Avelumab

Introduction Overview

Generic Name

avelumab

Brand Name

Bavencio

Dosage Form

Intravenous infusion (single-dose vial)

Drug Class

Anti-PD-1 and PD-L1 monoclonal antibodies (immune checkpoint inhibitors)

Pharmacokinetics

Absorption

Avelumab is administered via intravenous infusion, leading to direct entry into systemic circulation. Since it is a monoclonal antibody, the drug bypasses the gastrointestinal tract absorption barriers inherent to oral therapies. Absorption is effectively complete upon intravenous administration, with no bioavailability concerns related to absorption variability.

Distribution

As a monoclonal antibody, avelumab exhibits a typical distribution pattern confined primarily to the vascular and interstitial spaces. Its large molecular size precludes widespread diffusion into tissues. The volume of distribution approximates the plasma volume, indicating limited tissue penetration. Distribution may be influenced by Fc receptor interactions and binding to PD-L1 expressing cells within the tumor microenvironment and normal tissues.

Metabolism

Avelumab is catabolized via proteolytic degradation pathways common to endogenous IgG antibodies and other monoclonal antibodies. It is metabolized into small peptides and amino acids through lysosomal degradation within reticuloendothelial system cells, including macrophages and endothelial cells. Metabolism does not involve cytochrome P450 enzymes, minimizing the risk of hepatic enzyme-related drug interactions.

Elimination

The elimination of avelumab occurs through nonspecific catabolism. The estimated elimination half-life is approximately 6.1 days (range 5.3 to 7.5 days), allowing biweekly dosing. Clearance mechanisms include target-mediated drug disposition via binding to PD-L1 expressing cells and nonspecific proteolytic degradation. Renal and hepatic impairments appear to have limited impact on clearance, though formal dedicated studies are limited.

Dosage Forms

Adults

For adults, Bavencio is administered as an intravenous infusion of 800 mg over approximately 60 minutes every 2 weeks. Indications include metastatic Merkel cell carcinoma, locally advanced or metastatic urothelial carcinoma, and in combination with axitinib for advanced renal cell carcinoma. Treatment continues until disease progression or unacceptable toxicity.

Adolescents

In pediatric patients aged 12 years and older with metastatic Merkel cell carcinoma, the dosing regimen is identical to adults: 800 mg IV infusion over 60 minutes every 2 weeks until disease progression or unacceptable toxicity occurs.

Special Populations

Limited pharmacokinetic data exist for patients with renal or hepatic impairment; however, given monoclonal antibody elimination pathways, significant dose adjustment is not typically required. Caution is advised in patients with autoimmune disorders, organ transplant, or immune system dysfunction due to the risk of immune-related adverse effects. Pregnancy is contraindicated; effective contraception is mandatory during treatment and for at least one month after the last dose. Breastfeeding is not recommended during treatment and for one month afterward. No specific dosage recommendations exist for geriatric populations, but clinical trials included elderly patients without dose modification.

Mechanism Of Action

Avelumab is a fully human monoclonal antibody that selectively binds to programmed death-ligand 1 (PD-L1), a transmembrane protein that is frequently overexpressed on cancer cells and tumor-infiltrating immune cells. PD-L1 normally binds to programmed death-1 (PD-1) receptors on activated T-cells, transmitting an inhibitory signal that dampens T-cell mediated immune responses. By binding PD-L1, avelumab blocks this interaction, thereby preventing tumor-induced immunosuppression and restoring T-cell activity against cancer cells.

In addition to antagonizing PD-L1, avelumab's IgG1 backbone has the potential to engage immune effector functions such as antibody-dependent cell-mediated cytotoxicity (ADCC). This provides an additional mechanism by which avelumab can mediate tumor cell lysis, possibly augmenting antitumor efficacy.

Through these mechanisms, avelumab enhances the host immune system's ability to recognize and destroy tumor cells, leading to suppression of tumor growth and metastasis. This immune checkpoint blockade represents a paradigm shift in cancer therapy, focusing on immunomodulation rather than direct cytotoxicity.

Clinical studies have demonstrated that blocking the PD-1/PD-L1 axis with avelumab can induce durable tumor responses in cancers historically resistant to conventional chemotherapy, such as Merkel cell carcinoma and urothelial carcinoma. The combination with axitinib in renal cell carcinoma exploits complementary mechanisms, with axitinib inhibiting angiogenesis and avelumab enhancing immune-mediated tumor destruction.

Pharmacological Actions

Blocks the PD-L1 protein on tumor cells, preventing immune evasion
Restores and enhances T-cell mediated antitumor immune responses
Potentially induces antibody-dependent cell-mediated cytotoxicity (ADCC) against tumor cells
Modulates tumor microenvironment to favor immune activation
Exerts antineoplastic effects by inhibiting tumor growth and metastatic spread
Works synergistically with agents like axitinib to improve therapeutic outcomes in renal cell carcinoma
Demonstrates activity in multiple tumor types including Merkel cell carcinoma, urothelial carcinoma, and renal cell carcinoma
Prolongs progression-free and overall survival in advanced cancers

Therapeutic Clinical Uses

Treatment of metastatic Merkel cell carcinoma in adults and pediatric patients ≥12 years
Management of locally advanced or metastatic urothelial carcinoma following platinum-based chemotherapy failure
Maintenance treatment in urothelial carcinoma patients who have not progressed after first-line platinum chemotherapy
First-line treatment of advanced renal cell carcinoma in combination with axitinib
Used when surgery is not an option due to metastasis or unresectable tumors
Treatment aims to improve immune-mediated tumor control and prolong survival
Utilized in cancers resistant or refractory to conventional chemotherapy agents
Applied as monotherapy or in combination immunotherapy regimens in oncology practice

Side Or Adverse Effects

Immune-mediated pneumonitis presenting as cough, dyspnea, or chest discomfort
Hepatitis causing elevated liver enzymes, jaundice, or hepatic dysfunction
Pancreatitis with abdominal pain and elevated pancreatic enzymes
Nephritis and renal dysfunction indicated by decreased urine output or abnormal kidney function tests
Colitis manifesting as severe diarrhea, abdominal pain, or bloody stools
Thyroid dysfunction including hypothyroidism or hyperthyroidism symptoms
Adrenal insufficiency leading to fatigue, hypotension, and electrolyte disturbances
Infusion-related reactions such as fever, chills, flushing, and hypotension during administration
Fatigue, malaise, and flu-like symptoms
Rash, pruritus, or severe dermatologic reactions including Stevens-Johnson syndrome
Muscle pain, weakness, or neurologic symptoms resembling myasthenia gravis or Guillain-Barré syndrome
Headache, dizziness, and vision changes
Nausea, vomiting, and loss of appetite
Edema and swelling of extremities
Rare but serious allergic reactions including anaphylaxis

Precautions

Monitor patients closely for signs of immune-related adverse events and intervene promptly
Use caution in patients with pre-existing autoimmune disorders or those on immunosuppressive therapy
Avoid use in pregnant women due to potential teratogenic effects
Inform patients about contraception requirements during and post therapy
Cautiously administer to patients with a history of organ transplantation or graft-versus-host disease
Evaluate liver and kidney function regularly during treatment
Screen for latent infections prior to initiating therapy
Manage infusion reactions with premedications when needed
Regularly assess thyroid function tests and manage dysfunction accordingly
Monitor cardiac function and blood pressure in patients with cardiovascular comorbidities
Advise patients to report any new or worsening symptoms immediately
Avoid concomitant use with other immunosuppressive agents unless clinically justified
Ensure hydration to support renal function during therapy
Assess neurological status given risk of neuromuscular side effects
Use with caution in elderly patients with comorbidities

Warnings

Potential for severe and life-threatening immune-mediated adverse reactions affecting lungs, liver, pancreas, kidneys, intestines, thyroid, and adrenal glands
Risk of infusion-related hypersensitivity reactions necessitating immediate medical intervention
Pregnancy is contraindicated due to risk of fetal harm and birth defects
Not recommended during breastfeeding; discontinue during therapy and for at least one month after last dose
May exacerbate or unmask autoimmune conditions leading to severe complications
Possibility of severe dermatologic toxicities including bullous skin reactions
Risk of cytokine release syndrome and systemic inflammatory responses
Possible cardiac complications such as myocarditis or arrhythmias
Patients with underlying lung or respiratory disorders require careful monitoring
Close surveillance required for hepatic toxicity with routine liver function tests
Renal impairment can be serious and requires prompt evaluation
Infections may be worsened due to immune modulation
Potential for severe gastrointestinal adverse effects including perforation
Patients should be advised to report symptoms of hormonal imbalances promptly
Immunogenicity reactions including anti-drug antibody formation may alter efficacy

Contraindications

Known hypersensitivity to avelumab or any component of the formulation
Pregnancy due to teratogenicity risks and potential fetal harm
Breastfeeding during treatment and for at least one month after last dose
Patients with active or severe autoimmune diseases that could be exacerbated by immune stimulation
Patients who have received organ transplants needing immunosuppression
Concomitant use with other immune checkpoint inhibitors associated with increased toxicity without proven benefit
Severe infusion reaction unresponsive to standard management
Uncontrolled infections or active systemic infections at treatment initiation
Known hypersensitivity to antibodies of human or murine origin without suitable premedication options
Severe liver or kidney impairment where benefit-risk ratio is unfavorable

Drug Interactions

No clinically significant drug interactions have been definitively established; however, immunosuppressive agents may diminish therapeutic efficacy
Concomitant use with live vaccines is not recommended due to potential risk of infection
Other immune checkpoint inhibitors may increase risk of immune-related adverse events
Corticosteroids and other immunosuppressants may interfere with the immune activation effect of avelumab
Potential interaction with drugs affecting immune function requiring close monitoring
No known significant interactions with axitinib when used concomitantly
Avoid concurrent treatments that may exacerbate infusion reactions without adequate precaution
Limited data available on interactions with cytochrome P450-modulating drugs due to non-CYP metabolism
Potential interactions with drugs causing renal or hepatic toxicity warrant caution
No significant pharmacokinetic interactions with common supportive care medications have been reported
Interaction with vaccines necessitates careful timing and clinical evaluation
Herbal supplements influencing immune activity should be used cautiously
No known interactions with vitamins, but all concurrent agents should be reported to healthcare providers
Monitoring is advised when combining with other monoclonal antibodies or biopharmaceuticals
Drug interaction profiles are continually updated as new data emerges

Preparations Of The Drug

Single-dose vial containing 200 mg avelumab in 10 mL solution (20 mg/mL)
Prepared as intravenous infusion diluted in 0.9% sodium chloride or 5% dextrose for slow infusion
Available only for intravenous use with no oral or subcutaneous formulations
Supplied as sterile, preservative-free solution for infusion
Requires dilution prior to administration per prescribing guidelines
No biosimilar products currently approved; several products are under development
Stored refrigerated between 2°C and 8°C, protected from light
Single-use vial; discard unused portion to avoid contamination
Premedication with antihistamines and acetaminophen recommended to reduce infusion reactions
Commercially distributed by EMD Serono, Inc
Not available in tablet, capsule, or injectable bolus form
Available exclusively through healthcare professional administration settings
Packaging includes carton and vial label with detailed usage instructions
No combination formulations other than with axitinib for renal cancer indication
Formulation free from latex and common allergens in vial materials