Abstract
The receptor tyrosine kinase
(RTK), Rearranged during Transfection (RET), is an oncogenic driver activated
in multiple cancers including non-small cell lung cancer (NSCLC), medullary
thyroid carcinoma (MTC) and papillary thyroid cancer (PTC)
1. Currently there are no approved therapies
designed to selectively target RET.
Instead, current treatment employ kinase inhibitors primarily targeting
other RTKs such as cabozantinib and vandetanib, however these inhibitors also
target VEGFR-2/KDR, leading to dose-limiting toxicity.
We have identified selective RET
inhibitors using a defined biochemical and cellular cascade
2 which
includes assays to measure for activity against the predicted drug-acquired resistance mutation in the
gatekeeper region of the ATP binding domain such as RET
V804M. However, there are no disease relevant
cell line/xenograft models to allow validation of these inhibitors. This poster describes the use of CRIPSR
knock-in technology to generate a disease-relevant cell line model and testing
of our inhibitors.
With the advances in cellular target engagement
assays afforded by NanoBRET
3, direct compound target engagement
measurement in cells can be routinely performed and used to compare biochemical
and cellular potency correlations and drive compound optimization. This poster will also describe the
establishment of a NanoBRET Target Engagement In-cell Kinase RET cellular assay
and its use in compound profiling.
References
1. Mulligan, L. RET
revisited: Expanding the oncogenic portfolio. Nature Reviews Cancer (2014) 14:173.
2. Watson,
A., et al. Identification of selective
inhibitors of RET and comparison with current clinical candidates through
development and validation of a robust screening cascade. F1000Research (2016) 5:1005.
3. Robers,
M., et al. Target engagement and drug
residence time can be observed in living cells with BRET Nat Commun (2015) 6:10091
