Boosting osimertinib effectiveness with cobicistat for lung cancer treatment

Improving Osimertinib Exposure and Cost-effectiveness Using Pharmacokinetic Boosting With Cobicistat (OSIBOOST 2)

Phase 4 Interventional Maastricht University Medical Center · NCT05748093

This study is testing whether adding cobicistat to osimertinib can make lung cancer treatment more effective and easier on patients by allowing for lower doses while still working well.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment60 (estimated)
Ages18 Years and up
SexAll
SponsorMaastricht University Medical Center Academic / other
Drugs / interventionsosimertinib
Locations1 site (Maastricht, Limburg)
Trial IDNCT05748093 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to enhance the effectiveness and cost-efficiency of osimertinib, a treatment for advanced non-small cell lung cancer (NSCLC) with EGFR mutations, by using cobicistat to boost its pharmacokinetics. The study will assess whether this combination allows for reduced dosing of osimertinib while maintaining effective drug exposure. Additionally, it will evaluate if cobicistat improves the penetration of osimertinib into the central nervous system for patients experiencing oligoprogression. Participants will undergo blood sampling to monitor drug levels and effects.

Who should consider this trial

Good fit: Ideal candidates are adults with advanced non-squamous EGFR-mutated NSCLC who are set to receive osimertinib as part of their treatment plan.

Not a fit: Patients with squamous cell carcinoma or those who are not receiving osimertinib will not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could lead to more affordable and effective treatment options for patients with advanced lung cancer.

How similar studies have performed: Previous studies have shown that pharmacokinetic boosting can enhance drug exposure, indicating potential success for this approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

In order to be eligible to participate in this cohort 1, a subject must meet all of the following criteria:

* The patient is set to receive osimertinib 80 mg QD as part of their standard treatment plan
* The patient has a World Health Organization (WHO) Performance Status (PS) of ≤2.
* The patient is 18 years or older
* The patient is able and willing to sign informed consent
* The patient is able and willing to undergo blood sampling
* The patient has non-squamous advanced EGFR-mutated NSCLC with no signs of imminent progression (CT confirmed). If the patient does have signs of progression, they are only eligible if their treating physician deems the treatment to be appropriate beyond progression.
* The patient consents to their blood being analysed for CYP3A-genotype

In order to be eligible to participate in this cohort 2, a subject must meet all of the following criteria:

* The patient is set to receive osimertinib 80 mg QD as part of their standard treatment plan
* The patient has a World Health Organization (WHO) Performance Status (PS) of ≤2.
* The patient is 18 years or older
* The patient is able and willing to sign informed consent
* The patient is able and willing to undergo blood sampling
* The patient has non-squamous EGFR-mutated NSCLC with radiologically confirmed progressive (RECIST v1.1), but asymptomatic intracranial metastasis, not in an eloquent area (to be discussed with neurologist). Furthermore, the disease is controlled extracranially (no RECIST v1.1 progression).

Exclusion Criteria:

A potential participant who meets any of the following criteria will be excluded from participation in this study:

* The patient does not take any other drug which is known to strongly inhibit CYP3A4/CYP3A5 activity
* The patient does not take any other drug which is metabolized by CYP3A4/CYP3A5 and which has a small therapeutic window
* The patient does not take any drug or product which may otherwise affect CYP3A4/CYP3A5 metabolic activity
* The patient does not have impaired gastrointestinal function
* The patient is neither pregnant nor breastfeeding
* The patient does not have any contra-indication for cobicistat prescription, as listed in the summary of product characteristics for cobicistat

Where this trial is running

Maastricht, Limburg

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Non-small Cell Lung CancerOsimertinibCobicistatPharmacokineticsBoostingCNS metastases
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.