ClinicalTrials.gg
RecruitingNCT07704658Updated Aug 10, 2026

Pralsetinib DDI Study in Patients With Advanced or Metastatic Solid Tumors

A Phase 4 interventional study of Pralsetinib and CYP3A4, CYP2C8, and CYP2C9 substrates, and hormonal contraceptive in NSCLC (Non-small Cell Lung Cancer), Thyroid Cancer and Solid Tumor Malignancies, sponsored by Rigel Pharmaceuticals. Recruiting at 2 sites in Spain. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-10.

Sponsored by Rigel Pharmaceuticals · Phase 4, Interventional, and Other

From the registry’s dates

  • Registered 4 months after the study started (first participant enrolled Mar 2026, registered Jul 2026).
  • Started Mar 2026; still recruiting 8 months later.
Phase
Phase 4
Study type
Interventional
Enrollment
12
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

An open-label drug-drug interaction study to evaluate the effects of pralsetinib (Gavreto) on the pharmacokinetics of a CYP450 probe substrate cocktail and, in female participants, a hormonal probe substrate, in participants with rearranged during transfection (RET) fusion- or mutation-positive solid tumors

02

Conditions studied

  • NSCLC (Non-small Cell Lung Cancer)
  • Thyroid Cancer
  • Solid Tumor Malignancies
  • Advanced Malignancies

Keywords

  • Oncology
  • Drug-Drug Interactions
  • Medical Oncology
  • RET Fusion Positive
  • RET Gene Mutation
  • Pharmacokinetic (PK)
03

In context

Carcinoma, Non-Small-Cell Lung

7,620 studies on the registry are indexed under Carcinoma, Non-Small-Cell Lung; 1,838 are open to participants now.

This study's planned enrollment of 12 is below the median of 62 across 6,019 interventional studies indexed under Carcinoma, Non-Small-Cell Lung.

Browse Carcinoma, Non-Small-Cell Lung studies →

Lead sponsor

Rigel Pharmaceuticals is the lead sponsor of 28 studies on the registry; 5 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Must be willing and able to participate and comply with all study requirements and to provide signed and dated written
  • Adult male or female ≥ 18 years of age at the time of signing the informed consent form.
  • Must have a (BMI) ≥ 18 and ≤ 32 kg/m² and a minimum body weight of 50 kg at screening.
  • Must have an performance status ≤ 2.
  • Must have recovered from the non-hematologic toxic effects of prior treatment to Grade ≤ 1, or baseline value (excluding infertility, alopecia, or Grade 1 neuropathy)
  • Must have a confirmed diagnosis of advanced or solid tumor that has after, or is not responsive to, standard therapies and harbors an oncogenic RET fusion or mutation as determined by a validated test.
  • Must have adequate organ function, defined by the following:

    1. (ANC) ≥ 1.0 × 10⁹/L.
    2. count ≥ 75 × 10⁹/L.
    3. ≥ 9 g/dL.
    4. (AST) and alanine aminotransferase (ALT) ≤ 3 × (ULN), or ≤ 5 × ULN in patients with known liver metastases.
    5. Total ≤ 1.5 × ULN (≤ 3 × ULN in patients with Gilbert syndrome).
    6. ≥ 40 mL/min using the Cockcroft-Gault equation.
    7. Serum phosphorus ≤ 5.5 mg/dL.
    8. (INR), prothrombin time (PT), and activated partial thromboplastin time (aPTT) within normal laboratory limits.
  • Must be at least 4 weeks from major surgery, radiotherapy, chemotherapy, immunotherapy, kinase/targeted therapy, or gene therapy prior to the first dose of study treatment and recovered from treatment-related toxicities to ≤ Grade 1 (excluding alopecia). Must be ≥ 6 weeks since last treatment if they received a long-acting agent such as a nitrosourea, mitomycin, or monoclonal antibodies. In general, a treatment interval of two half-lives should be considered and discussed with the Sponsor. (Concurrent cancer therapy of any type is not permitted).
  • Female patients may participate if they are not of (e.g., surgically sterile or ).
  • Male patients with female partners of childbearing potential must agree to use highly effective during study treatment and for 90 days after the last dose of study treatment.
  • Male patients must refrain from sperm donation during study treatment and for 90 days after the last dose of study treatment.

Exclusion criteria

Exclusion Criteria:

  • abnormal medical history, abnormal findings on physical examination, vital signs, (ECG), or laboratory tests at screening that, in the investigator's judgment, are likely to interfere with the objectives of the trial or the safety of the patient.
  • Surgery (e.g., gastric bypass) or medical condition that may significantly affect absorption of study medications, as judged by the investigator.
  • History of pneumonitis within the last 12 months.
  • History of active or latent tuberculosis (TB), regardless of treatment history, or a positive screening test for latent Mycobacterium tuberculosis infection by QuantiFERON® TB Gold. Indeterminate results may be confirmed by repeat testing or by a purified protein derivative (PPD) skin test.
  • Serious infection requiring intravenous or systemic antibiotics within 7 days prior to initiation of study treatment, or any active infection that, in the opinion of the investigator, could impact patient safety (e.g., COVID-19 or influenza).
  • Clinically significant, uncontrolled cardiovascular disease, including:

    1. (NYHA) Class III or IV congestive heart failure.
    2. Myocardial infarction or unstable angina within the previous 6 months, clinically significant uncontrolled arrhythmias, including bradyarrhythmias that may cause (e.g., second- or third-degree heart block).
    3. Uncontrolled hypertension (i.e., mean systolic blood pressure ≥180 mmHg and/or diastolic blood pressure ≥110 mmHg on 3 repeated measurements) or clinically significant hypotension (i.e., systolic blood pressure \<90 mmHg and/or diastolic blood pressure \<50 mmHg) or severe episodes of orthostatic hypotension.
    4. History of prolonged QT syndrome or torsades de pointes, or familial history of long QT syndrome.
    5. QTcF ≥470 ms on at least 2 ECGs performed >30 minutes apart.
  • Central nervous system (CNS) or primary CNS tumor.
  • Use of systemic within 4 weeks prior to first dose of study treatment.
  • More than 30 Gy of radiotherapy to the lung within 6 months prior to check-in.
  • History of multiple and/or severe allergies to drugs or foods, or history of severe anaphylactic reaction.
  • Use of prohibited medications or procedures
  • Medical conditions, treatments, or underlying diseases that constitute to the use of study substrates or probe drugs
  • Ingestion of alcohol within 72 hours prior to first study drug administration and during the study period.
  • Participation in another drug trial within 30 days prior to study drug administration (or within 5 half-lives of the investigational drug, whichever is longer) or exposure to more than 3 investigational agents within 12 months prior to study drug administration.
  • Positive serology for surface antigen (HBsAg) or virus (HCV) antibody at screening (a negative PCR test overrides a positive serology).
  • Positive (HIV) test at screening.
  • Positive urine drug screen (unless attributable to concomitant medication) or positive alcohol breath test at screening and/or Day -1.
  • Patients who are legally incapacitated, have limited legal capacity, or are otherwise considered vulnerable.
  • Female patients who are pregnant or breastfeeding.
  • Patients who plan to become pregnant or father a child (including ova or sperm donation) during the study or within 3 months after the last dose of study drug.
  • Known allergy or history of to study drug(s) or their .
  • Concomitant use of strong or moderate CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, and/or inhibitors within 7 days or 5 half-lives (whichever is longer) prior to first dose of study treatment.
  • Concomitant use of strong or moderate CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, and/or CYP3A4 inducers within 14 days or 5 half-lives (whichever is longer) prior to first dose of study treatment.
  • History of or active clinically significant cardiovascular, respiratory, gastrointestinal, renal, hepatic, neurological, psychiatric, musculoskeletal, genitourinary, dermatologic, hematologic, or other disorder that, in the investigator's judgment, could interfere with study participation or the absorption, metabolism, or excretion of study treatment.
  • History of prior second unless disease-free for ≥ 12 months or considered surgically cured. Patients with nonmelanoma skin cancers or with carcinomas in situ at any time following curative intent surgery and low grade, early-stage prostate cancer (Gleason score 6 or below, stage 1 or 2) with no requirement for therapy at any time prior to the study, or previously resected are also eligible.
Terms in these criteria, in plain language(30)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

ECOG performance status

A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.

0
Fully active, no restrictions.
1
Limited in strenuous activity, but walking and able to do light work, such as housework or office work.
2
Walking and able to look after yourself, but unable to work; up and about more than half of waking hours.
3
Able to look after yourself only in part; in bed or a chair more than half of waking hours.
4
Unable to look after yourself at all; in bed or a chair all day.

Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.

Metastases

Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.

Relapsed and refractory

Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.

Absolute neutrophil count (ANC)

The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.

It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.

Platelets

Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.

Hemoglobin (Hb)

The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).

ALT and AST (liver enzymes)

Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.

Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.

ULN (upper limit of normal)

The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.

“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.

Bilirubin

A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.

Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.

Creatinine clearance (CrCl)

How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.

INR, PT and aPTT (clotting tests)

Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.

Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Postmenopausal

Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

ECG (electrocardiogram)

A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.

NYHA class (heart failure)

The New York Heart Association’s four classes of how much heart failure limits physical activity.

I
No limits: ordinary activity causes no undue tiredness or breathlessness.
II
Slight limits: comfortable at rest, ordinary activity causes symptoms.
III
Marked limits: comfortable at rest, less than ordinary activity causes symptoms.
IV
Symptoms even at rest; any activity makes them worse.

Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.

QT and QTc

On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.

The study may name a correction formula and a limit in milliseconds, often around 450–480.

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

Hypersensitivity

An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.

Excipients

The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.

CYP3A (CYP3A4) inhibitors and inducers

CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.

Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

05

Study design

Phase
Phase 4
Primary purpose
Other
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
12 participants (estimated)

Study arms

  • Experimental
    Pralsetinib with CYP450 Probe Substrates and Hormonal Contraceptive

    Drug: Pralsetinib · Drug: CYP3A4, CYP2C8, and CYP2C9 substrates, and hormonal contraceptive

Interventions

  • Pralsetinib 400mg orally (PO) once daily (QD) from Day 4 to Day 10, with an option to continue up to Day 33

  • DrugCYP3A4, CYP2C8, and CYP2C9 substrates, and hormonal contraceptive

    Midazolam, repaglinide, and losartan (CYP probe substrates) and, for female participants, estradiol/norethisterone acetate (hormonal probe substrate), administered orally (PO) once on Day 1 and once on Day 9.

06

What researchers measure

Primary outcomes

  1. Area Under the Plasma Concentration-Time Curve from zero to infinity (AUC0-inf)

    To evaluate the effect of pralsetinib on the overall exposure of CYP3A4, CYP2C8, and CYP2C9, probe substrates, and hormonal contraceptive by measuring AUC0-inf for each probe substrate and its relevant metabolites.

    Time frame: Up to 48 hours post-dose or as appropriate for each probe substrate

  2. Area under the plasma concentration-time curve from time zero to time of last measurable concentration (AUClast)

    To evaluate the effect of pralsetinib on the overall exposure of CYP3A4, CYP2C8, and CYP2C9 probe substrates, and hormonal contraceptive by measuring AUClast for each probe substrate and its relevant metabolites.

    Time frame: Up to 48 hours after each probe drug administration

  3. Maximum Peak Plasma Concentration (Cmax)

    To evaluate how pralsetinib affects the peak levels of probe substrates, and hormonal contraceptive, in the blood after they are taken alone and again after treatment with pralsetinib

    Time frame: Up to 48 hours after each probe drug administration

Secondary outcomes

  1. Time to Maximum Plasma Concentration (tmax)

    Venous whole blood samples will be collected for activity-based pharmacokinetics characterization to assess how pralsetinib affects the time required to reach peak plasma concentration for each probe drug.

    Time frame: Up to 48 hours after each probe drug administration

  2. Terminal Half-Life (t½)

    Venous whole blood samples will be collected for activity-based pharmacokinetics characterization To evaluate the effect of pralsetinib on the terminal half-life of each probe drug

    Time frame: Up to 48 hours after each probe drug administration

  3. Percent of Area Under the plasma concentration-time curve obtained at extrapolation (%AUCex)

    Venous whole blood samples will be collected for activity-based pharmacokinetics characterization to determine the proportion of the AUC that is extrapolated, providing insight into pralsetinib's effect on drug elimination

    Time frame: Up to 48 hours after each probe drug administration

  4. Mean residence time (MRT)

    Venous whole blood samples will be collected for activity-based pharmacokinetics characterization to assess how pralsetinib affects the average time each probe drug remains in the body

    Time frame: Up to 48 hours after each probe drug administration

  5. Terminal Elimination Rate Constant (λz)

    Venous whole blood samples will be collected for activity-based pharmacokinetics characterization to assess how pralsetinib affects the terminal elimination rate constant of each probe drug

    Time frame: Up to 48 hours after each probe drug administration

  6. Apparent Total Body Clearance (CL/F)

    Venous whole blood samples will be collected for activity-based pharmacokinetics characterization to evaluate the effect of pralsetinib on the apparent total body clearance of each probe drug

    Time frame: Up to 48 hours after each probe drug administration

  7. Apparent Volume of Distribution (Vz/F)

    Venous whole blood samples will be collected for activity-based pharmacokinetics characterization to assess how pralsetinib influences the apparent volume of distribution of each probe drug

    Time frame: Up to 48 hours after each probe drug administration

  8. Safety and Tolerability

    Incidence, frequency, relatedness, and severity of treatment-emergent adverse events (TEAEs) associated with co-administration of pralsetinib and probe substrates

    Time frame: From the start of treatment through approximately 30 days after the last dose of study treatment

07

Study locations

2 of 2 sites recruiting
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Aug 10, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT07704658
Responsible party
Sponsor
First posted
Jul 15, 2026
Start date
Mar 4, 2026
Primary completion
Jul 30, 2027 (estimated)
Completion
Aug 30, 2027 (estimated)
Last update
Aug 10, 2026

Study contacts

Kay Patel
Contact
kpatel@rigel.com
(650) 624-1100

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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