EMA Recommends First Bispecific T-Cell Engager for Relapsed Small Cell Lung Cancer
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European regulators back Amgen's Imdylltra as breakthrough treatment for extensive-stage SCLC, marking first BiTE therapy approval in solid tumors.
Key questions this brief answers
- What is Imdylltra and when did EMA recommend it?
- How does tarlatamab work against small cell lung cancer?
- What were the results of the DeLLphi-301 clinical trial?
- What are the common side effects of Imdylltra?
The European Medicines Agency recommended Imdylltra (tarlatamab) on March 27, 2026, as the first bispecific T-cell engager (BiTE) approved for a solid tumor in Europe. The CHMP backed Amgen's therapy for adults with relapsed extensive-stage small cell lung cancer (ES-SCLC) after platinum-based chemotherapy, based on Phase 2 DeLLphi-301 trial data showing 40% objective response rate.
Contents9 sections
Key Takeaways
- First BiTE for solid tumors: EMA's CHMP recommended Imdylltra on March 27, 2026, marking the first bispecific T-cell engager approved for a solid tumor indication in Europe. EMA News
- Strong efficacy in heavily pretreated patients: Phase 2 DeLLphi-301 trial demonstrated 40% objective response rate at 10 mg dose, with median progression-free survival of 4.9 months and 9-month overall survival of 68%. NEJM Publication
- Manageable safety profile: Cytokine release syndrome occurred in 51% of patients (mostly Grade 1-2), with only 3% discontinuing due to adverse events. FDA Approval
- Orphan designation since 2024: Tarlatamab received EMA orphan medicinal product designation on January 12, 2024 (EU/3/23/2876) for small cell lung cancer. EMA Orphan Designation
What is Imdylltra and When Did EMA Recommend It?
Imdylltra is the brand name for tarlatamab, a bispecific T-cell engager developed by Amgen. The EMA's Committee for Medicinal Products for Human Use (CHMP) issued a positive opinion on March 27, 2026, recommending marketing authorization for Imdylltra as monotherapy. This recommendation follows FDA accelerated approval on May 16, 2024, making it the first BiTE therapy approved for a solid tumor in either jurisdiction.
How Does Tarlatamab Work Against Small Cell Lung Cancer?
Tarlatamab operates through a novel bispecific mechanism. It simultaneously binds to the DLL3 protein on cancer cells and CD3 receptors on T-cells. This dual targeting redirects the patient's immune system to attack malignant cells directly. DLL3 (Delta-like ligand 3) is overexpressed in approximately 85% of small cell lung cancers, making it an attractive therapeutic target with limited expression in normal tissues.
What Were the DeLLphi-301 Trial Results?
The Phase 2 DeLLphi-301 trial evaluated tarlatamab in 220 patients with previously treated ES-SCLC. DeLLphi trial data show promising results in heavily pretreated patients. Key findings include:
- Objective Response Rate: 40% in the 10 mg dose group (97.5% CI: 29–52) and 32% in the 100 mg group
- Duration of Response: Responses lasted ≥6 months in 59% of patients
- Progression-Free Survival: Median PFS of 4.9 months (95% CI: 2.9–6.7) at 10 mg
- Overall Survival: 9-month OS estimates of 68% (10 mg) and 66% (100 mg)
- Platinum Sensitivity: ORR was higher in platinum-resistant patients (52%) versus platinum-sensitive (31%)
The 10 mg dose was selected for further development based on favorable efficacy and safety profiles.
What is the Safety Profile of Imdylltra?
The most common adverse events observed in DeLLphi-301 were:
| Adverse Event | Incidence | Grade 3+ Rate |
|---|---|---|
| Cytokine release syndrome | 51% | 1% |
| Decreased appetite | 37% | 3% |
| Pyrexia | 35% | 1% |
| Fatigue | 28% | 2% |
| Dysgeusia | 24% | 0% |
Importantly, only 3% of patients discontinued treatment due to adverse events. The FDA label carries a Boxed Warning for cytokine release syndrome and neurologic toxicity.
What is the Competitive Context for Relapsed SCLC?
Patients with relapsed ES-SCLC currently have limited therapeutic options. Zepzelca (lurbinectedin) from Jazz Pharmaceuticals and older chemotherapy agents like topotecan represent the standard of care. Imdylltra's novel mechanism positions it as a potential game-changer in this segment. Industry analysts estimate the global small cell lung cancer therapeutics market at approximately $1.2 billion.
What Are the Next Regulatory Steps?
The CHMP recommendation now advances to the European Commission for final marketing authorization, typically granted within 67 days. Individual EU member states will subsequently determine pricing and reimbursement. Conditional marketing authorizations may apply if confirmatory data is pending.
Frequently Asked Questions
What is Imdylltra and when did EMA recommend it?
Imdylltra (tarlatamab) is a bispecific T-cell engager immunotherapy. The EMA's CHMP recommended its approval on March 27, 2026, for adults with relapsed extensive-stage small cell lung cancer after platinum-based chemotherapy.
How does tarlatamab work against small cell lung cancer?
Tarlatamab is a bispecific T-cell engager that binds to DLL3 on cancer cells and CD3 on T-cells, redirecting the patient's immune system to attack malignant cells. DLL3 is overexpressed in approximately 85% of small cell lung cancers.
What were the results of the DeLLphi-301 clinical trial?
The Phase 2 DeLLphi-301 trial showed tarlatamab achieved a 40% objective response rate at the 10 mg dose, with median progression-free survival of 4.9 months and 9-month overall survival of 68%.
What are the common side effects of Imdylltra?
The most common adverse events are cytokine release syndrome (CRS) occurring in 51% of patients (mostly Grade 1-2), decreased appetite, pyrexia, fatigue, and dysgeusia. Only 3% of patients discontinued treatment due to adverse events.
Primary Sources
- European Medicines Agency. "New treatment for relapsed extensive-stage small cell lung cancer." March 27, 2026.
- European Medicines Agency. "Orphan designation for tarlatamab (EU/3/23/2876)." January 12, 2024.
- U.S. Food and Drug Administration. "FDA grants accelerated approval to tarlatamab-dlle for extensive-stage small cell lung cancer." May 16, 2024.
- U.S. Food and Drug Administration. "IMDELLTRA (tarlatamab-dlle) Prescribing Information." May 2024.
- Paz-Ares L, et al. "Tarlatamab in Previously Treated Small-Cell Lung Cancer." New England Journal of Medicine. 2023.
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