Dr Pan on the Real-World Utilization of Tarlatamab in Patients With SCLC

“[Researchers] did find that patients [with SCLC] who had active brain metastases and [fit] other exclusion criteria had a higher rate of CRS and ICANS. They also highlighted some of the CNS outcomes, such as PFS both intracranially and extracranially. That was very interesting for us to see because that was not evaluated in the original [phase 2 DeLLphi-301] trial.”

Kelsey Pan, MD, MPH, chief hematology/oncology fellow at MD Anderson Cancer Center, highlighted an analysis that evaluated the real-world utilization of tarlatamab-dlle (Imdelltra) in patients with relapsed/refractory small cell lung cancer (SCLC) with brain metastases and other factors that would present ineligibility in the phase 2 DeLLphi-301 trial (NCT05060016).

At the OncLive Fellows Forum on Thoracic Oncology, which took place during the 2025 ASCO Annual Meeting, fellows across the United States networked and carried out a variety of discussions about up-and-coming research within the thoracic oncology landscape. One interesting presentation at the forum detailed the differences in cytokine release syndrome (CRS) and immune effector cell–associated neurotoxicity syndrome (ICANS) among real-world patients with SCLC who were treated with tarlatamab, Pan began.

In May 2024, the FDA approved tarlatamab for the treatment of patients with extensive stage SCLC (ES-SCLC) with disease progression on or after platinum-based chemotherapy. The regulatory decision was supported by data from the DeLLphi-301 trial, which included 100 patients.

Pan noted that the real-world analysis evaluated intracranial and extracranial progression-free survival (PFS) outcomes. This was interesting because these aspects were not evaluated in the phase 2 study, she explained.

In a subgroup analysis from the DeLLphi-301 study, the objective response rate with 10 mg of tarlatamab administered once every 2 weeks was 52% (95% CI, 31%-73%) and 38% (95% CI, 27%-49%) in patients with and without brain metastases, respectively. Of note, the median PFS was 6.7 months (95% CI, 3-not evaluable [NE]) and 4.0 months (95% CI, 3-6) in these respective patient populations. Additionally, the median overall survival was 14.3 months (95% CI, 14-NE) and NE (95% CI, 9-NE), respectively.

Now that tarlatamab has been FDA-approved in the relapsed/refractory SCLC setting, it’s important to understand how patients outside of the trial responded to tarlatamab, Pan concluded.