Imdelltra Explained Simply: From First Infusion to Follow-Up Care
Starting a new treatment can come with a lot of questions, especially when it involves infusions, appointments, and ongoing follow-up care. If you’ve heard about Imdelltra and want a simple breakdown of what the overall treatment journey may look like, this guide walks through the process step by step, from the first infusion to ongoing monitoring and support.
What Is Imdelltra?
Imdelltra™ (tarlatamab) is a treatment approved by the US Food and Drug Administration (FDA) on May 16, 2024 for patients with advanced-stage small cell lung cancer (SCLC) that has progressed after platinum-based chemotherapy. It is given through intravenous (IV) infusion, first weekly for 3 doses and then once every 2 weeks.1
Small cell lung cancer is an aggressive type of lung cancer known for rapid growth, early spread (metastasis), treatment resistance, and poor survival outcomes. It accounts for about 15% of all lung cancers, and most patients initially respond to treatment but later experience relapse.1
What Is Imdelltra Used For?
Imdelltra is used for patients with advanced-stage small cell lung cancer (SCLC) that has progressed after platinum-based chemotherapy. It was developed to address challenges seen with current SCLC treatments, including treatment resistance, poor T-cell penetration, and ineffective antigen presentation.1
Research notes that tarlatamab showed anticancer activity, sustained clinical responses, and favorable survival outcomes in previously treated patients with SCLC, without identifying new safety concerns.1
How Does Imdelltra Work?
Imdelltra targets a protein called delta-like ligand 3 (DLL3), which is highly expressed in SCLC cancer cells but rarely found at high levels in normal cells. DLL3 is linked with tumor growth and metastasis, making it a promising target for therapy.1
Tarlatamab works by binding to DLL3 on SCLC cells and CD3 on T cells at the same time. This creates a cytolytic synapse, which helps trigger T cell-mediated tumor cell death.1
Imdelltra For Extensive-Stage Small Cell Lung Cancer
IMDELLTRA™ (tarlatamab) has shown promising efficacy in patients who had already received prior treatments. In a Phase I study of 107 patients, most had already received at least 2 prior treatments. About 23.4% of patients saw their cancer shrink after treatment, including some who had complete responses. The median duration of response was 12.3 months, while the median overall survival was 13.2 months.1
In a larger Phase II study involving 220 previously treated patients, about 40% of patients receiving the 10 mg dose saw their cancer respond to treatment, compared with 31.8% in the 100 mg group. Median overall survival with the 10 mg dose was 14.3 months.1
Why The First Infusion Needs Careful Monitoring
Tarlatamab is a type of immunotherapy called a bispecific T-cell engager (BiTE) used for treating extensive-stage small-cell lung cancer after disease progression or after platinum-based chemotherapy. Because it activates the immune system to target cancer cells, there is a risk of a reaction called cytokine release syndrome (CRS) and also of neurologic toxicity.2,3
Due to this risk, early clinical trials required patients receiving their first tarlatamab doses in cycle 1 to be monitored in the hospital for 48–72 hours after infusion. Careful monitoring during the first infusion helps healthcare teams watch for and manage CRS and other infusion-related reactions if they occur.2
What Happens Before Your First Imdelltra Infusion?
Before starting IMDELLTRA®, your healthcare team may do several checks to help prepare for treatment. This includes blood tests to check your complete blood count, liver enzymes, and bilirubin levels before treatment and during the early treatment cycles.3
Patients are also advised to stay well hydrated before receiving IMDELLTRA. During Cycle 1, additional medicines may be given before and after certain infusions to help lower the risk of CRS reactions.3
IMDELLTRA should only be given by a qualified healthcare professional in a setting with appropriate medical support available to manage serious reactions, including CRS and neurologic side effects such as ICANS (immune effector cell-associated neurotoxicity syndrome).3
Imdelltra Step-Up Dosing: What Patients Should Know
IMDELLTRA® is given as a 1-hour intravenous (IV) infusion using a “step-up dosing” schedule during the first treatment cycle. This approach is used on Cycle 1 Day 1 to help reduce the incidence and severity of CRS (Cytokine Release Syndrome).3
In the first cycle, patients receive:3
- Day 1: Step-up dose of 1 mg
- Day 8: 10 mg
- Day 15: 10 mg
After the step-up schedule is completed, IMDELLTRA is generally given every 2 weeks until disease progression or unacceptable toxicity.3
Patients are also monitored after infusions. Monitoring times may vary across cycles:3
- 24–48 hours monitoring after Cycle 1 Day 1 and Day 8 infusions
- 6–8 hours after Day 15 and Cycle 2 doses
- 3–4 hours during Cycles 3 and 4
- 2 hours from Cycle 5 onward
For Cycle 1 Day 8, patients are also advised to remain within 1 hour of an appropriate healthcare setting for 48 hours after the infusion and be accompanied by a caregiver.3
What Happens During An Imdelltra Infusion?
IMDELLTRA® is given through an intravenous (IV) infusion over 1 hour using an infusion pump at a constant rate of 250 mL/hour in an appropriate healthcare setting. Before the infusion, the IV catheter may be flushed using 0.9% Sodium Chloride Injection, and the same IV catheter can also be used for giving certain accompanying medicines.3
During Cycle 1, Days 1 and 8, patients receive additional medicines to help reduce the risk of CRS. This includes 8 mg intravenous dexamethasone (or equivalent) given within 1 hour before the IMDELLTRA infusion, followed by 1 litre of normal saline intravenously over 2 to 4 hours immediately after the infusion is completed. Patients are also monitored closely after treatment as part of the infusion process.3
What To Expect After The First Infusion
After the first IMDELLTRA® infusion, patients are usually monitored closely in the healthcare setting for a period of time. The care team may continue checking how the patient is feeling and provide guidance on the next steps before discharge.3
Patients may also be advised to stay near an appropriate healthcare facility for a certain period after the infusion and have a caregiver available for support. Follow-up visits, monitoring, and future infusion schedules are typically planned as part of the treatment process.3
Common Side Effects Of Imdelltra
Several side effects were commonly reported in patients receiving IMDELLTRA® treatment. The most frequently seen side effects included:3,4
- Cytokine Release Syndrome (CRS) – 53%
- Fever (pyrexia) – 38%
- Decreased appetite – 36%
- Changes in taste (dysgeusia) – 32%
- Anemia – 30%
- Constipation – 29%
- Weakness/asthenia – 25%
- Fatigue – 24%
- Neutropenia – 16%
- ICANS (immune effector cell-associated neurotoxicity syndrome) – 10%
Some side effects such as CRS, fatigue, and ICANS, were seen earlier during treatment, while neutropenia appeared later in some patients. Treatment-related side effects led to dose interruption in 15% of patients and treatment discontinuation in 3% of patients.3,4
Serious Side Effects And Warning Signs
One of the most important serious side effects linked with IMDELLTRA is CRS. Patients are closely monitored during treatment because CRS can sometimes become severe.3,4
Possible warning signs and symptoms of CRS may include:
- Fever (pyrexia)
- Low blood pressure (hypotension)
- Fatigue or weakness
- Fast heartbeat (tachycardia)
- Headache
- Low oxygen levels (hypoxia)
- Nausea and vomiting
In some cases, CRS may lead to serious complications such as:
- Cardiac dysfunction
- Acute respiratory distress syndrome
- Neurologic toxicity
- Kidney failure
- Liver failure
- Disseminated intravascular coagulation (DIC)
Because of these risks, IMDELLTRA is given in an appropriate healthcare setting with close monitoring and supportive care available if needed.3,4
What Is Cytokine Release Syndrome?
Cytokine Release Syndrome (CRS) is a systemic inflammatory response that can happen with certain immunotherapies, including BiTE therapies like tarlatamab. It happens when T cells become activated and release inflammatory proteins called cytokines, such as interferon gamma.4
Fever is considered the main defining symptom of CRS. In some cases, it can also involve symptoms such as low oxygen levels (hypoxia), low blood pressure (hypotension), fast breathing (tachypnea), headache, rapid heart rate (tachycardia), and rash. CRS can sometimes become serious and may lead to potentially life-threatening complications and organ damage.4
Because fever can happen for many different reasons in cancer patients, CRS can sometimes be difficult to diagnose. To help assess severity, CRS is graded using the ASTCT (American Society for Transplantation and Cellular Therapy) consensus grading criteria, which looks at symptoms such as fever, hypoxia, and hypotension. The research also notes that the incidence and severity of CRS are generally lower with BiTE therapies compared with CAR T-cell therapies.4
Neurological Side Effects Patients Should Know About
In the DeLLphi-301 trial involving 133 patients receiving tarlatamab 10 mg, 5.3% (7 patients) reported ICANS (immune effector cell-associated neurotoxicity syndrome), which refers to neurologic side effects linked to immune-based treatment.4
Among patients who experienced ICANS symptoms, the most commonly reported issue was:4
- confusion (57.1%)
- impaired attention (42.9%)
- motor weakness/findings (14.3%)
- dysgraphia (difficulty writing) (14.3%)
- increased muscle tone (14.3%).
Follow-Up Care During Imdelltra Treatment
Follow-up care is an important part of IMDELLTRA® treatment, especially during the first few doses when patients may be monitored more closely for side effects such as CRS and ICANS. Patients and caregivers are also educated on recognizing symptoms early and knowing when to contact their healthcare team.4
- After discharge, patients were advised to stay within 1 hour of a healthcare setting for 72 hours after the infusion and have a caregiver with them.
- Patients and caregivers were taught to watch for CRS symptoms such as fever (≥38°C), breathing difficulty, headache, chest pain, nausea, vomiting, chills, palpitations, and muscle pain.
- Monitoring of body temperature, blood pressure, oxygen saturation, and heart rate was also recommended for early identification of side effects.
- Patients were additionally educated on neurologic symptoms linked with ICANS, including confusion, dizziness, headache, muscular weakness, insomnia, disorientation, lethargy, amnesia, and ataxia.
- Patients were advised to contact their healthcare provider or go to the emergency room if neurologic symptoms occurred during treatment.
- Patients were also advised to avoid driving, operating heavy machinery, or hazardous activities until neurologic symptoms resolved.
- Some treatment centers also used symptom diaries and wallet cards with emergency contact information to support follow-up care.
What To Ask Your Doctor Before Starting Imdelltra
Before starting IMDELLTRA®, it can help to have an open discussion with your doctor so you better understand the treatment process, monitoring, and follow-up care. Asking questions ahead of time may help patients and caregivers feel more prepared and informed during treatment.
- How is IMDELLTRA given?
- How long does each infusion visit usually take?
- What monitoring may be needed after the first few doses?
- Will I need a caregiver during treatment?
- What symptoms should I watch for after an infusion?
- When should I contact my healthcare team or visit the emergency room?
- Are there any activity restrictions during treatment?
- What follow-up visits or tests may be needed?
- How should I prepare before each infusion appointment?
- What support resources are available for patients and caregivers?
Final Thoughts
Starting IMDELLTRA® treatment can involve several steps, including infusion visits, monitoring, follow-up care, and symptom awareness. Understanding what to expect before, during, and after treatment may help patients and caregivers feel more informed and prepared throughout the treatment journey.
FAQs
- What does Imdelltra do?
IMDELLTRA targets DLL3 on small cell lung cancer cells and CD3 on T cells to help trigger T cell-mediated tumor cell death.¹
- What is the most successful treatment for lung cancer?
Treatment approaches for lung cancer can vary depending on the type, stage, and prior treatments received.¹
- Is Imdelltra a TCE?
Yes, IMDELLTRA is a bispecific T-cell engager (BiTE) immunotherapy.²
- What are the common side effects of Imdelltra?
Common side effects include CRS, fever, decreased appetite, changes in taste, anemia, constipation, fatigue, and ICANS.³˒⁴
- Is Imdelltra chemotherapy?
No, IMDELLTRA is an immunotherapy given through intravenous (IV) infusion.¹
References
- Rehman RU, Anjum AF, Fatima R. Tarlatamab and the Future of Immunotherapy: A New Approach to Small Cell Lung Cancer. Curr Ther Res Clin Exp. 2024;102:100773. Published 2024 Dec 21. doi:10.1016/j.curtheres.2024.100773
- Chiang AC, Olmedo Garcia ME, Carlisle JW, et al. Safety of tarlatamab with 6-8-h outpatient versus 48-h inpatient monitoring during cycle 1: DeLLphi-300 phase 1 substudy. ESMO Open. 2025;10(4):104538. doi:10.1016/j.esmoop.2025.104538
- IMDELLTRA® (tarlatamab-dlle) prescribing information. Amgen Inc. Accessed May 19, 2026.
- Sands JM, Champiat S, Hummel HD, et al. Practical management of adverse events in patients receiving tarlatamab, a delta-like ligand 3-targeted bispecific T-cell engager immunotherapy, for previously treated small cell lung cancer. Cancer. 2025;131(3):e35738. doi:10.1002/cncr.35738
Note:
The information provided is for education purpose only and is subjected to prescribing information of the drug and the guidance of your treating physician. Always consult your health care provider before making any medical decision for starting your treatment.
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