Peristromal niches protect lung cancers from targeted therapies through a combined effect of multiple molecular mediators.

Targeted therapies directed against oncogenic signaling addictions, such as inhibitors of ALK in ALK+ NSCLC often induce strong and durable clinical responses. However, they are not curative in metastatic cancers, as some tumor cells persist through therapy, eventually developing resistance. Therapy sensitivity can reflect not only cell-intrinsic mechanisms but also inputs from stromal microenvironment. Yet, the contribution of tumor stroma to therapeutic responses in vivo remains poorly defined. To address this gap of knowledge, we assessed the contribution of stroma-mediated resistance to therapeutic responses to the frontline ALK inhibitor alectinib in xenograft models of ALK+ NSCLC. We found that stroma-proximal tumor cells are partially protected against cytostatic effects of alectinib. This effect is observed not only in remission, but also during relapse, indicating the strong contribution of stroma-mediated resistance to both persistence and resistance. This therapy-protective effect of the stromal niche reflects a combined action of multiple mechanisms, including growth factors and extracellular matrix components. Consequently, despite improving alectinib responses, suppression of any individual resistance mechanism was insufficient to fully overcome the protective effect of stroma. Focusing on shared collateral sensitivity of persisters offered a superior therapeutic benefit, especially when using an antibody-drug conjugate with bystander effect to limit therapeutic escape. These findings indicate that stroma-mediated resistance might be the major contributor to both residual and progressing disease and highlight the limitation of focusing on suppressing a single resistance mechanism at a time.

SHP2 inhibition displays efficacy as a monotherapy and in combination with JAK2 inhibition in preclinical models of myeloproliferative neoplasms.

Myeloproliferative neoplasms (MPNs), including polycythemia vera, essential thrombocytosis, and primary myelofibrosis, are clonal hematopoietic neoplasms driven by mutationally activated signaling by the JAK2 tyrosine kinase. Although JAK2 inhibitors can improve MPN patients' quality of life, they do not induce complete remission as disease-driving cells persistently survive therapy. ERK activation has been highlighted as contributing to JAK2 inhibitor persistent cell survival. As ERK is a component of signaling by activated RAS proteins and by JAK2 activation, we sought to inhibit RAS activation to enhance responses to JAK2 inhibition in preclinical MPN models. We found the SHP2 inhibitor RMC-4550 significantly enhanced growth inhibition of MPN cell lines in combination with the JAK2 inhibitor ruxolitinib, effectively preventing ruxolitinib persistent growth, and the growth and viability of established ruxolitinib persistent cells remained sensitive to SHP2 inhibition. Both SHP2 and JAK2 inhibition diminished cellular RAS-GTP levels, and their concomitant inhibition enhanced ERK inactivation and increased apoptosis. Inhibition of SHP2 inhibited the neoplastic growth of MPN patient hematopoietic progenitor cells and exhibited synergy with ruxolitinib. RMC-4550 antagonized MPN phenotypes and increased survival of an MPN mouse model driven by MPL-W515L. The combination of RMC-4550 and ruxolitinib, which was safe and tolerated in healthy mice, further inhibited disease compared to ruxolitinib monotherapy, including extending survival. Given SHP2 inhibitors are undergoing clinical evaluation in patients with solid tumors, our preclinical findings suggest that SHP2 is a candidate therapeutic target with potential for rapid translation to clinical assessment to improve current targeted therapies for MPN patients.

Differential network analysis of ROS1 inhibitors reveals lorlatinib polypharmacology through co-targeting PYK2.

Multiple tyrosine kinase inhibitors (TKIs) are often developed for the same indication. However, their relative overall efficacy is frequently incompletely understood and they may harbor unrecognized targets that cooperate with the intended target. We compared several ROS1 TKIs for inhibition of ROS1-fusion-positive lung cancer cell viability, ROS1 autophosphorylation and kinase activity, which indicated disproportionately higher cellular potency of one TKI, lorlatinib. Quantitative chemical and phosphoproteomics across four ROS1 TKIs and differential network analysis revealed that lorlatinib uniquely impacted focal adhesion signaling. Functional validation using pharmacological probes, RNA interference, and CRISPR-Cas9 knockout uncovered a polypharmacology mechanism of lorlatinib by dual targeting ROS1 and PYK2, which form a multiprotein complex with SRC. Rational multi-targeting of this complex by combining lorlatinib with SRC inhibitors exhibited pronounced synergy. Taken together, we show that systems pharmacology-based differential network analysis can dissect mixed canonical/non-canonical polypharmacology mechanisms across multiple TKIs enabling the design of rational drug combinations.

MIG6 Mediates Adaptive and Acquired Resistance to ALK/ROS1 Fusion Kinase Inhibition through EGFR Bypass Signaling.

Despite the initial benefit from tyrosine kinase inhibitors (TKI) targeting oncogenic ALK and ROS1 gene fusions in non-small cell lung cancer, complete responses are rare and resistance ultimately emerges from residual tumor cells. Although several acquired resistance mechanisms have been reported at the time of disease progression, adaptative resistance mechanisms that contribute to residual diseases before the outgrowth of tumor cells with acquired resistance are less clear. For the patients who have progressed after TKI treatments, but do not demonstrate ALK/ROS1 kinase mutations, there is a lack of biomarkers to guide effective treatments. Herein, we found that phosphorylation of MIG6, encoded by the ERRFI1 gene, was downregulated by ALK/ROS1 inhibitors as were mRNA levels, thus potentiating EGFR activity to support cell survival as an adaptive resistance mechanism. MIG6 downregulation was sustained following chronic exposure to ALK/ROS1 inhibitors to support the establishment of acquired resistance. A higher ratio of EGFR to MIG6 expression was found in ALK TKI-treated and ALK TKI-resistant tumors and correlated with the poor responsiveness to ALK/ROS1 inhibition in patient-derived cell lines. Furthermore, we identified and validated a MIG6 EGFR-binding domain truncation mutation in mediating resistance to ROS1 inhibitors but sensitivity to EGFR inhibitors. A MIG6 deletion was also found in a patient after progressing to ROS1 inhibition. Collectively, this study identifies MIG6 as a novel regulator for EGFR-mediated adaptive and acquired resistance to ALK/ROS1 inhibitors and suggests EGFR to MIG6 ratios and MIG6-damaging alterations as biomarkers to predict responsiveness to ALK/ROS1 and EGFR inhibitors.

Osimertinib vs. afatinib as first-line treatment for patients with metastatic non-small cell lung cancer with an EGFR exon 19 deletion or exon 21 L858R mutation.

Background: The optimal treatment sequencing for patients with metastatic epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) remains a subject of debate. In the United States, osimertinib is the preferred EGFR tyrosine kinase inhibitor (TKI) in the first-line setting. However, small retrospective studies suggest that alternative EGFR TKI sequencing strategies may produce similar outcomes. This study aimed to compare the outcomes of patients with metastatic NSCLC harboring an EGFR exon 19 deletion or exon 21 L858R mutation treated with osimertinib vs. afatinib as first-line therapy. Methods: This retrospective, single-institution study examined 86 patients with metastatic EGFR-mutant NSCLC treated with either afatinib (n=15) or osimertinib (n=71) in the first-line setting. The primary outcome was progression-free survival (PFS), and secondary endpoints included time on EGFR TKI, overall survival (OS), and the incidence of adverse events (AEs). Results: There was no difference in the PFS (median: 27.9 vs. 29.0 months, P=0.75), OS (P=0.18), and the median time on first-line EGFR TKI (23.9 vs. 15.2 months, P=0.10) between the afatinib and osimertinib groups, respectively. The number of AEs was also similar between the two treatment groups (P=0.17). Conclusions: In this real-world retrospective study, there were no differences in PFS or OS between patients treated with afatinib or osimertinib in the first-line setting. These findings should be further investigated in larger prospective studies.

Amivantamab plus lazertinib in osimertinib-relapsed EGFR-mutant advanced non-small cell lung cancer: a phase 1 trial.

Patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) often develop resistance to current standard third-generation EGFR tyrosine kinase inhibitors (TKIs); no targeted treatments are approved in the osimertinib-relapsed setting. In this open-label, dose-escalation and dose-expansion phase 1 trial, the potential for improved anti-tumor activity by combining amivantamab, an EGFR-MET bispecific antibody, with lazertinib, a third-generation EGFR TKI, was evaluated in patients with EGFR-mutant NSCLC whose disease progressed on third-generation TKI monotherapy but were chemotherapy naive (CHRYSALIS cohort E). In the dose-escalation phase, the recommended phase 2 combination dose was established; in the dose-expansion phase, the primary endpoints were safety and overall response rate, and key secondary endpoints included progression-free survival and overall survival. The safety profile of amivantamab and lazertinib was generally consistent with previous experience of each agent alone, with 4% experiencing grade ≥3 events; no new safety signals were identified. In an exploratory cohort of 45 patients who were enrolled without biomarker selection, the primary endpoint of investigator-assessed overall response rate was 36% (95% confidence interval, 22-51). The median duration of response was 9.6 months, and the median progression-free survival was 4.9 months. Next-generation sequencing and immunohistochemistry analyses identified high EGFR and/or MET expression as potential predictive biomarkers of response, which will need to be validated with prospective assessment. ClinicalTrials.gov identifier: NCT02609776 .

A phase I/IB trial of binimetinib in combination with erlotinib in NSCLC harboring activating KRAS or EGFR mutations.

BACKGROUND: Activating mutations in EGFR or KRAS are highly prevalent in NSCLC, share activation of the MAPK pathway and may be amenable to combination therapy to prevent negative feedback activation. METHODS: In this phase 1/1B trial, we tested the combination of binimetinib and erlotinib in patients with advanced NSCLC with at least 1 prior line of treatment (unless with activating EGFR mutation which could be treatment-naïve). A subsequent phase 1B expansion accrued patients with either EGFR- or KRAS-mutation using the recommended phase 2 dose (RP2D) from Phase 1. The primary objective was to evaluate the safety of binimetinib plus erlotinib and establish the RP2D. RESULTS: 43 patients enrolled (dose-escalation = 23; expansion = 20). 17 harbored EGFR mutation and 22 had KRAS mutation. The RP2D was erlotinib 100 mg daily and binimetinib 15 mg BID × 5 days/week. Common AEs across all doses included diarrhea (69.8%), rash (44.2%), fatigue (32.6%), and nausea (32.6%), and were primarily grade 1/2. Among KRAS mutant patients, 1 (5%) had confirmed partial response and 8 (36%) achieved stable disease as best overall response. Among EGFR mutant patients, 9 were TKI-naïve with 8 (89%) having partial response, and 8 were TKI-pretreated with no partial responses and 1 (13%) stable disease as best overall response. CONCLUSIONS: Binimetinib plus erlotinib demonstrated a manageable safety profile and modest efficacy including one confirmed objective response in a KRAS mutant patient. While clinical utility of this specific combination was limited, these results support development of combinations using novel small molecule inhibitors of RAS, selective EGFR- and other MAPK pathway inhibitors, many of which have improved therapeutic indices. CLINICAL TRIAL REGISTRATION: NCT01859026.

Deciphering Phenotypes from Protein Biomarkers for Translational Research with PIPER.

Liquid chromatography-multiple reaction monitoring mass spectrometry (LC-MRM) has widespread clinical use for detection of inborn errors of metabolism, therapeutic drug monitoring, and numerous other applications. This technique detects proteolytic peptides as surrogates for protein biomarker expression, mutation, and post-translational modification in individual clinical assays and in cancer research with highly multiplexed quantitation across biological pathways. LC-MRM for protein biomarkers must be translated from multiplexed research-grade panels to clinical use. LC-MRM panels provide the capability to quantify clinical biomarkers and emerging protein markers to establish the context of tumor phenotypes that provide highly relevant supporting information. An application to visualize and communicate targeted proteomics data will empower translational researchers to move protein biomarker panels from discovery to clinical use. Therefore, we have developed a web-based tool for targeted proteomics that provides pathway-level evaluations of key biological drivers (e.g., EGFR signaling), signature scores (representing phenotypes) (e.g., EMT), and the ability to quantify specific drug targets across a sample cohort. This tool represents a framework for integrating summary information, decision algorithms, and risk scores to support Physician-Interpretable Phenotypic Evaluation in R (PIPER) that can be reused or repurposed by other labs to communicate and interpret their own biomarker panels.

Targeting BET Proteins Downregulates miR-33a To Promote Synergy with PIM Inhibitors in CMML.

PURPOSE: Preclinical studies in myeloid neoplasms have demonstrated efficacy of bromodomain and extra-terminal protein inhibitors (BETi). However, BETi demonstrates poor single-agent activity in clinical trials. Several studies suggest that combination with other anticancer inhibitors may enhance the efficacy of BETi. EXPERIMENTAL DESIGN: To nominate BETi combination therapies for myeloid neoplasms, we used a chemical screen with therapies currently in clinical cancer development and validated this screen using a panel of myeloid cell line, heterotopic cell line models, and patient-derived xenograft models of disease. We used standard protein and RNA assays to determine the mechanism responsible for synergy in our disease models. RESULTS: We identified PIM inhibitors (PIMi) as therapeutically synergistic with BETi in myeloid leukemia models. Mechanistically, we show that PIM kinase is increased after BETi treatment, and that PIM kinase upregulation is sufficient to induce persistence to BETi and sensitize cells to PIMi. Furthermore, we demonstrate that miR-33a downregulation is the underlying mechanism driving PIM1 upregulation. We also show that GM-CSF hypersensitivity, a hallmark of chronic myelomonocytic leukemia (CMML), represents a molecular signature for sensitivity to combination therapy. CONCLUSIONS: Inhibition of PIM kinases is a potential novel strategy for overcoming BETi persistence in myeloid neoplasms. Our data support further clinical investigation of this combination.

Management of infusion-related reactions (IRRs) in patients receiving amivantamab in the CHRYSALIS study.

BACKGROUND: Amivantamab, a fully humanized EGFR-MET bispecific antibody, has antitumor activity in diverse EGFR- and MET-driven non-small cell lung cancer (NSCLC) and a safety profile consistent with associated on-target activities. Infusion-related reaction(s) (IRR[s]) are reported commonly with amivantamab. We review IRR and subsequent management in amivantamab-treated patients. METHODS: Patients treated with the approved dose of intravenous amivantamab (1050 mg, <80 kg; 1400 mg, ≥80 kg) in CHRYSALIS-an ongoing, phase 1 study in advanced EGFR-mutated NSCLC-were included in this analysis. IRR mitigations included split first dose (350 mg, day 1 [D1]; remainder, D2), reduced initial infusion rates with proactive infusion interruption, and steroid premedication before initial dose. For all doses, pre-infusion antihistamines and antipyretics were required. Steroids were optional after the initial dose. RESULTS: As of 3/30/2021, 380 patients received amivantamab. IRRs were reported in 256 (67%) patients. Signs/symptoms of IRR included chills, dyspnea, flushing, nausea, chest discomfort, and vomiting. Most of the 279 IRRs were grade 1 or 2; grade 3 and 4 IRR occurred in 7 and 1 patients, respectively. Most (90%) IRRs occurred on cycle 1, D1 (C1D1); median time-to-first-IRR onset during C1D1 was 60 min; and first-infusion IRRs did not compromise subsequent infusions. Per protocol, IRR was mitigated on C1D1 with holding of infusion (56% [214/380]), reinitiating at reduced rate (53% [202/380]), and aborting infusion (14% [53/380]). C1D2 infusions were completed in 85% (45/53) of patients who had C1D1 infusions aborted. Four patients (1% [4/380]) discontinued treatment due to IRR. In studies aimed at elucidating the underlying mechanism(s) of IRR, no pattern was observed between patients with versus without IRR. CONCLUSION: IRRs with amivantamab were predominantly low grade and limited to first infusion, and rarely occurred with subsequent dosing. Close monitoring for IRR with the initial amivantamab dose and early intervention at first IRR signs/symptoms should be part of routine amivantamab administration.

Network models of protein phosphorylation, acetylation, and ubiquitination connect metabolic and cell signaling pathways in lung cancer.

We analyzed large-scale post-translational modification (PTM) data to outline cell signaling pathways affected by tyrosine kinase inhibitors (TKIs) in ten lung cancer cell lines. Tyrosine phosphorylated, lysine ubiquitinated, and lysine acetylated proteins were concomitantly identified using sequential enrichment of post translational modification (SEPTM) proteomics. Machine learning was used to identify PTM clusters that represent functional modules that respond to TKIs. To model lung cancer signaling at the protein level, PTM clusters were used to create a co-cluster correlation network (CCCN) and select protein-protein interactions (PPIs) from a large network of curated PPIs to create a cluster-filtered network (CFN). Next, we constructed a Pathway Crosstalk Network (PCN) by connecting pathways from NCATS BioPlanet whose member proteins have PTMs that co-cluster. Interrogating the CCCN, CFN, and PCN individually and in combination yields insights into the response of lung cancer cells to TKIs. We highlight examples where cell signaling pathways involving EGFR and ALK exhibit crosstalk with BioPlanet pathways: Transmembrane transport of small molecules; and Glycolysis and gluconeogenesis. These data identify known and previously unappreciated connections between receptor tyrosine kinase (RTK) signal transduction and oncogenic metabolic reprogramming in lung cancer. Comparison to a CFN generated from a previous multi-PTM analysis of lung cancer cell lines reveals a common core of PPIs involving heat shock/chaperone proteins, metabolic enzymes, cytoskeletal components, and RNA-binding proteins. Elucidation of points of crosstalk among signaling pathways employing different PTMs reveals new potential drug targets and candidates for synergistic attack through combination drug therapy.

Differential Chemoproteomics Reveals MARK2/3 as Cell Migration-Relevant Targets of the ALK Inhibitor Brigatinib.

Metastasis poses a major challenge in cancer management, including EML4-ALK-rearranged non-small cell lung cancer (NSCLC). As cell migration is a critical step during metastasis, we assessed the anti-migratory activities of several clinical ALK inhibitors in NSCLC cells and observed differential anti-migratory capabilities despite similar ALK inhibition, with brigatinib displaying superior anti-migratory effects over other ALK inhibitors. Applying an unbiased in situ mass spectrometry-based chemoproteomics approach, we determined the proteome-wide target profile of brigatinib in EML4-ALK+ NSCLC cells. Dose-dependent and cross-competitive chemoproteomics suggested MARK2 and MARK3 as relevant brigatinib kinase targets. Functional validation showed that combined pharmacological inhibition or genetic modulation of MARK2/3 inhibited cell migration. Consistently, brigatinib treatment induced inhibitory YAP1 phosphorylation downstream of MARK2/3. Collectively, our data suggest that brigatinib exhibits unusual cross-phenotype polypharmacology as, despite similar efficacy for inhibiting EML4-ALK-dependent cell proliferation as other ALK inhibitors, it more effectively prevented migration of NSCLC cells due to co-targeting of MARK2/3.

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

INTRODUCTION: ERBB2 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. METHODS: ZENITH20 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. RESULTS: A 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%). CONCLUSIONS: Poziotinib was found to have clinically meaningful efficacy with a manageable toxicity profile for patients with treatment-naive NSCLC harboring HER2 exon 20 mutations.

Dose-Limiting Pulmonary Toxicity in a Phase 1/2 Study of Radiation and Chemotherapy with Ipilimumab Followed by Nivolumab for Patients With Stage 3 Unresectable Non-Small Cell Lung Cancer.

PURPOSE: We hypothesized that concurrent ipilimumab with chemoradiationtherapy (chemoRT) followed by maintenance nivolumab would be safe for patients with unresectable stage III non-small cell lung cancer (NSCLC). We aimed to assess the safety (phase 1) and the 12-month progression-free survival (PFS) (phase 2) in a multi-institution prospective trial. METHODS AND MATERIALS: Eligible patients had unresectable stage III NSCLC. The treatment included platinum doublet chemotherapy with concurrent thoracic radiation therapy to 60 Gy in 30 fractions and ipilimumab (1 mg/kg) delivered during weeks 1 and 4. After chemoRT, maintenance nivolumab (480 mg) was given every 4 weeks for up to 12 cycles. Adverse events (AEs) were assessed according to the Common Terminology Criteria for Adverse Events, version 5.0. Survival analyses were performed with Kaplan Meier (KM) methods and log-rank tests. RESULTS: The trial was discontinued early after enrolling 19 patients without proceeding to the phase 2 component because of unacceptable toxicity. Sixteen patients (84%) had grade ≥3 (G3+) possible treatment-related toxicity, most commonly pulmonary AEs (n = 8, 42%). Fourteen patients (74%) discontinued study therapy early because of AEs (n = 12, 63%) or patient choice (n = 2, 11%). Eleven patients (58%) experienced G2+ pulmonary toxicity with median time to onset 4.1 months (95% CI 2.6-not reached [NR]), and 12-month freedom from G2+ pulmonary toxicity 37% (95% CI, 16-59). Five patients had G5 AEs, including 3 with G5 pulmonary AEs (1 respiratory failure with pneumonitis and pulmonary embolism, 1 pneumonia/chronic obstructive pulmonary disease exacerbation, 1 pulmonary fibrosis). Despite toxicities, the median PFS was 19.2 months (95% CI 6.1-NR) and the median overall survival was NR (95% CI 6.1-NR) with median follow-up of 30.1 months by the reverse KM method. CONCLUSIONS: Concurrent ipilimumab with chemoRT for unresectable stage III NSCLC is associated with pulmonary toxicity that may limit opportunities for improved outcomes. Future studies aiming to incorporate ipilimumab or other anti-CTLA4 therapies into management of unresectable stage III NSCLC should consider careful measures to minimize toxicity risk.

Chemical Proteomics with Novel Fully Functionalized Fragments and Stringent Target Prioritization Identifies the Glutathione-Dependent Isomerase GSTZ1 as a Lung Cancer Target.

Photoreactive fragment-like probes have been applied to discover target proteins that constitute novel cellular vulnerabilities and to identify viable chemical hits for drug discovery. Through forming covalent bonds, functionalized probes can achieve stronger target engagement and require less effort for on-target mechanism validation. However, the design of probe libraries, which directly affects the biological target space that is interrogated, and effective target prioritization remain critical challenges of such a chemical proteomic platform. In this study, we designed and synthesized a diverse panel of 20 fragment-based probes containing natural product-based privileged structural motifs for small-molecule lead discovery. These probes were fully functionalized with orthogonal diazirine and alkyne moieties and used for protein crosslinking in live lung cancer cells, target enrichment via "click chemistry," and subsequent target identification through label-free quantitative liquid chromatography-tandem mass spectrometry analysis. Pair-wise comparison with a blunted negative control probe and stringent prioritization via individual cross-comparisons against the entire panel identified glutathione S-transferase zeta 1 (GSTZ1) as a specific and unique target candidate. DepMap database query, RNA interference-based gene silencing, and proteome-wide tyrosine reactivity profiling suggested that GSTZ1 cooperated with different oncogenic alterations by supporting survival signaling in refractory non-small cell lung cancer cells. This finding may form the basis for developing novel GSTZ1 inhibitors to improve the therapeutic efficacy of oncogene-directed targeted drugs. In summary, we designed a novel fragment-based probe panel and developed a target prioritization scheme with improved stringency, which allows for the identification of unique target candidates, such as GSTZ1 in refractory lung cancer.

Surgical results of the Lung Cancer Mutation Consortium 3 trial: A phase II multicenter single-arm study to investigate the efficacy and safety of atezolizumab as neoadjuvant therapy in patients with stages IB-select IIIB resectable non-small cell lung cancer.

OBJECTIVE: Multimodality treatment for resectable non-small cell lung cancer has long remained at a therapeutic plateau. Immune checkpoint inhibitors are highly effective in advanced non-small cell lung cancer and promising preoperatively in small clinical trials for resectable non-small cell lung cancer. This large multicenter trial tested the safety and efficacy of neoadjuvant atezolizumab and surgery. METHODS: Patients with stage IB to select IIIB resectable non-small cell lung cancer and Eastern Cooperative Oncology Group performance status 0/1 were eligible. Patients received atezolizumab 1200 mg intravenously every 3 weeks for 2 cycles or less followed by resection. The primary end point was major pathological response in patients without EGFR/ALK+ alterations. Pre- and post-treatment computed tomography, positron emission tomography, pulmonary function tests, and biospecimens were obtained. Adverse events were recorded by Common Terminology Criteria for Adverse Events v.4.0. RESULTS: From April 2017 to February 2020, 181 patients were entered in the study. Baseline characteristics were mean age, 65.1 years; female, 93 of 181 (51%); nonsquamous histology, 112 of 181 (62%); and clinical stages IIB to IIIB, 147 of 181 (81%). In patients without EGFR/ALK alterations who underwent surgery, the major pathological response rate was 20% (29/143; 95% confidence interval, 14-28) and the pathological complete response rate was 6% (8/143; 95% confidence interval, 2-11). There were no grade 4/5 treatment-related adverse events preoperatively. Of 159 patients (87.8%) undergoing surgery, 145 (91%) had pathologic complete resection. There were 5 (3%) intraoperative complications, no intraoperative deaths, and 2 postoperative deaths within 90 days, 1 treatment related. Median disease-free and overall survival have not been reached. CONCLUSIONS: Neoadjuvant atezolizumab in resectable stage IB to IIIB non-small cell lung cancer was well tolerated, yielded a 20% major pathological response rate, and allowed safe, complete surgical resection. These results strongly support the further development of immune checkpoint inhibitors as preoperative therapy in locally advanced non-small cell lung cancer.

Neoadjuvant atezolizumab for resectable non-small cell lung cancer: an open-label, single-arm phase II trial.

In an ongoing, open-label, single-arm phase II study ( NCT02927301 ), 181 patients with untreated, resectable, stage IB-IIIB non-small cell lung cancer received two doses of neoadjuvant atezolizumab monotherapy. The primary end point was major pathological response (MPR; ≤10% viable malignant cells) in resected tumors without EGFR or ALK alterations. Of the 143 patients in the primary end point analysis, the MPR was 20% (95% confidence interval, 14-28%). With a minimum duration of follow-up of 3 years, the 3-year survival rate of 80% was encouraging. The most common adverse events during the neoadjuvant phase were fatigue (39%, 71 of 181) and procedural pain (29%, 53 of 181), along with expected immune-related toxicities; there were no unexpected safety signals. In exploratory analyses, MPR was predicted using the pre-treatment peripheral blood immunophenotype based on 14 immune cell subsets. Immune cell subsets predictive of MPR in the peripheral blood were also identified in the tumor microenvironment and were associated with MPR. This study of neoadjuvant atezolizumab in a large cohort of patients with resectable non-small cell lung cancer was safe and met its primary end point of MPR ≥ 15%. Data from this single-arm, non-randomized trial suggest that profiles of innate immune cells in pre-treatment peripheral blood may predict pathological response after neoadjuvant atezolizumab, but additional studies are needed to determine whether these profiles can inform patient selection and new therapeutic approaches.

IGF-binding proteins secreted by cancer-associated fibroblasts induce context-dependent drug sensitization of lung cancer cells.

Cancer-associated fibroblasts (CAFs) in the tumor microenvironment are often linked to drug resistance. Here, we found that coculture with CAFs or culture in CAF-conditioned medium unexpectedly induced drug sensitivity in certain lung cancer cell lines. Gene expression and secretome analyses of CAFs and normal lung-associated fibroblasts (NAFs) revealed differential abundance of insulin-like growth factors (IGFs) and IGF-binding proteins (IGFBPs), which promoted or inhibited, respectively, signaling by the receptor IGF1R and the kinase FAK. Similar drug sensitization was seen in gefitinib-resistant, EGFR-mutant PC9GR lung cancer cells treated with recombinant IGFBPs. Conversely, drug sensitivity was decreased by recombinant IGFs or conditioned medium from CAFs in which IGFBP5 or IGFBP6 was silenced. Phosphoproteomics and receptor tyrosine kinase (RTK) array analyses indicated that exposure of PC9GR cells to CAF-conditioned medium also inhibited compensatory IGF1R and FAK signaling induced by the EGFR inhibitor osimertinib. Combined small-molecule inhibition of IGF1R and FAK phenocopied the CAF-mediated effects in culture and increased the antitumor effect of osimertinib in mice. Cells that were osimertinib resistant and had MET amplification or showed epithelial-to-mesenchymal transition also displayed residual sensitivity to IGFBPs. Thus, CAFs promote or reduce drug resistance in a context-dependent manner, and deciphering the relationship between the differential content of CAF secretomes and the signaling dependencies of the tumor may reveal effective combination treatment strategies.