Testing for RET is essential to identify patients who may be eligible for Retevmo1
NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) recommend testing for RET alterations in appropriate patients with advanced and/or metastatic NSCLC and thyroid carcinoma* to determine if they are eligible for RET inhibitors such as selpercatinib (Retevmo)2,3
NCCN makes no warranties of any kind whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way.
Next-generation sequencing (NGS) can be an accurate and tissue-efficient method to test for driver RET alterations and other targetable biomarkers4-7†
Retevmo may affect both healthy cells and tumor cells, which can result in side effects, some of which can be serious.1
- Both RET point mutations and fusions can be detected by NGS.4-6
- Immunohistochemistry (IHC) is not preferred for detecting RET alterations due to low sensitivity and variable specificity9,10
- Test the tissue: molecular testing of FFPE tumor tissue specimens is preferred for detecting RET fusions and point mutations8,11-13
- In the clinical trial, identification of a RET gene alteration was prospectively determined in local laboratories using NGS, PCR, or FISH1
- IHC testing was not used in LIBRETTO-0011
Why NGS?
Broad molecular profiling to identify appropriate targeted therapies can improve outcomes in NSCLC14
- NCCN Guidelines for NSCLC recommend that, when feasible, molecular testing of NSCLC specimens be performed via a broad, panel-based approach, most typically performed by NGS2
- Because of potential tissue limitations in metastatic NSCLC and the increased number of actionable biomarkers, NGS testing is part of the most comprehensive strategy to identify appropriate targeted therapies7
- Consider NGS testing to identify the 69% of patients with lung adenocarcinoma who have a potentially actionable oncogenic driver alteration and may benefit from appropriate approved or investigational targeted therapy15,16
Emerging=biomarkers with therapies under investigation but not approved.
Other=unknown oncogenic driver detected.16
EGFR=EGFR sensitizing mutations including exon 20 insertions.16,23
EGFR other=secondary EGFR mutations, including Thr790Met and Cys797Ser, and other less common EGFR mutations.16
KRAS other=all KRAS mutations other than KRAS G12C.16,22
NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®)
For NSCLC:
- recommend testing for RET fusions in eligible patients with metastatic non-small cell lung cancer2
- recommend molecular testing and strongly advise broad molecular profiling for multiple biomarkers, including RET, in eligible patients with metastatic NSCLC2*‡
*The NCCN Guidelines provide recommendations for certain individual biomarkers that should be tested and recommend testing techniques but do not endorse any specific commercially available biomarker assays or commercial laboratories.
†Through design and validation, the test has established high sensitivity, specificity, and reproducibility for the detection of genomic alterations.
‡It is recommended at this time that, when feasible, testing be performed via a broad, panel-based approach, most typically performed by NGS. For patients who, in broad panel testing, don’t have identifiable driver oncogenes (especially in never smokers), consider RNA-based NGS, if not already performed, to maximize detection of fusion events.
For Thyroid Carcinoma:
- recommend molecular testing for RET fusions and RET point mutations for certain patients with advanced or metastatic thyroid carcinomas3
Consider waiting for RET test results before making therapeutic decisions1
NGS testing
- NGS testing for RET fusions: when properly designed, NGS testing is able to detect known and unknown fusion events6
- A combination of RNA- and DNA-based NGS testing may be a more comprehensive approach to identify oncogenic drivers missed by DNA-based NGS alone24
Most common RET fusion partners identified in the LIBRETTO-001 phase I/II clinical trial:
NSCLC25:
- 59% KIF5B
- 22% CCDC6
- 11% Unknown§
- 6% Otherǁ
- 2% NCOA4
Thyroid cancer other than MTC26:
- 52% CCDC6
- 33% NCOA4
- 15% Other¶
§Unknown includes positive by FISH or PCR.
ǁOthers included KIAA1468(2), ARHGAP12, CCDC88C, CLIP1, DOCK1+RBPMS, ERC1, PRKAR1A, and TRIM24 (all 1 each).25
¶Others included CCDC1686, ERC1, KTN1, and RUFY (all 1 each).26
NGS testing
- NGS allows for multiplex testing on a small amount of tissue for the detection of rare, as well as common, cancer-related biomarkers4,7,27
- RET point mutations can be detected by NGS4-6
Most common RET mutations identified in the LIBRETTO-001 phase I/II clinical trial26:
- 57% M918T
- 19% Extracellular cysteine mutations
- 16% Other#
- 8% V804M/L
#Others included D631-L633delinsE(5), E632-L633del(4), A883F(4), D631-L633delinsV(2), L790F(2), D898-E901del(2), D898_E901del + D903_S904delinsEP, K666N, T636-V637insCRT, D378-G385delinsE (all 1 each).26
- While not recommended as a replacement for a diagnostic tissue biopsy, consider liquid biopsy when FFPE tumor tissue is unavailable or insufficient for molecular profiling11
- While a positive liquid biopsy result is considered reliable, a negative result requires confirmation with tumor tissue testing11
-
NCCN Guidelines: principles of molecular and biomarker analysis in metastatic NSCLC2
- Plasma ctDNA (liquid biopsy) should not be used in lieu of a histologic tissue diagnosis
- Studies have demonstrated liquid biopsy to generally have very high specificity but significantly compromised sensitivity, with a false-negative rate of up to 30%
- Standards and guidelines for liquid biopsy testing for genetic alterations have not been established
Test for RET1
Ensure your test can detect driver RET fusions in NSCLC and non-medullary thyroid cancer and driver RET mutations in MTC
INDICATIONS
Retevmo is a kinase inhibitor indicated for the treatment of:
- adult patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) with a rearranged during transfection (RET) gene fusion, as detected by an FDA-approved test
- adult and pediatric patients 2 years of age and older with advanced or metastatic medullary thyroid cancer (MTC) with a RET mutation, as detected by an FDA-approved test, who require systemic therapy*
- adult and pediatric patients 2 years of age and older with advanced or metastatic thyroid cancer with a RET gene fusion, as detected by an FDA-approved test, who require systemic therapy and who are radioactive iodine-refractory (if radioactive iodine is appropriate)
- adult and pediatric patients 2 years of age and older with locally advanced or metastatic solid tumors with a RET gene fusion, as detected by an FDA-approved test, that have progressed on or following prior systemic treatment or who have no satisfactory alternative treatment options*
*These indications are approved under accelerated approval based on overall response rate (ORR) and duration of response (DoR). Continued approval for these indications may be contingent upon verification and description of clinical benefit in confirmatory trials.