IMFINZI® (durvalumab) plus tarlatamab-dlle reduced the risk of death by 58% in 1st-line extensive-stage small cell lung cancer in the DeLLphi-305 Phase III trial

Novel combination demonstrated a median overall survival of nearly two years, the longest benefit ever reported in extensive stage disease in a Phase III trial

Results reinforce IMFINZI as the backbone immunotherapy across stages of small cell lung cancer

WILMINGTON, Del.–(BUSINESS WIRE)–Landmark results from the DeLLphi-305 Phase III trial showed IMFINZI® (durvalumab) plus Amgen’s tarlatamab-dlle demonstrated a statistically significant and highly clinically meaningful improvement in the primary endpoint of overall survival (OS) and in the key secondary endpoint of progression-free survival (PFS) versus IMFINZI alone as a 1st-line maintenance treatment. The trial included patients with extensive-stage small cell lung cancer (ES-SCLC) who had not progressed following standard induction treatment with IMFINZI plus platinum chemotherapy (investigator’s choice of carboplatin or cisplatin) and etoposide.


These results will be presented today in a Proffered Paper session during Presidential Symposium I at the European Society for Medical Oncology (ESMO) Congress 2026 in Madrid, Spain (abstract #LBA3).1 They were also simultaneously published in The New England Journal of Medicine.

In a planned interim analysis, IMFINZI plus tarlatamab-dlle reduced the risk of death by 58% compared to IMFINZI alone (based on an OS hazard ratio [HR] of 0.42; 95% confidence interval [CI] 0.32-0.54; p<0.001) at a median follow-up of approximately 16 months. Median OS was 21.1 months for the combination versus 12.7 months for IMFINZI alone. An estimated 79% of patients treated with the combination were alive at one year compared to 53% for IMFINZI alone.

Results from the key secondary endpoint of PFS showed the combination reduced the risk of disease progression or death by 66% compared to IMFINZI alone (based on a PFS HR of 0.34; 95% CI 0.28-0.42; p<0.001) at a median follow-up of 13.9 months. Median PFS was 7.4 months for the combination versus 1.9 months for IMFINZI alone. An estimated 38% of patients treated with the combination were alive and had not experienced disease progression at one year compared to 10% for IMFINZI alone.

The OS and PFS benefits observed were consistent across all prespecified subgroups, including patients with brain or liver metastases.

Confirmed objective response rate (ORR) with the combination was six times higher compared to IMFINZI alone (26.4% versus 4.1%; p<0.001). Median duration of response (DOR) for the combination exceeded 1 year (12.7 months) versus 5.6 months for IMFINZI alone.

Jacob Sands, MD, Associate Chief of the Lowe Center for Thoracic Oncology at Dana-Farber Cancer Institute and international coordinating investigator for the trial, said: “For a disease where durable survival has remained extremely difficult to achieve, the magnitude and consistency of benefit in DeLLphi-305 are striking. Importantly, the benefit was seen across clinically relevant groups, including patients with brain metastases. Today’s remarkable results demonstrate substantial progress in our work to achieve meaningfully longer disease control and survival for patients with extensive-stage small cell lung cancer, further highlighting the importance of effective treatment at the earliest possible opportunity.”

Leora Horn, Senior Vice President, Late Development Oncology, Oncology R&D, AstraZeneca, said: “IMFINZI-based induction therapy followed by maintenance treatment with IMFINZI plus tarlatamab-dlle will redefine treatment standards for patients with extensive-stage small cell lung cancer. As the only immunotherapy to demonstrate a significant survival benefit across stages of small cell lung cancer, and now the first in combination with a T-cell engager, these important data further reinforce IMFINZI as the backbone immunotherapy in this setting.”

Summary of results: DeLLphi-305i

 

IMFINZI plus tarlatamab-dlle

(n=282)

IMFINZI

(n=281)

OS

Median OS (95% CI) (in months)

21.1

(20.8-NEii)

12.7

(11.2-14.8)

HR (95% CI)

0.42

(0.32-0.54)

Stratified log-rank, 2-sided p-value

p<0.001

OS rate at 12 months (%)

79

53

Median follow-up (in months)

15.9

16.1

PFS

Median PFS (95% CI) (in months)

7.4

(5.6-9.1)

1.9

(1.9-2.0)

HR (95% CI)

0.34

(0.28-0.42)

Stratified log-rank, 2-sided p-value

p<0.001

PFS rate at 12 months (%)

38

10

Median follow-up (in months)

13.9

13.9

 

IMFINZI plus tarlatamab-dlle

(n=235)

IMFINZI

(n=244)

BORiii % (n)

Confirmed complete responseiv

0.9 (2)

0.4 (1)

Confirmed partial responseiv

25.5 (60)

3.7 (9)

Stable disease

54.0 (127)

30.3 (74)

Progressive disease

18.3 (43)

61.5 (150)

ORR

Confirmed ORR (%) (95% CI)

26.4

(20.9-32.5)

4.1

(2.0-7.4)

2-sided p-value

p<0.001

Median DOR in months (95% CI)

12.7

(7.4-NE)

5.6

(3.5-NE)

DOR rate at 12 months (%)

52

0

Remaining on treatment as of data cut-offi (%)​

43.6

11.4

Median follow-up (in months)

10.2

8.3

 

IMFINZI plus tarlatamab-dlle

(n=282)

IMFINZI

(n=278)

Median duration of treatment, weeks (IQRv)

46.9 (16.4-65.6)

8.1 (4.1-20.1)

  1. Data cut-off was July 7, 2026
  2. Not estimable
  3. Best overall response: Objective response was assessed in patients with measurable disease at randomization (after chemoimmunotherapy) (mITT Analysis Set) by Investigator. Events were based on RECIST 1.1 guidelines; complete response and partial response should be confirmed responses. Postbaseline scan data not available for 3 (1.3%) patients who received the IMFINZI combination and 10 (4.1%) who received IMFINZI alone.
  4. Confirmation of a complete response (CR) or a partial response (PR) was required and had to take place no fewer than 4 weeks after the initial documentation of a CR or a PR.
  5. Interquartile range.

The safety and tolerability of IMFINZI plus tarlatamab-dlle was consistent with the known safety profiles of the individual medicines. Grade 3 and 4 treatment-related adverse events related to any treatment occurred in 20.9% of patients treated with the combination and 10.8% of patients treated with IMFINZI alone. Treatment with the combination resulted in a low frequency of treatment discontinuations and no treatment-related fatalities.

IMPORTANT SAFETY INFORMATION

There are no contraindications for IMFINZI® (durvalumab) or IMJUDO® (tremelimumab-actl).

Severe and Fatal Immune-Mediated Adverse Reactions

Important immune-mediated adverse reactions listed under Warnings and Precautions may not include all possible severe and fatal immune-mediated reactions. Immune-mediated adverse reactions, which may be severe or fatal, can occur in any organ system or tissue. Immune-mediated adverse reactions can occur at any time after starting treatment or after discontinuation. Monitor patients closely for symptoms and signs that may be clinical manifestations of underlying immune-mediated adverse reactions. Evaluate clinical chemistries including liver enzymes, creatinine, adrenocorticotropic hormone (ACTH) level, and thyroid function at baseline and before each dose. In cases of suspected immune-mediated adverse reactions, initiate appropriate workup to exclude alternative etiologies, including infection. Institute medical management promptly, including specialty consultation as appropriate. Withhold or permanently discontinue IMFINZI and IMJUDO depending on severity. See USPI Dosing and Administration for specific details. In general, if IMFINZI and IMJUDO requires interruption or discontinuation, administer systemic corticosteroid therapy (1 mg to 2 mg/kg/day prednisone or equivalent) until improvement to Grade 1 or less. Upon improvement to Grade 1 or less, initiate corticosteroid taper and continue to taper over at least 1 month. Consider administration of other systemic immunosuppressants in patients whose immune-mediated adverse reactions are not controlled with corticosteroid therapy.

Immune-Mediated Pneumonitis

IMFINZI and IMJUDO can cause immune-mediated pneumonitis, which may be fatal. The incidence of pneumonitis is higher in patients who have received prior thoracic radiation.

  • IMFINZI as a Single Agent

    • In patients who did not receive recent prior radiation, the incidence of immune-mediated pneumonitis was 2.4% (34/1414), including fatal (<0.1%), and Grade 3-4 (0.4%) adverse reactions.
    • In patients who received recent prior radiation, the incidence of pneumonitis (including radiation pneumonitis) in patients with unresectable Stage III NSCLC following definitive chemoradiation within 42 days prior to initiation of IMFINZI in PACIFIC was 18.3% (87/475) in patients receiving IMFINZI and 12.8% (30/234) in patients receiving placebo. Of the patients who received IMFINZI (475), 1.1% were fatal and 2.7% were Grade 3 adverse reactions.
    • The incidence of pneumonitis (including radiation pneumonitis) in patients with LS-SCLC following chemoradiation within 42 days prior to initiation of IMFINZI in ADRIATIC was 14% (37/262) in patients receiving IMFINZI and 6% (16/265) in patients receiving placebo. Of the patients who received IMFINZI (262), 0.4% had a fatal adverse reaction and 2.7% had Grade 3 adverse reactions.
    • The frequency and severity of immune-mediated pneumonitis in patients who did not receive definitive chemoradiation prior to IMFINZI were similar in patients who received IMFINZI as a single agent or with ES-SCLC or BTC when given in combination with chemotherapy.
  • IMFINZI with IMJUDO

    • Immune‑mediated pneumonitis occurred in 1.3% (5/388) of patients receiving IMFINZI and IMJUDO, including fatal (0.3%) and Grade 3 (0.2%) adverse reactions.
  • IMFINZI with IMJUDO and Platinum-Based Chemotherapy

    • Immune-mediated pneumonitis occurred in 3.5% (21/596) of patients receiving IMFINZI in combination with IMJUDO and platinum-based chemotherapy, including fatal (0.5%), and Grade 3 (1%) adverse reactions.

Immune-Mediated Colitis

IMFINZI with IMJUDO and platinum-based chemotherapy can cause immune-mediated colitis, which may be fatal. IMFINZI and IMJUDO can cause immune-mediated colitis that is frequently associated with diarrhea. Cytomegalovirus (CMV) infection/reactivation has been reported in patients with corticosteroid-refractory immune-mediated colitis. In cases of corticosteroid-refractory colitis, consider repeating infectious workup to exclude alternative etiologies.

  • IMFINZI as a Single Agent

    • Immune-mediated colitis occurred in 2% (37/1889) of patients receiving IMFINZI, including Grade 4 (<0.1%) and Grade 3 (0.4%) adverse reactions.
  • IMFINZI with IMJUDO

    • Immune‑mediated colitis or diarrhea occurred in 6% (23/388) of patients receiving IMFINZI and IMJUDO, including Grade 3 (3.6%) adverse reactions. Intestinal perforation has been observed in other studies of IMFINZI and IMJUDO.
  • IMFINZI with IMJUDO and Platinum-Based Chemotherapy

    • Immune-mediated colitis occurred in 6.5% (39/596) of patients receiving IMFINZI in combination with IMJUDO and platinum-based chemotherapy including fatal (0.2%) and Grade 3 (2.5%) adverse reactions. Intestinal perforation and large intestine perforation were reported in 0.1% of patients.

Immune-Mediated Hepatitis

IMFINZI and IMJUDO can cause immune-mediated hepatitis, which may be fatal.

  • IMFINZI as a Single Agent

    • Immune-mediated hepatitis occurred in 2.8% (52/1889) of patients receiving IMFINZI, including fatal (0.2%), Grade 4 (0.3%) and Grade 3 (1.4%) adverse reactions.
  • IMFINZI with IMJUDO

    • Immune‑mediated hepatitis occurred in 7.5% (29/388) of patients receiving IMFINZI and IMJUDO, including fatal (0.8%), Grade 4 (0.3%) and Grade 3 (4.1%) adverse reactions.
  • IMFINZI with IMJUDO and Platinum-Based Chemotherapy

    • Immune-mediated hepatitis occurred in 3.9% (23/596) of patients receiving IMFINZI in combination with IMJUDO and platinum-based chemotherapy, including fatal (0.3%), Grade 4 (0.5%), and Grade 3 (2%) adverse reactions.

Immune-Mediated Endocrinopathies

  • Adrenal Insufficiency: IMFINZI and IMJUDO can cause primary or secondary adrenal insufficiency. For Grade 2 or higher adrenal insufficiency, initiate symptomatic treatment, including hormone replacement as clinically indicated.

    • IMFINZI as a Single Agent

      • Immune-mediated adrenal insufficiency occurred in 0.5% (9/1889) of patients receiving IMFINZI, including Grade 3 (<0.1%) adverse reactions.
    • IMFINZI with IMJUDO

      • Immune-mediated adrenal insufficiency occurred in 1.5% (6/388) of patients receiving IMFINZI and IMJUDO, including Grade 3 (0.3%) adverse reactions.
    • IMFINZI with IMJUDO and Platinum-Based Chemotherapy

      • Immune-mediated adrenal insufficiency occurred in 2.2% (13/596) of patients receiving IMFINZI in combination with IMJUDO and platinum-based chemotherapy, including Grade 3 (0.8%) adverse reactions.
  • Thyroid Disorders: IMFINZI and IMJUDO can cause immune-mediated thyroid disorders. Thyroiditis can present with or without endocrinopathy. Hypothyroidism can follow hyperthyroidism. Initiate hormone replacement therapy for hypothyroidism or institute medical management of hyperthyroidism as clinically indicated.

    • IMFINZI as a Single Agent

      • Immune-mediated thyroiditis occurred in 0.5% (9/1889) of patients receiving IMFINZI, including Grade 3 (<0.1%) adverse reactions.
      • Immune-mediated hyperthyroidism occurred in 2.1% (39/1889) of patients receiving IMFINZI.
      • Immune-mediated hypothyroidism occurred in 8.3% (156/1889) of patients receiving IMFINZI, including Grade 3 (<0.1%) adverse reactions.
    • IMFINZI with IMJUDO

      • Immune-mediated thyroiditis occurred in 1.5% (6/388) of patients receiving IMFINZI and IMJUDO.
      • Immune-mediated hyperthyroidism occurred in 4.6% (18/388) of patients receiving IMFINZI and IMJUDO, including Grade 3 (0.3%) adverse reactions.
      • Immune-mediated hypothyroidism occurred in 11% (42/388) of patients receiving IMFINZI and IMJUDO.
    • IMFINZI with IMJUDO and Platinum-Based Chemotherapy

      • Immune-mediated thyroiditis occurred in 1.2% (7/596) of patients receiving IMFINZI in combination with IMJUDO and platinum-based chemotherapy.
      • Immune-mediated hyperthyroidism occurred in 5% (30/596) of patients receiving IMFINZI in combination with IMJUDO and platinum-based chemotherapy, including Grade 3 (0.2%) adverse reactions.
      • Immune-mediated hypothyroidism occurred in 8.6% (51/596) of patients receiving IMFINZI in combination with IMJUDO and platinum-based chemotherapy, including Grade 3 (0.5%) adverse reactions.
    • IMFINZI with Carboplatin and Paclitaxel

      • Immune-mediated hypothyroidism occurred in 14% (34/235) of patients receiving IMFINZI in combination with carboplatin and paclitaxel.
  • Type 1 Diabetes Mellitus, which can present with diabetic ketoacidosis: Monitor patients for hyperglycemia or other signs and symptoms of diabetes. Initiate treatment with insulin as clinically indicated.

    • IMFINZI as a Single Agent

      • Grade 3 immune-mediated Type 1 diabetes mellitus occurred in <0.1% (1/1889) of patients receiving IMFINZI.
    • IMFINZI with IMJUDO

      • Two patients (0.5%, 2/388) had events of hyperglycemia requiring insulin therapy that had not resolved at last follow-up.
    • IMFINZI with IMJUDO and Platinum-Based Chemotherapy

      • Immune-mediated Type 1 diabetes mellitus occurred in 0.5% (3/596) of patients receiving IMFINZI in combination with IMJUDO and platinum-based chemotherapy including Grade 3 (0.3%) adverse reactions.

Immune-Mediated Nephritis with Renal Dysfunction

IMFINZI and IMJUDO can cause immune-mediated nephritis.

  • IMFINZI as a Single Agent

    • Immune-mediated nephritis occurred in 0.5% (10/1889) of patients receiving IMFINZI, including Grade 3 (<0.1%) adverse reactions.
  • IMFINZI with IMJUDO

    • Immune-mediated nephritis occurred in 1% (4/388) of patients receiving IMFINZI and IMJUDO, including Grade 3 (0.5%) adverse reactions.
  • IMFINZI with IMJUDO and Platinum-Based Chemotherapy

    • Immune-mediated nephritis occurred in 0.7% (4/596) of patients receiving IMFINZI in combination with IMJUDO and platinum-based chemotherapy, including Grade 3 (0.2%) adverse reactions.

Immune-Mediated Dermatology Reactions

IMFINZI and IMJUDO can cause immune-mediated rash or dermatitis. Exfoliative dermatitis, including Stevens-Johnson Syndrome (SJS), drug rash with eosinophilia and systemic symptoms (DRESS), and toxic epidermal necrolysis (TEN), has occurred with PD-1/L-1 and CTLA-4 blocking antibodies. Topical emollients and/or topical corticosteroids may be adequate to treat mild to moderate non-exfoliative rashes.

  • IMFINZI as a Single Agent

    • Immune-mediated rash or dermatitis occurred in 1.8% (34/1889) of patients receiving IMFINZI, including Grade 3 (0.4%) adverse reactions.
  • IMFINZI with IMJUDO

    • Immune-mediated rash or dermatitis occurred in 4.9% (19/388) of patients receiving IMFINZI and IMJUDO, including Grade 4 (0.3%) and Grade 3 (1.5%) adverse reactions.
  • IMFINZI with IMJUDO and Platinum-Based Chemotherapy

    • Immune-mediated rash or dermatitis occurred in 7.2% (43/596) of patients receiving IMFINZI in combination with IMJUDO and platinum-based chemotherapy, including Grade 3 (0.3%) adverse reactions.

Immune-Mediated Pancreatitis

IMFINZI in combination with IMJUDO can cause immune-mediated pancreatitis. Immune-mediated pancreatitis occurred in 2.3% (9/388) of patients receiving IMFINZI and IMJUDO, including Grade 4 (0.3%) and Grade 3 (1.5%) adverse reactions.

Other Immune-Mediated Adverse Reactions

The following clinically significant, immune-mediated adverse reactions occurred at an incidence of less than 1% each in patients who received IMFINZI and IMJUDO or were reported with the use of other immune-checkpoint inhibitors.

  • Cardiac/vascular: Myocarditis, pericarditis, vasculitis.
  • Nervous system: Meningitis, encephalitis, myelitis and demyelination, myasthenic syndrome/myasthenia gravis (including exacerbation), Guillain-Barré syndrome, nerve paresis, autoimmune neuropathy.
  • Ocular: Uveitis, iritis, and other ocular inflammatory toxicities can occur. Some cases can be associated with retinal detachment. Various grades of visual impairment to include blindness can occur. If uveitis occurs in combination with other immune-mediated adverse reactions, consider a Vogt-Koyanagi-Harada-like syndrome, as this may require treatment with systemic steroids to reduce the risk of permanent vision loss.
  • Gastrointestinal: Pancreatitis including increases in serum amylase and lipase levels, gastritis, duodenitis.
  • Musculoskeletal and connective tissue disorders: Myositis/polymyositis, rhabdomyolysis and associated sequelae including renal failure, arthritis, polymyalgia rheumatica.
  • Endocrine: Hypoparathyroidism.
  • Hematologic/Immune: Hemolytic anemia, aplastic anemia, hemophagocytic lymphohistiocytosis, systemic inflammatory response syndrome, histiocytic necrotizing lymphadenitis (Kikuchi lymphadenitis), sarcoidosis, immune thrombocytopenia, solid organ transplant rejection, other transplant (including corneal graft) rejection.
  • Other: Myocarditis-Myositis-Myasthenia Gravis (or Myasthenia-Like) Overlap Syndrome, reported as the co-occurrence of either two or all three adverse reactions

Infusion-Related Reactions

IMFINZI and IMJUDO can cause severe or life-threatening infusion-related reactions. Monitor for signs and symptoms of infusion-related reactions. Interrupt, slow the rate of, or permanently discontinue IMFINZI and IMJUDO based on the severity. See USPI Dosing and Administration for specific details. For Grade 1 or 2 infusion-related reactions, consider using pre-medications with subsequent doses.

  • IMFINZI as a Single Agent

    • Infusion-related reactions occurred in 2.2% (42/1889) of patients receiving IMFINZI, including Grade 3 (0.3%) adverse reactions.
  • IMFINZI with IMJUDO

    • Infusion-related reactions occurred in 2.6% (10/388) of patients receiving IMFINZI and IMJUDO.
  • IMFINZI with IMJUDO and Platinum-Based Chemotherapy

    • Infusion-related reactions occurred in 2.9% (17/596) of patients receiving IMFINZI in combination with IMJUDO and platinum-based chemotherapy, including Grade 3 (0.3%) adverse reactions.

Complications of Allogeneic HSCT after IMFINZI

Fatal and other serious complications can occur in patients who receive allogeneic hematopoietic stem cell transplantation (HSCT) before or after being treated with a PD-1/L-1 blocking antibody. Transplant-related complications include hyperacute graft-versus-host disease (GVHD), acute GVHD, chronic GVHD, hepatic veno-occlusive disease (VOD) after reduced intensity conditioning, and steroid-requiring febrile syndrome (without an identified infectious cause). These complications may occur despite intervening therapy between PD-1/L-1 blockade and allogeneic HSCT. Follow patients closely for evidence of transplant-related complications and intervene promptly. Consider the benefit versus risks of treatment with a PD-1/L-1 blocking antibody prior to or after an allogeneic HSCT.

Embryo-Fetal Toxicity

Based on their mechanism of action and data from animal studies, IMFINZI and IMJUDO can cause fetal harm when administered to a pregnant woman. Advise pregnant women of the potential risk to a fetus. In females of reproductive potential, verify pregnancy status prior to initiating IMFINZI and IMJUDO and advise them to use effective contraception during treatment with IMFINZI and IMJUDO and for 3 months after the last dose of IMFINZI and IMJUDO.

Lactation

There is no information regarding the presence of IMFINZI and IMJUDO in human milk; however, because of the potential for serious adverse reactions in breastfed infants from IMFINZI and IMJUDO, advise women not to breastfeed during treatment and for 3 months after the last dose.

Adverse Reactions

Unresectable Stage III NSCLC

  • In patients with Stage III NSCLC in the PACIFIC study receiving IMFINZI (n=475), the most common adverse reactions (≥20%) were cough (40%), fatigue (34%), pneumonitis or radiation pneumonitis (34%), upper respiratory tract infections (26%), dyspnea (25%), and rash (23%). The most common Grade 3 or 4 adverse reactions (≥3%) were pneumonia (7%) and pneumonitis/radiation pneumonitis (3.4%).
  • In patients with Stage III NSCLC in the PACIFIC study receiving IMFINZI (n=475), discontinuation due to adverse reactions occurred in 15% of patients in the IMFINZI arm. Serious adverse reactions occurred in 29% of patients receiving IMFINZI. The most frequent serious adverse reactions (≥2%) were pneumonitis or radiation pneumonitis (7%) and pneumonia (6%). Fatal pneumonitis or radiation pneumonitis and fatal pneumonia occurred in <2% of patients and were similar across arms.

Resectable NSCLC

  • In patients with resectable NSCLC in the AEGEAN study, the most common adverse reactions (occurring in ≥20% of patients) were anemia, nausea, constipation, fatigue, musculoskeletal pain, and rash.
  • In patients with resectable NSCLC in the neoadjuvant phase of the AEGEAN study receiving IMFINZI in combination with platinum-containing chemotherapy (n=401), permanent discontinuation of IMFINZI due to an adverse reaction occurred in 6.7% of patients. Serious adverse reactions occurred in 21% of patients. The most frequent (≥1%) serious adverse reactions were pneumonia (2.7%), anemia (1.5%), myelosuppression (1.5%), vomiting (1.2%), neutropenia (1%), and acute kidney injury (1%). Fatal adverse reactions occurred in 2% of patients, including death due to COVID-19 pneumonia (0.5%), sepsis (0.5%), myocarditis (0.2%), decreased appetite (0.

Contacts

Media Inquiries
Lauren-Jei McCarthy +1 347 918 7001

US Media Mailbox: usmediateam@astrazeneca.com

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