New research from the 2026 American Society of Clinical Oncology (ASCO) annual meeting, and presented on Cure Today, highlights an encouraging new treatment on the horizon for advanced non-small cell lung cancer (NSCLC), the most common type of lung cancer.

An early-stage clinical trial looked at an experimental drug called pumitamig. For patients who do not have specific genetic mutations that match existing targeted therapies, this new option is showing a lot of promise.

Here is a breakdown of what the study found.

How the Drug Works: A Two-in-One Approach

Most standard immunotherapy drugs target one specific protein to help the body fight cancer. Pumitamig belongs to a newer, advanced class of medicines called bispecific antibodies. You can think of it as a single medicine designed to tackle two targets at the same time:

• Target 1 (PD-L1): Cancer cells often use this protein as a “cloaking device” to hide from your immune system. Pumitamig strips away that camouflage so your immune cells can see and attack the tumor.
• Target 2 (VEGF-A): Tumors need blood vessels to feed them and help them grow. Pumitamig blocks this protein to essentially cut off the tumor’s food supply lines.

The Key Findings

The study followed 44 patients with advanced lung cancer who had not received treatment yet. They were given pumitamig combined with standard chemotherapy. The early results are highly encouraging:

• 70% Response Rate: In 7 out of 10 patients, the tumors shrank significantly. On average, tumors shrank by nearly 40%.
• 100% Disease Control: Every single evaluable patient in the study achieved “disease control”—meaning that for everyone in the trial, the cancer either shrank or at least stopped growing and stayed stable.
• Works Across Different Lung Cancer Types: The drug showed strong results regardless of whether a patient had the squamous or non-squamous subtype of non-small cell lung cancer.

Why This Matters for “PD-L1 Low” Patients

Currently, popular immunotherapy drugs like Keytruda tend to work best if your tumor has high levels of a protein marker called PD-L1. If your doctor tells you that your PD-L1 levels are low (less than 1%), standard immunotherapies often don’t work as well.

Remarkably, pumitamig helped patients across all levels of PD-L1, including those with virtually no PD-L1 expression. This could open a massive door for patients who previously had fewer immunotherapy options.

Side Effects and Safety

Because this treatment combines a strong new drug with standard chemotherapy, side effects are expected.

• Almost all patients experienced some side effects, which is very common with chemotherapy regimens.
• About 44% experienced more severe side effects, though doctors determined that less than one-fifth (18.6%) of those severe issues were caused by the new drug itself; most were from the chemo.
• Because the drug blocks blood vessel growth, there is a known risk of bleeding, which occurred in about 16% of patients, though only one case was severe.
• Very few patients (less than 5%) had to stop the treatment entirely due to side effects from pumitamig.

What is Next?

It is important to note that pumitamig is investigational, meaning it is still in testing and is not yet approved by the FDA.

Because these early results were so positive, researchers have already launched a larger, definitive “Phase 3” trial. This next phase is actively comparing pumitamig directly against Keytruda (the current standard of care) to see if it performs better in the long run.

If you or a loved one are navigating an advanced non-small cell lung cancer diagnosis and do not have actionable genetic mutations, you can ask your oncologist if a clinical trial like this might be a good fit. The trial is called ROSETTA Lung-02, and details can be found on ClinicalTrials.gov using the ID code NCT06712316.