Overview of Imfinzi

Quick Facts

Property	Description
Active ingredient	Durvalumab
Form	Concentrate for solution for infusion
Pharmacological class	Immune Checkpoint Inhibitor (Anti-PD-L1)
General purpose	Enhances antitumour immune responses
Origin	Biologic (Humanized monoclonal antibody)

Durvalumab: Defining the Medicine and its Class

Imfinzi is a highly specific, prescription-only antineoplastic agent whose active component is durvalumab. This substance is classified as an immunotherapy because its primary action is to utilize and enhance the patient's own immune system. Durvalumab is recognized as an Anti-PD-L1 inhibitor, belonging to the pharmacological class of Immune Checkpoint Inhibitors. This classification confirms the drug's purpose is to combat systemic illness by engaging a targeted biological pathway rather than relying on direct cytotoxicity. Imfinzi is a branded medicine developed and marketed by AstraZeneca.

Understanding Imfinzi's Biologic Composition and Origin

The active ingredient, durvalumab, is a large, complex biologic medicine engineered as a fully humanized monoclonal antibody (an Immunoglobulin G1 kappa subclass). This type of substance is produced using specialized recombinant DNA technology in living cells. The fact that it is an antibody designed by this process ensures its high specificity for its target protein. Imfinzi is a single active ingredient product, formulated as a sterile concentrate for solution for infusion. This preparation, which must be administered via intravenous infusion by a healthcare professional, confirms its identity as a systemic treatment intended for complex disease management.

How Imfinzi Functions: The High-Level Checkpoint Principle

The core function of Imfinzi is centered on reversing the signals that suppress the immune system to achieve the general benefit of enhancing antitumour immune responses. Durvalumab specifically targets the programmed death-ligand 1 (PD-L1) protein. By selectively binding to and blocking the PD-L1 signal, the medicine effectively disengages this inhibitory pathway, restoring the T-cells' ability to conduct a more sustained defense against systemic illness. This mechanism allows the body's defense cells to become active, a foundational approach supported by extensive international research.

Regulatory References

Durvalumab (Imfinzi) - NIH Bookshelf

What side effects are possible with Imfinzi?

The official safety profile for Imfinzi (durvalumab) is based on adverse event data gathered from clinical trials and documented by government regulatory agencies (such as the FDA and EMA). The core risk is the potential for immune-mediated adverse reactions, which can affect nearly any organ system and may be severe or life-threatening.

Adverse Reaction Scope

Category	Examples	Source Classification
Most Common Side Effects	Fatigue, cough, pneumonitis, rash, nausea, musculoskeletal pain, constipation.	Occurring in ge 20% of patients in specific regimens (FDA)
System-Organ Classes	Respiratory (Pneumonitis), Gastrointestinal (Colitis, Diarrhea), Endocrine (Hypothyroidism, Adrenal Insufficiency), Hepatobiliary (Hepatitis), and Skin (Dermatitis).	Classified by regulatory agencies
Serious Adverse Reactions	Immune-mediated Pneumonitis, Hepatitis, and Colitis, which are documented as potentially severe or fatal. Severe skin reactions (SJS, TEN, DRESS) are also documented.	Explicitly listed in regulatory labeling

Safety Constraints and Patterns

The onset of immune-mediated adverse reactions can occur anytime during treatment or even after the treatment course has concluded, according to official labeling.

Population-specific safety statements include the risk of Embryo-Fetal Toxicity and the need for effective contraception in females of reproductive potential during treatment and for three months after the final dose. Breastfeeding is not advised during the same three-month period. Safety documentation also addresses complications related to Allogeneic Hematopoietic Stem Cell Transplantation (HSCT) if performed before or after this therapy.

This structure ensures the core risk of heightened immune activity attacking healthy tissue is the central focus of the medicine's official safety profile.

Overdose and Emergency Response

Overdose and When to Seek Help

The official regulatory documents for Imfinzi (durvalumab) do not define a separate overdose syndrome, but rather treat excessive exposure or severe toxicity as the occurrence of severe or life-threatening immune-mediated adverse reactions (imAEs) or Infusion-Related Reactions.

Overdose Scope: Official Regulatory Information

Feature	Official Regulatory Statement
Documented Manifestations	Symptoms include those related to Infusion-Related Reactions (e.g., chills, wheezing, rash, flushing, dizziness) or severe immune-mediated adverse reactions affecting major organs [FDA Label, EMA SmPC].
Physiological Systems Affected	Systems impacted by severe imAEs include pulmonary (pneumonitis), hepatic (hepatitis), gastrointestinal (colitis), renal (nephritis), and endocrine (endocrinopathies) [EMA SmPC].
Antidote Information	No specific antidote is known for durvalumab overdosage [EMA SmPC].

Required Emergency Actions

When immediate medical help is required:

Users must call or see their healthcare provider right away for any new or worsening signs or symptoms [FDA Label].
The occurrence of Severe (Grade 3) or Life-threatening (Grade 4) immune-mediated adverse reactions mandates that the medicine be permanently discontinued [FDA Label].

Official Management:

Management procedures involve administering symptomatic and supportive treatment, including the immediate initiation of high-dose corticosteroids for severe imAEs, as specified in regulatory guidelines [EMA SmPC]. Laboratory values such as liver enzymes and creatinine must be monitored during treatment for a severe reaction [FDA Label].

Therapeutic Uses of Imfinzi

What Imfinzi Treats: Main Uses and Benefits

This medication may provide supportive therapeutic benefit across several key domains. Therapeutic applications are relevant for conditions presenting with significant symptomatic burden, including Non-Small Cell Lung Cancer (NSCLC), Small Cell Lung Cancer (SCLC), Biliary Tract Cancer (BTC), Unresectable Hepatocellular Carcinoma (uHCC), Gastric/Gastroesophageal Junction (GEJ) cancers, and Muscle-Invasive Bladder Cancer (MIBC).

Treatment Contexts and Patient Benefit

This immunotherapy is commonly used to address conditions presenting with systemic or localized discomfort and symptoms related to systemic imbalance. For instance, it is applied as consolidation therapy after definitive chemoradiotherapy to support the response achieved, or as a first-line treatment to help manage symptoms related to systemic imbalance. When integrated before and after surgery (perioperative therapy) for resectable tumors, it assists in managing the likelihood of the condition returning. Overall, the treatment provides supportive relief when symptoms interfere with routine activities and supports continued management of the condition.

“This therapy is commonly used in clinical settings that involve acute or unstable symptom patterns, supporting the patient during difficult episodes by easing distress.”

Quick Fact: Relief for Systemic Symptom Burden
Primary Goal	Management of conditions presenting with systemic discomfort.
Symptom Relevance	Helps ease symptoms related to disease-related fatigue and unexplained weight changes.
Scenario of Use	Consolidation, First-line combination, and Perioperative systemic support.
Benefit to Patient	Contributes to improved comfort during symptomatic periods and assists with maintaining functional stability.

Eligibility and Restrictions for Use

Eligibility Rules for Imfinzi Use

Imfinzi is officially designated for use in adult patients (individuals 18 years of age and older). Use is not established for children and adolescents under 18 years of age because safety and efficacy data are not available for this pediatric population. For older adults (65 years and above), no specific dose adjustment is typically required, although regulatory data are limited for patients aged 75 years and older.

The medicine's absolute prohibition status varies by regulator: the FDA labeling states no contraindications exist, while the EMA documents an absolute contraindication for patients with a known hypersensitivity to durvalumab or any excipient.

Use in Specific Populations

Population Group	Official Regulatory Status
Females of Reproductive Potential	Use is conditional; effective contraception must be used during treatment and for three months following the final dose due to potential fetal harm.
Lactating Women	Advised not to breastfeed during treatment and for three months after the last dose.
Hepatic/Renal Impairment	No dose adjustment is recommended for hepatic impairment (all degrees) or mild to moderate renal impairment. Data are limited for severe renal impairment.
History of HSCT	Patients who have received an allogeneic hematopoietic stem cell transplant (HSCT) before or after treatment may experience serious complications, a condition noted in the official labeling.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The official regulatory documents define the interaction profile of durvalumab (Imfinzi) primarily based on its biological clearance mechanism and its immune-modulating effects. There are no formal contraindications listed in the approved product labeling.

Pharmacokinetic and Metabolic Interactions

As a humanized monoclonal antibody, durvalumab is eliminated via protein catabolism rather than through major liver enzyme systems. Regulatory information states that the medicine is not expected to be a substrate, inhibitor, or inducer of Cytochrome P450 (CYP) enzymes or drug transporters. Therefore, the potential for clinically relevant pharmacokinetic interactions with most small-molecule medicines is considered low. Co-administration studies confirm that the exposure of agents such as cisplatin and gemcitabine is not significantly altered by durvalumab.

Pharmacodynamic Restrictions

The most significant documented interaction constraints are pharmacodynamic. Live or live attenuated vaccines are prohibited during therapy, and a mandatory timing-based separation period must be observed. Additionally, systemic immunosuppressive agents (e.g., high-dose systemic corticosteroids) should be avoided prior to initiation of treatment, as they may interfere with the intended immune-enhancing activity. No specific interactions with food, alcohol, or herbal products are formally documented.

Mechanism of Action

Targeting the PD-L1 Immune Checkpoint

Durvalumab is a monoclonal antibody that performs selective blockade and antagonism of the Programmed Death-Ligand 1 (PD-L1) protein. This targeted action prevents PD-L1 from binding to the inhibitory PD-1 and CD80 receptors on T-cells, which functionally disengages the primary inhibitory signal.

Reversing T-cell Functional Exhaustion

By lifting the inhibitory signal, the drug's mechanism leads to the reversal of T-cell functional exhaustion, allowing cytotoxic T-cells to resume proliferation and release signaling molecules like Interferon-gamma. This cascade modifies key immune signaling sequences, which leads to the physiological outcome of enhanced and sustained antitumor immune response. The mechanism's effectiveness is constrained by target availability, which requires sufficient PD-L1 presence, and can be limited by other active immune-suppressive pathways.

Dosage and Administration Information

How to Use Imfinzi: Official Administration Guidelines

Imfinzi (durvalumab) is a prescription medicine administered solely via intravenous (IV) infusion in a clinical setting. The usage protocol is standardized, establishing clear requirements for dosing, frequency, and preparation.

Dosing and Schedule Patterns

The standard dosing for patients weighing geq 30 kg is typically a fixed dose of 1,500 mg, administered on a cyclic schedule. For patients weighing < 30 kg, a weight-based dose is used, often 10 mg/kg or 20 mg/kg. The frequency of administration varies by treatment phase, commonly occurring every two weeks (q2w), three weeks (q3w), or four weeks (q4w).

For most regimens, no dose adjustment is required for older adults (65 years) or patients with mild or moderate renal or hepatic impairment. If a dose is missed, it should be administered as soon as possible to maintain the prescribed interval.

Administration and Duration Constraints

Prior to administration, the sterile concentrate must be diluted using 0.9% Sodium Chloride or 5% Dextrose. Requirements for preparation specify that the vial or final solution must not be shaken. The resulting solution is then administered as a single, consistent 60-minute infusion.

Treatment duration is defined by the specific use context. For consolidation therapy, the duration is finite, such as up to 12 months for unresectable Stage III non-small cell lung cancer or up to 24 months for limited-stage small cell lung cancer. In other contexts, administration continues until disease progression or a non-use event occurs.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Imfinzi (Durvalumab)

I. Evidence for Use as Consolidation Therapy in Unresectable Stage III NSCLC

Research has primarily studied durvalumab in adults with unresectable Stage III Non-Small Cell Lung Cancer (NSCLC) who had already received full concurrent chemotherapy and radiation, and whose condition had not worsened. This evaluation was largely conducted through a large, randomized, placebo-controlled Phase 3 trial. Researchers focused on extended observations, with key measures including Overall Survival (OS) and PFS, a key measure used in research. The studies evaluated survival patterns and reported measurements of OS and PFS that differed between the group receiving durvalumab and the placebo group. Long-term follow-up research, extending to five years in some analyses, described that a differing proportion of patients were observed to be alive at the five-year mark between the two groups. The evidence contributes to the broader evidence landscape.

II. Evidence for Use in Extensive-Stage Small Cell Lung Cancer (ES-SCLC)

The main body of evidence for Extensive-Stage Small Cell Lung Cancer (ES-SCLC) comes from a large, randomized Phase 3 trial that was studied for durvalumab when added to the standard initial chemotherapy (platinum-etoposide). The primary focus of the evaluation was Overall Survival (OS). The studies report how survival evolved in the observed populations, and findings describe patterns of differing overall survival between the durvalumab combination group and the chemotherapy-alone group. Updated analyses described a difference in the estimated proportion of patients observed to be alive at three years between the two groups.

III. Evidence for Use in Unresectable Hepatocellular Carcinoma (uHCC)

The combination of durvalumab with tremelimumab was evaluated in a large comparative Phase 3 trial for adults with unresectable Hepatocellular Carcinoma (uHCC) who had not received prior systemic treatment. The study focused heavily on extended observation survival patterns. The primary analysis reported measurements demonstrating differences in median Overall Survival (OS) when comparing the combination to the prior standard systemic therapy. The research observed differences in the 48-month OS rate between the combination (25.2%) and sorafenib (15.1%). These findings describe group patterns, not personal outcomes. Extended follow-up has provided data for up to five years of observation in this condition.

IV. What Is Still Uncertain About the Research Evidence

Research has examined observations over extended follow-up periods, especially in NSCLC and uHCC. However, long-term effects for some indications are not fully established, and more research is ongoing to confirm the durability of observed patterns. Evidence quality varies across studies that focus on extremely small subgroups, which may provide limited insight into treatment response in those specific settings. Research does not determine whether an individual will respond similarly, and findings describe group patterns, not personal outcomes.

Key Studies & References

Durvalumab after Chemoradiotherapy in Stage III Non–Small-Cell Lung Cancer (PACIFIC Trial)

Frequently Asked Questions (FAQ)

Common questions about Imfinzi (FAQ)

Q: Why is Imfinzi often given after chemoradiation therapy (CRT)?

Regulatory approval for this use is based on evidence when the drug is administered after the disease has not progressed following concurrent platinum-based chemotherapy and radiation therapy. This treatment schedule, known as consolidation therapy, is based on the results of a large Phase 3 clinical trial.

Q: What specific conditions or previous treatments affect eligibility to receive Imfinzi?

Official documents note warnings for individuals with an active autoimmune disease, which is a condition where the immune system attacks healthy tissue. Regulatory documents describe risks for individuals who have a history of breathing problems or those who have received radiation to the chest area, as these factors may increase the risk of lung inflammation.

Q: Are there any common health issues, like diabetes or thyroid problems, that prevent someone from being eligible for Imfinzi?

Official product information indicates that immune-mediated thyroid disorders and Type 1 diabetes mellitus are potential side effects of the treatment. Due to these risks, regulatory information notes that monitoring for signs of high blood sugar (hyperglycemia) or new-onset diabetes is typically performed. The regulatory documents do not explicitly list pre-existing diabetes or thyroid problems as conditions that exclude eligibility.

Q: What are the signs of liver problems or hepatitis caused by Imfinzi that I should watch for?

Official safety documents list signs of liver problems (hepatitis) for which patients are typically advised to be monitored, including the yellowing of the skin or eyes (jaundice), severe nausea or vomiting, pain on the right side of the stomach area, and urine that appears dark or tea colored.

Q: What are the symptoms of lung inflammation (pneumonitis) that can happen with Imfinzi?

Official safety information states that problems with the lungs, such as inflammation called pneumonitis, are a serious risk. Official documentation describes signs of lung inflammation (pneumonitis) that may include a new or worsening cough, shortness of breath, or chest pain.

Q: Can Imfinzi cause serious intestinal issues like colitis, and what are the warning signs?

The treatment may cause intestinal problems like colitis, which is inflammation of the colon. Official materials document warning signs for intestinal problems (colitis), which may include diarrhea or more frequent bowel movements than usual. Other serious signs include stools that are black, tarry, sticky, or contain blood or mucus, and severe stomach-area pain or tenderness.

Q: Is a rash or itching a common side effect, or does it indicate a more serious problem?

A mild rash or itching is listed in regulatory documents as a common side effect of treatment. However, serious skin problems are also documented. Official documentation notes that symptoms indicating these serious conditions include skin blistering or peeling, and the development of painful sores or ulcers in the mouth or nose.

Q: How quickly do side effects from Imfinzi typically start or stop?

Official warnings state that immune-mediated side effects can occur at any time after starting treatment, and potentially after the treatment has ended. While side effects often improve over time or upon cessation of the medication, the timeframe can vary significantly.

Q: What is an infusion reaction, and what symptoms might indicate one during treatment?

An infusion-related reaction is a response that happens during the administration of the medicine. These reactions can sometimes be severe or life-threatening. Official sources document symptoms such as chills or shaking, itching or rash, flushing, and shortness of breath or wheezing. Other signs may include dizziness, fever, or pain in the back or neck.

Q: Does Imfinzi interact with common over-the-counter medications, vitamins, or supplements?

Regulatory information states that the potential for significant interaction with most small-molecule medicines, including over-the-counter products, vitamins, or general supplements, is considered low. This is attributed to the fact that Imfinzi is eliminated via protein breakdown, rather than through major liver enzyme systems often involved in drug interactions.

Q: Is it necessary to avoid certain foods or activities while receiving Imfinzi?

Regulatory documents do not list mandatory food restrictions. Regulatory information indicates that avoiding strenuous activities may be appropriate if a patient is experiencing certain immune-mediated symptoms, such as chest pain or irregular heartbeat, which might indicate heart inflammation.

Q: What types of long-term side effects might be expected after completing Imfinzi treatment?

Official information indicates that certain immune-mediated side effects may be long-term or appear after the treatment course has stopped. Examples of these types of reactions include inflammation of the lungs, liver, or colon, or problems with hormone glands like the thyroid.

Q: Does Imfinzi affect fertility in men or women?

Based on its targeted action and studies conducted in animals, official documents indicate that Imfinzi may impair fertility in both females and males. For women of reproductive potential, regulatory guidelines state that effective contraception should be used during treatment and for a period afterward.

Q: Is Imfinzi treatment still effective if a dose has to be delayed due to side effects?

Regulatory authorities provide specific guidelines for dosage modifications, including withholding (delaying) or permanently discontinuing treatment based on the severity of adverse reactions. These guidelines are designed to safely manage side effects, but the overall effect of dose delays on long-term effectiveness is not summarized for the patient in official materials.

Q: Can Imfinzi be used in patients who have previously had an organ transplant?

The product labeling specifically includes warnings about the use of the drug in patients who have received a solid organ transplant. Warnings are also documented for those who have received an allogeneic hematopoietic stem cell transplant (HSCT) before or after treatment, due to the risk of serious complications.

Q: What do the official documents say about Imfinzi's use in earlier stages of lung cancer (before or after surgery)?

Official indications state that the drug can be used in certain adult patients with resectable (surgically removable) non-small cell lung cancer (NSCLC). The indication involves use in combination with chemotherapy before surgery (neoadjuvant setting) and then alone after surgery (adjuvant setting).

Q: How is the patient monitored for potential organ problems while on Imfinzi?

Regulatory documents state that monitoring by healthcare professionals is necessary to detect immune-mediated reactions. Monitoring typically involves evaluating liver enzymes, creatinine (a measure of kidney function), and thyroid function at the start of treatment and regularly throughout the course of therapy.

Q: What is the mechanism by which Imfinzi can affect the kidneys or pancreas?

The treatment can affect organs like the kidneys and pancreas due to the same general principle that underlies all serious side effects: immune-mediated adverse reactions. This means the heightened immune response can mistakenly cause inflammation of the kidneys (nephritis) or the pancreas (pancreatitis).

Q: Why do official materials mention a risk of Graft-versus-Host Disease (GVHD) with Imfinzi?

Official materials mention the risk of complications for patients who have received an allogeneic hematopoietic stem cell transplant (HSCT), which is a transplant using donor cells. Graft-versus-Host Disease (GVHD) is a known, serious complication that can occur after this type of transplant, and the drug labeling addresses this risk.

How should Imfinzi be stored and disposed of?

Storage and Disposal Requirements for IMFINZI (durvalumab)

The storage and disposal of IMFINZI must strictly follow official regulatory guidelines to maintain the drug's quality and ensure safety.

Storage Conditions

Item	Requirement
Unopened Vial	Store in a refrigerator at 2°C to 8°C (36°F to 46°F).
Freezing	Do not freeze the vial or the diluted solution.
Protection	Keep the vial in the original carton to protect it from light.

The solution diluted for infusion should be used immediately. If necessary, it can be stored for a total time of up to 24 hours in the refrigerator or up to 4 hours at room temperature (not exceeding 25°C).

Disposal and Safety

All unused product, including partially used or empty vials, must be disposed of in accordance with local requirements. The medicine must be kept out of the sight and reach of children.

Imfinzi