Amgen and AstraZeneca Report Landmark Survival Gains in Lung Cancer Trial

2026-10-24 biotech

Breda, Saturday 24 October 2026
Phase 3 trial results revealed combining Imdelltra with Imfinzi cut the risk of death by 58% in aggressive lung cancer, lifting one-year survival to an unprecedented 80%.

Unprecedented Survival Margins in ES-SCLC

The oncology landscape marked a pivotal turning point on 23 October 2026, when Amgen released interim Phase 3 findings from the DeLLphi-305 trial, conducted in collaboration with AstraZeneca [1]. Presented at the European Society for Medical Oncology (ESMO) Congress 2026 Presidential Symposium under abstract LBA3 and published concurrently in The New England Journal of Medicine, the study evaluated Imdelltra (tarlatamab-dlle) combined with AstraZeneca’s PD-L1 checkpoint inhibitor Imfinzi (durvalumab) as first-line maintenance therapy for extensive-stage small cell lung cancer (ES-SCLC) [1]. Small cell lung cancer accounts for 13% to 15% of the more than 2.6 million lung cancer diagnoses recorded worldwide each year, carrying a historical median survival of roughly one year, with only approximately 40% of patients progressing to receive second-line therapeutic interventions [1]. Across a cohort of 563 enrolled patients, the combination regimen demonstrated a 58% reduction in the risk of death compared to durvalumab monotherapy, reflecting a hazard ratio of 0.42 (95% CI: 0.32, 0.54; P < 0.001) at a median follow-up of approximately 16 months [1].

Transformative Clinical Endpoints and Tumour Control

The trial’s primary survival metrics showed a significant divergence between arms. Patients administered the Imdelltra and durvalumab combination achieved a median overall survival of 21.1 months, compared with 12.7 months for patients receiving durvalumab alone, conferring an absolute survival advantage of 8.4 months [1]. Furthermore, 12-month landmark survival figures revealed that nearly 80% of patients receiving the combination remained alive, whereas the monotherapy arm registered a 53% one-year survival rate, representing an absolute improvement of 27 percentage points [1]. Dr Jacob Sands, Associate Chief of the Lowe Center for Thoracic Oncology at the Dana-Farber Cancer Institute, highlighted that for an aggressive malignancy where durable responses have proven elusive, the consistency and magnitude of the benefit observed in DeLLphi-305 remain striking [1].

Mechanistic Precision and Progression-Free Milestones

Secondary endpoints from DeLLphi-305 further demonstrated superior disease control, with median progression-free survival reaching 7.4 months in the combination cohort compared to 1.9 months in the monotherapy control arm, representing a hazard ratio of 0.34 (P < 0.001) [1]. The objective response rate similarly expanded to 26.4% in the investigational group compared to 4.1% with durvalumab monotherapy, yielding an absolute increase of 22.3 percentage points [1]. As an engineered bispecific T-cell engager (BiTE), tarlatamab functions by simultaneously binding the DLL3 protein—which is expressed on the surface of roughly 85% to 96% of small cell lung cancer tumour cells—and the CD3 complex on endogenous T cells, directing targeted cytolytic immune responses [1]. These outcomes build directly upon earlier clinical cohorts; extended follow-up from the Phase 1b DeLLphi-303 trial demonstrated a median overall survival of 37.9 months at a median follow-up of 30.8 months in first-line maintenance, whilst the Phase 3 DeLLphi-304 trial documented a survival outcome of 13.6 months for Imdelltra versus 8.4 months for conventional chemotherapy [1].

Clinical Safety and Manageability Profiles

Immuno-oncology regimens harnessing bispecific constructs require rigorous clinical toxicity oversight, as highlighted during ESMO 2026 discussions regarding evolving combination standards and radiation practices [1][5]. Across an evaluated pooled safety cohort of 473 small cell lung cancer patients spanning the DeLLphi-300, DeLLphi-301, and DeLLphi-304 clinical trials, 40% received exposure for at least 6 months and 19% remained on therapy for greater than one year under a dosing schedule of 1 mg on Cycle 1 Day 1, followed by 10 mg on Days 8 and 15, and every two weeks thereafter [1]. Cytokine Release Syndrome (CRS) occurred in 57% of patients, characterised primarily as low-grade events (39% Grade 1, 15% Grade 2, 1.7% Grade 3, and 0.2% Grade 4) [1]. Neurological toxicities were documented in 65% of treated individuals, with Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS) showing a median time to onset of 16 days across an observed range of 1 to 862 days, resolving at a median interval of 4 days [1]. Severe Grade 3 or 4 haematological and biochemical laboratory anomalies included decreased lymphocytes in 43% of cases, hyponatraemia in 12%, decreased absolute neutrophils in 9%, and hyperuricaemia in 6% [1].

Biopharma Valuations and Capital Redeployment

From a commercial standpoint, the clinical breakthrough bolsters Amgen’s core pharmaceutical business, which drives 95.8% of its total revenue, with the United States market contributing 71.9% of total net sales [2]. The company’s equity closed at 439.26 USD prior to the announcement on 23 October 2026, comparing against an average analyst target price of 396.70 USD [2]. Sector investment entities have swiftly recalibrated around high-conviction clinical pipelines; specialised life-sciences investment trust BB Biotech reported its third-quarter 2026 performance on 23 October 2026, registering an investment portfolio net profit of CHF 175 million for the quarter and nine-month earnings of CHF 605 million, compared to CHF 106 million for the corresponding period in 2025 [3][4]. BB Biotech’s net asset value advanced by 5.6% in CHF while its share price rose 6.5% during the quarter, narrowing its NAV trading discount from 12.9% on 30 June 2026 to 12.2% on 30 September 2026, anchored by top core portfolio holdings including Amgen at 9.4%, Gilead Sciences at 8.3%, and Vertex Pharmaceuticals at 7.8% [3][4].

Regulatory Trajectory and Commercial Outlook

Accelerating M&A liquidity has reshaped capital redeployment across late-stage clinical oncology, with BB Biotech reinvesting approximately CHF 280 million generated from acquisitions such as Vertex’s takeover of Crinetics Pharmaceuticals and GSK’s purchase of Nuvalent into 12 new bio-venture holdings [3][4]. In parallel, global legal frameworks continue to grapple with patient access pathways for breakthrough therapeutics [5][alert! ‘Instagram legal citation discusses unspecified cancer pill access, not verified to be tarlatamab’]. The DeLLphi-305 findings were scheduled for presentation on 24 October 2026 at 17:18 CEST at ESMO, followed by a scheduled virtual briefing hosted by Amgen executive leadership on 24 October 2026 at 20:30 CEST (14:30 EDT / 11:30 PDT) to detail regulatory submission timelines to institutional investors [1]. Dr Jay Bradner, Executive Vice President of Research and Development, Artificial Intelligence and Data at Amgen, characterised the survival gains as an unprecedented advance for patients, establishing a clinical and commercial benchmark as the combination advances towards global regulatory submissions [1].

Sources & Ecosystem Partners

Clinical trials Immuno-oncology