targeted therapy and adds to a growing range of medicines that can potentially be used in sequence over the course of treatment.

Recent clinical trials have also placed greater emphasis on outcomes that reflect people's daily experience of living with lung cancer, including quality of life, symptom control and cognitive function alongside tumour response. New patient-reported outcomes data from the TRUST-II study of taletrectinib, presented at the ASCO Annual Meeting in May 2026, showed rapid and durable relief from key symptoms alongside preserved cognitive function, reinforcing this shift in what trials are now measuring.

Looking ahead

Ensuring timely access to biomarker testing, regulatory review, reimbursement and treatment will be important if people across Europe are to benefit from these advances.

As more targeted therapies become available, improving equitable access will remain an important challenge for healthcare systems, policymakers and the wider lung cancer community across Europe.