- Trial Phase
- Approved
- Time to Market
- Already approved and marketed. The current label covers second-line ES-SCLC. A label expansion to first-line maintenance (based on DeLLphi-305) would require a supplemental BLA submission; no specific submission or PDUFA date has been announced as of November 2026.
- Why 4/10
- IMDELLTRA is already approved and generating significant revenue ($406M in Q3 2026). The next hard binary catalyst would be a regulatory submission for first-line maintenance label expansion based on DeLLphi-305, but no specific PDUFA or submission date has been announced. Without a dated binary catalyst in the next ~12 months, the impact score is capped at 4-5. Additionally, Amgen is a large diversified biotech where this single drug represents only ~3-4% of revenue, further limiting stock-level impact from any single catalyst.
Watch for Amgen's announcement of a supplemental BLA submission to the FDA for first-line maintenance use of IMDELLTRA based on the DeLLphi-305 data. That submission would trigger a 6-10 month review cycle and a PDUFA date, creating a clear binary catalyst. Also monitor DeLLphi-306 enrollment updates for the limited-stage SCLC opportunity. IMDELLTRA's quarterly sales trajectory (currently doubling YoY) will be a key metric in Amgen's earnings reports.
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Executive Summary
IMDELLTRA (tarlatamab-dlle) is Amgen's first-in-class bispecific T-cell engager approved for extensive-stage small cell lung cancer. Originally granted accelerated FDA approval in May 2024, it received traditional approval in November 2025 after the confirmatory Phase 3 DeLLphi-304 trial succeeded. In October 2026, Amgen reported landmark Phase 3 DeLLphi-305 results showing IMDELLTRA plus durvalumab reduced the risk of death by 58% as first-line maintenance therapy, with results published in NEJM. The drug generated $406 million in Q3 2026 sales (128% YoY growth). As an approved, commercial-stage drug at a large diversified biotech, IMDELLTRA is a meaningful growth driver but not a single-asset binary for Amgen. The next catalyst is a potential label expansion to first-line maintenance, but no regulatory submission date has been announced.
How It Works
IMDELLTRA is a bispecific T-cell engager (BiTE) antibody. It works like a bridge: one end grabs onto a protein called DLL3 found on small-cell lung cancer cells, and the other end grabs onto CD3 proteins on the body's own T-cells (a type of immune cell). This brings the T-cells close to the cancer cells, activating them to attack and kill the DLL3-expressing tumor cells.
Trial Status
IMDELLTRA received accelerated FDA approval in May 2024 for extensive-stage small cell lung cancer (ES-SCLC) after progression on platinum-based chemotherapy, based on Phase 2 data. The confirmatory Phase 3 DeLLphi-304 trial (tarlatamab vs chemotherapy as second-line treatment) met its primary endpoint, leading to conversion to traditional FDA approval in November 2025. The Phase 3 DeLLphi-305 trial (first-line maintenance: IMDELLTRA + durvalumab vs durvalumab alone) met its primary endpoint at a September 2026 interim analysis, with full results presented at ESMO 2026 showing a 58% reduction in risk of death (HR 0.42) and median overall survival of 21.1 months vs 12.7 months. A separate Phase 3 trial, DeLLphi-306, is evaluating IMDELLTRA in limited-stage SCLC after chemoradiotherapy.
The Two-Sided Case
Upcoming Catalysts
- Regulatory submission (sBLA) for first-line maintenance label expansion based on DeLLphi-305 data -- timing not yet announced
- DeLLphi-306 Phase 3 readout in limited-stage SCLC -- enrollment ongoing
Source Filing
The SecBot filing or press-release report that triggered this drug report:
Amgen PRESS-RELEASE AMGN ·Originating report