And Still They Come Over Troubled Waters: Can Asia's Third-Generation EGFR Tyrosine Kinase Inhibitors (Furmonertinib, Aumolertinib, Rezivertinib, Limertinib, Befotertinib, SH-1028, and Lazertinib) Affect Global Treatment of EGFR+ NSCLC

Synthetic Approaches to the New Drugs Approved during 2023

This review is the next installment of an annual series that discusses the synthetic routes to access 28 small molecule drugs that were approved worldwide in 2023. A brief description of each drug's mechanism of action, the history of its discovery and development, and the synthetic approaches published in primary or patent literature that were most likely used for clinical studies or development are included. Synthetic chemistry, used to convert complex intermediates to active compounds or build a new drug from basic building block chemicals, is critical to delivery of new drugs and treatments for disease to patients.

Updated overall survival and ctDNA analysis in patients with EGFR T790M-positive advanced non-small cell lung cancer treated with lazertinib in the phase 1/2 LASER201 study

BACKGROUND

Lazertinib is a potent, irreversible, third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) with significant efficacy in patients with EGFR T790M-mutated non-small cell lung cancer (NSCLC). This is the final overall survival (OS) report from the phase 1/2 LASER201 study in patients with advanced NSCLC with disease progression on or after prior EGFR TKI therapy.

METHODS

Eligible patients were aged ≥ 20 years, with advanced EGFR-mutated NSCLC and previous therapy with EGFR TKI. Patients in this integrated analysis received oral lazertinib 240 mg/day. Endpoints included efficacy and safety; exploratory analyses included associations between circulating EGFR-mutant tumor DNA (ctDNA) and efficacy parameters.

RESULTS

This integrated analysis included 78 patients in Korea who received second- or later-line lazertinib. The median OS was 38.9 months; estimated survival rates at 12, 24, and 36 months were 89.5%, 73.9%, and 52.8%, respectively. The cumulative 12-month incidence of central nervous system progression was 9.4%. EGFR-mutant ctDNA was detected in 46 patients (62.2%) at baseline. The presence of ctDNA at baseline significantly predicted progression-free survival (PFS), disease control rate (DCR), and OS. PFS, response rate, and DCR were significantly associated with EGFR-mutant ctDNA clearance at cycle 3; PFS and OS were significantly associated with ctDNA clearance at cycle 5. The safety profile of lazertinib 240 mg/day was consistent with previous findings.

CONCLUSIONS

Lazertinib is a promising treatment option for patients with EGFR T790M-positive NSCLC following disease progression on prior EGFR-directed TKIs. Patients in LASER201 experienced prolonged OS, regardless of their EGFR mutation, brain metastases, or prior brain radiation status. Clearance of plasma EGFR mutations after lazertinib was associated with patient outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT03046992.

ATTLAS, IMpower151 and ORIENT-31: Dusting off IMpower150 for Post-Osimertinib in EGFR-Mutated NSCLC?

Treatment strategies for post-epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) therapy in EGFR-mutant non-small cell lung cancer (NSCLC) is an ongoing challenge. Previously, the IMPRESS trial comparing platinum doublet chemotherapy with or without EGFR-TKI did not demonstrate any progression-free survival (PFS) benefit. The retrospective subgroup analysis of IMpower150 indicated that the quad regimen (carboplatin, paclitaxel, bevacizumab, atezolizumab) improved PFS and overall survival (OS) in patients with EGFR-mutant NSCLC who progressed on first-generation EGFR-TKIs. Given the retrospective nature of the analysis, the IMpower150 regimen is not approved in the US for post-EGFR-TKI treatment. Currently, osimertinib or other third-generation (3G) EGFR-TKIs is the first-line standard of care for advanced EGFR-mutant NSCLC. MARIPOSA-2 provided the first randomized trial post-osimertinib in EGFR-mutant NSCLC patients with another quad regimen (platinum, pemetrexed, lazertinib, amivantamab). The IMpower150 and MARIPOSA-2 quad regimens differ in the principle of whether to continue or even "double-down" on EGFR inhibition. Recently, three prospective randomized trials conducted in Asia offered promising results, showing that a quad regimen of doublet platinum chemotherapy plus anti-angiogenesis agent and ICI may be as efficacious as MARIPOSA-2 with a lower rate of toxicities and accounting for the PFS difference if 1L chemotherapy plus osimertinib instead of osimertinib monotherapy. In particular, the median PFS achieved by the quad regimens of ATTLAS and IMpower151 is 8.5 months. However, only 8.2% and 17.9% of the EGFR-mutant NSCLC patients who received the quad regimens progressed on 3G EGFR-TKI, respectively. Here, we discuss how the results of IMpower151 and ATTLAS may rejuvenate interest in a non-EGFR containing quad regimen as a potential post-osimertinib monotherapy treatment. Randomized trials comparing the results of these studies, including the quad regimen of MARIPOSA-2 versus the quad regimen of IMpower151/Impower150/ATTLAS in post-osimertinib (or other 3G EGFR-TKI) progression, are urgently needed.

MARIPOSA-2: Is the treatment worse than the disease?

Passaro et al.1 demonstrated in EGFR+ NSCLC post-1L osimertinib both "quad" (lazertinib [L] + amivantamab [A] + chemotherapy [CP]) and "triplet" (ACP) regimens achieved improved median progression-free survival over CP. Nonetheless, a high incidence of adverse events requiring dose modifications may limit adaptation of the triplet and quad MARIPOSA-2 regimens.

Befotertinib: First Approval

Befotertinib (Surmana®) is an orally administered, highly selective, third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) being developed by Betta Pharmaceuticals and InventisBio for the treatment of non-small cell lung cancer (NSCLC). In May 2023, befotertinib was approved in China for the second-line treatment of patients with locally advanced or metastatic NSCLC who have received EGFR TKI therapy and have disease progression with positive EGFR T790M mutation. Befotertinib is under regulatory review for the first-line treatment of NSCLC in China. Clinical studies assessing befotertinib as an adjuvant therapy after surgery for early EGFR-mutant NSCLC (phase III) and in combination with icotinib for advanced or metastatic EGFR-mutant NSCLC (phase II) are currently underway in China. This article summarizes the milestones in the development of befotertinib leading to this first approval for the second-line treatment of EGFR T790M-mutated locally advanced or metastatic NSCLC.

Small molecule protein kinase inhibitors approved by regulatory agencies outside of the United States

Owing to genetic alterations and overexpression, the dysregulation of protein kinases plays a significant role in the pathogenesis of many autoimmune and neoplastic disorders and protein kinase antagonists have become an important drug target. Although the efficacy of imatinib in the treatment of chronic myelogenous leukemia in the United States in 2001 was the main driver of protein kinase inhibitor drug discovery, this was preceded by the approval of fasudil (a ROCK antagonist) in Japan in 1995 for the treatment of cerebral vasospasm. There are 21 small molecule protein kinase inhibitors that are approved in China, Japan, Europe, and South Korea that are not approved in the United Sates and 75 FDA-approved inhibitors in the United States. Of the 21 agents, eleven target receptor protein-tyrosine kinases, eight inhibit nonreceptor protein-tyrosine kinases, and two block protein-serine/threonine kinases. All 21 drugs are orally bioavailable or topically effective. Of the non-FDA approved drugs, sixteen are prescribed for the treatment of neoplastic diseases, three are directed toward inflammatory disorders, one is used for glaucoma, and fasudil is used in the management of vasospasm. The leading targets of kinase inhibitors approved by both international regulatory agencies and by the FDA are members of the EGFR family, the VEGFR family, and the JAK family. One-third of the 21 internationally approved drugs are not compliant with Lipinski's rule of five for orally bioavailable drugs. The rule of five relies on four parameters including molecular weight, number of hydrogen bond donors and acceptors, and the Log of the partition coefficient.

The Additional Exclusions of ROS1 Fusions (In Addition to EGFR Mutation and ALK Fusions) in the Cemiplimab NSCLC FDA Indication (EMPOWER-Lung 1 and -Lung 3). Catching Up with Current Scientific View of Immunotherapy in Never-Smoker Predominant Actionable Driver Mutation Positive NSCLC?

Cemiplimab is one of seven immune checkpoint inhibitors (ICIs) approved for the first-line (1L) treatment of advanced NSCLC in the US based on EMPOWER-Lung 1 and -Lung 3 trials. In addition to exclusion of NSCLC patients harboring EGFR mutations and ALK fusion from 1L treatment with ICIs, exclusion of ROS1 fusion is an additional unique exclusion the use of criterion for cemiplimab in the US FDA indication based on the design of the EMPOWER lung trials. We review the effectiveness of ICIs in never-smoker predominant NSCLC with driver mutations (EGFR, ALK, ROS1, RET, HER2) and question whether exclusion of ROS1 fusion would put cemiplimab at a competitive disadvantage given the requirement for insurance to prove ROS1 fusion negativity. We further discuss whether the US FDA as a regulatory authority has the right and responsibility to harmonize the use of ICIs in these actionable driver mutations to standardize community practice for the benefit of patients and to advance the development of next-generation treatment for these driver mutations.

CodeBreaK 200: Sotorasib (AMG510) Has Broken the KRAS G12C+ NSCLC Enigma Code

Per the US FDA sotorasib approval summary, KRAS G12C mutation is found in approximately 14% of adenocarcinoma of the lung, primarily in patients with a history of smoking. Until recently, targeted therapies against KRAS G12C have been largely unsuccessful due to the small protein size of KRAS and thus lack of binding pockets in KRAS and rapid hydrolysis of GTP to GDP by KRAS enzymes from abundance of GTP in the cytoplasm. Sotorasib, a first-in-class covalent KRAS G12C inhibitor that binds to the switch pocket II in the KRAS G12C-GDP "off" state, received US FDA accelerated approval on May 21, 2021 in the US, based on a Phase II dose expansion cohort of CodeBreaK 100 trial. Sotorasib at 960 mg once daily achieved an ORR of 36% (95% CI: 28%, 45%), with a median response duration of 10 months (range 1.3+, 11.1) in 124 KRAS G12C+ NSCLC. At the European Society of Medical Oncology (ESMO) 2022 annual meeting, sotorasib achieved a statistically significant improved PFS over docetaxel (HR = 0.66; 95% CI: 0. 51-0.86; P = 0.002). The modest magnitude of PFS improvement of 1.1 months (from 4.5 months to 5.6 months) and the ORR of 28% led to a vigorous debate on whether sotorasib was indeed a true breakthrough. In this pros and cons debate, we argue thatsotorasib has achieved a true breakthrough.

Spotlight on Furmonertinib (Alflutinib, AST2818). The Swiss Army Knife (del19, L858R, T790M, Exon 20 Insertions, "uncommon-G719X, S768I, L861Q") Among the Third-Generation EGFR TKIs?

Osimertinib, a third-generation (3G) epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) is now considered the standard of care for the first-line (1L) treatment of advanced EGFR+ NSCLC due to statistically significant improved progression-free survival (PFS) and overall survival (OS) compared with first-generation (1G) treatment from the FLAURA trial. Recently two other 3G EGFR TKIs (aumolertinib and furmonertinib) have been approved in China for treatment of EGFR T790M+ NSCLC. Randomized Phase 3 trials of these two 3G EGFR TKIs have also demonstrated PFS over gefitinib respectively. Among these two Chinese home-grown, 3G EGFR TKIs, furmonertinib seems to most closely resemble osimertinib in terms of dosing regimen, efficacy and adverse events profile. In this article, we reviewed the clinical activity and adverse events of furmonertinib at 80 mg daily (approved dose), potential usage of 160 mg daily for CNS metastasis in EGFR+ NSCLC, and usage of 160 mg or 240 mg daily in EGFR exon20 insertion positive (EGFRex20ins+) NSCLC patients.