HER2 exon 20 insertions in non-small-cell lung cancer are sensitive to the irreversible pan-HER receptor tyrosine kinase inhibitor pyrotinib

BackgroundEffective targeted therapy for non-small-cell lung cancer (NSCLC) patients with human epidermal growth factor receptor 2 (HER2) mutations remains an unmet need. This study investigated the antitumor effect of an irreversible pan-HER receptor tyrosine kinase inhibitor, pyrotinib.Patients and methodsUsing patient-derived organoids and xenografts established from an HER2-A775_G776YVMA-inserted advanced lung adenocarcinoma patient sample, we investigated the antitumor activity of pyrotinib. Preliminary safety and efficacy of pyrotinib in 15 HER2-mutant NSCLC patients in a phase II clinical trial are also presented.ResultsPyrotinib showed significant growth inhibition of organoids relative to afatinib in vitro (P = 0.0038). In the PDX model, pyrotinib showed a superior antitumor effect than afatinib (P = 0.0471) and T-DM1 (P = 0.0138). Mice treated with pyrotinib displayed significant tumor burden reduction (mean tumor volume, −52.2%). In contrast, afatinib (25.4%) and T-DM1 (10.9%) showed no obvious reduction. Moreover, pyrotinib showed a robust ability to inhibit pHER2, pERK and pAkt. In the phase II cohort of 15 patients with HER2-mutant NSCLC, pyrotinib 400 mg resulted in a objective response rate of 53.3% and a median progression-free survival of 6.4 months.ConclusionPyrotinib showed activity against NSCLC with HER2 exon 20 mutations in both patient-derived organoids and a PDX model. In the clinical trial, pyrotinib showed promising efficacy.Clinical trial registrationNCT02535507.     

Phase II Study of Afatinib as Third‐Line Treatment for Patients in Korea With Stage IIIB/IV Non‐Small Cell Lung Cancer Harboring Wild‐Type EGFR

Background.

This phase II single-arm trial evaluated afatinib, an irreversible inhibitor of the ErbB receptor family as third-line treatment of Korean patients with advanced non-small cell lung cancer (NSCLC) and tumors with wild-type EGFR. Currently, no standard therapy exists for these patients.

Methods.

Eligible patients had stage IIIB/IV wild-type EGFR lung adenocarcinoma and had failed to benefit from two previous lines of chemotherapy but had not received anti-EGFR treatment. Patients received oral afatinib at 40 mg per day until disease progression or occurrence of intolerable adverse events (AEs). The primary endpoint was confirmed objective tumor response (OR) rate (confirmed complete response [CR] or partial response [PR]). Secondary endpoints included disease control rate (DCR; OR or stable disease for ≥6 weeks), progression-free survival (PFS), and safety.

Results.

Forty-two patients received afatinib treatment, and 38 of those were included in efficacy analyses. No confirmed CRs or PRs were reported. DCR was 24% (9 of 38 patients), with a median disease control duration of 19.3 weeks. Median PFS was 4.1 weeks (95% confidence interval: 3.9–8.0). Frequently reported AEs (mainly grades 1 and 2) were rash/acne (88%), diarrhea (62%), and stomatitis (57%).

Conclusion.

Heavily pretreated patients with wild-type EGFR NSCLC treated with afatinib monotherapy did not experience an objective response and only 24% had disease stabilization lasting more than 6 weeks. AEs were manageable and consistent with the expected safety profile.     

Lung cancer patients with HER2 mutations treated with chemotherapy and HER2-targeted drugs: results from the European EUHER2 cohort

BackgroundHER2 mutations have been identified as oncogenic drivers in lung cancers and are found in 1–2% of lung adenocarcinomas. There is, to date, no standard of care for these patients. We thus aim to study the therapeutic outcomes of patients harboring HER2 mutations and establish the efficacy of various drug regimens.Patients and methodsThis retrospective cohort study in European centers assessed patients with advanced non-small-cell lung cancer (NSCLC), a known HER2 exon-20 insertion, treated with chemotherapy and/or HER2-targeted drugs.ResultsWe identified 101 eligible patients from 38 centers: median age 61 years (range: 30–87), 62.4% women, 60.4% never-smokers. All tumors were adenocarcinomas. Concomitant EGFR mutations, ALK translocations, and ROS translocations were observed in 5, 1, and 1 patients, respectively. The median number of treatment lines was 3 (range: 1–11). The median overall survival was 24 months. Overall response rate (ORR) and the median progression-free survival (PFS) with conventional chemotherapy (excluding targeted therapies) were 43.5% and 6 months in first-line (n = 93), and 10% and 4.3 months in second-line (n = 52) therapies. Sixty-five patients received HER2-targeted therapies: trastuzumab = 57, neratinib = 14, afatinib = 9, lapatinib = 5, T-DM1 = 1. ORR was 50.9% and PFS was 4.8 months with trastuzumab or T-DM1.ConclusionThis series shows the chemosensitivity of HER2-driven NSCLC, and the potential interest of HER2-targeted agents. Our results should help to define the best therapeutic strategy for these patients and to orient future clinical trials.     

Activity of Afatinib in Heavily Pretreated Patients With ERBB2 Mutation–Positive Advanced NSCLC: Findings From a Global Named Patient Use Program

Introduction

Approximately 1% to 4% of NSCLC tumors harbor erb-b2 receptor tyrosine kinase 2 (ERBB2) mutation; there is no approved targeted treatment for this subgroup.

Phase 2 Study of Afatinib Alone or Combined With Bevacizumab in Chemonaive Patients With Advanced Non–Small-Cell Lung Cancer Harboring EGFR Mutations: AfaBev-CS Study Protocol

Afatinib, a second-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI), has demonstrated a significant survival benefit over platinum-based chemotherapy in a first-line setting in advanced non–small-cell lung cancer (NSCLC) harboring EGFR exon 19 deletion. In addition, we and other groups have shown there to be favorable progression-free survival (PFS) outcomes, with acceptable toxicity profiles, with bevacizumab and first-generation EGFR-TKI combination therapy. On the basis of the above, we hypothesized that a combination of bevacizumab and afatinib could potentially improve efficacy. In our phase 1 study, a daily 30 mg dose of afatinib and 15 mg/kg intravenous bevacizumab every 3 weeks was well tolerated and was defined as the recommended dose. We have initiated a randomized phase 2 trial comparing afatinib (30 mg daily) and bevacizumab (15 mg/kg every 3 weeks) with afatinib (40 mg daily) alone for nonsquamous NSCLC harboring EGFR common mutations as a first-line therapy. A total of 100 patients will be enrolled onto this study and randomized in a 1:1 ratio. Patients will continue to receive treatment until disease progression or unacceptable toxicity. The primary end point is PFS, and the secondary end points are overall survival, tumor response, and time to treatment failure. The power is greater than 50% under the assumptions of a median PFS of 12 months for the afatinib group and a hazard ratio of 0.6 for the combination group (2-sided α = 0.05). We hypothesize that the combination therapy will be more efficacious than standard therapies for EGFR-mutant NSCLC patients.     

Afatinib beyond progression in patients with non-small-cell lung cancer following chemotherapy,erlotinib/gefitinib and afatinib: phase III randomized LUX-Lung 5 trial

BackgroundAfatinib has demonstrated clinical benefit in patients with non-small-cell lung cancer progressing after treatment with erlotinib/gefitinib. This phase III trial prospectively assessed whether continued irreversible ErbB-family blockade with afatinib plus paclitaxel has superior outcomes versus switching to chemotherapy alone in patients acquiring resistance to erlotinib/gefitinib and afatinib monotherapy.Patients and methodsPatients with relapsed/refractory disease following ≥1 line of chemotherapy, and whose tumors had progressed following initial disease control (≥12 weeks) with erlotinib/gefitinib and thereafter afatinib (50 mg/day), were randomized 2:1 to receive afatinib plus paclitaxel (40 mg/day; 80 mg/m²/week) or investigator's choice of single-agent chemotherapy. The primary end point was progression-free survival (PFS). Other end points included objective response rate (ORR), overall survival (OS), safety and patient-reported outcomes.ResultsTwo hundred and two patients with progressive disease following clinical benefit from afatinib were randomized to afatinib plus paclitaxel (n = 134) or single-agent chemotherapy (n = 68). PFS (median 5.6 versus 2.8 months, hazard ratio 0.60, P = 0.003) and ORR (32.1% versus 13.2%, P = 0.005) significantly improved with afatinib plus paclitaxel. There was no difference in OS. Global health status/quality of life was maintained with afatinib plus paclitaxel over the entire treatment period. The median treatment duration was 133 and 51 days with afatinib plus paclitaxel and single-agent chemotherapy, respectively; 48.5% of patients receiving afatinib plus paclitaxel and 30.0% of patients receiving single-agent chemotherapy experienced drug-related grade 3/4 adverse events. Treatment-related adverse events were consistent with those previously reported with each agent.ConclusionAfatinib plus paclitaxel improved PFS and ORR compared with single-agent chemotherapy in patients who acquired resistance to erlotinib/gefitinib and progressed on afatinib after initial benefit. LUX-Lung 5 is the first prospective trial to demonstrate the benefit of continued ErbB targeting post-progression, versus switching to single-agent chemotherapy.Trial registration numberNCT01085136 (clinicaltrials.gov).     

The Effects of HER2 Alterations in EGFR Mutant Non-small Cell Lung Cancer

BackgroundHER2 alteration (mutation and/or amplification) is associated with poor survival in NSCLC and can mediate resistance to EGFR tyrosine kinase inhibitors.MethodsWe retrospectively analyzed de-identified molecular information from 12,946 NSCLC samples that underwent next-generation sequencing (NGS) with Caris Life Sciences. The objectives were to determine the prevalence and type of HER2 alterations with and without EGFR as a co-mutation. Insurance claims were utilized to obtain outcomes data.ResultsThree hundred and twenty-one patients (2.5%) had HER2 alteration: mutation in 197 patients and amplification in 134. Median age was 65 years and 62% were female. A total of 84% were adenocarcinoma. HER2 exon 20 insertion was most common (69%). A total of 1551 (12%) patients had EGFR mutations. Among samples with EGFR mutations, 24 (1.5%) had concurrent HER2 alteration (8 with HER2 mutation and 16 with amplification). Among 8 patients who had both EGFR and HER2 mutations, 3 had EGFR exon 19 deletions and exon 8 HER2 mutation (S310F). One-third of the patients (7/21) with HER2 extracellular domain (ECD) mutation had co-occurring EGFR mutations. All 7 were S310. Patients with concurrent EGFR mutation and HER2 amplification had longer median time on treatment with EGFR TKI(s) than those with EGFR mutation without HER2 amplification (HR 2.284, P =.004).ConclusionA minority of NSCLC samples with EGFR mutations had HER2 alterations. In patients with both mutations, exon 21 mutations for EGFR and exon 8 mutations for HER2 were common. It will be critical to continue to accumulate valuable clinical data for further real-world outcomes analysis.     

Afatinib for the Treatment of NSCLC Harboring Uncommon EGFR Mutations: A Database of 693 Cases

IntroductionLimited clinical data are available regarding the efficacy of EGFR tyrosine kinase inhibitors (EGFR TKIs) in patients with NSCLC harboring uncommon EGFR mutations. This pooled analysis assessed the activity of afatinib in 693 patients with tumors harboring uncommon EGFR mutations treated in randomized clinical trials, compassionate-use and expanded-access programs, phase IIIb trials, noninterventional trials, and case series or studies.MethodsPatients had uncommon EGFR mutations, which were categorized as follows: (1) T790M; (2) exon 20 insertions; (3) “major” uncommon mutations (G719X, L861Q, and S768I, with or without any other mutation except T790M or an exon 20 insertion); (4) compound mutations; and (5) other uncommon mutations. Key end points were overall response rate (ORR), duration of response, and time to treatment failure (TTF).ResultsIn EGFR TKI–naive patients (n = 315), afatinib demonstrated activity against major uncommon mutations (median TTF = 10.8 mo; 95% confidence interval [CI]: 8.1–16.6; ORR = 60.0%), compound mutations (median TTF = 14.7 mo; 95% CI: 6.8–18.5; ORR = 77.1%), other uncommon mutations (median TTF = 4.5 mo; 95% CI: 2.9–9.7; ORR = 65.2%), and some exon 20 insertions (median TTF = 4.2 mo; 95% CI: 2.8–5.3; ORR = 24.3%). The median duration of response for major uncommon mutations, compound mutations, other uncommon mutations, and some exon 20 insertions was 17.1, 16.6, 9.0, and 11.9 months, respectively. Activity of afatinib was also observed in EGFR TKI–pretreated patients (n = 378). A searchable database of these outcomes by individual genotype was generated.ConclusionsAfatinib has clinical activity in NSCLC against major uncommon and compound EGFR mutations. It also has broad activity against other uncommon EGFR mutations and some exon 20 insertions. The data support the use of afatinib in these settings.     

Randomized,open-label trial evaluating the preventive effect of tetracycline on afatinib induced-skin toxicities in non-small cell lung cancer patients

BackgroundAfatinib has shown long progression free survival and improvement in quality of life in advanced Non-Small Cell Lung Cancer (NSCLC) patients. Although afatinib causes acneiform rash, it can be manageable. Tetracyclines are usually used to treat it; nonetheless, there is no trial that evaluates their prophylactic efficacy on afatinib induced-skin toxicities (AIST).Patients and methodsThis open-label, randomized, controlled trial assessed the preventive effect of tetracycline for reducing afatinib-skin toxicities in NSCLC patients receiving afatinib 40 mg/day. Patients were randomly assigned to receive pre-emptive treatment with tetracycline 250 mg every 12 h for 4 weeks or not. Reactive treatment in both groups included general dermatological recommendations such as use of skin moisturizers, sunscreen and topical steroids, according to toxicity severity. All patients were blindly monitored for skin toxicities by an expert dermatologist at the start of treatment with afatinib (day 0), weeks 2 and 4 of treatment. The protocol is registered on clinicaltrials.gov (NCT01880515).ResultsWe included 90 patients, no differences were found in clinical and dermatological baseline characteristics. Rash incidence of any grade, and grade ≥2 was less frequent in the pre-emptive arm vs. the control arm (44.5 vs. 75.6%, RR 0.4 [95% CI 0.17–0.99], p = 0.046 and 15.6 vs. 35.6%, RR 0.35 [95% CI, 0.12–0.91], p = 0.030, respectively). No difference was found in paronychia, xerosis, mucositis, folliculitis, and skin fissure. No adverse event was associated with tetracycline. Neither rash nor pre-emptive tetracycline impacted on response rate, progression-free or overall survivals.ConclusionPre-emptive tetracycline was well tolerated and reduced the rash incidence and severity associated with afatinib in more than 60%.     

Alternating Therapy With Osimertinib and Afatinib Blockades EGFR Secondary Mutation in EGFR-Mutant Lung Cancer: A Single-Arm Phase II Trial

BackgroundResistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) has limited treatment options for patients with EGFR-mutated non–small-cell lung cancer (NSCLC). Although osimertinib or afatinib alone induced drug-resistant clones with EGFR secondary mutation in a preclinical model, its combination prevented the appearance of these mutations. We investigated alternating-dose therapy of osimertinib and afatinib in patients with EGFR-mutant NSCLC in a single-arm Phase II trial.MethodsTreatment-naïve patients with stage IV NSCLC harboring an activating EGFR mutation were enrolled. Alternating cycles of osimertinib (80 mg/day) followed by afatinib (20 mg/day) were administered every 8 weeks. Genomic analysis was performed using circulating tumor DNA obtained before and after the treatment.ResultsAmong the 46 enrolled patients, the median progression-free survival was 20.2 months. The overall response rate was 69.6%. The median overall survival was not reached. Among the 26 plasma samples obtained after the acquisition of resistance, 3 showed an increased MET gene copy number, and 1 showed BRAF mutation. Meanwhile, no EGFR secondary mutation was detected.ConclusionThe efficacy of our treatment was not significantly different from osimertinib alone, as reported previously in untreated advanced NSCLC patients with EGFR mutations. Although the sample size was limited, this treatment may prevent the emergence of EGFR secondary mutations that trigger drug resistance. Further studies are warranted to establish the significance of this treatment.Clinical Trial RegistrationjRCTs051180009.     

Poziotinib in Treatment-Naive NSCLC Harboring HER2 Exon 20 Mutations: ZENITH20-4, A Multicenter,Multicohort, Open-Label,Phase 2 Trial (Cohort 4)

IntroductionERBB2 or HER2 alterations are found in approximately 2% to 5% of NSCLCs; most are exon 20 insertion mutations. The efficacy and safety of poziotinib, an oral tyrosine kinase inhibitor, were assessed in patients with treatment-naive NSCLC whose tumors harbor HER2 exon 20 insertions.MethodsZENITH20 is an open-label, multicohort, multicenter, global, phase 2 trial. ZENITH20-C4 enrolled treatment-naive patients with NSCLC with tumors harboring HER2 exon 20 insertions. Poziotinib was administered 16 mg once daily (QD) or 8 mg twice daily (BID). The primary end point was objective response rate (ORR) by independent central review. Secondary and exploratory end points included disease control rate, duration of response, progression-free survival, and safety.ResultsA total of 80 patients (16 mg QD, n = 47; 8 mg BID, n = 33) were treated in ZENITH20-C4. ORR was 39% (95% confidence interval [CI]: 28%–50%; 31 of 80), with a disease control rate of 73% (95% CI: 61%–82%; 58 of 80); 80% of the patients experienced tumor reduction. Median duration of response was 5.7 (95% CI: 4.6–11.9) months, and median progression-free survival was 5.6 (95% CI: 5.4–7.3) months. The most common grade 3 treatment-related adverse events were rash (QD, 45%; BID, 39%), stomatitis (QD, 21%; BID, 15%), and diarrhea (QD, 15%; BID, 21%). Among all subtypes of HER2 exon 20 insertions, seven patients (9%) harboring tumors with G778_P780dupGSP had the best clinical outcomes (ORR, 71%).ConclusionsPoziotinib was found to have clinically meaningful efficacy with a manageable toxicity profile for patients with treatment-naive NSCLC harboring HER2 exon 20 mutations.     

The LUX-Lung clinical trial program of afatinib for non-small-cell lung cancer

Epidermal growth factor receptor (EGFR)-mutant non-small-cell lung cancer (NSCLC) represents a distinct disease entity whose molecular phenotype predicts exquisite sensitivity to the reversible EGFR-tyrosine kinase inhibitors (TKIs) gefitinib or erlotinib. However, primary or acquired resistance to these agents remains a major clinical problem. Afatinib is a novel dual irreversible EGFR/HER2 TKI that has been shown in preclinical studies to potentially prevent, delay or overcome resistance to reversible EGFR-TKIs. On this basis, the LUX-Lung clinical trial program has been recently launched for testing this molecule in advanced NSCLC patients. Notably, early results from the randomized LUX-Lung 1 trial indicate that afatinib significantly prolongs progression-free survival compared with placebo in pretreated patients with clinically acquired resistance to gefitinib or erlotinib. On the other hand, the LUX-Lung 2 trial shows that afatinib is highly active in the EGFR-mutant subgroup of patients. While these preliminary data open a new exciting scenario for the future development of anti-EGFR therapies in NSCLC, ongoing afatinib trials will definitively establish a role for this molecule in the treatment of advanced NSCLC.     

Novel EGFR Inhibitors in Non-small Cell Lung Cancer: Current Status of Afatinib

Afatinib, a second-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, has been approved worldwide as a first-line treatment for advanced non-small cell lung cancer (NSCLC) that harbors activating EGFR mutations. Here, we have reviewed the recent clinical developments in the treatment of lung cancer using afatinib. Emerging data have revealed the overall survival benefit of first-line afatinib therapy in patients with advanced EGFR ^del19-positive NSCLC. Phase III studies of afatinib have shown the effectiveness of afatinib as a second-line treatment for advanced lung squamous cell carcinoma, as well as the benefit of continuing afatinib therapy in combination with cytotoxic chemotherapy for advanced NSCLC after the occurrence of disease progression in patients who are receiving afatinib monotherapy. Therapeutic benefits of afatinib have also been reported in studies of patients with central nervous system metastasis and patients with HER2 mutation. The utility of afatinib-based combination therapies is being investigated in ongoing research.     

Intracranial Responses to Afatinib at Different Doses in Patients With EGFR-mutated Non–small-cell Lung Carcinoma and Brain Metastases

BackgroundAs the first-line treatment, afatinib is commonly used in patients with EGFR-mutated non–small-cell lung cancer (NSCLC). However, dose adjustments are frequently required. The optimal dose of afatinib for brain metastasis has seldom been investigated.Patients and MethodsFrom May 2014 to March 2017, treatment-naive patients with advanced EGFR-mutated NSCLC and brain metastases at diagnosis who received afatinib therapy were retrospectively enrolled. Clinical data was reviewed and analyzed, including age, gender, performance status, smoking history, EGFR mutation status, initial doses of afatinib, average daily doses of afatinib, and best intracranial treatment responses.ResultsA total of 74 patients were included for analysis. The overall intracranial objective response rate (IORR) and intracranial disease control rate (IDCR) were 81.1% and 95.9%, respectively. For patients treated with afatinib alone (N = 45), no significant difference between an initial daily dose of 30 mg (N = 15) and 40 mg (N = 30) (30 mg vs. 40 mg, IORR: 86.7% vs. 80.0%; P = .581 and IDCR: 93.3% vs. 93.3%; P = 1.000, respectively). The IORRs were 75.0%, 91.7%, 80.0%, and 85.7% (P = .707), and the IDCRs were 93.8%, 100.0%, 90.0%, and 85.7% (P = .638) in patients with an average daily dose of 40 mg (N = 16), < 40 mg and > 30 mg (N = 12), 30 mg (N = 10), and < 30 mg and > 20 mg (N = 7), respectively. No significant differences in intracranial treatment responses between groups treated with afatinib alone or afatinib plus local treatments.ConclusionDose reduction may not affect intracranial treatment responses to afatinib therapy, either alone or combined with local treatments, in patients with advanced EGFR-mutated NSCLC and brain metastases.     

Subtypes of EGFR- and HER2-Mutant Metastatic NSCLC Influence Response to Immune Checkpoint Inhibitors

IntroductionThe efficacy of immune checkpoint inhibitors (ICIs) is low among EGFR-mutated non–small-cell lung cancer (NSCLC), although prolonged responses have occasionally been reported. We investigated the association between mutation subtypes and ICI outcomes among HER2- and EGFR-mutated NSCLC.Patients and MethodsThis retrospective single-center study analyzed patients with EGFR- and HER2-mutated advanced NSCLC who received at least 1 cycle of ICI between 2013 and 2019. Patient characteristics, mutation subtype, and ICI outcomes.ResultsAmong 48 patients with advanced NSCLC, 14 (29%) had HER2 mutations and 34 (71%) had EGFR mutations. EGFR mutations included 16 (47%) exon 19 deletion, 7 (21%) L858R, 5 (15%) uncommon, and 6 (18%) exon 20 insertion. Compared to EGFR-sensitizing mutations (ESMs), HER2 and EGFR exon 20 mutations were associated with a trend toward better response (respectively, ESM, HER2, and EGFR exon 20: 11%, 29%, and 50%; P = .07) and significantly better disease control rates (respectively, 18%, 57%, and 67%; P = .008). Compared to ESM, HER2 mutations (adjusted hazard ratio, 0.35; P = .02) and EGFR exon 20 mutations (adjusted hazard ratio, 0.37; P = .10 trend) were also associated with improved PFS. Programmed death ligand 1 (PD-L1) expression remained an independent predictor of PFS (adjusted hazard ratio, 0.42; 95% confidence interval, 0.23-0.76; P = .004). The 6-month PFS rates were 29% (HER2), 33% (EGFR exon 20), and 4% (ESM). ICIs were generally well tolerated in this population. Importantly, no immune-related toxicity was observed in 10 patients who received a tyrosine kinase inhibitor (TKI) as the immediate next line treatment after ICI.ConclusionHER2 and EGFR exon 20 mutations derive greater benefit from ICIs with comparable PFS to wild-type historical second/third-line unselected cohorts. ICIs remain a treatment option for this genomic subgroup, given the absence of approved targeted therapies for these rare mutations.     

A randomised,open-label phase II trial of afatinib versus cetuximab in patients with metastatic colorectal cancer

PurposeThis randomised phase II trial aimed to compare efficacy of the irreversible ErbB family blocker, afatinib, with cetuximab in patients with KRAS wild-type metastatic colorectal adenocarcinoma (mCRC) with progression following oxaliplatin- and irinotecan-based regimens. Efficacy in patients with KRAS mutations was also evaluated.Patients and methodsPatients with KRAS wild-type tumours were randomised 2:1 to afatinib (40 mg/day, increasing to 50 mg/day if minimal toxicity) or cetuximab weekly (400 mg/m² loading dose, then 250 mg/m²/week) according to number of previous chemotherapy lines. All patients with KRAS-mutated tumours received afatinib. Primary end-points were objective response (OR) for the wild-type group and disease control for the KRAS-mutated group. Secondary end-points were progression-free survival (PFS) and overall survival (OS).ResultsPatients with KRAS wild-type tumours (n = 50) received afatinib (n = 36) or cetuximab (n = 14). Unconfirmed and confirmed ORs were 3% and 0% for afatinib versus 20% and 13% for cetuximab (odds ratio: 0.122 [P = 0.0735] and <0.001, respectively). Median PFS was 46.0 and 144.5 days for afatinib and cetuximab, respectively. Median OS was 355 days with afatinib but not reached for cetuximab. In the KRAS-mutated group (n = 41), five (12%) patients achieved confirmed disease control (stable disease; P = 0.6394 [comparison versus 10%]); no ORs were reported. Median PFS and OS were 41.0 and 173 days, respectively. Most frequent treatment-related adverse events were diarrhoea and rash across groups.ConclusionsThe efficacy of afatinib was inferior to cetuximab in patients with KRAS wild-type mCRC. In patients with KRAS-mutated tumours, disease control was modest with afatinib. Afatinib had a manageable safety profile.     

Monitoring of somatic mutations in circulating cell-free DNA by digital PCR and next-generation sequencing during afatinib treatment in patients with lung adenocarcinoma positive for EGFR activating mutations

BackgroundAnalysis of circulating cell-free DNA (cfDNA) is under intensive investigation for its potential to identify tumor somatic mutations. We have now explored the usefulness of such liquid biopsy testing with both the digital polymerase chain reaction (dPCR) and next-generation sequencing (NGS) during treatment of patients with the epidermal growth factor receptor (EGFR) inhibitor afatinib.Patients and methodsEligible patients had advanced lung adenocarcinoma with EGFR activating mutations and were treated with afatinib. Plasma samples were collected before and during (4 and 24 weeks) afatinib treatment as well as at disease progression. Tumor and plasma DNA were analyzed by dPCR and NGS.ResultsThirty-five patients were enrolled. The objective response rate and median progression-free survival (PFS) were 77.1% and 13.8 months, respectively. Tumor and plasma DNA were available for 32 patients. dPCR and NGS detected EGFR activating mutations in 81.3% and 71.9% of baseline cfDNA samples, respectively. In 19 patients treated with afatinib for ≥24 weeks, the number of EGFR mutant alleles detected in cfDNA by dPCR declined rapidly and markedly after treatment onset, becoming undetectable or detectable at only a low copy number (<10 copies per milliliter) at 4 weeks. Median PFS was slightly longer for patients with undetectable EGFR mutant alleles in cfDNA at 4 weeks than for those in whom such alleles were detectable (14.3 versus 10.0 months). A total of 45 somatic mutations was identified in baseline tumor DNA, and 30 (66.7%) of these mutations were identified in cfDNA by NGS. Allele frequency for somatic mutations in cfDNA determined by NGS changed concordantly during afatinib treatment with the number of EGFR mutant alleles determined by dPCR.ConclusionsMonitoring of cfDNA by dPCR is informative for prediction of afatinib efficacy, whereas that by NGS is reliable and has the potential to identify mechanisms of treatment resistance.     

Therapeutic strategies for afatinib‐resistant lung cancer harboring HER2 alterations

Human epidermal growth factor receptor 2 (HER2) plays an important role in the pathogenesis of various cancers. HER2 alterations have been suggested to be a therapeutic target in non‐small‐cell lung cancer (NSCLC), just as in breast and gastric cancers. We previously reported that the pan‐HER inhibitor afatinib could be a useful therapeutic agent as HER2‐targeted therapy for patients with NSCLC harboring HER2 alterations. However, acquired resistance to afatinib was observed in the clinical setting, similar to the case for other HER inhibitors. Thus, elucidation of the mechanisms underlying the development of acquired drug resistance and exploring means to overcome acquired drug resistance are important issues in the treatment of NSCLC. In this study, we experimentally established afatinib‐resistant cell lines from NSCLC cell lines harboring HER2 alterations, and investigated the mechanisms underlying the acquisition of drug resistance. The established cell lines showed several unique afatinib‐resistance mechanisms, including MET amplification, loss of HER2 amplification and gene expression, epithelial‐to‐mesenchymal transition (EMT) and acquisition of cancer stem cell (CSC)‐like features. The afatinib‐resistant cell lines showing MET amplification were sensitive to the combination of afatinib plus crizotinib (a MET inhibitor), both in vitro and in vivo. The resistant cell lines which showed EMT or had acquired CSC‐like features remained sensitive to docetaxel, like the parental cells. These findings may provide clues to countering the resistance to afatinib in NSCLC patients with HER2 alterations.     

A randomized phase II study of the MEK1/MEK2 inhibitor trametinib (GSK1120212) compared with docetaxel in KRAS-mutant advanced non-small-cell lung cancer (NSCLC)

KRAS mutations in non-small-cell lung cancer (NSCLC) are associated with poor prognosis. Trametinib, a selective inhibitor of MEK1/MEK2, demonstrated similar efficacy to docetaxel in patients with advanced KRAS-mutant NSCLC, with median progression-free survival of 12 and 11 weeks, respectively. With moderate activity as a monotherapy, trametinib-based combination regimens may show improve efficacy.BackgroundKRAS mutations are detected in 25% of non-small-cell lung cancer (NSCLC) and no targeted therapies are approved for this subset population. Trametinib, a selective allosteric inhibitor of MEK1/MEK2, demonstrated preclinical and clinical activity in KRAS-mutant NSCLC. We report a phase II trial comparing trametinib with docetaxel in patients with advanced KRAS-mutant NSCLC.Patients and methodsEligible patients with histologically confirmed KRAS-mutant NSCLC previously treated with one prior platinum-based chemotherapy were randomly assigned in a ratio of 2 : 1 to trametinib (2 mg orally once daily) or docetaxel (75 mg/m² i.v. every 3 weeks). Crossover to the other arm after disease progression was allowed. Primary end point was progression-free survival (PFS). The study was prematurely terminated after the interim analysis of 92 PFS events, which showed the comparison of trametinib versus docetaxel for PFS crossed the futility boundary.ResultsOne hundred and twenty-nine patients with KRAS-mutant NSCLC were randomized; of which, 86 patients received trametinib and 43 received docetaxel. Median PFS was 12 weeks in the trametinib arm and 11 weeks in the docetaxel arm (hazard ratio [HR] 1.14; 95% CI 0.75–1.75; P = 0.5197). Median overall survival, while the data are immature, was 8 months in the trametinib arm and was not reached in the docetaxel arm (HR 0.97; 95% CI 0.52–1.83; P = 0.934). There were 10 (12%) partial responses (PRs) in the trametinib arm and 5 (12%) PRs in the docetaxel arm (P = 1.0000). The most frequent adverse events (AEs) in ≥20% of trametinib patients were rash, diarrhea, nausea, vomiting, and fatigue. The most frequent grade 3 treatment-related AEs in the trametinib arm were hypertension, rash, diarrhea, and asthenia.ConclusionTrametinib showed similar PFS and a response rate as docetaxel in patients with previously treated KRAS-mutant-positive NSCLC.Clinicaltrials.gov registration numberNCT01362296.     

A Phase I,Open-Label,Dose Confirmation,Escalation, and Expansion Trial of BI 1810631 as Monotherapy in Patients With Advanced or Metastatic Solid Tumors With HER2 Aberrations

BackgroundBI 1810631 is a human HER2-selective tyrosine kinase inhibitor that covalently binds to both wild-type and mutated HER2 receptors, including exon 20 insertion mutations, whilst sparing EGFR signaling. This phase Ia/Ib, open-label, non-randomized study will determine the safety, maximum tolerated dose (MTD), pharmacokinetics (PK), pharmacodynamics, and preliminary efficacy of BI 1810631 in patients with HER2 aberration-positive solid tumors (NCT04886804).Patients and MethodsIn phase Ia, patients with histologically/cytologically confirmed HER2 aberration-positive advanced/metastatic solid tumors will receive BI 1810631 orally twice daily (BID) or once daily (QD) at escalating doses. Starting dose level is 15 mg BID; QD schedule will begin after one dose level above estimated therapeutic dose of BI 1810631 is determined safe by the Dose Escalation Committee. Dose escalation will continue until MTD/recommended phase II dose and preferred phase Ib schedule for each schedule is determined. In phase Ib, patients with HER2 tyrosine kinase domain (TKD) mutation-positive non-small cell lung cancer (NSCLC) who have previously received ≥1 line of systemic therapy will be enrolled initially, with possible inclusion of additional NSCLC cohorts in the future, including untreated patients. The primary endpoints will be MTD based on number of dose-limiting toxicities (DLTs)/number of patients with DLTs (phase Ia) and objective response (phase Ib). Secondary endpoints include PK parameters (phase Ia/Ib); duration of response, disease control, duration of disease control, and progression-free survival (phase Ib).ConclusionsBI 1810631 could be an effective and tolerable EGFR-sparing oral treatment for patients with HER2 mutation-positive NSCLC, including exon 20 insertion mutations.ClinicalTrials.gov identifierNCT04886804.