LeukoStrat CDx FLT3
Mutation Assay®

Clinical utility of the LeukoStrat® CDx FLT3
Mutation Assay
The fms related tyrosine kinase 3 (FLT3) is one of the mostcommonly mutated genes in acute myeloid leukemia (AML),
occurring in approximately 30% of patients at the timeof diagnosis1. Although generally associated with normal
cytogenetics where patients have standard risk of relapse,
FLT3 mutations have also been identifi ed in sub-groups ofpatients with chromosomal abnormalities that are associatedwith high risk of disease relapse2-3.
The most prevalent type of FLT3 mutation is an internal
tandem duplication (ITD) in the juxtamembrane domain4.
The second most common mutation type in the FLT3 gene is atyrosine kinase domain (TKD) point mutation in the codon for
an aspartate (D835) or an isoleucine (I836) residue.
TKD mutations result in constitutive autophosphorylation andactivation of FLT3 5-6 and have also been linked to poor overall
survival, but to a lesser extent as compared to ITD mutations7.
To determine the best treatment options, it is recommended
that patients with AML be screened for the presence of
FLT3 mutations.

Intended Use
The LeukoStrat® CDx FLT3 Mutation Assay is a PCR-based,in vitro diagnostic test designed to detect internal tandem
duplication (ITD) mutations and the tyrosine kinase domain(TKD) mutations D835 and I836 in genomic DNA extracted
from mononuclear cells obtained from peripheral blood orbone marrow aspirates of patients diagnosed with acute
myelogenous leukemia.
The LeukoStrat® CDx FLT3 Mutation Assay is used as an aid in
the assessment of acute myeloid leukemia patients for whom
midostaurin (RYDAPT®) treatment is being considered.
The LeukoStrat® CDx FLT3 Mutation Assay is to be performed
only at Laboratory for Personalized Molecular Medicine(LabPMM) LLC.

Descriptionof Testing

TurnaroundTime

Specimen
Requirements

Shipping
Conditions

Storage
Conditions

Primers flanking exons 14, 15 and the activation
loop region of exon 20 of the FLT3 gene are used toamplify DNA extracted from a patient sample. The
forward and reverse PCR primers are fluorescently
labeled with different fluorophores that serve toconfirm the presence of sample signal.

2-3 business days

• 5 mL ofperipheral bloodin Heparin• Cool; Do
not freeze• 4 °C up to7 days

• 3 mL of bonemarrow inHeparin

The size of the ITD PCR product is determined bycapillary electrophoresis and the signal ratio (SR)compares the signal intensity of the mutant to thewild-type.
The FLT3 TKD PCR product is digested with EcoRVand the presence of the mutation is further assessedusing capillary electrophoresis and the signal ratio(SR) compares the signal intensity of the mutant tothe wild-type.

Test Code
FLT3-CDx

CPT Code81245, 81246* FLT3 ITD testing is covered by United States and other jurisdiction patents licensed exclusively to Invivoscribe by Takara Bio, Inc.

6330 Nancy Ridge Drive, Ste. 106 | San Diego, CA 92121, USA
www.invivoscribe.com | +1.858.224.6650

References
1. Acute Myeloid Leukemia, Clinical Practice Guidelines in Oncology, (v.2.2014) National Comprehensive Cancer Network.
2. Lowenberg, B. et al. (1999) “Acute myeloid leukemia.” N Engl J Med 341(14):1051-62.
3. Thiede, C. et al. (2002) “Analysis of FLT3-activating mutations in 979 patients with acute myelogenous leukemia: association with FAB and identification of subgroups withpoor prognosis.” Blood 99(12): 4326-35.
4. Nakao, M. et al. (1996) “Internal tandem duplication of the FLT3 gene found in acute myeloid leukemia.” Leukemia 10(12):1911-18.
5. Yamamoto, Y, Kiyoi H, Nakano Y, Suzuki R, Kodera Y, Miyawaki S, Asou N, Kuriyama K, Yagasaki F, Shimazaki C, Akiyama H, Saito K, Nishimura M, Motoji T, Shinagawa K,Takeshita A, Saito H, Ueda R, Ohno R, Naoe T. Activating mutation of D835 within the activation loop of FLT3 in human hematologic malignancies. Blood, 2001, 97(8):2434-9.
6. Gilliland, D.G. and Griffin, JD. (2002) The roles of FLT3 in hematopoiesis and leukemia. Blood 100(5):1532-154.
7. Yanada M, et al. (2005) Prognostic significance of FLT3 internal tandem duplication and tyrosine kinase domain mutations for acute myeloid leukemia: a meta-analysis.
Leukemia 19 (8): 1345-1349.Leukemia 19 (8): 1345-1349.

6330 Nancy Ridge Drive, Ste. 106 | San Diego, CA 92121, USA
www.invivoscribe.com | +1.858.224.6650