pilaralisib (SAR245408)

Aims To characterize functional responses to 10 PI3Ki in CLL To study PI3Ki drug class activity in idelalisib-refractory CLL To investigate whether ex vivo drug sensitivity can predict in vivo treatment responses Methods CLL cells from patients that were treatment naïve (n=7), idelalisib refractory (n=9), or on idelalisib treatment (longitudinal samples from n=6 patients) were screened against 10 PI3Ki (buparlisib, compound 7n, copanlisib, duvelisib, idelalisib, nemiralisib, pictilisib, pilaralisib, umbralisib, ZSTK474), both alone and in combination with the B-cell lymphoma 2 (Bcl-2) antagonist venetoclax...Ex vivo drug testing on CLL cells from a patient who presented with relapsed disease after sequential treatment with FCR, ibrutinib, idelalisib and venetoclax revealed sensitivity to PI3Ki+venetoclax treatment...Conclusion Our findings indicate PI3Ki drug class activity in idelalisib-refractory CLL, and suggest that ex vivo drug sensitivity may guide precision medicine and predict treatment responses. These results warrant further testing in larger cohorts and in clinical trials.