Pralsetinib
Pralsetinib is a targeted cancer medicine used to treat certain types of non-small cell lung cancer and thyroid cancer that have a specific genetic change called a RET fusion.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 2 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Pralsetinib (Gavreto) is a once-daily specialist cancer medicine, on the market since about 2020, that blocks the stuck-on RET protein driving non-small cell lung cancer and thyroid cancer with a RET fusion, so it is used only when testing confirms that gene change. Many people stay on it with dose adjustments, though muscle and joint aches, constipation, fatigue and swelling are common. The boxed warning is serious infections, including rare opportunistic ones, so report fever or chills, and treat new breathlessness or cough as urgent since lung inflammation is another serious risk. Expect regular blood pressure and liver checks, and women who could become pregnant need non-hormonal birth control.
Clinical pearls
- Take it on an empty stomach, with no food for two hours before and one hour after each dose.
- Birth control pills, patches and rings may not work while on it, so use a non-hormonal method instead.
- Tell your surgeon or dentist before any procedure, because it must be paused around surgery to let wounds heal.
- Antifungals like fluconazole or voriconazole and the antibiotic rifampin shift its levels, so every new prescriber should know you take it.
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾
Gavreto can significantly increase your risk of serious infections — including bacterial, fungal, viral, and rare opportunistic infections — that may require hospitalization or can be life-threatening. This applies to all patients taking Gavreto. Watch for signs such as fever, chills, unusual fatigue, or difficulty breathing, and report them to your doctor right away. Depending on how serious the infection is, your dose may need to be paused, reduced, or stopped permanently.
Patient information guide A plain-language walkthrough of Pralsetinib, written from its FDA label.
What Pralsetinib is used for
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Pralsetinib is a targeted cancer treatment approved for specific tumor types that carry a RET gene fusion — a genetic change that causes uncontrolled cancer cell growth.
- Gavreto is approved for adult patients with metastatic RET fusion-positive non-small cell lung cancer (NSCLC) — lung cancer that has spread and is confirmed by an FDA-approved genetic test.
- Gavreto is approved for adult and pediatric patients aged 12 and older with advanced or metastatic RET fusion-positive thyroid cancer who need systemic therapy and whose cancer no longer responds to radioactive iodine treatment (when radioactive iodine was appropriate). This approval for thyroid cancer is based on tumor response data and is considered an accelerated approval — final confirmation of benefit is pending.
How Pralsetinib works
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Pralsetinib is a kinase inhibitor that targets RET — a protein that, when altered by a gene fusion, becomes permanently switched on and drives cancer cells to divide out of control. By blocking RET and related abnormal RET fusion proteins, pralsetinib cuts off that growth signal, slowing or shrinking tumors. It has shown activity against several specific RET fusion and mutation types in lab models, including in brain tumor models.
In lab studies, pralsetinib was shown to be much more selective for RET than for other kinases like VEGFR2 and JAK2, meaning it targets the cancer driver more precisely at clinically relevant levels.
Pralsetinib dosage
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Gavreto capsules are taken by mouth once daily on an empty stomach — meaning no food for at least 2 hours before and at least 1 hour after taking the capsule. Food, especially a high-fat meal, significantly increases the amount of drug that reaches the bloodstream, so consistency with the fasting rule matters.
- If a dose is missed, take it as soon as possible on the same day, then return to the regular schedule the next day.
- If you vomit after taking a dose, do not take another — continue with the next scheduled dose.
- Your dose may be adjusted or paused by your doctor if side effects occur or if you start certain other medications.
Dosing details from the FDA-approved label
From the Pralsetinib prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Adults and pediatric patients 12 years and older with RET gene fusion (NSCLC or thyroid cancer)
- 400 mg orally once daily on an empty stomach (no food intake for at least 2 hours before and at least 1 hour after taking GAVRETO)
- Continue until disease progression or unacceptable toxicity
- Adverse reaction dose reductions: first 300 mg once daily, second 200 mg once daily, third 100 mg once daily; permanently discontinue if unable to tolerate 100 mg once daily
- Coadministration with combined P-gp and strong CYP3A inhibitors (if it cannot be avoided)
- Current 400 mg once daily: reduce to 200 mg orally once daily
- Current 300 mg: 200 mg once daily
- Current 200 mg: 100 mg once daily
- After inhibitor discontinued for 3 to 5 elimination half-lives, resume the dose taken prior to the inhibitor
- Coadministration with strong CYP3A inhibitors, moderate CYP3A inhibitors, P-gp inhibitors, or combined P-gp and moderate CYP3A inhibitors (if it cannot be avoided)
- Current 400 mg once daily: reduce to 300 mg orally once daily
- Current 300 mg: 200 mg once daily
- Current 200 mg: 100 mg once daily
- After inhibitor discontinued for 3 to 5 elimination half-lives, resume the dose taken prior to the inhibitor
- Coadministration with strong CYP3A inducers (if it cannot be avoided)
- Current 400 mg once daily: increase to 800 mg orally once daily
- Current 300 mg: 600 mg once daily
- Current 200 mg: 400 mg once daily
- Increase starting on Day 7 of coadministration; after inducer discontinued for at least 14 days, resume the prior dose
- Coadministration with moderate CYP3A inducers (if it cannot be avoided)
- Current 400 mg once daily: increase to 600 mg orally once daily
- Current 300 mg: 500 mg once daily
- Current 200 mg: 300 mg once daily
- Increase starting on Day 7 of coadministration; after inducer discontinued for at least 14 days, resume the prior dose
Read the label’s full dosing text
2 DOSAGE AND ADMINISTRATION Select patients for treatment with GAVRETO based on the presence of a RET gene fusion. ( 2.1 , 14 ) The recommended dosage in adults and pediatric patients 12 years and older is 400 mg orally once daily on an empty stomach (no food intake for at least 2 hours before and at least 1 hour after taking GAVRETO). ( 2.2 ) 2.1 Patient Selection Select patients for treatment with GAVRETO based on the presence of a RET gene fusion (NSCLC or thyroid cancer) [see Clinical Studies (14) ] . Information on FDA-approved tests for RET gene fusion (NSCLC) is available at http://www.fda.gov/CompanionDiagnostics. An FDA-approved test for the detection of RET gene fusion (thyroid cancer) is not currently available. 2.2 Recommended Dosage The recommended dosage of GAVRETO is 400 mg orally once daily on an empty stomach (no food intake for at least 2 hours before and at least 1 hour after taking GAVRETO ) [see Clinical Pharmacology (12.3) ] . Continue treatment until disease progression or until unacceptable toxicity. If a dose of GAVRETO is missed, it can be taken as soon as possible on the same day. Resume the regular daily dose schedule for GAVRETO the next day. Do not take an additional dose if vomiting occurs after GAVRETO but continue with the next dose as scheduled. 2.3 Dosage Modifications for Adverse Reactions The recommended dose reductions and dosage modifications for adverse reactions are provided in Table 1 and Table 2 . Table 1: Recommended Dose Reductions for GAVRETO for Adverse Reactions Dose Reduction Recommended Dosage First 300 mg once daily Second 200 mg once daily Third 100 mg once daily Permanently discontinue GAVRETO in patients who are unable to tolerate 100 mg taken orally once daily. The recommended dosage modifications for adverse reactions are provided in Table 2 . Table 2: Recommended Dosage Modifications for GAVRETO for Adverse Reactions Adverse Reactions Severity Adverse reactions graded by the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) version 4.03 Dosage Modification Serious Infections, Including Opportunistic Infections [see Warnings and Precautions (5.1) ] Grade 2 or 3 Withhold GAVRETO until resolution. Resume at a reduced dose ( Table 1 ). Grade 4 Permanently discontinue GAVRETO.
Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →
Pralsetinib side effects
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The most common side effects with Gavreto include:
Common side effects
- Musculoskeletal pain (muscle and joint aches)
- Constipation
- High blood pressure (hypertension)
- Diarrhea
- Fatigue or weakness
- Swelling (edema)
- Fever (pyrexia)
- Cough
- Nausea
- Taste changes
When to get medical help
- Call your doctor right away if you develop fever, chills, or other signs of infection — serious and life-threatening infections, including rare opportunistic infections, can occur
- Seek urgent care for new or worsening shortness of breath, cough, or fever — these could be signs of serious lung inflammation (ILD/pneumonitis)
- Contact your doctor if you have severe or unusual bleeding anywhere in the body
- Get your blood pressure checked regularly; tell your doctor if it becomes hard to control
- Report yellowing of the skin or eyes, dark urine, or severe abdominal pain — these may signal liver problems
- If you are having surgery, tell your surgeon and oncologist — Gavreto needs to be stopped before and after surgery to allow proper wound healing
- Tell your doctor immediately if you notice unusual rapid swelling, muscle cramps, or decreased urination — these can be signs of tumor lysis syndrome
Serious reactions — including severe infections, lung inflammation, significant bleeding, liver enzyme elevations, and dangerously high blood pressure — also occur and require prompt medical attention. Lab abnormalities such as low blood cell counts and electrolyte changes are common and are monitored regularly.
Pralsetinib warnings and precautions
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- Serious infections: Gavreto significantly raises the risk of bacterial, fungal, viral, and opportunistic infections, some fatal. Monitor for fever, chills, or unusual symptoms and report them immediately.
- Lung inflammation (ILD/pneumonitis): Can be severe or fatal. Tell your doctor right away if you develop new or worsening shortness of breath, cough, or fever.
- High blood pressure (hypertension): Occurs in about 1 in 3 patients; blood pressure must be controlled before starting and monitored at least monthly during treatment.
- Liver toxicity (hepatotoxicity): Elevated liver enzymes are common; liver function is tested regularly and dose adjustments may be needed.
- Bleeding (hemorrhagic events): Serious and fatal bleeding has occurred; report any unusual or heavy bleeding right away.
- Tumor lysis syndrome: A rapid breakdown of cancer cells that can cause dangerous electrolyte imbalances — patients with large tumors or kidney problems are at higher risk.
- Wound healing: Gavreto must be stopped before elective surgery and not restarted until healing is complete.
- Fetal harm: Gavreto causes birth defects and pregnancy loss in animal studies. Non-hormonal contraception is required during treatment.
- Bone growth plate effects in adolescents: Growth plates must be monitored in patients whose bones are still developing.
Pralsetinib interactions
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Pralsetinib is processed mainly by liver enzymes (CYP3A4), so several medications can significantly affect its levels in your body:
- Strong or moderate CYP3A inhibitors (e.g., itraconazole, voriconazole, fluconazole) — raise pralsetinib blood levels, increasing side-effect risk; avoid if possible, or dose reduction is needed.
- P-glycoprotein (P-gp) inhibitors (e.g., cyclosporine, verapamil) — also raise pralsetinib levels; avoid or adjust dose.
- Strong or moderate CYP3A inducers (e.g., rifampin, efavirenz) — lower pralsetinib levels, potentially making it less effective; avoid if possible, or a dose increase may be needed.
- Hormonal contraceptives — Gavreto may reduce their effectiveness; switch to non-hormonal birth control during treatment.
Interactions listed in the FDA-approved label
From the Pralsetinib prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Strong or moderate CYP3A inhibitors and/or P-gp inhibitors: Increases pralsetinib exposure, which may increase the risk of adverse reactions related to GAVRETO. Avoid coadministration. If it cannot be avoided, reduce the GAVRETO dose.
- Strong or moderate CYP3A inducers: Concomitant use with a strong CYP3A inducer decreases pralsetinib exposure, which may decrease efficacy of GAVRETO. Avoid concomitant use. If it cannot be avoided, increase the GAVRETO dose.
Read the label’s full interactions text
7 DRUG INTERACTIONS Strong or moderate CYP3A inhibitors and/or P-gp inhibitors : Avoid coadministration. If coadministration cannot be avoided, reduce the dose of GAVRETO. ( 2.4 , 7.1 , 12.3 ) Strong or moderate CYP3A inducers : Avoid coadministration. If coadministration cannot be avoided, increase the dose of GAVRETO. ( 2.5 , 7.1 , 12.3 ) 7.1 Effects of Other Drugs on GAVRETO Strong or Moderate CYP3A and/or P-gp Inhibitors Concomitant use with a strong or moderate CYP3A inhibitor and/or a P-gp inhibitor increases pralsetinib exposure [ Clinical Pharmacology (12.3) ] , which may increase the risk of adverse reactions related to GAVRETO. Avoid coadministration of GAVRETO with a strong or moderate CYP3A and/or P-gp inhibitor. If coadministration with any of the above inhibitors cannot be avoided, reduce the GAVRETO dose [see Dosage and Administration (2.4) ]. Strong or Moderate CYP3A Inducers Concomitant use with a strong CYP3A inducer decreases pralsetinib exposure [see Clinical Pharmacology (12.3) ] , which may decrease efficacy of GAVRETO. Avoid concomitant use of GAVRETO with strong or moderate CYP3A inducers. If coadministration of GAVRETO with strong or moderate CYP3A inducers cannot be avoided, increase the GAVRETO dose [see Dosage and Administration (2.5) ].
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before taking Pralsetinib
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- Pregnancy: Gavreto causes serious fetal harm and pregnancy loss. A pregnancy test is required before starting. Do not use if pregnant.
- Breastfeeding: Do not breastfeed while taking Gavreto or for 1 week after the last dose.
- Females of childbearing potential: Must use effective non-hormonal contraception during treatment and for 2 weeks after the last dose.
- Male patients with female partners who could become pregnant: Should use effective contraception during treatment and for 1 week after the last dose.
- Fertility: Based on animal studies, Gavreto may impair fertility in both males and females.
- Adolescents (ages 12 and up): Gavreto is approved for RET fusion-positive thyroid cancer in this age group, but growth plates (open areas in growing bones) must be monitored during treatment.
- Uncontrolled high blood pressure: Must be brought under control before starting Gavreto.
- Liver or kidney disease: No dose adjustment is required for liver impairment or mild-to-moderate kidney impairment based on available data, but your doctor will monitor you closely. Severe kidney impairment has not been studied.
- Upcoming surgery: Tell your care team — Gavreto must be paused before and after procedures.
What Pralsetinib does in the body
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Studies in patients with RET-altered tumors found that Gavreto at the standard dosage did not cause a large increase in the QTc interval (a measure of heart electrical activity), meaning it is not expected to significantly affect heart rhythm at recommended doses. The full relationship between pralsetinib blood levels and its effects in the body has not been completely mapped out.
How your body processes Pralsetinib
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After taking Gavreto by mouth on an empty stomach, pralsetinib reaches its peak blood level in about 2 to 4 hours, with steady levels in the blood established within 3 to 5 days of daily dosing. Eating a high-fat meal roughly doubles the amount absorbed, which is why it must be taken on an empty stomach. The drug has a half-life of about 16 to 20 hours — meaning it takes that long for blood levels to drop by half — and it is processed mainly by the liver enzyme CYP3A4. About 73% of the drug is eliminated in the stool and 6% in urine. Age, sex, race, and mild-to-moderate kidney or liver impairment do not significantly affect how the body handles pralsetinib.
How to store Pralsetinib
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Store at 20°C to 25°C (68°F to 77°F); excursions are permitted from 15°C to 30°C (59°F to 86°F) . Protect from moisture.
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Supplements & herbs that interact with Pralsetinib
181 supplements and herbal products have documented interactions with Pralsetinib in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 11
- Moderate · 134
- Minor · 36
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Pralsetinib: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Pralsetinib — the kind of thing our pharmacy team would talk through with you at the counter.
What exactly is a RET fusion, and why does my cancer need to have it for this drug to work?
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Does it matter when I take my Gavreto capsule, and can I take it with food?
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I missed my dose today — what should I do?
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What side effects are most likely, and which ones should make me call the doctor right away?
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Can I use my regular birth control pill while taking Gavreto?
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I'm having a minor surgical procedure soon — do I need to stop Gavreto?
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Is Pralsetinib available over the counter?
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When was Pralsetinib first available?
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Who makes Pralsetinib?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More about Pralsetinib on HelloPharmacist
Pralsetinib forms and strengths (how it comes)
Pralsetinib is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Need a version that does not list lactose, a gluten source, a dye or gelatin? Inactive ingredients differ by manufacturer: see Pralsetinib inactive ingredients by manufacturer.
Capsule
How this form is used
- Gavreto capsules treat adult patients with metastatic RET fusion-positive non-small cell lung cancer (NSCLC) confirmed by an FDA-approved test
- Gavreto capsules treat adults and patients aged 12 and older with advanced or metastatic RET fusion-positive thyroid cancer that no longer responds to radioactive iodine (if appropriate)
- Gavreto capsules are taken by mouth once daily on an empty stomach — no food for at least 2 hours before and 1 hour after each dose
- Gavreto: if a dose is missed, take it as soon as possible on the same day; resume the normal schedule the next day — never take two doses to make up for a missed one
- Gavreto: if vomiting occurs after taking a dose, do not repeat it — continue with the next scheduled dose
- Gavreto: eating a high-fat meal significantly increases drug levels in the blood, so the empty-stomach rule is important to follow consistently
Pralsetinib on the U.S. market: products, makers and brands
How Pralsetinib appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
2 companies list 2 Pralsetinib product records with the FDA, mostly as capsule; the earliest marketing or approval year on record is 2020. Brand names on the directory include Gavreto; the rest are generics.
Also listed with the FDA, not a patient dose form: Powder (3) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
Compare Pralsetinib products
A representative set of FDA-listed product records for Pralsetinib — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Capsule | ||||
| 100 mg | Oral | Genentech, Inc. | NDA | View NDC → |
| 100 mg | Oral | Rigel Pharmaceuticals, Inc. | NDA | View NDC → |
Showing 2 of 2 products — FDA National Drug Code Directory. See every product, package size and price: browse all 2 Pralsetinib NDCs →
Pralsetinib side effects reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Pralsetinib — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Pralsetinib in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Pralsetinib FDA approval history
How Pralsetinib went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
Pralsetinib recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Pralsetinib recalls since July 2021.
✅No Pralsetinib recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 2394936 1 dose form · 1 strength
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Dose form (SCDF) Oral Capsule RxCUI 2394940In current FDA listingsClinical drug / strength (SCD) 100 MGRxCUI 2394941
Look up RxCUI 2394936 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Pralsetinib supply and shortage status
Whether Pralsetinib is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
Pralsetinib brand names
Pralsetinib is sold under one brand name in the FDA directory — Gavreto. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who makes Pralsetinib: manufacturers and labelers
2 companies list Pralsetinib products with the FDA. By number of product records, the largest are Genentech, Inc., Rigel Pharmaceuticals, Inc.. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Pralsetinib drug class (RxNorm)
Pralsetinib belongs to the Kinase Inhibitor class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for this Pralsetinib page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Rigel Pharmaceuticals, Inc. is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →