erlotinib + pilaralisib

The combination of erlotinib and pilaralisib is a dual-targeting therapy that has been investigated in clinical trials. This combination aims to simultaneously inhibit both the epidermal growth factor receptor (EGFR) and phosphoinositide 3-kinase (PI3K) pathways, which are frequently dysregulated in various cancers. Erlotinib is an established EGFR tyrosine kinase inhibitor, while pilaralisib (also known as SAR245408 or XL147) is an oral pan-class I PI3K inhibitor. The rationale behind combining these agents is to potentially overcome resistance mechanisms and enhance antitumor activity by targeting two critical signaling pathways involved in cancer cell growth and survival. A Phase I dose-escalation study evaluated this combination in patients with advanced solid tumors. The maximum tolerated dose (MTD) was determined to be pilaralisib 400 mg plus erlotinib 150 mg. Common treatment-related adverse events included rash (62.9%), diarrhea (42.9%), and fatigue (40.0%). ## Clinical Efficacy and Development Status The clinical efficacy of this combination appears limited. In the Phase I trial, among 27 evaluable patients, only one patient (3.7%) achieved a partial response, while 14 patients (51.9%) had stable disease. Pharmacodynamic analyses indicated moderate inhibition of PI3K, mitogen-activated protein kinase, and EGFR pathways. Interestingly, there was no association found between molecular alterations of PI3K pathway components and clinical activity. The combination has been specifically studied in non-small cell lung cancer (NSCLC) patients who had previously received treatment with an EGFR inhibitor, as part of an MTD expansion cohort. The clinical trial identifier for this study was NCT00692640, sponsored by Sanofi and Exelixis. ## Pharmacokinetics and Drug Interaction The pharmacokinetic findings of pilaralisib in combination with erlotinib were consistent with previous studies of pilaralisib alone, suggesting that erlotinib had no significant effect on pilaralisib pharmacokinetics. ## Similar Combination Approaches It's worth noting that a similar approach has been studied with pictilisib (another PI3K inhibitor) in combination with erlotinib. This combination also showed limited antitumor activity, though it was determined to be feasible with a recommended phase II dose of 340 mg pictilisib on a "5 days on, 2 days off" schedule plus 100 mg erlotinib daily. The limited clinical activity observed with these combinations suggests that additional studies may be needed to identify specific patient populations most likely to benefit from combined EGFR and PI3K inhibition.

Other names

Pilaralisib + erlotinib