Small cell lung cancer (SCLC) is one of the most aggressive and lethal cancers, with a five-year survival rate of just five to 10 percent. Black Americans, in particular, face disproportionately worse outcomes. They experience higher incidence rates, are less likely to be diagnosed early, and often encounter systemic barriers to timely and effective treatment. These disparities persist even among non-smokers, pointing to deeper issues like healthcare access, socioeconomic status, and structural inequality.
Early detection and prompt treatment are key to survival, but they remain unevenly distributed. The need for more effective, accessible therapies that can bridge these gaps has never been more urgent.
At the 2025 ASCO Annual Meeting, that urgency met a potential breakthrough.
A Major Advance: Tarlatamab Shows 40% Reduction in Death Risk
Amgen announced new interim results from the global Phase 3 DeLLphi-304 trial, showing that IMDELLTRA® (tarlatamab-dlle)—a first-in-class T-cell engager—reduced the risk of death by 40 percent and extended median overall survival by more than five months compared to standard chemotherapy in previously treated SCLC patients. These results were published simultaneously in The New England Journal of Medicine.
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“This is typically a pretty lethal disease,” Dr. Charles Rudin, chair of the study’s steering committee and a thoracic medical oncologist at Memorial Sloan Kettering Cancer Center, tells BlackDoctor.org. “Median survival with chemotherapy in this context is seven to nine months. So, there was a real need for a new therapy.”
IMDELLTRA delivered.
Highlights from the DeLLphi-304 Trial
- Survival Benefit: IMDELLTRA significantly improved median overall survival in patients who had progressed on or after platinum-based chemotherapy.
- Safety and Monitoring: Cytokine release syndrome (CRS), a known risk with T-cell engagers, occurred at similar rates whether patients were monitored for six to eight hours or 48 hours after their first two doses. This insight could help streamline treatment protocols.
- Patient-Centered Outcomes: The therapy not only improved survival but also reduced high-grade toxicities and improved quality-of-life markers such as breathlessness and cough.
How IMDELLTRA Works
Unlike traditional chemotherapy, which broadly attacks fast-dividing cells and causes widespread toxicity, tarlatamab is a bispecific T-cell engager. It binds to both the cancer cell and the patient’s T-cells, bringing them together so the immune system can directly kill the tumor.
“It’s an immune therapy,” Dr. Rudin says. “It brings the immune cell into the tumor and activates it in a pretty tumor-specific way.”
This mechanism not only improves efficacy but also drastically reduces harmful side effects—a major factor in long-term patient outcomes and quality of life.
Implications for Health Equity
Given the disproportionate burden of SCLC on Black communities, a therapy like IMDELLTRA could be game-changing. Black individuals are less likely to be diagnosed early, more likely to face treatment delays, and often receive substandard care—factors that worsen survival.
While smoking is a major risk factor, disparities persist even among non-smokers, indicating that structural and biological factors also contribute. Recent research suggests potential genetic differences, like variations in EGFR mutations, that may affect lung cancer development in Black patients.
Bringing forward therapies that are more tolerable, require less hospitalization, and deliver better outcomes can help close this gap.
What’s Next?
Amgen plans to submit the DeLLphi-304 data to the FDA to support converting IMDELLTRA’s May 2024 accelerated approval into full approval.
“We’re not done,” Dr. Rudin cautions. “But this is a really important milestone.”
Looking ahead, researchers hope to move IMDELLTRA earlier in the treatment process, including as a maintenance therapy following first-line chemo. If it can prevent relapse in this setting, its impact could be even more profound.
“We try to give our best drug first,” Dr. Rudin says. “If we think this is really a transformative therapy, we should try to move it as early as possible.”
