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Not yet recruitingRare disease

Study of ZL-1310, BI 764532 and atezolizumab in patients with advanced small cell lung cancer and neuroendocrine tumors

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

The study looks at patients with advanced forms of neuroendocrine tumors, including small cell lung cancer and other rare neuroendocrine cancer types that grow quickly and are poorly differentiated. The treatment being tested combines two experimental medicines, obrixtamig and ZL-1310, given by a drip into a vein (intravenous infusion). In some participants the regimen also adds the approved immunotherapy drug atezolizumab, which helps the immune system recognize cancer cells.

The main goal of the trial is to determine how safe the combination is, how well patients can tolerate it, and whether it shows early signs that it might slow tumor growth. The study is a phase Ib/II, open‑label trial, meaning that the medicines are given in a step‑wise dose‑finding phase followed by a larger safety phase, and both doctors and participants know which drugs are being used. Safety refers to the occurrence of serious side effects, tolerability means how easily patients can continue the treatment, and early clinical efficacy looks at whether the cancer stops growing for a period of time.

Participants will receive the study drugs through an infusion at regular clinic visits over several weeks, with additional visits to check blood work, imaging scans, and overall health. The schedule may be adjusted based on how each person responds, and the study follows each participant for several months to monitor side effects and any changes in tumor size. Simple terms like “progression‑free survival” mean the length of time the cancer does not get worse.

The research process

The trial runs in 7 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Baseline assessments

    After joining the study you will undergo initial medical examinations, laboratory tests, and imaging scans to document the current status of your disease.

    These assessments provide the reference point for evaluating the effects of the study medications.

  2. Step 2

    First infusion of study drugs

    On the first treatment day you will receive obrixtamig and zl-1310 as an intravenous infusion (solution for infusion).

    The exact dose and infusion duration are defined by the study protocol and will be administered by qualified staff.

    If you are enrolled in part 2 of the trial, an additional intravenous infusion of atezolizumab will be given during the same visit.

  3. Step 3

    Dose‑limiting toxicity evaluation

    During the early evaluation period (the first treatment cycle) you will be closely monitored for any dose‑limiting toxicities, which are side effects that may require dose adjustment or discontinuation.

    Monitoring includes frequent vital‑sign checks, laboratory tests, and symptom reporting.

  4. Step 4

    Subsequent treatment cycles

    If no dose‑limiting toxicity occurs, you will return for additional treatment cycles according to the schedule defined in the protocol.

    Each cycle includes an intravenous infusion of obrixtamig and zl-1310; in part 2, atezolizumab is also infused.

    The dose for each drug remains the same as established during the first cycle and is given on each treatment visit.

  5. Step 5

    Regular safety monitoring

    At every visit you will have laboratory tests and physical examinations to detect any new or worsening side effects.

    You will be asked to report any symptoms you experience, and the study team will decide whether any dose modifications are needed.

  6. Step 6

    Disease response assessment

    Periodically (as specified in the protocol) imaging studies will be performed to evaluate tumor response and progression‑free survival.

    The results help determine the early clinical efficacy of the drug combination.

  7. Step 7

    Treatment discontinuation

    Treatment will be stopped if disease progression is documented, if unacceptable side effects occur, or if the study reaches its planned end date.

    After discontinuation you will continue to be followed for safety and outcome assessments as outlined in the protocol.

Who can join the trial?

9 criteria

  • You have been diagnosed with an advanced or returning form of cancer that is one of the following: small cell lung cancer, large cell neuroendocrine lung cancer, or extrapulmonary neuroendocrine carcinoma of either small‑cell or large‑cell type. (Advanced means the tumor has grown beyond its original spot; metastatic means it has spread to other parts of the body; relapsed means it came back after previous treatment.)
  • If your tumor contains more than one type of cancer cells, the neuroendocrine or small‑cell component must make up at least half of the tumor tissue.
  • You must have no other proven treatment options left and you should have already tried at least one line of platinum‑based chemotherapy (a common chemotherapy that contains a platinum drug), unless a doctor has recorded a medical reason you cannot use platinum.
  • You need a confirmed diagnosis of Extended stage small cell lung cancer (the cancer has spread widely) using standard staging systems (AJCC stage IV or T3–T4 criteria for multiple lung nodules or large tumor volume).
  • You must not have received any prior systemic therapy (treatment that affects the whole body) for this extended stage disease. If you previously had chemoradiotherapy for limited stage disease, it must have been given with curative intent and you must have been free of treatment for at least 6 months before this study.
  • You need at least one measurable tumor outside the CNS (brain or spinal cord) as defined by RECIST 1.1 criteria. The tumor should not have been previously treated, or if it was, there must be imaging proof that it is still growing.
  • Your overall health must be good enough to have an ECOG score of 0 or 1 (0 = fully active; 1 = restricted in physically strenuous activity but able to do light work).
  • An archival (previously collected) sample of your tumor tissue must be available for testing.
  • You must be an adult (generally 18 years or older) and can be male or female.

Who cannot join the trial?

16 criteria

  • Serious other illnesses such as brain or nerve problems, mental health conditions (including substance use), active sores in the stomach, skin or other organs, or abnormal lab test results that could make the study unsafe for you.
  • Having a diagnosis of Merkel cell carcinoma or medullary thyroid cancer, which are specific types of cancer.
  • Having leptomeningeal disease or carcinomatous meningitis, meaning cancer that has spread to the thin membranes covering the brain and spinal cord.
  • Known allergy (hypersensitivity) to any of the study drugs or their inactive ingredients, or a previous severe allergic reaction to similar laboratory‑made immune proteins called monoclonal antibodies.
  • Having experienced a severe, life‑threatening immune‑related problem (graded 3 or higher) or a serious reaction during infusion of immune‑targeting cancer medicines that caused you to stop the treatment permanently.
  • Still having side effects from earlier cancer treatments that are more than mild (greater than CTCAE Grade 1), except for mild hair loss, tiredness, menstrual changes, controlled hormone problems, or stable nerve symptoms that have been stable for at least four weeks.
  • Having received any of the following treatments within the time frames shown before the first dose of the study drug:
    • Any therapy that targets DLL3 or more than 30 Gy of chest radiation at any time.
    • Systemic steroids higher than 10 mg of prednisone (or equivalent) daily, or other strong immune‑suppressing drugs, within the past 7 days.
    • Radiation to areas outside the chest (except bone lesions) within the past 2 weeks.
    • Chest radiation, monoclonal antibodies, antibody‑drug conjugates, or radio‑immunoconjugates for small‑cell lung cancer within the past 4 weeks.
    • Major surgery (as judged by the doctor) within the past 28 days or planned during the study.
    • Live weakened (attenuated) vaccines within the past 4 weeks or planned during the study.
    • Any other experimental drug or device within the past 30 days (or five drug half‑lives, whichever is longer).
    • Strong inhibitors of the liver enzymes CYP3A4 or CYP2D6 within the past 14 days (or five half‑lives, whichever is longer).
    • Having had a previous organ or tissue transplant (allograft).
    • Other exclusion reasons not listed here may also prevent participation.
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Investigated drugs

  • ZL-1310

    is an experimental monoclonal antibody that targets a protein called DLL3 on cancer cells. It is given through an IV infusion. In this trial it is being tested to see if it is safe and how well it works when combined with other study drugs.

  • BI 764532

    is a new type of therapy called an IgG‑like T‑cell engager. It attaches to DLL3 on tumor cells and to CD3 on T‑cells, helping the immune system find and kill the cancer. It is also administered by IV infusion and is being evaluated for safety and activity in the study.

  • Atezolizumab

    (brand name Tecentriq) is an immunotherapy that blocks the PD‑L1 protein, allowing the body’s immune system to recognize and attack cancer cells. It is given by IV infusion and is used in the trial together with ZL‑1310 and obrixtamig to see if the combination improves outcomes.

  • Obrixtamig

    is the main investigational drug in this study. It is given intravenously and is designed to target a specific pathway involved in poorly differentiated neuroendocrine tumors. The trial is testing obrixtamig alone and in combination with ZL‑1310, with or without atezolizumab, to assess safety, tolerability, and early signs of effectiveness.

  • Tocilizumab

    (brand name RoActemra) is a medication that blocks the IL‑6 receptor, which can reduce inflammation and manage immune‑related side effects. It is administered by IV infusion and is used as a background therapy to help control any inflammatory reactions that might occur during the trial.

What is already known about the treatment

  • ZL-1310

    This medication is given as an intravenous solution for infusion and works as a human‑derived IgG1 antibody that targets the protein DLL3 found on certain tumor cells. It is still investigational and is being studied in early‑phase clinical trials. The main aim is to treat poorly differentiated neuroendocrine cancers by marking the cancer cells for destruction by the immune system. It belongs to the class of monoclonal antibodies designed for cancer therapy.

  • BI 764532

    BI 764532 is administered by IV infusion as an IgG‑like bispecific antibody that binds both DLL3 on tumor cells and CD3 on T‑cells. It is an experimental drug currently in early clinical testing. The drug is intended for neuroendocrine tumors, where it brings T‑cells into close contact with cancer cells to trigger immune killing. It is classified as a bispecific T‑cell engager.

  • Tecentriq

    Tecentriq is a solution for IV infusion that contains the monoclonal antibody atezolizumab. It is an approved medicine worldwide and has extensive data in many cancer types. It is used to treat lung cancer and other tumors, and in this trial it is added to explore benefit in neuroendocrine carcinoma. The drug works by blocking the PD‑L1 protein, allowing the body's immune cells to recognize and attack cancer, and it is classified as an immune‑checkpoint inhibitor.

  • RoActemra

    RoActemra is given by IV infusion and contains the antibody tocilizumab. It is an approved treatment for inflammatory diseases such as rheumatoid arthritis and for severe inflammatory reactions. Although not a cancer drug, it is included as a background therapy to manage inflammation in patients. It blocks the interleukin‑6 (IL‑6) receptor, reducing inflammatory signals, and belongs to the class of IL‑6 receptor antagonists.

Investigated diseases

  • Extrapulmonary large cell neuroendocrine carcinoma

    A rare cancer that arises outside the lungs and is made up of large neuroendocrine cells. It grows quickly and can spread to nearby lymph nodes and distant organs. Symptoms depend on the organ where it starts and any hormones the tumor may release.

  • Large cell neuroendocrine carcinoma of the lung

    A high‑grade lung tumor composed of large neuroendocrine cells. It enlarges rapidly, invading surrounding lung tissue and often reaching lymph nodes or other sites. Common signs include cough, shortness of breath, or chest discomfort.

  • Extrapulmonary small cell neuroendocrine carcinoma

    An aggressive cancer occurring outside the lungs, formed by small neuroendocrine cells. It expands swiftly and can metastasize early to lymph nodes and distant locations. Clinical features vary with the affected organ and any hormone‑related effects.

  • Small cell lung carcinoma

    A fast‑growing lung cancer made of small neuroendocrine cells. It quickly invades nearby lung structures and frequently spreads to lymph nodes, brain, liver, and bone. Patients often notice cough, weight loss, or symptoms caused by hormone secretion.

Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase ITrial ID2026-525634-27-00Protocol code1438-0036Estimated enrolment54 patientsSponsorBoehringer Ingelheim Espana S.A.

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