Antibody-drug conjugates in lung and breast cancer: Current evidence and future directions - a position statement from the ETOP IBCSG Partners Foundation.

Following the approval of the first antibody-drug conjugates (ADCs) in the early 2000s, development has increased dramatically, with 14 ADCs now approved and >100 in clinical development. In lung cancer, trastuzumab deruxtecan (T-DXd) is approved in human epidermal growth factor receptor 2 (HER2)-mutated, unresectable or metastatic non-small cell lung cancer, with ADCs targeting HER3 (patritumab deruxtecan), trophoblast cell-surface antigen 2 (datopotamab deruxtecan and sacituzumab govitecan [SG]) and mesenchymal-epithelial transition factor (telisotuzumab vedotin) in late-stage clinical development. In breast cancer, several agents are already approved and widely used, including trastuzumab emtansine, T-DXd and SG, and multiple late-stage trials are ongoing. Thus, in the coming years, we are likely to see significant changes to treatment algorithms. As the number of available ADCs increases, biomarkers (of response and resistance) to better select patients are urgently needed. Biopsy sample collection at the time of treatment selection and incorporation of translational research into clinical trial designs are therefore critical. Biopsy samples taken peri- and post-ADC treatment combined with functional genomics screens could provide insights into response/resistance mechanisms as well as the impact of ADCs on tumour biology and the tumour microenvironment, which could improve understanding of the mechanisms underlying these complex molecules. Many ADCs are undergoing evaluation as combination therapy, but a high bar should be set to progress clinical evaluation of any ADC-based combination, particularly considering the high cost and potential toxicity implications. Efforts to optimise ADC dosing/duration, sequencing and the potential for ADC rechallenge are also important, especially considering sustainability aspects. The ETOP IBCSG Partners Foundation are driving strong collaborations in this field and promoting the generation/sharing of databases, repositories and registries to enable greater access data. This will allow the most important research questions to be identified and prioritised, which will ultimately accelerate progress and help to improve patient outcomes.

Translational insights and overall survival in the U31402-A-U102 study of patritumab deruxtecan (HER3-DXd) in EGFR-mutated NSCLC.

BACKGROUND: Human epidermal growth factor receptor 3 (HER3) is broadly expressed in non-small-cell lung cancer (NSCLC) and is the target of patritumab deruxtecan (HER3-DXd), an antibody-drug conjugate consisting of a HER3 antibody attached to a topoisomerase I inhibitor payload via a tetrapeptide-based cleavable linker. U31402-A-U102 is an ongoing phase I study of HER3-DXd in patients with advanced NSCLC. Patients with epidermal growth factor receptor (EGFR)-mutated NSCLC that progressed after EGFR tyrosine kinase inhibitor (TKI) and platinum-based chemotherapy (PBC) who received HER3-DXd 5.6 mg/kg intravenously once every 3 weeks had a confirmed objective response rate (cORR) of 39%. We present median overall survival (OS) with extended follow-up in a larger population of patients with EGFR-mutated NSCLC and an exploratory analysis in those with acquired genomic alterations potentially associated with resistance to HER3-DXd. PATIENTS AND METHODS: Safety was assessed in patients with EGFR-mutated NSCLC previously treated with EGFR TKI who received HER3-DXd 5.6 mg/kg; efficacy was assessed in those who also had prior PBC. RESULTS: In the safety population (N = 102), median treatment duration was 5.5 (range 0.7-27.5) months. Grade ≥3 adverse events occurred in 76.5% of patients; the overall safety profile was consistent with previous reports. In 78/102 patients who had prior third-generation EGFR TKI and PBC, cORR by blinded independent central review (as per RECIST v1.1) was 41.0% [95% confidence interval (CI) 30.0% to 52.7%], median progression-free survival was 6.4 (95% CI 4.4-10.8) months, and median OS was 16.2 (95% CI 11.2-21.9) months. Patients had diverse mechanisms of EGFR TKI resistance at baseline. At tumor progression, acquired mutations in ERBB3 and TOP1 that might confer resistance to HER3-DXd were identified. CONCLUSIONS: In patients with EGFR-mutated NSCLC after EGFR TKI and PBC, HER3-DXd treatment was associated with a clinically meaningful OS. The tumor biomarker characterization comprised the first description of potential mechanisms of resistance to HER3-DXd therapy.

Molecular markers of metastatic disease in KRAS-mutant lung adenocarcinoma.

BACKGROUND: Prior studies characterized the association of molecular alterations with treatment-specific outcomes in KRAS-mutant (KRASMUT) lung adenocarcinoma (LUAD). Less is known about the prognostic role of molecular alterations and their associations with metastatic disease. PATIENTS AND METHODS: We analyzed clinicogenomic data from 1817 patients with KRASMUT LUAD sequenced at the Dana-Farber Cancer Institute (DFCI) and Memorial Sloan Kettering Cancer Center (MSKCC). Patients with metastatic (M1) and nonmetastatic (M0) disease were compared. Transcriptomic data from The Cancer Genome Atlas (TCGA) were investigated to characterize the biology of differential associations with clinical outcomes. Organ-specific metastasis was associated with overall survival (OS). RESULTS: KEAP1 (DFCI: OR = 2.3, q = 0.04; MSKCC: OR = 2.2, q = 0.00027) and SMARCA4 mutations (DFCI: OR = 2.5, q = 0.06; MSKCC: OR = 2.6, q = 0.0021) were enriched in M1 versus M0 tumors. On integrative modeling, NRF2 activation was the genomic feature most associated with OS. KEAP1 mutations were enriched in M1 versus M0 tumors independent of STK11 status (KEAP1MUT/STK11WT: DFCI OR = 3.0, P = 0.0064; MSKCC OR = 2.0, P = 0.041; KEAP1MUT/STK11MUT: DFCI OR = 2.3, P = 0.0063; MSKCC OR = 2.5, P = 3.6 × 10-05); STK11 mutations without KEAP1 loss were not associated with stage (KEAP1WT/STK11MUT: DFCI OR = 0.97, P = 1.0; MSKCC OR = 1.2, P = 0.33) or outcome. KEAP1/KRAS-mutated tumors with and without STK11 mutations exhibited high functional STK11 loss. The negative effects of KEAP1 were compounded in the presence of bone (HR = 2.3, P = 4.4 × 10-14) and negated in the presence of lymph node metastasis (HR = 1.0, P = 0.91). CONCLUSIONS: Mutations in KEAP1 and SMARCA4, but not STK11, were associated with metastatic disease and poor OS. Functional STK11 loss, however, may contribute to poor outcomes in KEAP1MUT tumors. Integrating molecular data with clinical and metastatic-site annotations can more accurately risk stratify patients.

Dissecting the clinicopathologic, genomic, and immunophenotypic correlates of KRASG12D-mutated non-small-cell lung cancer.

BACKGROUND: Allele-specific KRAS inhibitors are an emerging class of cancer therapies. KRAS-mutant (KRASMUT) non-small-cell lung cancers (NSCLCs) exhibit heterogeneous outcomes, driven by differences in underlying biology shaped by co-mutations. In contrast to KRASG12C NSCLC, KRASG12D NSCLC is associated with low/never-smoking status and is largely uncharacterized. PATIENTS AND METHODS: Clinicopathologic and genomic information were collected from patients with NSCLCs harboring a KRAS mutation at the Dana-Farber Cancer Institute (DFCI), Memorial Sloan Kettering Cancer Center, MD Anderson Cancer Center, and Imperial College of London. Multiplexed immunofluorescence for CK7, programmed cell death protein 1 (PD-1), programmed death-ligand 1 (PD-L1), Foxp3, and CD8 was carried out on a subset of samples with available tissue at the DFCI. Clinical outcomes to PD-(L)1 inhibition ± chemotherapy were analyzed according to KRAS mutation subtype. RESULTS: Of 2327 patients with KRAS-mutated (KRASMUT) NSCLC, 15% (n = 354) harbored KRASG12D. Compared to KRASnon-G12D NSCLC, KRASG12D NSCLC had a lower pack-year (py) smoking history (median 22.5 py versus 30.0 py, P < 0.0001) and was enriched in never smokers (22% versus 5%, P < 0.0001). KRASG12D had lower PD-L1 tumor proportion score (TPS) (median 1% versus 5%, P < 0.01) and lower tumor mutation burden (TMB) compared to KRASnon-G12D (median 8.4 versus 9.9 mt/Mb, P < 0.0001). Of the samples which underwent multiplexed immunofluorescence, KRASG12D had lower intratumoral and total CD8+PD1+ T cells (P < 0.05). Among 850 patients with advanced KRASMUT NSCLC who received PD-(L)1-based therapies, KRASG12D was associated with a worse objective response rate (ORR) (15.8% versus 28.4%, P = 0.03), progression-free survival (PFS) [hazard ratio (HR) 1.51, 95% confidence interval (CI) 1.45-2.00, P = 0.003], and overall survival (OS; HR 1.45, 1.05-1.99, P = 0.02) to PD-(L)1 inhibition alone but not to chemo-immunotherapy combinations [ORR 30.6% versus 35.7%, P = 0.51; PFS HR 1.28 (95%CI 0.92-1.77), P = 0.13; OS HR 1.36 (95%CI 0.95-1.96), P = 0.09] compared to KRASnon-G12D. CONCLUSIONS: KRASG12D lung cancers harbor distinct clinical, genomic, and immunologic features compared to other KRAS-mutated lung cancers and worse outcomes to PD-(L)1 blockade. Drug development for KRASG12D lung cancers will have to take these differences into account.

ESMO expert consensus statements on the management of EGFR mutant non-small-cell lung cancer.

The European Society for Medical Oncology (ESMO) held a virtual consensus-building process on epidermal growth factor receptor (EGFR)-mutant non-small-cell lung cancer in 2021. The consensus included a multidisciplinary panel of 34 leading experts in the management of lung cancer. The aim of the consensus was to develop recommendations on topics that are not covered in detail in the current ESMO Clinical Practice Guideline and where the available evidence is either limited or conflicting. The main topics identified for discussion were: (i) tissue and biomarkers analyses; (ii) early and locally advanced disease; (iii) metastatic disease and (iv) clinical trial design, patient's perspective and miscellaneous. The expert panel was divided into four working groups to address questions relating to one of the four topics outlined above. Relevant scientific literature was reviewed in advance. Recommendations were developed by the working groups and then presented to the entire panel for further discussion and amendment before voting. This manuscript presents the recommendations developed, including findings from the expert panel discussions, consensus recommendations and a summary of evidence supporting each recommendation.

Osimertinib plus platinum-pemetrexed in newly diagnosed epidermal growth factor receptor mutation-positive advanced/metastatic non-small-cell lung cancer: safety run-in results from the FLAURA2 study.

BACKGROUND: The phase III FLAURA2 (NCT04035486) study will evaluate efficacy and safety of first-line osimertinib with platinum-pemetrexed chemotherapy versus osimertinib monotherapy in epidermal growth factor receptor mutation-positive (EGFRm) advanced/metastatic non-small-cell lung cancer (NSCLC). The safety run-in, reported here, assessed the safety and tolerability of osimertinib with chemotherapy prior to the randomized phase III evaluation. PATIENTS AND METHODS: Patients (≥18 years; Japan: ≥20 years) with EGFRm locally advanced/metastatic NSCLC received oral osimertinib 80 mg once daily (QD), with either intravenous (IV) cisplatin 75 mg/m2 or IV carboplatin target area under the curve 5, plus pemetrexed 500 mg/m2 every 3 weeks (Q3W) for four cycles. Maintenance was osimertinib 80 mg QD with pemetrexed 500 mg/m2 Q3W until progression/discontinuation. The primary objective was to evaluate safety and tolerability of the osimertinib-chemotherapy combination. RESULTS: Thirty patients (15 per group) received treatment [Asian, 73%; female, 63%; median age (range) 61 (45-84) years]. Adverse events (AEs) were reported by 27 patients (90%): osimertinib-carboplatin-pemetrexed, 100%; osimertinib-cisplatin-pemetrexed, 80%. Most common AEs were constipation (60%) with osimertinib-carboplatin-pemetrexed and nausea (60%) with osimertinib-cisplatin-pemetrexed. In both groups, 20% of patients reported serious AEs. No specific pattern of AEs leading to dose modifications/discontinuations was observed; one patient discontinued all study treatments including osimertinib due to pneumonitis (study-specific discontinuation criterion). Hematologic toxicities were as expected and manageable. CONCLUSIONS: Osimertinib-chemotherapy combination had a manageable safety and tolerability profile in EGFRm advanced/metastatic NSCLC, supporting further assessment in the FLAURA2 randomized phase.

Ultra-deep next-generation sequencing of plasma cell-free DNA in patients with advanced lung cancers: results from the Actionable Genome Consortium.

BACKGROUND: Noninvasive genotyping using plasma cell-free DNA (cfDNA) has the potential to obviate the need for some invasive biopsies in cancer patients while also elucidating disease heterogeneity. We sought to develop an ultra-deep plasma next-generation sequencing (NGS) assay for patients with non-small-cell lung cancers (NSCLC) that could detect targetable oncogenic drivers and resistance mutations in patients where tissue biopsy failed to identify an actionable alteration. PATIENTS AND METHODS: Plasma was prospectively collected from patients with advanced, progressive NSCLC. We carried out ultra-deep NGS using cfDNA extracted from plasma and matched white blood cells using a hybrid capture panel covering 37 lung cancer-related genes sequenced to 50 000× raw target coverage filtering somatic mutations attributable to clonal hematopoiesis. Clinical sensitivity and specificity for plasma detection of known oncogenic drivers were calculated and compared with tissue genotyping results. Orthogonal ddPCR validation was carried out in a subset of cases. RESULTS: In 127 assessable patients, plasma NGS detected driver mutations with variant allele fractions ranging from 0.14% to 52%. Plasma ddPCR for EGFR or KRAS mutations revealed findings nearly identical to those of plasma NGS in 21 of 22 patients, with high concordance of variant allele fraction (r = 0.98). Blinded to tissue genotype, plasma NGS sensitivity for de novo plasma detection of known oncogenic drivers was 75% (68/91). Specificity of plasma NGS in those who were driver-negative by tissue NGS was 100% (19/19). In 17 patients with tumor tissue deemed insufficient for genotyping, plasma NGS identified four KRAS mutations. In 23 EGFR mutant cases with acquired resistance to targeted therapy, plasma NGS detected potential resistance mechanisms, including EGFR T790M and C797S mutations and ERBB2 amplification. CONCLUSIONS: Ultra-deep plasma NGS with clonal hematopoiesis filtering resulted in de novo detection of targetable oncogenic drivers and resistance mechanisms in patients with NSCLC, including when tissue biopsy was inadequate for genotyping.

Plasma HPV cell-free DNA monitoring in advanced HPV-associated oropharyngeal cancer.

Background: Measuring cell-free (cf)DNA in blood and tissues holds significant potential as a minimally invasive method for disease monitoring in cancer. Cancers arising in the oropharynx and causally linked to human papillomavirus (HPV) represent an ideal model in which to interrogate these methods. Patients and methods: We designed an ultrasensitive and quantitative droplet digital (dd)PCR assay to detect the five dominant high-risk HPV subtypes linked to oropharyngeal cancer (OPC). We enrolled a pilot observational cohort of 22 patients with advanced HPV+ OPC to evaluate the clinical utility of our assay and explore its predictive and prognostic potential. Results: Total tumor burden (TTB) strongly correlated with HPV cfDNA levels (R = 0.91, P = 2.3×10-6) at this cohort size, and in most cases more distant anatomic disease locations predicted increasing HPV cfDNA levels. All participants demonstrated a corresponding change in their HPV cfDNA levels at a median of 16 days (range 12-38) before restaging scans confirming treatment response or progression. Patients with locoregional disease in the head and neck or pulmonary-only metastases had worse outcomes (P = 0.01). Both TTB and median plasma HPV cfDNA levels negatively correlated with survival (R=-0.65, P = 0.01; R=-0.48, P = 0.05, respectively). Conclusion(s): Plasma HPV cfDNA monitoring recapitulates fluctuations in disease status. While blood-based HPV DNA monitoring does not currently have a role in managing HPV+ OPC, these data speak to their broad clinical potential in an era of precision medicine.

CNS response to osimertinib in patients with T790M-positive advanced NSCLC: pooled data from two phase II trials.

Background: Central nervous system (CNS) metastases are common in patients with non-small-cell lung cancer (NSCLC). Osimertinib has shown systemic efficacy in patients with CNS metastases, and early clinical evidence shows efficacy in the CNS. To evaluate osimertinib activity further, we present a pre-specified subgroup analysis of CNS response using pooled data from two phase II studies: AURA extension (NCT01802632) and AURA2 (NCT02094261). Patients and methods: Patients with T790M-positive advanced NSCLC, who had progressed following prior epidermal growth factor receptor-tyrosine kinase inhibitor treatment, received osimertinib 80 mg od (n = 411). Patients with stable, asymptomatic CNS metastases were eligible for enrolment; prior CNS treatment was allowed. Patients with ≥1 measurable CNS lesion (per RECIST 1.1) on baseline brain scan by blinded independent central neuroradiology review (BICR) were included in the evaluable for CNS response set (cEFR). The primary outcome for this CNS analysis was CNS objective response rate (ORR) by BICR; secondary outcomes included CNS duration of response, disease control rate (DCR) and progression-free survival (PFS). Results: Of 128 patients with CNS metastases on baseline brain scans, 50 were included in the cEFR. Confirmed CNS ORR and DCR were 54% [27/50; 95% confidence interval (CI) 39-68] and 92% (46/50; 95% CI 81-98), respectively. CNS response was observed regardless of prior radiotherapy to the brain. Median CNS duration of response (22% maturity) was not reached (range, 1-15 months); at 9 months, 75% (95% CI 53-88) of patients were estimated to remain in response. Median follow-up for CNS PFS was 11 months; median CNS PFS was not reached (95% CI, 7, not calculable). The safety profile observed in the cEFR was consistent with the overall patient population. Conclusions: Osimertinib demonstrated clinically meaningful efficacy against CNS metastases, with a high DCR, encouraging ORR, and safety profile consistent with that reported previously. ClinicalTrials.gov number: NCT01802632; NCT02094261.

SELECT-2: a phase II, double-blind, randomized, placebo-controlled study to assess the efficacy of selumetinib plus docetaxel as a second-line treatment of patients with advanced or metastatic non-small-cell lung cancer.

BACKGROUND: Combination of selumetinib plus docetaxel provided clinical benefit in a previous phase II trial for patients with KRAS-mutant advanced non-small-cell lung cancer (NSCLC). The phase II SELECT-2 trial investigated safety and efficacy of selumetinib plus docetaxel for patients with advanced or metastatic NSCLC. PATIENTS AND METHODS: Patients who had disease progression after first-line anti-cancer therapy were randomized (2 : 2 : 1) to selumetinib 75 mg b.i.d. plus docetaxel 60 or 75 mg/m2 (SEL + DOC 60; SEL + DOC 75), or placebo plus docetaxel 75 mg/m2 (PBO + DOC 75). Patients were initially enrolled independently of KRAS mutation status, but the protocol was amended to include only patients with centrally confirmed KRAS wild-type NSCLC. Primary end point was progression-free survival (PFS; RECIST 1.1); statistical analyses compared each selumetinib group with PBO + DOC 75 for KRAS wild-type and overall (KRAS mutant or wild-type) populations. RESULTS: A total of 212 patients were randomized; 69% were KRAS wild-type. There were no statistically significant improvements in PFS or overall survival for overall or KRAS wild-type populations in either selumetinib group compared with PBO + DOC 75. Overall population median PFS for SEL + DOC 60, SEL + DOC 75 compared with PBO + DOC 75 was 3.0, 4.2, and 4.3 months, HRs: 1.12 (90% CI: 0.8, 1.61) and 0.92 (90% CI: 0.65, 1.31), respectively. In the overall population, a higher objective response rate (ORR; investigator assessed) was observed for SEL + DOC 75 (33%) compared with PBO + DOC 75 (14%); odds ratio: 3.26 (90% CI: 1.47, 7.95). Overall the tolerability profile of SEL + DOC was consistent with historical data, without new or unexpected safety concerns identified. CONCLUSION: The primary end point (PFS) was not met. The higher ORR with SEL + DOC 75 did not translate into prolonged PFS for the overall or KRAS wild-type patient populations. No clinical benefit was observed with SEL + DOC in KRAS wild-type patients compared with docetaxel alone. No unexpected safety concerns were reported. TRIAL IDENTIFIER: Clinicaltrials.gov NCT01750281.

Dacomitinib versus erlotinib in patients with EGFR-mutated advanced nonsmall-cell lung cancer (NSCLC): pooled subset analyses from two randomized trials.

BACKGROUND: The irreversible epidermal growth factor receptor (EGFR) inhibitors have demonstrated efficacy in NSCLC patients with activating EGFR mutations, but it is unknown if they are superior to the reversible inhibitors. Dacomitinib is an oral, small-molecule irreversible inhibitor of all enzymatically active HER family tyrosine kinases. METHODS: The ARCHER 1009 (NCT01360554) and A7471028 (NCT00769067) studies randomized patients with locally advanced/metastatic NSCLC following progression with one or two prior chemotherapy regimens to dacomitinib or erlotinib. EGFR mutation testing was performed centrally on archived tumor samples. We pooled patients with exon 19 deletion and L858R EGFR mutations from both studies to compare the efficacy of dacomitinib to erlotinib. RESULTS: One hundred twenty-one patients with any EGFR mutation were enrolled; 101 had activating mutations in exon 19 or 21. For patients with exon19/21 mutations, the median progression-free survival was 14.6 months [95% confidence interval (CI) 9.0-18.2] with dacomitinib and 9.6 months (95% CI 7.4-12.7) with erlotinib [unstratified hazard ratio (HR) 0.717 (95% CI 0.458-1.124), two-sided log-rank, P = 0.146]. The median survival was 26.6 months (95% CI 21.6-41.5) with dacomitinib versus 23.2 months (95% CI 16.0-31.8) with erlotinib [unstratified HR 0.737 (95% CI 0.431-1.259), two-sided log-rank, P = 0.265]. Dacomitinib was associated with a higher incidence of diarrhea and mucositis in both studies compared with erlotinib. CONCLUSIONS: Dacomitinib is an active agent with comparable efficacy to erlotinib in the EGFR mutated patients. The subgroup with exon 19 deletion had favorable outcomes with dacomitinib. An ongoing phase III study will compare dacomitinib to gefitinib in first-line therapy of patients with NSCLC harboring common activating EGFR mutations (ARCHER 1050; NCT01774721). CLINICAL TRIALS NUMBER: ARCHER 1009 (NCT01360554) and A7471028 (NCT00769067).

Anti-HER3 monoclonal antibody patritumab sensitizes refractory non-small cell lung cancer to the epidermal growth factor receptor inhibitor erlotinib.

Human epidermal growth factor receptor (HER) 3 is aberrantly overexpressed and correlates with poor prognosis in non-small cell lung cancer (NSCLC). Patritumab is a monoclonal antibody against HER3 that has shown promising results in early-phase clinical trials, but an optimal target population for the drug has yet to be identified. In the present study, we examined whether heregulin, a HER3 ligand that is also overexpressed in a subset of NSCLC, can be used as a biomarker to predict the antitumorigenic efficacy of patritumab and whether the drug can overcome the epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) resistance induced by heregulin. Patritumab sensitivity was associated with heregulin expression, which, when abolished, resulted in the loss of HER3 and AKT activation and growth arrest. Furthermore, heregulin overexpression induced EGFR TKI resistance in NSCLC cells harbouring an activating EGFR mutation, while HER3 and AKT activation was maintained in the presence of erlotinib in heregulin-overexpressing, EGFR-mutant NSCLC cells. Sustained HER3-AKT activation was blocked by combining erlotinib with either anti-HER2 or anti-HER3 antibody. Notably, heregulin was upregulated in tissue samples from an NSCLC patient who had an activating EGFR mutation but was resistant to the TKI gefitinib. These results indicate that patritumab can overcome heregulin-dependent EGFR inhibitor resistance in NSCLC in vitro and in vivo and suggest that it can be used in combination with EGFR TKIs to treat a subset of heregulin-overexpressing NSCLC patients.

Impact of KRAS codon subtypes from a randomised phase II trial of selumetinib plus docetaxel in KRAS mutant advanced non-small-cell lung cancer.

BACKGROUND: Selumetinib (AZD6244, ARRY-142886)+docetaxel increases median overall survival (OS) and significantly improves progression-free survival (PFS) and objective response rate (ORR) compared with docetaxel alone in patients with KRAS mutant, stage IIIB/IV non-small-cell lung cancer (NSCLC; NCT00890825). METHODS: Retrospective analysis of OS, PFS, ORR and change in tumour size at week 6 for different sub-populations of KRAS codon mutations. RESULTS: In patients receiving selumetinib+docetaxel and harbouring KRAS G12C or G12V mutations there were trends towards greater improvement in OS, PFS and ORR compared with other KRAS mutations. CONCLUSION: Different KRAS mutations in NSCLC may influence selumetinib/docetaxel sensitivity.

Targeting HER2 aberrations as actionable drivers in lung cancers: phase II trial of the pan-HER tyrosine kinase inhibitor dacomitinib in patients with HER2-mutant or amplified tumors.

BACKGROUND: HER2 mutations and amplifications have been identified as oncogenic drivers in lung cancers. Dacomitinib, an irreversible inhibitor of HER2, EGFR (HER1), and HER4 tyrosine kinases, has demonstrated activity in cell-line models with HER2 exon 20 insertions or amplifications. Here, we studied dacomitinib in patients with HER2-mutant or amplified lung cancers. PATIENTS AND METHODS: As a prespecified cohort of a phase II study, we included patients with stage IIIB/IV lung cancers with HER2 mutations or amplification. We gave oral dacomitinib at 30-45 mg daily in 28-day cycles. End points included partial response rate, overall survival, and toxicity. RESULTS: We enrolled 30 patients with HER2-mutant (n = 26, all in exon 20 including 25 insertions and 1 missense mutation) or HER2-amplified lung cancers (n = 4). Three of 26 patients with tumors harboring HER2 exon 20 mutations [12%; 95% confidence interval (CI) 2% to 30%] had partial responses lasting 3+, 11, and 14 months. No partial responses occurred in four patients with tumors with HER2 amplifications. The median overall survival was 9 months from the start of dacomitinib (95% CI 7-21 months) for patients with HER2 mutations and ranged from 5 to 22 months with amplifications. Treatment-related toxicities included diarrhea (90%; grade 3/4: 20%/3%), dermatitis (73%; grade 3/4: 3%/0%), and fatigue (57%; grade 3/4: 3%/0%). One patient died on study likely due to an interaction of dacomitinib with mirtazapine. CONCLUSIONS: Dacomitinib produced objective responses in patients with lung cancers with specific HER2 exon 20 insertions. This observation validates HER2 exon 20 insertions as actionable targets and justifies further study of HER2-targeted agents in specific HER2-driven lung cancers. CLINICALTRIALSGOV: NCT00818441.

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)†.

BACKGROUND: KRAS 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 METHODS: Eligible 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/m(2) 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. RESULTS: One 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. CONCLUSION: Trametinib showed similar PFS and a response rate as docetaxel in patients with previously treated KRAS-mutant-positive NSCLC. CLINICALTRIALSGOV REGISTRATION NUMBER: NCT01362296.

Ligand-associated ERBB2/3 activation confers acquired resistance to FGFR inhibition in FGFR3-dependent cancer cells.

Somatic alterations of fibroblast growth factor receptors (FGFRs) have been described in a wide range of malignancies. A number of anti-FGFR therapies are currently under investigation in clinical trials for subjects with FGFR gene amplifications, mutations and translocations. Here, we develop cell line models of acquired resistance to FGFR inhibition by exposure of cell lines harboring FGFR3 gene amplification and translocation to the selective FGFR inhibitor BGJ398 and multitargeted FGFR inhibitor ponatinib. We show that the acquisition of resistance is rapid, reversible and characterized by an epithelial to mesenchymal transition and a switch from dependency on FGFR3 to ERBB family members. Acquired resistance was associated with demonstrable changes in gene expression including increased production of ERBB2/3 ligands, which were sufficient to drive resistance in the setting of FGFR3 dependency but not dependency on other FGFR family members. These data support the concept that activation of ERBB family members is sufficient to bypass dependency on FGFR3 and suggest that concurrent inhibition of these two pathways may be desirable when targeting FGFR3-dependent cancers.

Revisiting the relationship between tumour volume and diameter in advanced NSCLC patients: An exercise to maximize the utility of each measure to assess response to therapy.

AIM: To revisit the presumed relationship between tumour diameter and volume in advanced non-small-cell lung cancer (NSCLC) patients, and determine whether the measured volume using volume-analysis software and its proportional changes during therapy matches with the calculated volume obtained from the presumed relationship and results in concordant response assessment. MATERIALS AND METHODS: Twenty-three patients with stage IIIB/IV NSCLC with a total of 53 measurable lung lesions, treated in a phase II trial of erlotinib, were studied with institutional review board approval. Tumour volume and diameter were measured at baseline and at the first follow-up computed tomography (CT) examination using volume-analysis software. Using the measured diameter (2r) and the equation, calculated volume was obtained as (4/3)πr(3) at baseline and at the follow-up. Percent volume change was obtained by comparing to baseline for measured and calculated volumes, and response assessment was assigned. RESULTS: The measured volume was significantly smaller than the calculated volume at baseline (median 11,488.9 mm(3) versus 17,148.6 mm(3); p < 0.0001), with a concordance correlation coefficient (CCC) of 0.7022. At follow-up, the measured volume was once again significantly smaller than the calculated volume (median 6573.5 mm(3) versus 9198.1 mm(3); p = 0.0022), with a CCC of 0.7408. Response assessment by calculated versus measured volume changes had only moderate agreement (weighted κ = 0.545), with discordant assessment results in 20% (8/40) of lesions. CONCLUSION: Calculated volume based on the presumed relationship significantly differed from the measured volume in advanced NSCLC patients, with only moderate concordance in response assessment, indicating the limitations of presumed relationship.

Clinical benefit of continuing ALK inhibition with crizotinib beyond initial disease progression in patients with advanced ALK-positive NSCLC.

BACKGROUND: Crizotinib is approved to treat advanced ALK-positive non-small-cell lung cancer (NSCLC), but most patients ultimately develop progressive disease (PD). We investigated whether continuing ALK inhibition with crizotinib beyond PD (CBPD) is clinically beneficial and attempted to identify clinicopathologic characteristics associated with patients who experience clinical benefit. PATIENTS AND METHODS: Patients with advanced ALK-positive NSCLC enrolled in two ongoing multicenter, single-arm trials who developed RECIST-defined PD were allowed to continue crizotinib if they were deriving ongoing clinical benefit. In the present retrospective analysis, continuation of CBPD was defined as >3 weeks of crizotinib treatment after PD documentation. Patients who had PD as best response to initial crizotinib treatment were excluded. Baseline and post-progression characteristics, sites of PD, and overall survival (OS) were compared in patients who continued CBPD versus those who did not. The impact of continuing CBPD on OS after adjusting for potential confounding factors was assessed. RESULTS: Among 194 crizotinib-treated patients with RECIST-defined PD, 120 (62%) continued CBPD. A significantly higher proportion of patients who continued CBPD than patients who did not had an ECOG performance status (PS) of 0/1 at PD (96% versus 82%; P=0.02). CBPD patients had significantly longer OS from the time of PD [median 16.4 versus 3.9 months; hazards ratio (HR) 0.27, 95% confidence interval (CI): 0.17-0.42; P<0.0001] and from the time of initial crizotinib treatment (median 29.6 versus 10.8 months; HR 0.30, 95% CI: 0.19-0.46; P<0.0001). The multiple-covariate Cox regression analysis revealed that CBPD remained significantly associated with improved OS after adjusting for relevant factors. CONCLUSIONS: Patients who continued CBPD were more likely to have good ECOG PS (0/1) at the time of PD. Continuing ALK inhibition with crizotinib after PD may provide survival benefit to patients with advanced ALK-positive NSCLC.

Oncogenic and drug-sensitive NTRK1 rearrangements in lung cancer.

We identified new gene fusions in patients with lung cancer harboring the kinase domain of the NTRK1 gene that encodes the high-affinity nerve growth factor receptor (TRKA protein). Both the MPRIP-NTRK1 and CD74-NTRK1 fusions lead to constitutive TRKA kinase activity and are oncogenic. Treatment of cells expressing NTRK1 fusions with inhibitors of TRKA kinase activity inhibited autophosphorylation of TRKA and cell growth. Tumor samples from 3 of 91 patients with lung cancer (3.3%) without known oncogenic alterations assayed by next-generation sequencing or fluorescence in situ hybridization demonstrated evidence of NTRK1 gene fusions.