An investigator-initiated monocentric phase I dose escalation trial of temsirolimus and irinotecan (TEMIR) in patients with relapsing glioblastoma multiforme (reGBM).

2086 Background: Deregulation of the PI3K/AKT pathway has been preclinically involved in the pathophysiology of GBM. The mammalian target of rapamycin (mTOR) is an important downstream mediator of PI3K/AKT signalling. The mTOR-inhibitor temsirolimus (Tem) achieves significant drug levels in brain. Thus, Tem may be effectively combined with irinotecan (Iri) which has shown promising results in combination with bevacizumab in patients (pts) with reGBM refractory to temozolomide (Tmz) in phase II. Exposure to Tem as well as Iri is substantially reduced in pts receiving CYP3A4 enzyme-inducing anticonvulsants (CYP3A4-Ind). Methods: TEMIR is a phase I trial of escalating doses of Tem in combination with Iri in pts with reGBM refractory to Tmz depending on the cotreatment with CYP3A4-Ind. In pts without CYP3A4-Ind dose escalation of Tem was performed according to the “3+3 protocol” from 15 via 20 to 25 mg iv wkly together with 85 mg/m2 Iri iv wkly. In pts with CYP3A4-Ind the doses of Tem were 30, 40 and 50 mg iv...