The expression of PD-1 and its ligands PD-L1 and PD-L2 is heterogeneous within KRAS-mutant NSCLC and suggests an inducible expression of PD-L1 by smoking.

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Summary We conducted a large-scale functional genetic study to characterize mechanisms of resistance to ALK inhibition in ALK-dependent lung cancer cells. We identify members of known resistance pathways and additional putative resistance drivers. Among the latter were members of the P2Y purinergic receptor family of G-protein coupled receptors (P2Y1, P2Y2, and P2Y6). P2Y receptors mediated resistance in part through a protein kinase C (PKC)-dependent mechanism. Moreover, PKC activation alone was sufficient to confer resistance to ALK inhibitors whereas combined ALK and PKC inhibition restored sensitivity. We observed enrichment of gene signatures associated with several resistance drivers (including P2Y receptors) in crizotinib-resistant ALK-rearranged lung tumors compared to treatment-naïve controls, supporting a role for identified resistance mechanisms in clinical resistance.

Insertion mutations in EGFR and HER2 both occur at analogous positions in exon 20. Non-small cell lung cancer (NSCLC) patients with tumors harboring these mutations seldom achieve clinical responses to dacomitinib and afatinib, two covalent quinazoline-based inhibitors of EGFR or HER2, respectively. In this study, we investigated the effects of specific EGFR and HER2 exon 20 insertion mutations from NSCLC patients that had clinically achieved a partial response after dacomitinib treatment. We identified Gly770 as a common feature among the drug-sensitive mutations. Structural modeling suggested that this mutation may facilitate inhibitor binding to EGFR. Introduction of Gly770 into two dacomitinib-resistant EGFR exon 20 insertion mutants restored sensitivity to dacomitinib. Based on these findings we used afatinib to treat a NSCLC patient whose tumor harbored the HER2 V777_G778insGSP mutation and achieved a durable partial response. We further identified secondary mutations in EGFR (T790M or C797S) and HER2 (C805S) that mediated acquired drug resistance in drug-sensitive EGFR or HER2 exon 20 insertion models. Overall, our findings identified a subset of EGFR and HER2 exon 20 insertion mutations that are sensitive to existing covalent quinazoline-based EGFR/HER2 inhibitors, with implications for current clinical treatment and next-generation small molecule inhibitors.

C-C chemokine ligand 2 (CCL2) stimulates tumor growth, metastasis, and angiogenesis. Carlumab, a human IgG1κ anti-CCL2 mAb, has shown antitumor activity in preclinical and clinical trials. We conducted a first-in-human phase 1b study of carlumab with one of four chemotherapy regimens (docetaxel, gemcitabine, paclitaxel + carboplatin, and pegylated liposomal doxorubicin HCl [PLD]). Patients had advanced solid tumors for which ≥1 of these regimens was considered standard of care or for whom no other treatment options existed. Dose-limiting toxicities included one grade 4 febrile neutropenia (docetaxel arm) and one grade 3 neutropenia (gemcitabine arm). Combination treatment with carlumab had no clinically relevant pharmacokinetic effect on docetaxel (n = 15), gemcitabine (n = 12), paclitaxel or carboplatin (n = 12), or PLD (n = 14). Total serum CCL2 concentrations increased post-treatment with carlumab alone, consistent with carlumab-CCL2 binding, and continued increase in the presence of all chemotherapy regimens. Free CCL2 declined immediately post-treatment with carlumab but increased with further chemotherapy administrations in all arms, suggesting that carlumab could sequester CCL2 for only a short time. Neither antibodies against carlumab nor consistent changes in circulating tumor cells (CTCs) or circulating endothelial cells (CECs) enumeration were observed. Three of 19 evaluable patients showed a 30 % decrease from baseline urinary cross-linked N-telopeptide of type I collagen (uNTx). One partial response and 18 (38 %) stable disease responses were observed. The most common drug-related grade ≥3 adverse events were docetaxel arm-neutropenia (6/15) and febrile neutropenia (4/15); gemcitabine arm-neutropenia (2/12); paclitaxel + carboplatin arm-neutropenia, thrombocytopenia (4/12 each), and anemia (2/12); and PLD arm-anemia (3/14) and stomatitis (2/14). Carlumab could be safely administered at 10 or 15 mg/kg in combination with standard-of-care chemotherapy and was well-tolerated, although no long-term suppression of serum CCL2 or significant tumor responses were observed.

Background Current technology permits an unbiased massive analysis of somatic genetic alterations from tumor DNA as well as the generation of individualized mouse xenografts (Avatar models). This work aimed to evaluate our experience integrating these two strategies to personalize the treatment of patients with cancer. Methods We performed whole-exome sequencing analysis of 25 patients with advanced solid tumors to identify putatively actionable tumor-specific genomic alterations. Avatar models were used as an in vivo platform to test proposed treatment strategies. Results Successful exome sequencing analyses have been obtained for 23 patients. Tumor-specific mutations and copy-number variations were identified. All samples profiled contained relevant genomic alterations. Tumor was implanted to create an Avatar model from 14 patients and 10 succeeded. Occasionally, actionable alterations such as mutations in NF1, PI3KA, and DDR2 failed to provide any benefit when a targeted drug was tested in the Avatar and, accordingly, treatment of the patients with these drugs was not effective. To date, 13 patients have received a personalized treatment and 6 achieved durable partial remissions. Prior testing of candidate treatments in Avatar models correlated with clinical response and helped to select empirical treatments in some patients with no actionable mutations. Conclusion The use of full genomic analysis for cancer care is encouraging but presents important challenges that will need to be solved for broad clinical application. Avatar models are a promising investigational platform for therapeutic decision making. While limitations still exist, this strategy should be further tested.

Purpose: LKB1 loss is common in lung cancer, but no assay exists to efficiently evaluate the presence or absence of LKB1. We validated an IHC assay for LKB1 loss and determined the impact of LKB1 loss in KRAS-mutant non-small cell lung cancer (NSCLC).Experimental Design: We optimized and validated an IHC assay for LKB1 (clone Ley37D/G6) using a panel of lung cancer cell lines and tumors with known LKB1 mutations, including 2 patients with Peutz-Jeghers syndrome (PJS) who developed lung adenocarcinoma. We retrospectively analyzed tumors for LKB1 using IHC from 154 KRAS-mutant NSCLC patients, including 123 smokers and 31 never-smokers, and correlated the findings with patient and tumor characteristics and clinical outcome.Results: LKB1 expression was lost by IHC in 30% of KRASmutant NSCLC (smokers 35% vs. never-smokers 13%, P ¼ 0.017). LKB1 loss did not correlate with a specific KRAS mutation but was more frequent in tumors with KRAS transversion mutations (P ¼ 0.029). KRAS-mutant NSCLC patients with concurrent LKB1 loss had a higher number of metastatic sites at the time of diagnosis (median 2.5 vs. 2, P ¼ 0.01), higher incidence of extrathoracic metastases (P ¼ 0.01), and developed brain metastasis more frequently (48% vs. 25%, P ¼ 0.02). There was a nonsignificant trend to worse survival in stage IV KRAS-mutant NSCLC patients with LKB1 loss.Conclusions: LKB1 IHC is a reliable and efficient assay to evaluate for loss of LKB1 in clinical samples of NSCLC. LKB1 loss is more common in smokers, and is associated with a more aggressive clinical phenotype in KRAS-mutant NSCLC patients, accordingly to preclinical models.

Purpose: Targeting mutations leading to PI3K/mTOR/Akt activation are of interest in thyroid cancer (TC). We evaluated the efficacy of everolimus in aggressive, radioactive iodine refractory (RAIR) TC and correlated tumor mutational profiling with response. Exploratory medullary and anaplastic TC cohorts were included.Experimental Design: This single-arm, multi-institutional phase II study was conducted from 2009-2013 in patients with incurable RAIR TC who had radiographic progression six months prior to enrollment. The primary endpoint was progression-free survival (PFS) with a median follow-up of 31.8 months. The study is closed to enrollment but treatment and follow-up are ongoing. A targeted next-generation sequencing platform was used for mutational analysis.Results: Thirty-three patients with differentiated TC (DTC), 10 with medullary TC (MTC), and 7 with anaplastic TC (ATC) enrolled. For the DTC cohort, median PFS was 12.9 months (95% CI, 7.3-18.5) with a 2-year PFS of 23.6% (95% CI, 10.5-39.5). Median OS was not reached; 2-year OS was 73.5% (95% CI, 53.8-85.8). Among ATC patients, 1 had a partial response and was progression-free until 17.9 months post study entry and one had disease stability for 26 months, respectively. The genomically profiled cohort enriched for PI3K/mTOR/Akt alterations. PI3K/mTOR/Akt mutated ATC subgroups appeared to benefit from everolimus. Treatmentrelated adverse events were as anticipated. Conclusion:Everolimus has significant anti-tumor activity in TC. While genomic profiling does not currently guide therapeutic selection in TC patients, these data have important implications when considering the use of an mTOR inhibitor in an era of precision medicine.