A Study of Therapeutic Drug Monitoring-Based Atezolizumab Dosing

September 4, 2026 updated by: National Cancer Institute (NCI)

A Feasibility Phase I Study of Therapeutic Drug Monitoring-Based Atezolizumab Dosing

Background:

A type of drug called monoclonal antibody immune checkpoint inhibitors are often used in cancer treatment. These drugs help the body s immune system fight cancer by blocking proteins that cause cancer cells to grow. One of these drugs (atezolizumab) is approved to treat certain cancers. Researchers want to find out if lower doses of this drug might provide the same benefit with fewer adverse effects.

Objective:

To test different doses and timing of atezolizumab for people with cancer.

Eligibility:

People aged 18 years and older with cancer that has spread locally or to other organs. They must be eligible for treatment with the study drug.

Design:

Participants will be screened. They will have blood tests and imaging scans. They will provide a sample of tissue from their tumor.

Atezolizumab is administered through a tube attached to a needle inserted into a vein in the arm. Participants will take this drug alone or combined with other drugs prescribed for their care.

The first 2 treatments will be done per the FDA recommended dose and schedule. Before administering the second dose of the study drug, researchers will check the level of the drug in the participant s blood. Depending on those results, their 3rd dose will be scheduled 2 to 6 weeks later.

For the 3rd dose of the study drug, participants will switch to the FDA minimum dosage. Dosages of any other drugs will not change.

Researchers will continue to test the levels of the drug in participants blood before each treatment for 16 weeks. After that, these levels will be tested every 3 months.

Study treatment may last up to 2 years....

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Background:

  • The treatment of many cancers has been revolutionized through the use of monoclonal antibody immune checkpoint inhibitor drugs, particularly those that block the interaction of the anti-programmed death-ligand 1 (PD-L1) with the programmed death-1 (PD-1) receptor.
  • Atezolizumab was initially tested in a phase 1a multicenter, dose-escalation, and dose- expansion study (NCT01375842) which showed that the drug was well tolerated and produced clinical responses in a variety of tumors.
  • The initially approved atezolizumab regimen was 1,200 mg every 3 weeks, but 840 mg every 2 weeks was added based on the data from the TNBC trial (NCT01375842). This was taken further by Morrissey et al., who used population pharmacokinetic (PK) simulations to determine that dosing regimens of 840 mg every 2 weeks and 1,680 mg every 4 weeks are interchangeable with 1,200 every 3 weeks in terms of efficacy, leading the Food and Drug Administration (FDA) to expand the dosing regimens for atezolizumab.
  • The standard dosing regimens yield steady-state concentrations greater than 10-fold above the stated minimum effective concentration of 6 microg/mL, to ensure adequate exposure for all patients, including patients that may experience lower exposure due to the incidence of anti-drug-antibodies (ADA). Atezolizumab exhibits a flat exposure- response relationship.

Objective:

-To test the feasibility of reducing drug exposure while maintaining plasma drug concentration at or above the expected target trough value during a 16-week study period by using a method for therapeutic drug monitoring of atezolizumab.

Eligibility:

  • Age >= 18 years old.
  • Participants with a locally advanced or metastatic cancer whose NCI Licensed Independent Practitioner (LIP) determined they are candidates for treatment with atezolizumab, either alone or in combination with other FDA-approved drug(s).
  • Eastern Cooperative Oncology Group (ECOG) Performance Score of 0-2.
  • Adequate organ and marrow function.

Design:

  • This is a phase I feasibility study of a therapeutic drug monitoring (TDM)-based method for atezolizumab dosing.
  • The participants will start with FDA approved dose and frequency of atezolizumab (840 mg every 2 weeks, 1,200 mg every 3 weeks, or 1,680 mg every 4 weeks) selected by their treating physician for the first two doses of the drug per standard of care.
  • After the second dose, starting at 3rd dose, the dose of the drug will be switched to 840 mg and will be used going forward in the trial in all participants.
  • Prior to each dose a trough will be drawn which will be by the population PK model to predict the timing of the next dose to maintain the atezolizumab target trough for each

participant specifically. This will be repeated for the first 16 weeks of treatment.

-After 16 weeks of treatment, the timing of the next dose to maintain the atezolizumab target trough for each participant will be monitored and adjusted (if necessary) every 3 months for each participant until 2 years.

Study Type

Interventional

Enrollment (Estimated)

30

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United States
    • Maryland
      • Bethesda, Maryland, United States, 20892
        • Recruiting
        • National Institutes of Health Clinical Center
        • Contact:
          • National Cancer Institute Referral Office
          • Phone Number: 888-624-1937

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

  • INCLUSION CRITERIA:
  • Participants with a locally advanced or metastatic pathologically confirmed cancer whose NCI Licensed Independent Practitioner (LIP) determined they are candidates for treatment with atezolizumab, either alone or in combination with other FDA-approved drug(s), for example, TMB-high, PDL-1 positive, or other disease states that respond to PD(L)-1 inhibitors. Regimens with atezolizumab alone or in combination with agents that have previously demonstrated safety in published clinical trials may be used. An LIP may be either an MD, DO, PA, or NP and must be qualified for oncologic management per institutional practice.
  • Age >=18 years old.
  • Measurable disease per RECIST 1.1 criteria.
  • ECOG performance status of 0-2.

  • Participants must have adequate organ and marrow function as defined below:

    • Absolute neutrophil count (ANC) >=1,200/microliter
    • Hemoglobin >9.0 g/dL
    • Platelets >=75,000/microliter
    • Total bilirubin <= 1.5 mg/dL, except in participants with Gilbert s Syndrome who must have a total bilirubin less than 3.0 mg/dL
    • Aspartate aminotransferase (AST) / Alanine aminotransferase (ALT) <=2.5 X institutional upper limit of normal (ULN)
    • Creatinine Clearance (CrCl) >=30 mL/min/1.73 m^2 (calculated using the Cockcroft-Gault formula).
    • Serum albumin > 3 g/dL
  • Individuals of child-bearing potential (IOCBP) must agree to use a highly effective method of contraception (hormonal, intrauterine device (IUD), surgical sterilization) for the duration of the study treatment and up to 5 months after the last dose of the atezolizumab (restriction period). NOTE: abstinence, defined as no vaginal heterosexual intercourse within 6 months prior to the treatment initiation and willingness to continue abstinence for restriction period is also acceptable.

Individuals who can father children must agree to use an effective method of contraception (barrier, surgical sterilization) at study entry and up to 5 months after the last dose of the atezolizumab.

  • Nursing participants must be willing to discontinue nursing from study treatment initiation through 5 months after atezolizumab treatment discontinuation.
  • Participants with history of human immunodeficiency virus (HIV) infection must be on effective anti-retroviral therapy and have undetectable viral load.
  • Participants with history of chronic hepatitis B virus (HBV) infection must be on suppressive therapy, if indicated, and have undetectable HBV viral load.
  • Participants with history of hepatitis C virus (HCV) infection must have an undetectable HCV viral load.
  • Participants with history of treated brain metastases must have follow-up brain imaging after central nervous system (CNS)-directed therapy with no evidence of progression.
  • Participants with a prior or concurrent malignancy whose natural history or treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational regimen are eligible.
  • All participants must have the ability to understand and willingness to sign a written informed consent.

EXCLUSION CRITERIA:

Participants who have received an investigational agent for treating participants' disease not approved by FDA within 28 days prior to study treatment initiation.

  • Participants who have received immunostimulatory agents, including, but not limited to, IFN-alpha, IFN-gamma, or IL-2, immunosuppressive medications, and any herbal medicines within 1 month prior to study treatment initiation. NOTE: Physiologic doses of systemic steroids (<= 10 mg prednisone or equivalent) or local (e.g., topical, nasal, intraarticular, inhaled) steroid use is permitted.
  • Prior treatment with CD137 agonists
  • Prior treatment with immune checkpoint blockade therapies, including anti-CTLA-4, anti-PD-1, and anti-PD-L1 therapeutic antibodies; (including atezolizumab) within 28 days prior to study treatment initiation.

  • History or risk of autoimmune disease, including, but not limited to, myasthenia gravis, myositis, autoimmune hepatitis, systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, antiphospholipid antibody syndrome, Wegener granulomatosis, Sjogren syndrome, Guillain-Barre syndrome, or multiple sclerosis, with the following exceptions:

    • Participants with a history of autoimmune-related hypothyroidism on a stable dose of thyroid replacement hormone.
    • Participants with controlled Type 1 diabetes mellitus on a stable insulin regimen.

    • Participants with eczema, psoriasis, lichen simplex chronicus, or vitiligo with dermatologic manifestations only (e.g., participants with psoriatic arthritis would be excluded) are permitted provided all of the following conditions are met:

      • Rash must cover less than 10% of body surface area (BSA)
      • Disease is well controlled at screening and only requiring low potency topical steroids
      • No acute exacerbations of underlying condition within 12 months prior to study treatment initiation (not requiring psoralen plus ultraviolet A radiation [PUVA], methotrexate, retinoids, biologic agents, oral calcineurin inhibitors; high potency or oral steroids) within 12 months prior to study treatment initiation.
  • Persisting toxicity related to prior therapy of Grade >1 per Common Terminology Criteria for Adverse Events (CTCAE) v 5.0 unless deemed not clinically significant or irreversible. NOTE: alopecia and sensory neuropathy Grade <= 2 are acceptable.
  • Participants with prior allogeneic bone marrow transplantation or prior solid organ transplantation.
  • History of severe allergic anaphylactic reactions to chimeric or humanized antibodies or fusion proteins
  • Known hypersensitivity to Chinese hamster ovary cell products or to any component of the atezolizumab formulation
  • Treatment with a live, attenuated vaccine within 4 weeks prior to initiation of study treatment
  • Active tuberculosis at screening
  • History of idiopathic pulmonary fibrosis, pneumonitis (including drug induced), organizing pneumonia (i.e., bronchiolitis obliterans, cryptogenic organizing pneumonia, etc.), or evidence of active pneumonitis on screening chest computed tomography (CT) scan. Note: History of radiation pneumonitis in the radiation field (fibrosis) is permitted
  • Participants with significant cardiovascular disease (such as New York Heart Association Class II or greater cardiac disease, myocardial infarction, or cerebrovascular accident (https://www.heart.org/en/health-topics/heart-failure/what-isheart-failure/classes-of-heart-failure), unstable arrhythmia, or unstable angina within 3 months prior to study treatment initiation.
  • Pregnancy (confirmed with Beta-Human chorionic gonadotropin (Beta-HCG) serum or urine pregnancy test in IOCBP performed at screening).
  • Uncontrolled intercurrent illness or situation that would limit compliance with study requirements.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Arm 1
Atezolizumab treatment course
Drug: Atezolizumab
Atezolizumab administered via IV at either 1,200 mg q3 weeks, or 1,680 mg q4 weeks for the first 2 doses followed by 840mg q2 weeks or q6 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Feasibility of reducing drug exposure while maintaining plasma drug concentration
Time Frame: 16 weeks
The fraction of participants that can be dosed with 840mg of atezolizumab at less frequent intervals while maintaining a trough PK concentration at or above 6 mg/mL
16 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Minimal frequency (median, range) of atezolizumab dosing to keep the trough concentration at or above 6 microgram/mL
Time Frame: 16 weeks and every 3 months on treatment
PK evaluations before every atezolizumab infusion starting from the second dose until 16 weeks after atezolizumab treatment and every 3 months after 16 weeks on treatment.
16 weeks and every 3 months on treatment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

National Cancer Institute (NCI)

Investigators

  • Principal Investigator: James L Gulley, M.D., National Cancer Institute (NCI)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 4, 2025

Primary Completion (Estimated)

January 31, 2027

Study Completion (Estimated)

January 31, 2028

Study Registration Dates

First Submitted

October 3, 2023

First Submitted That Met QC Criteria

October 3, 2023

First Posted (Actual)

October 4, 2023

Study Record Updates

Last Update Posted (Actual)

September 8, 2026

Last Update Submitted That Met QC Criteria

September 4, 2026

Last Verified

July 24, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 10001559
  • 001559-C

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

All collected IPD will be shared.

IPD Sharing Time Frame

Data from this study may be requested from other researchers within 10 years after the completion of the primary endpoint by contacting the NCI Principal Investigator.

IPD Sharing Access Criteria

Data from this study may be requested by contacting the NCI Principal Investigator

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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