Gavreto (pralsetinib)
An approved treatment for RET Fusion Cancer.
Drug facts
The same compound appears under different names depending on the context. Here is how to identify Pralsetinib wherever you encounter it, plus the key facts at a glance.
- Generic name
- Pralsetinib
- Brand name
- Gavreto
- Development code
- BLU-667
- Drug class
- RET kinase inhibitor
- Manufacturer
- Rigel Pharmaceuticals
- How it's taken
- Oral capsules once a day on an empty stomach
A once-daily pill taken on an empty stomach that blocks RET, the growth signal a RET gene fusion keeps switched on. It is approved for adults with metastatic RET fusion-positive non-small cell lung cancer and, under accelerated approval, for people 12 and older with advanced RET fusion-positive thyroid cancer that needs systemic treatment and no longer responds to radioactive iodine.
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Where Pralsetinib fits
One of 2 selective RET inhibitors approved for RET fusion-positive lung and thyroid cancer; selpercatinib (Retevmo) is the other. No trial has compared them directly.
How Pralsetinib works
In a RET fusion, part of the RET gene joins another gene, most often KIF5B or CCDC6, and the resulting protein keeps the RET growth signal on. Pralsetinib blocks wild-type RET and these fusion proteins at very low concentrations, and blocks some other kinases, such as VEGFR2 and JAK2, only at higher levels[1]. Treatment is chosen only after a test finds a RET fusion. FDA-approved tests exist for lung cancer, while the label says no FDA-approved test is currently available for thyroid cancer[1].
Side effects and safety
- Serious infections. Including fatal and opportunistic infections such as pneumocystis pneumonia; in AcceleRET-Lung, 72% had an infection on Gavreto, fatal in 7%.
- Lung inflammation (pneumonitis). In 12% of patients, grade 3 or 4 in 3.3% and fatal in 0.2%; new or worse cough, shortness of breath or fever needs prompt checking.
- High blood pressure. In 35%, grade 3 in 18%; blood pressure should be controlled before starting.
- Liver toxicity. AST rose in 49% and ALT in 37%; serious liver reactions in 1.5%.
- Bleeding. Grade 3 or worse bleeding in 4.1%, including 1 fatal event.
- Tumor lysis syndrome. Reported in people with medullary thyroid cancer, more likely with fast-growing or large tumors, kidney problems or dehydration.
- Wound healing. Gavreto is paused at least 5 days before elective surgery and for at least 2 weeks after major surgery.
- Pregnancy. Can harm an unborn baby; the label advises non-hormonal contraception during treatment and for 2 weeks after the last dose.
- Blood pressure after 1 week, then at least monthly
- AST and ALT before starting, every 2 weeks for the first 3 months, then monthly
- Breathing symptoms such as cough, shortness of breath or fever
- Signs of infection and bleeding
Gavreto carries a boxed warning, added in December 2025, for serious infections, including bacterial, fungal, viral and opportunistic infections, which can lead to hospitalization or death, and it has no contraindications[1]. In the AcceleRET-Lung trial, infections occurred in 72% of patients on Gavreto and were fatal in 7%.
The label also warns about lung inflammation in 12% (fatal in 0.2%), high blood pressure in 35% (grade 3 in 18%), liver enzyme rises (AST in 49%, ALT in 37%) with serious liver reactions in 1.5%, serious bleeding (grade 3 or worse in 4.1%), tumor lysis syndrome in medullary thyroid cancer, slower wound healing, and harm to an unborn baby[1].
The most common side effects, in 25% or more of 540 patients in the ARROW trial, were musculoskeletal pain, constipation, high blood pressure, diarrhea, fatigue, swelling, fever and cough[1].
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Pralsetinib
The dose for adults and children 12 and older is 400mg (four 100mg capsules) by mouth once a day on an empty stomach, with no food for at least 2 hours before and at least 1 hour after, until the cancer progresses or side effects become unacceptable[1]. A missed dose can be taken the same day, and the usual schedule resumes the next day; no extra dose is taken after vomiting. The label lowers the dose when Gavreto is combined with CYP3A or P-gp inhibitors and changes it with CYP3A inducers[1].
Availability and cost
Only available as the brand-name product.
Help paying for Gavreto
The maker of Gavreto publishes no copay card, but its support program can check your insurance and explain any help that exists. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE. Pick your insurance below to see which offers fit you.
- Insurance and case manager help
RIGEL ONECARE case managers help with coverage and financial assistance for Gavreto. Call 1-833-RIGELOC (1-833-744-3562), Monday to Friday, 8 AM to 8 PM ET.
For: private insurance, Medicare, Medicaid, TRICARE, no insurance, underinsured · source
Good to know: The RIGEL ONECARE home page links Gavreto patient pages but does not state Gavreto copay or free drug terms, and the patient page returned 404 on November 2, 2026. Third-party listings describe a $0 copay with a $25,000 annual cap; those are not recorded until Rigel's own page confirms them.
Access and eligibility
Adults with metastatic non-small cell lung cancer whose tumor has a RET fusion found by an FDA-approved test, or people 12 and older with advanced or metastatic RET fusion-positive thyroid cancer who need systemic treatment and whose cancer no longer responds to radioactive iodine, when radioactive iodine is appropriate.
Source: RIGEL ONECARE
Access program details are provided for informational purposes and may vary based on insurance coverage, geographic location, and individual circumstances. Confirm current eligibility directly with the manufacturer or your specialty pharmacy.
Clinical trial results
ARROW (NCT03037385) was a single-arm trial. Among 130 adults with metastatic RET fusion-positive lung cancer who had already had platinum chemotherapy, 63% responded (6% completely) and the median response lasted 38.8 months; among 107 with no earlier treatment, 78% responded (7% completely), with a median response of 13.4 months[1].
In 7 of 10 previously treated patients with measurable brain metastases, the brain tumors responded. Among 9 people with RET fusion-positive thyroid cancer, all with the papillary type, 89% responded, and every responder was still responding at 6 months[1]. The randomized AcceleRET-Lung trial (NCT04222972) of 223 patients adds safety data to the label[1].
Development history
Pralsetinib (BLU-667) was developed by Blueprint Medicines. The FDA approved Gavreto for RET fusion-positive lung cancer on September 4, 2020 and for RET fusion-positive thyroid cancer on December 1, 2020[2][3]. The lung cancer use moved from accelerated to regular approval on August 9, 2023, while the thyroid cancer use remains an accelerated approval[2][1]. Rigel took over the US application in June 2024[4], and a boxed warning for serious infections was added in December 2025[1].
Explore RET Fusion Cancer trials
Common questions about Pralsetinib
▸What is Pralsetinib (Gavreto)?
A once-daily pill taken on an empty stomach that blocks RET, the growth signal a RET gene fusion keeps switched on. It is approved for adults with metastatic RET fusion-positive non-small cell lung cancer and, under accelerated approval, for people 12 and older with advanced RET fusion-positive thyroid cancer that needs systemic treatment and no longer responds to radioactive iodine.
▸How does Pralsetinib work?
In a RET fusion, part of the RET gene joins another gene, most often KIF5B or CCDC6, and the resulting protein keeps the RET growth signal on. Pralsetinib blocks wild-type RET and these fusion proteins at very low concentrations, and blocks some other kinases, such as VEGFR2 and JAK2, only at higher levels[1]. Treatment is chosen only after a test finds a RET fusion. FDA-approved tests exist for lung cancer, while the label says no FDA-approved test is currently available for thyroid cancer[1].
▸What are the side effects of Pralsetinib?
Gavreto carries a boxed warning, added in December 2025, for serious infections, including bacterial, fungal, viral and opportunistic infections, which can lead to hospitalization or death, and it has no contraindications[1]. In the AcceleRET-Lung trial, infections occurred in 72% of patients on Gavreto and were fatal in 7%. The label also warns about lung inflammation in 12% (fatal in 0.2%), high blood pressure in 35% (grade 3 in 18%), liver enzyme rises (AST in 49%, ALT in 37%) with serious liver reactions in 1.5%, serious bleeding (grade 3 or worse in 4.1%), tumor lysis syndrome in medullary thyroid cancer, slower wound healing, and harm to an unborn baby[1]. The most common side effects, in 25% or more of 540 patients in the ARROW trial, were musculoskeletal pain, constipation, high blood pressure, diarrhea, fatigue, swelling, fever and cough[1].
▸How is Pralsetinib taken?
The dose for adults and children 12 and older is 400mg (four 100mg capsules) by mouth once a day on an empty stomach, with no food for at least 2 hours before and at least 1 hour after, until the cancer progresses or side effects become unacceptable[1]. A missed dose can be taken the same day, and the usual schedule resumes the next day; no extra dose is taken after vomiting. The label lowers the dose when Gavreto is combined with CYP3A or P-gp inhibitors and changes it with CYP3A inducers[1].
▸Is Pralsetinib FDA approved?
Yes, Pralsetinib (Gavreto) is FDA approved (2020) for the treatment of RET Fusion Cancer.
▸How do I know if my cancer has a RET fusion?
Through a test of the tumor or of blood. Gavreto is chosen only after a test finds a RET gene fusion[1].
Lung cancer: FDA-approved tests for RET fusions are listed on the FDA's companion diagnostics page.
Thyroid cancer: the label says no FDA-approved test is currently available.
In the ARROW trial: most fusions were found by next-generation sequencing, and the most common partner genes were KIF5B and CCDC6.
Source: Gavreto prescribing information, January 2026.
▸How is Gavreto taken?
As 400mg (four 100mg capsules) once a day on an empty stomach, with no food for at least 2 hours before and at least 1 hour after, according to the label[1].
Missed dose: it can be taken later the same day, and the usual schedule resumes the next day.
Vomiting: no extra dose is taken.
Surgery: the label pauses Gavreto at least 5 days before elective surgery and for at least 2 weeks after major surgery.
Source: Gavreto prescribing information, January 2026.
Sources and references
Every factual claim on this page is drawn from the public sources listed below. Click any reference to open the original document.
- Rigel Pharmaceuticals via DailyMed · 2026-01-28. Gavreto (pralsetinib) capsules prescribing information. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=16edd46e-28b8-f06d-e063-6394a90ae31b
- FDA. Gavreto approval history, lung cancer. https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=213721
- FDA. Gavreto approval history, thyroid cancer. https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=214701
- Rigel Pharmaceuticals. Rigel Pharmaceuticals completes transfer of GAVRETO (pralsetinib) New Drug Application. https://www.rigel.com/news-media/press-releases/detail/390/rigel-pharmaceuticals-completes-transfer-of-gavreto
- Rigel Pharmaceuticals. RIGEL ONECARE patient support. https://www.rigelonecare.com/