Shannon S. Zhang

Thirteen percent of non-small cell lung cancer (NSCLC) patients are estimated to have the KRAS G12C mutation. Sotorasib is a novel KRAS G12C inhibitor that has shown promising results in preclinical and clinical studies, granting its conditional approval by the FDA in May 2021. The phase I clinical trial resulted in a confirmed response of 32% and progression free survival (PFS) of 6.3 months while the phase II trial resulted in a confirmed response of 37.1% and a PFS of 6.8 months. It was also shown to be tolerable with most subjects experiencing grade one or two adverse events, most commonly diarrhea and nausea. The CodeBreaK 200 phase III trial data have recently resulted and showed an improved PFS with the use of sotorasib at 5.6 months compared to that of standard docetaxel of 4.5 months in locally advanced or unresectable metastatic KRAS G12C NSCLC previously treated with at least one platinum-based chemotherapy and checkpoint inhibitor. The lower than expected PFS of sotorasib from the phase III trial opens up opportunities for other G12C inhibitors to join the field. Indeed, adagrasib, another G12C inhibitor just recently gained FDA accelerated approval in NSCLC patients based on the KRYSTAL-1 study where the response rate was 43% with a median duration of response of 8.5 months. With novel agents and combinations, the field of KRAS G12C is quickly evolving. While sotorasib was an exciting start, there is more to do to break the KRAS G12C Enigma code.

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.

Mesenchymal-epithelial transition (MET) receptor tyrosine kinase is overexpressed, amplified, or mutated in 1– 20% of NSCLC. MET dysregulation is associated with a poor prognosis. Recently, development of targeted therapies against MET exon 14 mutations has demonstrated efficacy and tolerability in early trials. Here we focus on tepotinib and capmatinib in regards to molecular characteristics, early preclinical and clinical data, and the emerging role in future studies and clinical practice.

Adjuvant cisplatin-based chemotherapy is considered the standard of care for resected stage IB (tumor ≥ 4m)–IIIA non-small cell lung cancer (NSCLC). The ADAURA trial is a randomized placebo-controlled Phase III trial that demonstrated statistically significant improved disease-free survival (DFS) with the use of 3-years of adjuvant osimertinib in resected stage IB–IIIA NSCLC harboring epidermal growth factor receptor (EGFR) del 19 or L858R mutations. Subgroup analysis revealed that the DFS improvement with adjuvant osimertinib is independent of adjuvant chemotherapy in the primary analysis. A recent follow-up report suggested that adjuvant cisplatin-based chemotherapy provided no additional 2-year DFS improvement on top of adjuvant osimertinib regardless of stage (IB, II, or IIIA) and minimal numerical DFS benefit in stage II or IIIA resected EGFR+ NSCLC for those patients who did not receive adjuvant osimertinib. Here, we argue that if clinicians adopt the use of 3 years of adjuvant osimertinib in resected early-stage EGFR+ NSCLC, there is no role for adjuvant platinum-based chemotherapy. The use of adjuvant chemotherapy was balanced between the osimertinib and the placebo arms by stage even though adjuvant chemotherapy was not one of the three stratification factors (del 19 vs L858R; Stage IA vs II vs III; Asians versus non-Asian) in ADAURA. There may be a potential role of adjuvant cisplatin/vinorelbine in a small subgroup of EGFR+ NSCLC patients whose tumor harbors retinoblastoma (RB) gene alterations but requires further investigation.

Mutations in codon 12 of KRAS have been identified in 13% of non-small cell lung cancer patients. Developing targeted therapies against KRAS^G12C mutation has proven to be challenging due to the abundance of GTP in the cytoplasm, rapid hydrolysis of GTP, and difficulty designing small molecules to achieve sufficient concentration for KRAS inhibition. Based on promising results in both preclinical and clinical trials, sotorasib, a novel KRAS^G12C inhibitor, was given conditional approval by the FDA in May 2021. The Phase I portion of the clinical trial produced 32% confirmed response with 56% of patients with stable disease. About 91.2% of patients who received the highest dose of 960mg daily achieved disease control. The Phase II portion, which used 960mg daily dosing resulted in 37.1% of patients with confirmed response and 80.6% of patients with disease control. Both phase I and phase II had similar progression-free survival, in 6.3 months and 6.8 months, respectively. In both phases, grade 4 adverse events occurred in only one patient. The most common adverse events were elevations in LFTs, which down-trended upon dose reduction and steroid treatment. While the conditional approval of sotorasib was a major breakthrough for those patients harboring KRAS^G12C mutations, resistance mutations to sotorasib are increasingly common. Many proposals have been made to address this, such as the use of combination therapy for synthetic lethality, which are producing encouraging results. Here, we explore in further detail the development of sotorasib, its efficacy, mechanism of resistance, and strategies to overcome these resistances.

Myeloid sarcoma is a rare variant of acute myeloid leukemia (AML) which presents as an extramedullary soft tissue mass. Due to the rarity of this disease, along with nonspecific presenting symptoms, diagnosis can be delayed or missed without a high index of suspicion. In this case, we discuss a patient diagnosed with AML relapse in the form of myeloid sarcoma two years after allogeneic hematopoietic stem cell transplant (alloHSCT) for myelodysplastic syndrome (MDS) with the initial presentation for back pain misdiagnosed as spinal stenosis. This case report aims to help healthcare providers in recognizing the early signs and symptoms of this disorder as well as provide information in regards to treatment options and risk assessment.

Checkpoint inhibitors have demonstrated efficacy in patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC). However, the majority of patients do not benefit from these agents. To improve the efficacy of checkpoint inhibitors, intratumoral (i.t.) injection with innate immune activators, TLR7 and TLR9 agonists, were tested along with programmed death-1 receptor (PD-1) blockade. The combination therapy suppressed tumor growth at the primary injected and distant sites in human papillomavirus–negative (HPV-negative) SCC7 and MOC1, and HPV-positive MEER syngeneic mouse models. Abscopal effects and suppression of secondary challenged tumor suggest that local treatment with TLR agonists in combination with anti–PD-1 provided systemic adaptive immunity. I.t. treatment with a TLR7 agonist increased the ratio of M1 to M2 tumor-associated macrophages (TAMs) and promoted the infiltration of tumor-specific IFNγ-producing CD8 ⁺ T cells. Anti–PD-1 treatment increased T cell receptor (TCR) clonality of CD8 ⁺ T cells in tumors and spleens of treated mice. Collectively, these experiments demonstrate that combination therapy with i.t. delivery of TLR agonists and PD-1 blockade activates TAMs and induces tumor-specific adaptive immune responses, leading to suppression of primary tumor growth and prevention of metastasis in HNSCC models.