The impact of TP53 co-mutations and immunologic microenvironment on outcome of lung cancer with EGFR exon 20 insertions

External quality assessment for EGFR exon 20 mutation testing in patients with non-small cell lung cancer in Spain

INTRODUCTION AND AIM

Non-small cell lung cancer (NSCLC) can arise from insertions in exon 20 of the EGFR gene, among other alterations. We carried out an external quality assessment (EQA) to evaluate the accuracy of laboratory methods and to highlight the importance of detecting and identifying genetic alterations, such as EGFR exon 20 insertion, in patients with NSCLC.

MATERIALS AND METHODS

The 2021 EGRF exon 20 EQA program consisted of two rounds, in which four formalin-fixed paraffin-embedded specimens (round 1: two positive for EGFR exon 20 insertions/duplications, one positive for a common EGFR alteration, and one wild-type; round 2: three positive for EGFR exon 20 insertions/duplications and one wild-type) obtained from patients with NSCLC were tested.

RESULTS

Approximately 80% of the invited laboratories participated in each round. The most common DNA isolation techniques used were the cobas® DNA Sample Preparation Kit (46.7%) in round 1 and QIAamp (37.1%) in round 2. The most frequently used genotyping method in both rounds was the cobas® EGFR Mutation Test (round 1: 53.3%; round 2: 37.1%). In both rounds, 71.1% and 73.6% of the tests, respectively, reported the expected result. The lowest success rate was observed in the H773delinsRY Exon 20 determination (round 1: 17.8%; round 2: 31.4%). This alteration was correctly determined only by next-generation sequencing.

CONCLUSIONS

The variability in the genotyping methods and the success rate obtained in our study highlight the importance of EQA in Spain to ensure high performance.

Prognostic and predictive effects of TP53 co-mutation in patients with non-small cell lung cancer with rare treatable driver mutations

BACKGROUND

TP53 mutations (TP53-MUT) are common in NSCLC and have been reported as predictive of response and prognostic of poor outcome in EGFR-mutant NSCLC. The impact of TP53-MUT in NSCLCs with rarer driver mutations and approved targeted treatments is unclear.

METHODS

Records of 436 patients were reviewed and associations between TP53 status, demographics, and outcomes (overall response [ORR], survival [OS] and progression-free survival [PFS], and incidence of brain metastases [BM]), were investigated.

RESULTS

TP53-MUTs were found in 184/436 (42.4 %) with a significant demographic difference noted in stage distribution (p = 0.044). Median (m)OS was significantly shorter in TP53-MUT at 23.3 m (95 %CI 19.6-30.7) v 66.4 m (CI 55.0-not reached [NR]) (stage adjusted harzard ratio [aHR] 2.62, CI 1.98-3.46, p < 0.001). mRFS in early stage trended towards worse outcomes in TP53-MUT (p = 0.142). mPFS on first line treatment was shorter in TP53-MUT 5.0 m (CI 3.4-7.6) v 10.0 m (CI 6.1-13.5) (aHR 1.64, CI 1.23-2.19, p < 0.001). ORR to first instance of targeted treatment was 62 % v 70 % (TP53-MUT v WT) with more progressive disease as best response 24 % v 11 % (p = 0.0177). TP53-MT had a non-significant trend towards more BM at any point (46 % v 34 % p = 0.063) and a higher cumulative incidence of BM in stage I-III patients (Gray's test p < 0.001). When comparing disruptive versus non-disruptive TP53 mutations, there were no significant differences in demographics or survival outcomes.

CONCLUSIONS

Co-occurring TP53 variants with rare driver mutations are predictive of a poor response to targeted treatments and associated with shorter OS and PFS in NSCLC.

Effects of Tp53 Gene Mutations on the Survival of Non-Small Cell Lung Cancer (NSCLC); A Short Review

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related deaths worldwide. Mutations within the TP53 gene represent critical molecular events in NSCLC, contributing to the tumorigenesis in the pulmonary epithelial tissues. TP53 is a widely researched prognostic indicator in NSCLC, and pathological investigations have revealed a weak to mild negative predictive effect for TP53. Mutated p53 protein may have some pro-oncogenic impact, and the variations may change tumor inhibitors into oncogenes. The diverse mutational spectrum of TP53 in NSCLC with different mutations is linked to varied treatment responses. In contrast, first-line chemotherapeutics to this progress are limited, however, randomized trials with new chemotherapeutics have shown significant survival benefits. This review highlighted the critical influence of TP53 gene mutations on pathological-sensitivity and overall survival outcomes in NSCLC. Further research is needed to explore TP53 mutation-specific pathways and their effects on NSCLC progression and treatment effectiveness.

The combination of immune checkpoint inhibitor and chemotherapy may be efficacious for advanced non-small cell lung cancer with near-loop insertions of EGFR exon 20: A retrospective analysis

ObjectiveThe sensitivity of immune checkpoint inhibitors (ICIs) as monotherapy is low in non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) exon 20 insertion mutations (ex20ins). This study aims at investigating the effectiveness of the combination of ICI and chemotherapy (ICI-combined regimen) in a real-world population of NSCLC patients harboring near-loop insertions of EGFR exon 20.MethodsWe conducted a retrospective study of advanced NSCLC with EGFR ex20ins from April 2016 to March 2021 at Guangdong Provincial People's Hospital, Southern Medical University, China. A total of 126 cases of EGFR ex20ins were screened from 1610 patients with advanced NSCLC harboring EGFR mutations and 62 cases were further analyzed for different therapeutic efficacy.ResultsThe first-line ICI-combined regimen showed marked efficacy for near-loop insertions of EGFR exon 20, with an ORR of 71.4% and a mPFS of 11.5 months, compared to ORRs of 12.5% for traditional targeted therapy (P = .003) and 18.8% for chemotherapy (P = .013). The first-line mPFS of traditional EGFR-TKIs and chemotherapy were only 5.6 and 5.8 months, respectively. Similar results were observed for any-line therapy of ICI-combined regimen, with an ORR of 80%. The median progression-free survival (PFS) of any-line therapy of ICI-combined regimen was 11.5 months, which were significantly longer than that of traditional targeted therapy (4.5 months, P = .026) and chemotherapy (5.0 months, P = .013).ConclusionsICI-combined regimen may be superior compared to targeted therapy and chemotherapy for advanced NSCLC with near-loop insertions of EGFR exon 20. Further exploration is warranted to confirm the efficacy of ICI-combined regimen.

Mobocertinib in Patients with EGFR Exon 20 Insertion-Positive Non-Small Cell Lung Cancer (MOON): An International Real-World Safety and Efficacy Analysis

EGFR exon 20 (EGFR Ex20) insertion mutations in non-small cell lung cancer (NSCLC) are insensitive to traditional EGFR tyrosine kinase inhibitors (TKIs). Mobocertinib is the only approved TKI specifically designed to target EGFR Ex20. We performed an international, real-world safety and efficacy analysis on patients with EGFR Ex20-positive NSCLC enrolled in a mobocertinib early access program. We explored the mechanisms of resistance by analyzing postprogression biopsies, as well as cross-resistance to amivantamab. Data from 86 patients with a median age of 67 years and a median of two prior lines of treatment were analyzed. Treatment-related adverse events (TRAEs) occurred in 95% of patients. Grade ≥3 TRAEs were reported in 38% of patients and included diarrhea (22%) and rash (8%). In 17% of patients, therapy was permanently discontinued, and two patients died due to TRAEs. Women were seven times more likely to discontinue treatment than men. In the overall cohort, the objective response rate to mobocertinib was 34% (95% CI, 24-45). The response rate in treatment-naïve patients was 27% (95% CI, 8-58). The median progression-free and overall survival was 5 months (95% CI, 3.5-6.5) and 12 months (95% CI, 6.8-17.2), respectively. The intracranial response rate was limited (13%), and one-third of disease progression cases involved the brain. Mobocertinib also showed antitumor activity following EGFR Ex20-specific therapy and vice versa. Potential mechanisms of resistance to mobocertinib included amplifications in MET, PIK3CA, and NRAS. Mobocertinib demonstrated meaningful efficacy in a real-world setting but was associated with considerable gastrointestinal and cutaneous toxicity.

High expression of KIFC1 is a poor prognostic biomarker and correlates with TP53 mutation in lung cancer

The Kinesin Family Member C1 (KIFC1) is highly expressed in a variety of tumors. Since it is linked with tumorigenesis and progression, KIFC1 has emerged as a promising candidate for targeted chemotherapies. Thus, this study aims to find out the association between KIFC1 and lung cancer. The original data were assessed from The Cancer Genome Atlas and Gene Expression Omnibus databases. Compared to normal lung tissues, both mRNA and protein levels of KIFC1 were significantly increased in lung cancer tissues. The upregulation of KIFC1 was significantly correlated with sex, pathological stage, and TMN stage. Survival analysis revealed that increased KIFC1 expression was associated with poor overall survival, first-progression survival and post-progression survival in lung cancer. Based on the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis, we observed that KIFC1 upregulation was linked to enrichment of the cell cycle and TP53 signaling pathway. Additionally, the overexpression of KIFC1 was positively correlated with TP53 mutations in lung cancer. Based on real-world cohort results, western blotting and RT-qPCR showed high-KIFC1 expression in lung cancer, which may be related to the malignancy of lung cancer. Finally, experiments in vitro showed that KIFC1 inhibitor could significantly inhibit the proliferation and invasion of lung cancer cells. In conclusion, KIFC1 is a poor prognostic biomarker, and patients with high-KIFC1 levels may benefit from targeted therapy.

Advances in the Diagnosis and Treatment of Advanced Non-Small-Cell Lung Cancer With EGFR Exon 20 Insertion Mutation

The discovery of epidermal growth factor receptor (EGFR) mutations has greatly changed the clinical outlook for patients with advanced non-small-cell lung cancer (NSCLC). Unlike the most common EGFR mutations, such as exon 19 deletion (del19) and exon 21 L858R point mutation, EGFR exon 20 insertion mutation (EGFR ex20ins) is a rare mutation of EGFR. Due to its structural specificity, it exhibits primary resistance to traditional epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), leading to poor overall survival prognosis for patients. In recent years, there has been continuous progress in the development of new drugs targeting EGFR ex20ins, bringing new hope for the treatment of this patient population. In this regard, we conducted a systematic review of the molecular characteristics, diagnostic advances, and treatment status of EGFR ex20ins. We summarized the latest data on relevant drug development and clinical research, aiming to provide reference for clinical diagnosis, treatment, and drug development.

Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of YK-029A in Treatment-Naive Patients With Advanced NSCLC Harboring EGFR Exon 20 Insertion Mutations: A Phase 1 Trial

INTRODUCTION

Treatment options for treatment-naive patients with advanced NSCLC harboring EGFR exon 20 insertion (ex20ins) mutations are limited. This study evaluated the safety, tolerability, and pharmacokinetics of YK-029A, a third-generation EGFR tyrosine kinase inhibitor, and the preliminary efficacy of YK-029A in treatment-naive patients with EGFR ex20ins mutation.

METHODS

This multicenter, dose-escalation, and dose-expansion phase 1 clinical trial enrolled patients with NSCLC harboring EGFR mutations. During the dose-escalation phase, YK-029A was orally administered using the traditional 3+3 principle at 50, 100, 150, 200, and 250 mg/d. In the dose-expansion phase, treatment-naive patients with EGFR ex20ins mutations were enrolled and administered YK-029A 200 mg/d. The primary end point was safety and tolerability.

RESULTS

The safety analysis included 108 patients. No dose-limiting toxicity was observed, and the maximum tolerated dose was not reached. The most common treatment-emergent adverse events were anemia (50.9%), diarrhea (49.1%), and rash (34.3%). There was minimal drug accumulation after multiple doses. A total of 28 treatment-naive patients with EGFR ex20ins mutations were enrolled in the dose-expansion and 26 were included in the efficacy analysis. According to the independent review committee evaluation, the objective response rate was 73.1% (95% confidence interval: 52.21%-88.43%), and the disease control rate was 92.3% (95% confidence interval: 74.87%-99.05%).

CONCLUSIONS

YK-029A was found to have manageable safety and be tolerable in patients with NSCLC harboring EGFR mutations and have promising antitumor activity in untreated patients with EGFR ex20ins mutations.

Amivantamab Compared with Real-World Physician's Choice after Platinum-Based Therapy from a Pan-European Chart Review of Patients with Lung Cancer and Activating EGFR Exon 20 Insertion Mutations

Patients with advanced non-small cell lung cancer (NSCLC) with epidermal growth factor receptor gene (EGFR) Exon 20 insertions (Exon20ins) at the second line and beyond (2L+) have an unmet need for new treatment. Amivantamab, a bispecific EGFR- and MET-targeted antibody, demonstrated efficacy in this setting in the phase 1b, open-label CHRYSALIS trial (NCT02609776). The primary objective was to compare the efficacy of amivantamab to the choices made by real-world physicians (RWPC) using an external control cohort from the real-world evidence (RWE) chart review study, CATERPILLAR-RWE. Adjustment was conducted to address differences in prognostic variables between cohorts using inverse probability weighting (IPW) and covariate adjustments based on multivariable regression. In total, 114 patients from CHRYSALIS were compared for 55 lines of therapy from CATERPILLAR-RWE. Baseline characteristics were comparable between the amivantamab and IPW-weighted RWPC cohorts. For amivantamab versus RWPC using IPW adjustment, the response rate ratio for the overall response was 2.14 (p = 0.0181), and the progression-free survival (PFS), time-to-next-treatment (TTNT) and overall survival (OS) hazard ratios (HRs) were 0.42 (p < 0.0001), 0.47 (p = 0.0063) and 0.48 (p = 0.0207), respectively. These analyses provide evidence of clinical and statistical benefits across multiple outcomes and adjustment methods, of amivantamab in platinum pre-treated patients with advanced NSCLC harboring EGFR Exon20ins. These results confirm earlier comparisons versus pooled national registry data.

Clinical Utility of Mobocertinib in the Treatment of NSCLC - Patient Selection and Reported Outcomes

Mobocertinib is an oral tyrosine kinase inhibitor (TKI) that selectively targets epidermal growth factor receptor exon 20 insertion (EGFRex20ins) mutations. It is a structural analog of the third-generation TKI osimertinib, which targets EGFR T790M mutant non-small cell lung cancer (NSCLC); however, mobocertinib gains selectivity for EGFRex20ins mutants over wild type (WT) by interacting with the C790 gatekeeper residue of EGFR. This is accomplished via a carboxylated isopropyl ester moiety at the C5-position of mobocertinib's central pyrimidine core. In Phase 1/2 dose-escalation and dose-expansion studies, mobocertinib was found to have an investigator-confirmed overall response rate (ORR) of 56% (9/16; 95% CI: 30-80%) and 25% (3/12; 95% CI: 5-57%) in patients without and with baseline brain metastasis, respectively. Median investigator-assessed progression-free survival (mPFS) was 10.2 months (95% CI: 5.6 - not reached) and 3.7 months (95% CI: 1.8-15.9) in patients without and with baseline brain metastasis, respectively. A third phase evaluated patients who had received pre-treatment with platinum-based chemotherapy (PPP) and included an extension cohort (EXCLAIM cohort) which evaluated patients treated previously with 1 or 2 lines of therapy. An Independent Review Committee (IRC) found both cohorts to have similar outcomes in terms of ORR, median time to response, mPFS, and disease progression or death. The treatment-emergent adverse events (TEAE) related to mobocertinib are similar to other EGFR inhibitors and are predominately gastrointestinal (eg diarrhea, nausea, vomiting) and cutaneous (eg rash). In September 2021, the FDA granted accelerated approval for mobocertinib in the treatment of patients with locally advanced or metastatic NSCLC with EGFRex20ins mutation whose disease progressed while on platinum-based chemotherapy. The present review describes data that led to the approval of mobocertinib.

The significance of co-mutations in EGFR-mutated non-small cell lung cancer: Optimizing the efficacy of targeted therapies?

Non-small cell lung cancer (NSCLC) is the most common cause of cancer death worldwide. In non-squamous NSCLC, the identification of oncogenic drivers and the development of target-specific molecules led to remarkable progress in therapeutic strategies and overall survival over the last decade. Nevertheless, responses are limited by systematically acquired mechanisms of resistance early on after starting a targeted therapy. Moreover, mounting evidence has demonstrated that each oncogenic-driven cluster is actually heterogeneous in terms of molecular features, clinical behaviour, and sensitivity to targeted therapy. In this review, we aimed to examine the prognostic and predictive significance of oncogene-driven co-mutations, focusing mainly on EGFR and TP53. A narrative review was performed by searching MEDLINE databases for English articles published over the last decade (from January 2012 until November 2022). The bibliographies of key references were manually reviewed to select those eligible for the topic. The genetic landscape of EGFR-mutated NSCLC is more complicated than what is known so far. In particular, the occurrence of TP53 co-mutations stratify patients carrying EGFR mutations in terms of treatment response. The study provides a deeper understanding of the mechanisms underlying the variability of the genetic landscape of EGFR-mutated NSCLC and summarizes notably the clinical importance of TP53 co-mutations for an open avenue to more properly addressing the clinical decision-making in the near future.

Indirect comparison of mobocertinib and real-world therapies for pre-treated non-small cell lung cancer with EGFR exon 20 insertion mutations

OBJECTIVES

Mobocertinib, a novel oral epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, is available for the treatment of non-small cell lung cancer (NSCLC) with EGFR exon 20 insertion (ex20ins) mutations after platinum chemotherapy. We performed an indirect comparison of clinical trial data and real-world data (RWD) to determine the relative efficacy of mobocertinib vs. other treatments for these patients.

MATERIALS AND METHODS

Data on the efficacy of mobocertinib from a phase I/II trial (NCT02716116) were compared to RWD from a retrospective study in 12 German centers using inverse probability of treatment weighting to adjust for age, sex, Eastern Cooperative Oncology Group score, smoking status, presence of brain metastasis, time from advanced diagnosis, and histology. Tumor response assessment was based on RECIST v1.1.

RESULTS

The analysis included 114 patients in the mobocertinib group and 43 in the RWD group. The confirmed overall response rate (cORR) according to investigator assessment was 0% for standard treatments and 35.1% (95% confidence interval [CI], 26.4-44.6) for mobocertinib (p < 0.0001). Compared to standard regimens in the weighted population, mobocertinib prolonged overall survival (OS, median [95% CI] = 9.8 [4.3-13.7] vs. 20.2 [14.9-25.3] months; hazard ratio [HR] = 0.42 [0.25-0.69], p = 0.0035), progression-free survival (PFS, median [95% CI] = 2.6 [1.5-5.7] vs. 7.3 [5.6-8.8] months; HR = 0.28 [0.18-0.44], p < 0.0001), and time to treatment discontinuation (median [95% CI] = 2.1 [1.2-3.1] vs. 7.4 [6.4-8.5] months; HR = 0.34 [0.18-0.65], p = 0.0004).

CONCLUSION

Mobocertinib was associated with an improved cORR and prolonged PFS and OS compared to standard treatments for patients with EGFR ex20ins-positive NSCLC previously treated with platinum-based chemotherapy.

Real-world data for precision cancer medicine-A European perspective

Leveraging real-world data (RWD) for drug access is necessary to overcome a key challenge of modern precision oncology: tackling numerous low-prevalence oncogenic mutations across cancers. Withholding a potentially active medication in patients with rare mutations for the sake of control chemotherapy or "best" supportive care is neither practicable nor ethically justifiable anymore, particularly as RWD could meanwhile be used instead, according to scientific principles outlined by the US Food and Drug Administration, European Medicines Agency and other stakeholders. However, practical implementation varies, with occasionally opposite recommendations based on the same evidence in different countries. In the face of growing need for precision drugs, more transparency of evaluation, a priori availability of guidance for the academia and industry, as well as a harmonized framework for health technology assessment across the European Union (EU) are imperative. These could in turn trigger infrastructural changes in national and pan-European registries, cancer management guidelines (e.g., frequency of routine radiologic restaging, inclusion of patient-reported outcomes), and the health data space, to ensure conformity with declared standards and facilitate extraction of RWD sets (including patient-level data) suitable for approval and pricing with minimal effort. For an EU-wide unification of precision cancer medicine, collective negotiation of drug supply contracts and funding solidarity would additionally be required to handle the financial burden. According to experience from pivotal European programs, off-label use could potentially also be harmonized across EU-states to accelerate availability of novel drugs, streamline collection of valuable RWD, and mitigate related costs through wider partnerships with pharmaceutical companies.

Meta-analysis of the prognostic impact of TP53 co-mutations in EGFR-mutant advanced non-small-cell lung cancer treated with tyrosine kinase inhibitors

PURPOSE

To assess the prognostic impact of TP53 mutations in EGFR-mutant advanced NSCLC patients treated with TKIs.

METHODS

Studies exploring the clinical outcomes of EGFR mutant/TP53 wild-type versus EGFR/TP53 co-mutant patients treated with TKIs were selected. Data were cumulated by adopting a fixed and random-effect model.

RESULTS

Overall, 29 trials were eligible. The PFS analysis showed that TP53 co-mutant group has shorter PFS versus EGFR mutant/TP53 wild-type group (HR = 1.67, 95% CI 1.51-1.83, heterogeneity I² =20%, p = 0.18). Patients affected by EGFR/TP53 co-mutant NSCLC have a higher chance of shorter OS versus EGFR mutant/TP53 wild type (HR= 1.89, 95% CI 1.67-2.14, heterogeneity I² = 21%; p = 0.19). The subgroup analysis showed no significant difference between first-second versus third-generation TKIs in both PFS and OS (p = 0.31, p = 0.08).

CONCLUSIONS

TP53 mutations represent a clinically relevant mechanism of resistance to EGFR-TKIs, regardless of their generation. A personalized therapeutical approach should be explored in dedicated clinical trials.

Distribution and Detectability of EGFR Exon 20 Insertion Variants in NSCLC

INTRODUCTION

EGFR exon 20 insertion (ex20ins) mutations represent 5% to 10% of EGFR mutations in NSCLC. Identifying patients with EGFR ex20ins is challenging owing to the limited coverage of polymerase chain reaction (PCR) assays and the relatively recent use of next-generation sequencing (NGS). This study analyzes the spectrum of EGFR ex20ins variants in a large patient population from a global clinical trial and several real-world cohorts and the ability of PCR kits to identify these alterations.

METHODS

We conducted this retrospective analysis in patients with NSCLC who underwent NGS or other sequencing testing and had a known EGFR ex20ins mutation. Patients were gathered from a clinical trial (NCT02716116), a chart review study in Germany, and the LC-SCRUM-Japan, GENIE, and U.S. COTA databases. Proportions of patients with ex20ins variants that could have been detected by six commercially available and widely used PCR kits were calculated in each data set.

RESULTS

Overall, 636 patients with NSCLC harboring EGFR ex20ins mutations were included in this analysis and 104 unique EGFR ex20ins variants were identified across the data sources. The proportion of patients whose ex20ins could have been detected by any PCR test alone ranged from 11.8% to 58.9% across the data sources.

CONCLUSIONS

Our findings suggest that the PCR tests evaluated would have missed more than 40% of patients with NSCLC harboring EGFR ex20ins mutations. NGS-based genetic testing is preferable than standard PCR assays and can substantially improve the identification of the diverse profile of EGFR ex20ins variants in NSCLC.

Characterization and management of adverse events observed with mobocertinib (TAK-788) treatment for EGFR exon 20 insertion-positive non-small cell lung cancer

BACKGROUND

Mobocertinib has demonstrated durable clinical benefit in platinum-pretreated patients (PPP) with epidermal growth factor receptor exon 20 insertion-positive non-small cell lung cancer (NSCLC).

RESEARCH DESIGN AND METHODS

Pooled safety analysis of two studies included patients with NSCLC (N = 257) treated with the recommended phase 2 dose (RP2D) of mobocertinib (160 mg once daily). We report overall safety (treatment-emergent adverse events [TEAEs]) in the RP2D population; characterization of GI and skin-related events in 114 PPP from a phase 1/2 study (NCT02716116); and clinical activity in PPP with and without dose reductions due to TEAEs.

RESULTS

In the RP2D population (N = 257), the most common TEAEs were diarrhea (93%), nausea (47%), rash (38%), and vomiting (37%). In PPP (N = 114), median times to diarrhea onset and resolution were 5 and 2 days, respectively. Median times to onset and resolution of skin-related events were 9 and 78 days, respectively. Among PPP with (n = 29) or without (n = 85) dose reductions due to TEAEs, overall response rates were 21% and 31% and median durations of response were 5.7 and 17.5 months, respectively.

CONCLUSIONS

GI and skin-related events are common with mobocertinib; minimizing dose reductions with proactive management may improve clinical outcomes.

TRIAL REGISTRATION

NCT02716116; NCT03807778.

Real-world efficacy and safety of mobocertinib in EGFR exon 20 insertion-mutated lung cancer

Background

Non-small cell lung cancer (NSCLC) harboring EGFR exon 20 insertions (EGFRex20ins) is relatively resistant to the existing EGFR tyrosine kinase inhibitors (TKIs). Mobocertinib is a novel TKI that selectively targets EGFRex20ins and has demonstrated therapeutic efficacy in pretreated patients with tumors harboring these mutations.

Methods

This is a retrospective, non-interventional, multicenter real-world study aimed at assessing the efficacy and safety of mobocertinib in patients with EGFRexon20ins who received 160 mg QD monotherapy as part of expanded access. Data collection was based on patients' records. PET-CT or CT scans were used to measure systemic response, while brain MRIs were used to examine intracranial response as part of the follow-up.

Results

16 patients were included in this report. Mobocertinib was administered to 31.3% (5) of patients as first-line, 50% (8) as second-line, and 18.7% (3) as a later-line therapy. The median age was 65 years (range, 38-83), 75% (12/16) were female, and 50% (8/16) had brain metastases at baseline before mobocertinib treatment. The objective response rate (ORR) to mobocertinib was 25% (4/16) (1/5 for first line and 3/11 for other lines), disease control rate (DCR) was 75% (12/16) with a follow-up period of 11 months. The median duration of treatment (mDoT) was 5.6 months across all patients, and 8.6 months in responders. Based on the presence or absence of brain metastasis, the mDoT was 14.8 and 5.4 months (p=0.01), respectively. Mobocertinib Grade ≥3 treatment-related adverse events (TRAEs) included diarrhea (19%), nausea (6%) and renal failure (6%). Dose reduction was reported in 25% of cases to 80 mg.

Conclusion

Mobocertinib in compassionate use exhibited an ORR of 25%, which is very similar to that of the phase 2 EXCLAIM study and clearly better than historical data of monochemotherapy or conventional EGFR inhibitors. The greatest benefit was noted in patients without brain metastases, who showed durable effects with mDoT 14.8 months, while intracranial activity was limited. These findings may assist therapeutic considerations, inasmuch as results from the EXCLAIM cohort-3 dedicated to brain lesions are not available yet.