dactolisib dactolisib dactolisib (codenamed nvp-bez235 and bez-235, also known as rtb101) is an imidazoquinoline derivative acting as a pi3k inhibitor. it also inhibits mtor. it is being investigated as a possible cancer treatment. dactolisib names preferred iupac name 2-methyl-2-propanenitrile other names nvp-bez235; bez-235; rtb101 identifiers cas number 915019-65-7 y 3d model (jsmol) interactive image chembl chembl1879463 n chemspider 10151099 y iuphar/bps 7950 kegg d10552 pubchem cid 11977753 unii ruj6z9y0dt y comptox dashboard (epa) dtxsid10238599 inchi inchi=1s/c30h23n5o/c1-30(2,18-31)22-9-11-23(12-10-22)35-28-24-15-19(21-14-20-6-4-5-7-25(20)32-16-21)8-13-26(24)33-17-27(28)34(3)29(35)36/h4-17h,1-3h3 ykey: jogkukxhtywrgz-uhfffaoysa-n y smiles n#cc(c6ccc(n5c4c(cnc3ccc(c1cc2ccccc2nc1)cc34)n(c5=o)c)cc6)(c)c properties chemical formula c30h23n5o molar mass 469.548 g·mol−1 except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). n verify (what is yn ?) infobox references it has been shown to be toxic to waldenström's macroglobulinemia cells. it was the first pi3k inhibitor to enter clinical trials, in 2006. a phase ib/ii clinical trial for locally advanced or metastatic her2 negative breast cancer has completed. a phase ii clinical trial for advanced pancreatic neuroendocrine tumors (pnet) had initially reported results, but was later terminated because insufficient normal tissue tolerance to the drug. a phase i clinical trial of bez235 in patients with advanced renal cell carcinoma had to be terminated prematurely due to toxicity and a lack of clinical efficacy . another phase ib study on patients with various solid cancers found severe normal tissue toxicity as well when bez235/dactolisib was administered in combination with the mtor inhibitor everolimus. the authors concluded that the combination of both drugs demonstrated limited efficacy and tolerance. bez235 systemic exposure increased in a dose-proportional manner while oral bioavailability was quite low, which may be related to gastrointestinal-specific toxicity . a phase i study of bez-235 to treat acute lymphoid leukaemia was initiated in 2012, but no results were published since then. a phase 2a randomized, placebo-controlled clinical trial published in 2018 showed that everolimus in combination with dactolisib decreased the rate of reported infections in an elderly population.