Successful Salvage Therapy With a High Dose of Furmonertinib in a Case of Lung Adenocarcinoma Harboring EGFR Exon 20 Insertion

Recent advances in targeting the "undruggable" proteins: from drug discovery to clinical trials

Undruggable proteins are a class of proteins that are often characterized by large, complex structures or functions that are difficult to interfere with using conventional drug design strategies. Targeting such undruggable targets has been considered also a great opportunity for treatment of human diseases and has attracted substantial efforts in the field of medicine. Therefore, in this review, we focus on the recent development of drug discovery targeting "undruggable" proteins and their application in clinic. To make this review well organized, we discuss the design strategies targeting the undruggable proteins, including covalent regulation, allosteric inhibition, protein-protein/DNA interaction inhibition, targeted proteins regulation, nucleic acid-based approach, immunotherapy and others.

A real-world study of the efficacy and safety of furmonertinib for patients with non-small cell lung cancer with EGFR exon 20 insertion mutations

BACKGROUND

Furmonertinib is a novel third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI). A phase Ib study (FAVOUR, NCT04858958) initially demonstrated the efficacy of furmonertinib in non-small cell lung cancer (NSCLC) with EGFR exon 20 insertion (ex20ins). This study aimed to investigate the real-world efficacy and safety of furmonertinib in patients with advanced NSCLC with EGFR ex20ins.

METHODS

We retrospectively examined patients with advanced NSCLC with EGFR ex20ins having complete follow-up data, who were treated with furmonertinib from April 14, 2021, to March 15, 2022, at our institution and multiple hospitals in China. Objective response rate (ORR), disease control rate (DCR), 6-month progression-free survival (PFS) rates and treatment related adverse events (TRAEs) were assessed.

RESULTS

This study included 53 patients with advanced NSCLC with EGFR ex20ins. A767_V769dup (28.3%) and S768_D770dup (11.3%) are the major variants. The ORR and DCR were 37.7% (20/53) and 92.5% (49/53), respectively. The 6-month PFS rate was 69.4% (95% CI 53.7-85.1%). The ORR of patients in the 240 mg once-daily dosage group was higher (42.9%) than that of patients in the 80 mg once-daily (25.0%) and 160 mg once-daily (39.5%) groups, but with no statistically significant difference (P = 0.816). The ORR of furmonertinib is not dependent on insertion location (P = 0.893). Patients with central nervous system (CNS) metastases at baseline responded similarly to those without CNS metastases (ORR: 33.3% vs. 40.6%, P = 0.773). The most common AEs were diarrhea (26.4%) and rash (26.4%). No grade ≥ 3 TRAEs were observed. No statistically significant difference was observed in the incidence of TRAEs between dosage groups (P = 0.271).

CONCLUSIONS

Furmonertinib has shown encouraging antitumor activity and CNS activity in patients with advanced NSCLC with EGFR ex20ins. Moreover, furmonertinib had a good safety profile and no dose-dependent toxicity.

Persistent response of furmonertinib plus anlotinib in a lung adenocarcinoma patient with an EGFR exon 20 insertion mutation: A case report

Insertions in exon 20 represent the third most common type of EGFR mutation following in-frame deletions in exon 19 and the point mutation L858R in exon 21. They are generally associated with primary resistance to EGFR-TKIs. Although mobocertinib and amivantamab were approved for adult patients with non-small cell lung cancer (NSCLC) harboring EGFR exon 20 insertion mutations, the efficacy of these two agents was rather moderate. Therefore, other more potent targeted agents are urgently needed. Here, we report a patient with advanced lung adenocarcinoma harboring an EGFR exon 20 insertion mutation (NM_005228: exon 20: c.2316_2321dup: p.773_774dup). After experiencing platinum-based chemotherapy, this patient received a combination of furmonertinib and anlotinib and achieved lasting stable disease (SD). The treatment was well tolerated, and only mild hand-foot syndrome was reported from the patient. To the best of our knowledge, this case firstly reported the encouraging efficacy of combined furmonertinib and anlotinib in an advanced lung adenocarcinoma patient with an EGFR exon 20 insertion mutation who was previously treated with platinum-based chemotherapy. In addition, we summarize the recent literature on therapies against NSCLC with EGFR exon 20 insertion mutations. This case might provide an alternative approach for clinical oncologists.

"Sandwich" Strategy to Intensify EGFR Blockade by Concurrent Tyrosine Kinase Inhibitor and Monoclonal Antibody Treatment in Highly Selected Patients

EGFR TKIs are not curative, and targeted resistance inevitably results in therapeutic failure. Additionally, there are numerous uncommon EGFR mutations that are insensitive to EGFR TKIs, and there is a lack of clinical strategies to overcome these limitations. EGFR TKI and mAbs target EGFR at different sites, and a combination regimen for delaying/preventing resistance to targeted therapy or obtaining more intensive inhibition for uncommon mutations at cellular, animal and human levels has been explored. This review critically focuses on a combination strategy for uncommon EGFR mutation-positive NSCLC, and discuss the preclinical data, clinical implications, limitations and future prospects of the combination strategy.