CAPIVASERTIB

Potency assay (off target): AZD5363 was assayed against a larger enzyme panel of 75 kinases, of which 35 were also AGC family kinases. Significant activity, defined as >75% inhibition at a fixed concentration of 1 μM, was seen for just 15 kinases, of which 14 were from the AGC family. In addition to Akt1–3, these were ROCK2, MKK1, MSK1, MSK2, PKCγ, PKGα, PKGβ, PRKX, RSK2, RSK3, P70S6K, and PKA. Only P70S6K and PKA, were inhibited with enzyme IC50 values comparable to Akt1–3 inhibition, at 6 and 7 nM. Rock2 IC50 56 nM in biochemical assay.

Potency assay, off target (cells): The cellular IC50 against P70S6K was approximately 5 μM, as measured by inhibition of S6 phosphorylation in TSC1 null RT4 bladder cancer cells, while activity against PKA was around 1 μM, as determined by inhibition of VASP phosphorylation in A431 cells. Activity against related ROCK1 isoform was much reduced relative to ROCK2, with an IC50 of 470 nM. The growth inhibitory effect of AZD5363 was also examined across a cellular panel of 182 tumor cell lines in standard proliferation assay format. Sensitive cell lines were defined as those inhibited with an IC50 of 3 μM or less. A majority of breast cell lines proved to be sensitive (64%), with gastric, endometrial, prostate, and hematologic lines showing intermediate sensitivity (24−33% responsive). Lines that showed a poor response to 64 were derived from lung (12% sensitive), colorectal (7%), and bladder (0%) cells. Kinobeads assessment (chemical proteomic) has been performed for AZD5363 (DOI:10.1126/science.aan4368). According to this publication, AZD5363 is not selective in cells.