Amgen’s IMDELLTRA® Significantly Boosts Survival in Phase 3 Small Cell Lung Cancer Trial, Poised to Redefine Standard of Care

THOUSAND OAKS, Calif. — Amgen (NASDAQ:AMGN) today announced that the global Phase 3 DeLLphi-304 clinical trial evaluating IMDELLTRA® (tarlatamab-dlle) as a treatment for patients with small cell lung cancer (SCLC) who progressed on or after a single line of platinum-based chemotherapy met its primary endpoint at a planned interim analysis. IMDELLTRA demonstrated statistically significant and clinically meaningful improvement in overall survival (OS) compared to local standard-of-care (SOC) chemotherapy.

“Small cell lung cancer is one of the most aggressive malignancies, with a high unmet need for more effective therapies.The topline results from DeLLphi-304 demonstrate overwhelming clinical benefit for people living with this devastating disease and affirm IMDELLTRA as standard of care,” said Jay Bradner, M.D., executive vice president, Research and Development, at Amgen. “We look forward to sharing these results with the scientific community and health authorities as we continue our efforts to bring IMDELLTRA to patients worldwide.”

The safety profile for IMDELLTRA was consistent with its known profile. Detailed data from DeLLphi-304 will be presented at an upcoming medical congress.

DeLLphi-304 is a global Phase 3 randomized controlled open-label clinical trial evaluating the efficacy and safety of IMDELLTRA as a treatment for patients with SCLC who progressed on or after a single line of platinum-based chemotherapy.2 Patients were randomized to receive either IMDELLTRA or local SOC chemotherapy (topotecan in all countries except Japan; lurbinectedin in the U.S., CanadaAustraliaSingapore, Korea; and amrubicin in Japan).2,3 The primary outcome measure of the trial is OS.2

 

About IMDELLTRA® (tarlatamab-dlle)
IMDELLTRA is a first-in-class immunotherapy engineered by Amgen researchers that binds to both DLL3 on tumor cells and CD3 on T cells, activating T cells to kill DLL3-expressing SCLC cells. This results in the formation of a cytolytic synapse with lysis of the cancer cell.4,5 DLL3 is a protein that is expressed on the surface of SCLC cells in ~85-96% of patients with SCLC, but is minimally expressed on healthy cells, making it an exciting target.6,7

 

IMDELLTRA® (tarlatamab-dlle) U.S. Indication
IMDELLTRA® (tarlatamab-dlle) is indicated for the treatment of adult patients with extensive-stage small cell lung cancer (ES-SCLC) with disease progression on or after platinum-based chemotherapy.

This indication is approved under accelerated approval based on overall response rate and duration of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial(s).

 

About Small Cell Lung Cancer (SCLC)
SCLC is one of the most aggressive and devastating solid tumor malignancies, with a 5-10% five-year relative survival rate across all stages combined.1 SCLC comprises about 15% of the more than 2.4 million patients diagnosed with lung cancer worldwide each year.8-10 Despite initial high response rates to first-line platinum-based chemotherapy, most patients quickly relapse within months and require subsequent treatment options.9

 

About Tarlatamab Clinical Trials
Amgen’s robust tarlatamab development program includes the DeLLphi clinical trials, which evaluate tarlatamab as both a monotherapy and in combination regimens in earlier lines of SCLC.

Tarlatamab is being investigated in multiple studies including DeLLphi-303, a Phase 1b study investigating tarlatamab in combination with standard of care therapies in first-line ES-SCLC; DeLLphi-304, a randomized Phase 3 trial comparing tarlatamab monotherapy with standard of care chemotherapy in second-line treatment of SCLC; DeLLphi-305, a randomized Phase 3 trial comparing tarlatamab in combination with durvalumab versus durvalumab alone as first-line maintenance treatment in ES-SCLC; DeLLphi-306, a randomized placebo-controlled Phase 3 trial of tarlatamab following concurrent chemoradiotherapy in limited-stage SCLC; DeLLphi-308, a Phase 1b study evaluating subcutaneous tarlatamab in second line or later ES-SCLC; and DeLLphi-309, a Phase 2 study evaluating alternative intravenous dosing regimens with tarlatamab in second-line ES-SCLC.11

For more information, please visit www.tarlatamabclinicaltrials.com.

 

About Amgen 
Amgen discovers, develops, manufactures and delivers innovative medicines to help millions of patients in their fight against some of the world’s toughest diseases. More than 40 years ago, Amgen helped to establish the biotechnology industry and remains on the cutting-edge of innovation, using technology and human genetic data to push beyond what’s known today. Amgen is advancing a broad and deep pipeline that builds on its existing portfolio of medicines to treat cancer, heart disease, osteoporosis, inflammatory diseases and rare diseases.

In 2024, Amgen was named one of the “World’s Most Innovative Companies” by Fast Company and one of “America’s Best Large Employers” by Forbes, among other external recognitions. Amgen is one of the 30 companies that comprise the Dow Jones Industrial Average®, and it is also part of the Nasdaq-100 Index®, which includes the largest and most innovative non-financial companies listed on the Nasdaq Stock Market based on market capitalization.

 

IMDELLTRA® (tarlatamab-dlle) Important Safety Information

WARNING: CYTOKINE RELEASE SYNDROME AND NEUROLOGIC TOXICITY including IMMUNE EFFECTOR CELL-ASSOCIATED NEUROTOXICITY SYNDROME

  • Cytokine release syndrome (CRS), including serious or life-threatening reactions, can occur in patients receiving IMDELLTRA®. Initiate treatment with IMDELLTRA® using the step-up dosing schedule to reduce the incidence and severity of CRS. Withhold IMDELLTRA® until CRS resolves or permanently discontinue based on severity.
  • Neurologic toxicity, including immune effector cell-associated neurotoxicity syndrome (ICANS), including serious or life-threatening reactions, can occur in patients receiving IMDELLTRA®. Monitor patients for signs and symptoms of neurologic toxicity, including ICANS, during treatment and treat promptly. Withhold IMDELLTRA® until ICANS resolves or permanently discontinue based on severity.

 

WARNINGS AND PRECAUTIONS

  • Cytokine Release Syndrome (CRS): IMDELLTRA® can cause CRS including serious or life-threatening reactions. In the pooled safety population, CRS occurred in 55% of patients who received IMDELLTRA®, including 34% Grade 1, 19% Grade 2, 1.1% Grade 3 and 0.5% Grade 4. Recurrent CRS occurred in 24% of patients, including 18% Grade 1 and 6% Grade 2.

    Most events (43%) of CRS occurred after the first dose, with 29% of patients experiencing any grade CRS after the second dose and 9% of patients experiencing CRS following the third dose or later. Following the Day 1, Day 8, and Day 15 infusions, 16%, 4.3% and 2.1% of patients experienced ≥ Grade 2 CRS, respectively. The median time to onset of all grade CRS from most recent dose of IMDELLTRA® was 13.5 hours (range: 1 to 268 hours). The median time to onset of ≥ Grade 2 CRS from most recent dose of IMDELLTRA® was 14.6 hours (range: 2 to 566 hours).

    Clinical signs and symptoms of CRS included pyrexia, hypotension, fatigue, tachycardia, headache, hypoxia, nausea, and vomiting. Potentially life-threatening complications of CRS may include cardiac dysfunction, acute respiratory distress syndrome, neurologic toxicity, renal and/or hepatic failure, and disseminated intravascular coagulation (DIC).

    Administer IMDELLTRA® following the recommended step-up dosing and administer concomitant medications before and after Cycle 1 IMDELLTRA® infusions as described in Table 3 of the Prescribing Information (PI) to reduce the risk of CRS. Administer IMDELLTRA® in an appropriate health care facility equipped to monitor and manage CRS. Ensure patients are well hydrated prior to administration of IMDELLTRA®.

    Closely monitor patients for signs and symptoms of CRS during treatment with IMDELLTRA®. At the first sign of CRS, immediately discontinue IMDELLTRA® infusion, evaluate the patient for hospitalization and institute supportive care based on severity. Withhold or permanently discontinue IMDELLTRA® based on severity. Counsel patients to seek medical attention should signs or symptoms of CRS occur.
  • Neurologic Toxicity, Including ICANS: IMDELLTRA® can cause serious or life-threatening neurologic toxicity, including ICANS. In the pooled safety population, neurologic toxicity, including ICANS, occurred in 47% of patients who received IMDELLTRA®, including 10% Grade 3. The most frequent neurologic toxicities were headache (14%), peripheral neuropathy (7%), dizziness (7%), insomnia (6%), muscular weakness (3.7%), delirium (2.1%), syncope (1.6%), and neurotoxicity (1.1%).

    ICANS occurred in 9% of IMDELLTRA®-treated patients. Recurrent ICANS occurred in 1.6% of patients. Most patients experienced ICANS following Cycle 2 Day 1 (24%). Following Day 1, Day 8, and Day 15 infusions, 0.5%, 0.5% and 3.7% of patients experienced ≥ Grade 2 ICANS, respectively. The median time to onset of ICANS from the first dose of IMDELLTRATM was 29.5 days (range: 1 to 154 days). ICANS can occur several weeks following administration of IMDELLTRATM. The median time to resolution of ICANS was 33 days (range: 1 to 93 days).

    The onset of ICANS can be concurrent with CRS, following resolution of CRS, or in the absence of CRS. Clinical signs and symptoms of ICANS may include but are not limited to confusional state, depressed level of consciousness, disorientation, somnolence, lethargy, and bradyphrenia.

    Patients receiving IMDELLTRA® are at risk of neurologic adverse reactions and ICANS resulting in depressed level of consciousness. Advise patients to refrain from driving and engaging in hazardous occupations or activities, such as operating heavy or potentially dangerous machinery, in the event of any neurologic symptoms until they resolve.

    Closely monitor patients for signs and symptoms of neurologic toxicity and ICANS during treatment. At the first sign of ICANS, immediately evaluate the patient and provide supportive therapy based on severity. Withhold IMDELLTRA® or permanently discontinue based on severity.
  • Cytopenias: IMDELLTRA® can cause cytopenias including neutropenia, thrombocytopenia, and anemia. In the pooled safety population, decreased neutrophils occurred in 12% including 6% Grade 3 or 4 of IMDELLTRA®-treated patients. The median time to onset for Grade 3 or 4 neutropenia was 29.5 days (range: 2 to 213). Decreased platelets occurred in 33% including 3.2% Grade 3 or 4. The median time to onset for Grade 3 or 4 decreased platelets was 50 days (range: 3 to 420). Decreased hemoglobin occurred in 58% including 5% Grade 3 or 4. Febrile neutropenia occurred in 0.5% of patients treated with IMDELLTRA®.

    Monitor patients for signs and symptoms of cytopenias. Perform complete blood counts prior to treatment with IMDELLTRA®, before each dose, and as clinically indicated. Based on the severity of cytopenias, temporarily withhold, or permanently discontinue IMDELLTRA®.
  • Infections: IMDELLTRA® can cause serious infections, including life-threatening and fatal infections. In the pooled safety population, infections, including opportunistic infections, occurred in 41% of patients who received IMDELLTRA®. Grade 3 or 4 infections occurred in 13% of patients. The most frequent infections were COVID-19 (9%, majority during the COVID-19 pandemic), urinary tract infection (10%), pneumonia (9%), respiratory tract infection (3.2%), and candida infection (3.2%).

    Monitor patients for signs and symptoms of infection prior to and during treatment with IMDELLTRA® and treat as clinically indicated. Withhold or permanently discontinue IMDELLTRA® based on severity.
  • Hepatotoxicity: IMDELLTRA® can cause hepatotoxicity. In the pooled safety population, elevated ALT occurred in 42%, with Grade 3 or 4 ALT elevation occurring in 2.1%. Elevated AST occurred in 44% of patients, with Grade 3 or 4 AST elevation occurring in 3.2%. Elevated bilirubin occurred in 15% of patients; Grade 3 or 4 total bilirubin elevations occurred in 1.6% of patients. Liver enzyme elevation can occur with or without concurrent CRS. Monitor liver enzymes and bilirubin prior to treatment with IMDELLTRA®, before each dose, and as clinically indicated. Withhold IMDELLTRA® or permanently discontinue based on severity.
  • Hypersensitivity: IMDELLTRA® can cause severe hypersensitivity reactions. Clinical signs and symptoms of hypersensitivity may include, but are not limited to, rash and bronchospasm. Monitor patients for signs and symptoms of hypersensitivity during treatment with IMDELLTRA® and manage as clinically indicated. Withhold or consider permanent discontinuation of IMDELLTRA® based on severity.
  • Embryo-Fetal Toxicity: Based on its mechanism of action, IMDELLTRA® may cause fetal harm when administered to a pregnant woman. Advise patients of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during treatment with IMDELLTRA® and for 2 months after the last dose.

 

ADVERSE REACTIONS

  • The most common (> 20%) adverse reactions were CRS (55%), fatigue (51%), pyrexia (36%), dysgeusia (36%), decreased appetite (34%), musculoskeletal pain (30%), constipation (30%), anemia (27%) and nausea (22%). The most common (≥ 2%) Grade 3 or 4 laboratory abnormalities were decreased lymphocytes (57%), decreased sodium (16%), increased uric acid (10%), decreased total neutrophils (6%), decreased hemoglobin (5%), increased activated partial thromboplastin time (5%), decreased potassium (5%), increased aspartate aminotransferase (3.2%), decreased white blood cells (3.8%), decreased platelets (3.2%), and increased alanine aminotransferase (2.1%).
  • Serious adverse reactions occurred in 58% of patients. Serious adverse reactions in > 3% of patients included CRS (24%), pneumonia (6%), pyrexia (3.7%), and hyponatremia (3.6%). Fatal adverse reactions occurred in 2.7% of patients including pneumonia (0.5%), aspiration (0.5%), pulmonary embolism (0.5%), respiratory acidosis (0.5%), and respiratory failure (0.5%).

 

DOSAGE AND ADMINISTRATION: Important Dosing Information

  • Administer IMDELLTRA® as an intravenous infusion over one hour.
  • Administer IMDELLTRA® according to the step-up dosing schedule in the IMDELLTRA® PI (Table 1) to reduce the incidence and severity of CRS.
  • For Cycle 1, administer recommended concomitant medications before and after Cycle 1 IMDELLTRA® infusions to reduce the risk of CRS reactions as described in the PI (Table 3).
  • IMDELLTRA® should only be administered by a qualified healthcare professional with appropriate medical support to manage severe reactions such as CRS and neurologic toxicity including ICANS.
  • Due to the risk of CRS and neurologic toxicity, including ICANS, monitor patients from the start of the IMDELLTRA® infusion for 22 to 24 hours on Cycle 1 Day 1 and Cycle 1 Day 8 in an appropriate healthcare setting.
  • Recommend that patients remain within 1 hour of an appropriate healthcare setting for a total of 48 hours from start of the infusion with IMDELLTRA® following Cycle 1 Day 1 and Cycle 1 Day 8 doses, accompanied by a caregiver.
  • Prior to administration of IMDELLTRA® evaluate complete blood count, liver enzymes, and bilirubin before each dose, and as clinically indicated.
  • Ensure patients are well hydrated prior to administration of IMDELLTRA®.

 

Please see IMDELLTRA® full Prescribing Information, including BOXED WARNINGS.

 

Contact

Amgen, Thousand Oaks

Elissa Snook, 609-251-1407 (media)

Justin Claeys, 805-313-9775 (investors)

 

References

  1. PDQ® Adult Treatment Editorial Board. PDQ Small Cell Lung Cancer Treatment. Bethesda, MD: National Cancer Institute. Updated June 27, 2024. Available at: https://www.cancer.gov/types/lung/hp/small-cell-lung-treatment-pdq. Accessed March 25, 2025.
  2. DeLLphi-304 Clinical Trial Listing. Available at: https://www.clinicaltrials.gov/study/NCT05740566?term=NCT05740566&limit=10&cond=NCT05740566%20&rank=1. Accessed March 24, 2025.
  3. Paz-Ares, et al. JCO. 41, TPS8611-TPS8611(2023). DOI:10.1200/JCO.2023.41.16_suppl.TPS8611
  4. Giffin MJ, Cooke K, Lobenhofer EK, et al. AMG 757, a Half-Life Extended, DLL3-Targeted Bispecific T-Cell Engager, Shows High Potency and Sensitivity in Preclinical Models of Small-Cell Lung Cancer. Clin Cancer Res. 2021;27:1526-1537.
  5. Baeuerle PA, Kufer P, Bargou R. BiTE: Teaching antibodies to engage T-cells for cancer therapy. Curr Opin Mol Ther. 2009;11:22-30.
  6. Ahn MJ, Cho BC, Felip E, et al. Tarlatamab for Patients with Previously Treated Small-Cell Lung Cancer. N Engl J Med. 2023;389:2063-2075.
  7. Rojo F, Corassa M, Mavroudis D, et al. International real-world study of DLL3 expression in patients with small cell lung cancer. Lung Cancer. 2020;147:237-243.
  8. World Health Organization. Lung. 2022. Available at: https://gco.iarc.who.int/media/globocan/factsheets/cancers/15-trachea-bronchus-and-lung-fact-sheet.pdf. Accessed on March 24, 2025.
  9. Oronsky B, Abrouk N, Caroen S, et al. A 2022 Update on Extensive Stage Small-Cell Lung Cancer (SCLC). J Cancer. 2022;13:2945-2953.
  10. Sabari JK, Lok BH, Laird JH, et al. Unravelling the biology of SCLC: implications for therapy. Nat Rev Clin Oncol. 2017;14:549-561.
  11. Clinical Trials. Tarlatamab Clinical Trial Listings. www.clinicaltrials.gov. Accessed March 25, 2025.