Protective autophagy elicited by RAF→MEK→ERK inhibition suggests a treatment strategy for RAS-driven cancers.

Pancreatic ductal adenocarcinoma (PDA) was responsible for ~ 44,000 deaths in the United States in 2018 and is the epitome of a recalcitrant cancer driven by a pharmacologically intractable oncoprotein, KRAS1-4. Downstream of KRAS, the RAF→MEK→ERK signaling pathway plays a central role in pancreatic carcinogenesis5. However, paradoxically, inhibition of this pathway has provided no clinical benefit to patients with PDA6. Here we show that inhibition of KRAS→RAF→MEK→ERK signaling elicits autophagy, a process of cellular recycling that protects PDA cells from the cytotoxic effects of KRAS pathway inhibition. Mechanistically, inhibition of MEK1/2 leads to activation of the LKB1→AMPK→ULK1 signaling axis, a key regulator of autophagy. Furthermore, combined inhibition of MEK1/2 plus autophagy displays synergistic anti-proliferative effects against PDA cell lines in vitro and promotes regression of xenografted patient-derived PDA tumors in mice. The observed effect of combination trametinib plus chloroquine was not restricted to PDA as other tumors, including patient-derived xenografts (PDX) of NRAS-mutated melanoma and BRAF-mutated colorectal cancer displayed similar responses. Finally, treatment of a patient with PDA with the combination of trametinib plus hydroxychloroquine resulted in a partial, but nonetheless striking disease response. These data suggest that this combination therapy may represent a novel strategy to target RAS-driven cancers.

Publisher Correction: Protective autophagy elicited by RAF→MEK→ERK inhibition suggests a treatment strategy for RAS-driven cancers.

In the version of this article initially published, the label over the bottom schematic in Fig. 1a was "pH > 5.0"; it should have been "pH < 5.0". Further, the original article misspelt the surname of Katrin P. Guillen as "Gullien". These errors have been corrected in the print, PDF and HTML versions of the article.

Ceritinib: A primer for pharmacists.

Clinical pharmacists are important contributors to the care of patients with cancer; it is therefore critical for oncology clinical pharmacists to stay current with new anticancer therapies. This review summarizes the epidemiology and pathogenesis of non-small cell lung cancer, including the most common genetic alterations, as well as the mechanism of action, clinical development, pharmacodynamics and pharmacokinetics of the anaplastic lymphoma kinase inhibitor ceritinib for the treatment of patients with anaplastic lymphoma kinase-positive non-small cell lung cancer. Targeted therapies based on the presence of specific mutations are an important development in the treatment of non-small cell lung cancer. However, acquired resistance to the first anaplastic lymphoma kinase-inhibitor approved by the U.S. Food and Drug Administration, crizotinib, is observed in almost half of patients treated with it. Ceritinib is an oral anaplastic lymphoma kinase-inhibitor that has demonstrated more potent antitumor activity than crizotinib in preclinical models. It was granted accelerated approval in 2014 to treat anaplastic lymphoma kinase-positive metastatic non-small cell lung cancer patients who have progressed on or are intolerant to crizotinib. Ceritinib represents an important alternative second-line therapy for patients with metastatic non-small cell lung cancer who have traditionally limited treatment options.