Phase 2 Trial of Consolidation Pembrolizumab After Proton Reirradiation for Thoracic Recurrences of Non-Small Cell Lung Cancer

PURPOSE

Reirradiation (reRT) with proton beam therapy (PBT) may offer a chance of cure while minimizing toxicity for patients with isolated intrathoracic recurrences of non-small cell lung cancer (NSCLC). However, distant failure remains common, necessitating strategies to integrate more effective systemic therapy.

METHODS AND MATERIALS

This was a phase 2, single-arm trial (NCT03087760) of consolidation pembrolizumab after PBT reRT for locoregional recurrences of NSCLC. Four to 12 weeks after completion of 60 to 70 Gy PBT reRT, patients without progressive disease received pembrolizumab for up to 12 months. Primary endpoint was progression-free survival (PFS), measured from the start of reRT. Secondary endpoints were overall survival (OS) and National Cancer Institute Common Terminology Criteria for Adverse Events, version 5.0 toxicity.

RESULTS

Between 2017 and 2021, 22 patients received PBT reRT. Median interval from prior radiation end to reRT start was 20 months. Most recurrences (91%) were centrally located. Most patients received concurrent chemotherapy (95%) and pencil beam scanning PBT (77%), and 36% had received prior durvalumab. Fifteen patients (68%) initiated consolidation pembrolizumab on trial and received a median of 3 cycles (range, 2-17). Pembrolizumab was discontinued most commonly due to toxicity (n = 5; 2 were pembrolizumab-related), disease progression (n = 4), and completion of 1 year (n = 3). Median follow-up was 38.7 months. Median PFS and OS were 8.8 months (95% CI, 4.2-23.7) and 22.8 months (95% CI, 6.9-not reached), respectively. There was only one isolated in-field failure after reRT. Grade ≥3 toxicities occurred in 10 patients (45%); 2 were pembrolizumab-related. There were 2 grade 5 toxicities, an aorto-esophageal fistula at 6.9 months and hemoptysis at 46.8 months, both probably from reRT. The trial closed early due to widespread adoption of immunotherapy off-protocol.

CONCLUSIONS

In the first-ever prospective trial combining PBT reRT with consolidation immunotherapy, PFS was acceptable and OS favorable. Late grade 5 toxicity occurred in 2 of 22 patients. This approach may be considered in selected patients with isolated thoracic recurrences of NSCLC.

Patterns of Failure, Low-Volume Relapse, and Subsequent Ablative Management in Locally Advanced Non-Small Cell Lung Cancer Treated With Definitive Chemoradiation and Consolidation Immune Checkpoint Inhibitors

PURPOSE

The objective of this study was to describe the patterns of failure, frequency of low-volume relapse (LVR), and candidacy for ablative therapy at time of disease progression (PD) after chemoradiation and consolidative immunotherapy (CRT + ICI) in patients with stage III non-small cell lung cancer.

METHODS AND MATERIALS

We identified 229 consecutive patients with stage III non-small cell lung cancer treated with CRT + ICI between October 2017 and December 2021 at a single institution. PD was classified as isolated locoregional failure (LRF), isolated distant failure (DF), or synchronous LRF + DF. Any LRF was subclassified as in-field failure, marginal failure, or out-of-field failure. LVR was defined as 3 or fewer sites of PD in any number of organs. Ablative candidates were defined as having 5 or fewer sites of PD radiographically amenable to high-dose radiation or surgery. Time-to-event data were calculated using cumulative incidence analysis and Kaplan-Meier methods. Multivariable Cox modeling was used to examine the correlations between characteristics of relapse and postprogression survival.

RESULTS

Of the 229 patients, 119 (52%) had PD. Of these 119 patients, 20 (21%) had isolated LRF, 28 (24%) had synchronous LRF + DF, and 71 (60%) had isolated DF. Of the 48 patients with any LRF, 28 (58%) had in-field failure, 10 (21%) marginal failure, and 10 (21%) out-of-field failure. The cumulative incidence of LRF and DF was 13% (95% CI, 9.2%-18%) and 32% (95% CI, 26%-38%) at 1 year and 19% (95% CI, 14%-24%) and 39% (95% CI, 33%-46%) at 2 years, respectively. Overall, 64 patients (54%) were considered to have LVR. At time of PD, 60 patients (50%) were eligible for ablative therapy. Patients with LVR had longer median survival versus with high-volume relapse (37.4 vs 15.2 months, P < .001). On multivariable analysis, LVR (hazard ratio, 0.32; 95% CI, 0.18-0.56; P < .001) was associated with improved postprogression survival.

CONCLUSIONS

After CRT + ICI, approximately half of patients experience LVR at time of PD and are candidates for ablative therapies. Prospective trials are needed to validate the optimal treatment strategy for LVR.

The Efficacy and Safety of Treating Acquired MET Resistance Through Combinations of Parent and MET Tyrosine Kinase Inhibitors in Patients With Metastatic Oncogene-Driven NSCLC

Introduction

Acquired MET gene amplification, MET exon 14 skip mutations, or MET fusions can emerge as resistance mechanisms to tyrosine kinase inhibitors (TKIs) in patients with lung cancer. The efficacy and safety of combining MET TKIs (such as crizotinib, capmatinib, or tepotinib) with parent TKIs to target acquired MET resistance are not well characterized.

Methods

Multi-institutional retrospective chart review identified 83 patients with metastatic oncogene-driven NSCLC that were separated into the following two pairwise matched cohorts: (1) MET cohort (n = 41)-patients with acquired MET resistance continuing their parent TKI with a MET TKI added or (2) Chemotherapy cohort (n = 42)-patients without any actionable resistance continuing their parent TKI with a platinum-pemetrexed added. Clinicopathologic features, radiographic response (by means of Response Evaluation Criteria in Solid Tumors version 1.1), survival outcomes, adverse events (AEs) (by means of Common Terminology Criteria for Adverse Events version 5.0), and genomic data were collected. Survival outcomes were assessed using Kaplan-Meier methods. Multivariate modeling adjusted for lines of therapy, brain metastases, TP53 mutations, and oligometastatic disease.

Results

Within the MET cohort, median age was 56 years (range: 36-83 y). Most patients were never smokers (28 of 41, 68.3%). Baseline brain metastases were common (21 of 41, 51%). The most common oncogenes in the MET cohort were EGFR (30 of 41, 73.2%), ALK (seven of 41, 17.1%), and ROS1 (two of 41, 4.9%). Co-occurring TP53 mutations (32 of 41, 78%) were frequent. Acquired MET alterations included MET gene amplification (37 of 41, 90%), MET exon 14 mutations (two of 41, 5%), and MET gene fusions (two of 41, 5%). After multivariate adjustment, the objective response rate (ORR) was higher in the MET cohort versus the chemotherapy cohort (ORR: 69.2% versus 20%, p < 0.001). Within the MET cohort, MET gene copy number (≥10 versus 6-10) did not affect radiographic response (54.5% versus 68.4%, p = 0.698). There was no difference in ORR on the basis of MET TKI used (F [2, 36] = 0.021, p = 0.978). There was no difference in progression-free survival (5 versus 6 mo; hazard ratio = 0.64; 95% confidence interval: 0.34-1.23, p = 0.18) or overall survival (13 versus 11 mo; hazard ratio = 0.75; 95% confidence interval: 0.42-1.35, p = 0.34) between the MET and chemotherapy cohorts. In the MET cohort, dose reductions for MET TKI-related toxicities were common (17 of 41, 41.4%) but less frequent for parent TKIs (two of 41, 5%). Grade 3 AEs were not significant between crizotinib, capmatinib, and tepotinib (p = 0.3). The discontinuation rate of MET TKIs was 17% with no significant differences between MET TKIs (p = 0.315). Among pre- and post-treatment biopsies (n = 17) in the MET cohort, the most common next-generation sequencing findings were loss of MET gene amplification (15 of 17, 88.2%), MET on-target mutations (seven of 17, 41.2%), new Ras-Raf-MAPK alterations (three of 17, 17.6%), and EGFR gene amplification (two of 17, 11.7%).

Conclusions

The efficacy and safety of combining MET TKIs (crizotinib, capmatinib, or tepotinib) with parent TKIs for acquired MET resistance are efficacious. Radiographic response and AEs did not differ significantly on the basis of the underlying MET TKI used. Loss of MET gene amplification, development of MET on-target mutations, Ras-Raf-MAPK alterations, and EGFR gene amplification were molecular patterns found on progression with dual parent and MET TKI combinations.

Patterns of Failure in Metastatic NSCLC Treated With First Line Pembrolizumab and Use of Local Therapy in Patients With Oligoprogression

INTRODUCTION

The patterns of failure (POF) for metastatic non-small-cell lung cancer (mNSCLC) treated with immunotherapy are not well established.

METHODS

We conducted a retrospective cohort study of mNSCLC that received first-line pembrolizumab with or without chemotherapy at a single academic center from 2015 to 2021. We defined POF with 2 classifications: 1) local, regional, or distant failure, or 2) failure in existing lesions, new lesions, or a combination. Oligoprogression was defined as disease progression (PD) in ≤3 sites of failure. Overall survival (OS) was measured via Kaplan-Meier and modelled with Cox regression.

RESULTS

Of 298 patients identified, 198 had PD. Using POF classification 1, most failures were distant (43.9%) or a combination of locoregional and distant (34.4%). For POF classification 2, failures occurred in a combination of new and existing lesions (45.0%), existing lesions alone (33.3%), or in new lesions only (21.7%). Oligoprogression occurred in 39.9% (n = 79) cases. Median OS was higher in the following: PD in existing lesions vs. new or new + existing lesions (28.7 vs. 20.2 vs. 13.9 months, P < .001) and oligoprogression vs. polyprogression (35.1 vs. 12.2 months, P < .001). In oligoprogression, median OS was better for those who received radiation to all sites of PD (62.2 months) than for those who changed systemic therapy (22.9 months, P = .007). On multivariable analysis, radiation for oligoprogression (HR 0.35, 95% CI: 0.20-0.62, P < .001) was associated with improved OS.

CONCLUSIONS

In mNSCLC treated with pembrolizumab, oligoprogression is relatively common. Randomized data are needed to define the benefits of radiation in oligoprogressive mNSCLC.

Plunging Into the PACIFIC: Outcomes of Patients With Unresectable KRAS-Mutated Non-Small Cell Lung Cancer Following Definitive Chemoradiation and Durvalumab Consolidation

BACKGROUND

Immune checkpoint inhibitor (ICI) consolidation following concurrent chemoradiotherapy (CRT) substantially improved progression free survival (PFS) and overall survival (OS) in the PACIFIC trial becoming the standard of care in locally-advanced, unresectable NSCLC. KRAS mutation may influence response to ICI.

METHODS

In this single-institution, retrospective analysis, we compared treatment outcomes for patients with unresectable KRAS mutated (KRAS-mt) and wild-type (KRAS-wt) NSCLC treated with CRT between October 2017 and December 2021. Kaplan-Meier analysis was conducted comparing median progression free survival and median overall survival from completion of radiotherapy in all KRAS-mt patients and KRAS-G12C-mutated patients. Outcomes were also compared with and without ICI consolidation.

RESULTS

Of 156 patients, 42 (26.9%) were KRAS-mt and 114 (73.1%) were KRAS-wt. Baseline characteristics differed only in histology; KRAS-mt NSCLC more likely to be adenocarcinoma. KRAS-mt patients had worse PFS (median 6.3 vs. 10.7 months, P = .041) but similar OS (median 23.1 vs. 27.3 months, P = .237). KRAS-mt patients were more likely to not receive ICI due to rapid disease progression post-CRT (23.8% vs. 4.4%, P = .007). Among patients who received ICI (n = 114), KRAS-mt was not associated with inferior PFS (8.1 vs. 11.9 months, P = .355) or OS (30.5 vs. 31.7 months, P = .692). KRAS-G12C patients (n = 22) had similar PFS and OS to other KRAS-mt.

CONCLUSION

In one of the largest post-CRT KRAS-mt cohort published, KRAS-mt was associated with inferior PFS, largely due to rapid progression prior to ICI consolidation, but did not affect OS. Among those who received ICI consolidation, outcomes were comparable regardless of KRAS-mt status.

Disparities in outcomes between Black and White patients in North America with thoracic malignancies and COVID-19 infection (TERAVOLT)

BACKGROUND

Patients with thoracic malignancies who develop COVID-19 infection have a higher hospitalization rate compared to the general population and to those with other cancer types, but how this outcome differs by race and ethnicity is relatively understudied.

METHODS

The TERAVOLT database is an international, multi-center repository of cross-sectional and longitudinal data studying the impact of COVID-19 on individuals with thoracic malignancies. Patients from North America with thoracic malignancies and confirmed COVID-19 infection were included for this analysis of racial and ethnic disparities. Patients with missing race data or races and ethnicities with fewer than 50 patients were excluded from analysis. Multivariable analyses for endpoints of hospitalization and death were performed on these 471 patients.

RESULTS

Of the 471 patients, 73% were White and 27% were Black. The majority (90%) were non-Hispanic ethnicity, 5% were Hispanic, and 4% were missing ethnicity data. Black patients were more likely to have an Eastern Cooperative Oncology Group (ECOG) Performance Status ≥ 2 (p-value = 0.04). On multivariable analysis, Black patients were more likely than White patients to require hospitalization (Odds Ratio (OR): 1.69, 95% CI: 1.01-2.83, p-value = 0.044). These differences remained across different waves of the pandemic. However, no statistically significant difference in mortality was found between Black and White patients (OR 1.29, 95% CI: 0.69-2.40, p-value = 0.408).

CONCLUSIONS

Black patients with thoracic malignancies who acquire COVID-19 infection are at a significantly higher risk of hospitalization compared to White patients, but there is no significant difference in mortality. The underlying drivers of racial disparity among patients with thoracic malignancies and COVID-19 infection require ongoing investigation.

Patterns of Failure, Volume of Disease Progression, and Subsequent Ablative Management in Locally Advanced Non-Small Cell Lung Cancer (LA-NSCLC) Treated with Definitive Chemoradiation and Consolidation Immune Checkpoint Inhibitors (ICI)

PURPOSE/OBJECTIVE(S)

For patients (pts) with LA-NSCLC treated with chemoradiation and consolidation ICI (CRT+ICI), the patterns of failure (POF) and volume of disease progression (PD) are not well characterized. The primary objective of this study was to classify POFs, the frequency of low volume relapse (LVR), and identify pts eligible for further ablative therapy.

MATERIALS/METHODS

We retrospectively identified pts with unresectable stage III NSCLC treated with CRT+ICI between October 2017 and December 2021 at a single institution. Site of first failure was classified as locoregional (LRF), distant (DF), or synchronous LRF + DF. Any LRF was subclassified as in field (IFF; PD within 90% isodose line), marginal (MF; within 50% isodose line) or out of field (OOF; outside of 50% isodose line). LVR was defined as < 3 discrete sites of PD in any number or location of organs. Pts with distant LVR were considered to have oligometastatic relapse. Ablative candidates were defined as pts with < 3 discrete sites of PD amenable to further RT or surgery. Cumulative incidence of PD was calculated with death as a competing risk. Progression free survival (PFS) and overall survival (OS) were calculated from the end of RT and assessed via Kaplan Meier. Multivariable Cox modeling was used to assess correlation of pt characteristics and time-to-event outcomes. Logistic regression was used to predict variables associated with LVR.

RESULTS

A total of 229 pts received CRT+ICI. Median follow up was 39 months and 119 pts experienced PD. Median PFS and OS were 18.4 and 34.5 months, respectively. Of pts with PD, 71 (60%) had DF, 28 (24%) had LRF+DF, and 20 (17%) had LRF. Of pts with any LRF, 28 (57%) had IFF, 10 (21%) had MF, and 10 (21%) had OOF. Estimated 1-year cumulative incidence of LRF, DF, and LRF+DF were 9.3% (95% CI 4.5-16), 39% (95% CI 31-48), and 19% (95% CI 12-27), respectively. A total of 63 (53%) pts had LVR. In pts with LVR, 19 (30%) had isolated thoracic relapse and 44 (69%) had oligometastatic relapse. Most oligometastatic disease was intracranial (22 metastases, 44%). Pts with LVR had a longer median OS vs pts with high volume relapse (37.4 vs 15.2 months, p<0.001). At time of PD, 56 (47%) pts were candidates for further ablative therapies. Subsequent anticancer therapies were local therapy alone (35%), local and systemic therapy (16%), systemic therapy alone (36%), or no therapy (13%). On multivariable analysis, LVR (HR 0.39; 95% CI 0.21-0.73, p = 0.003) and longer receipt of ICI (HR 0.96; 95% CI 0.95-0.98; p<0.001) were associated with improved survival while squamous histology (HR 2.26; 95% CI 1.18-4.32; p = 0.039) was associated with worse survival. Longer receipt of ICI was the only variable predictive for the development of LVR (OR 1.03; 95% CI 1.01-1.05; p = 0.004).

CONCLUSION

This is the largest real-world series reporting POF after CRT+ICI for stage III NSCLC. Approximately half of pts experience LVR and are candidates for further ablative therapy. Further data are needed to define optimal treatment strategies for pts with LVR after CRT+ICI.

Brief Report: Second-line treatment outcomes in patients with advanced NSCLC previously treated with first-line immunotherapy regimens

CLINICAL PRACTICE POINTS

In the United States of America, nearly all patients with advanced NSCLC, absent oncogenic drivers, receive some form of immunotherapy (IO) as part of initial treatment. Current national guidelines currently recommend against IO re-challenge if there is disease progression on IO in the first line, but re-treatment with IO is attractive given its favorable toxicity profile and descriptions of durable clinical benefit in a subset of patients treated beyond disease progression on initial IO (Gandara, J Thorac Oncol, 2018). Data in the non-clinical trial setting on the efficacy of IO in sequential lines of treatment after initial IO are lacking. In our large cohort study of patients with advanced NSCLC treated with immunotherapy regimens in the first-line setting, we find that outcomes after second-line treatment did not differ statistically by type of treatment used in the second line. While current prospective clinical trials are investigating several aspects of the utility of continuing immunotherapy and adding novel agents, our study offers data outside of a clinical trial. In addition, with the increased prevalence of adjuvant immunotherapy we urgently need to wrestle with whether to continue immunotherapy in the first-line metastatic setting if a patient experiences disease progression on adjuvant immunotherapy. While this analysis does not directly investigate that question, it does provide hypothesis-generating evidence for further evaluations.

Association Between Duration of Immunotherapy and Overall Survival in Advanced Non-Small Cell Lung Cancer

Importance

For patients with advanced non-small cell lung cancer (NSCLC) treated with frontline immunotherapy-based treatment, the optimal duration of immune checkpoint inhibitor (ICI) treatment is unknown.

Objective

To assess practice patterns surrounding ICI treatment discontinuation at 2 years and to evaluate the association of duration of therapy with overall survival in patients who received fixed-duration ICI therapy for 2 years vs those who continued therapy beyond 2 years.

Design, Setting, and Participants

This retrospective, population-based cohort study included adult patients in a clinical database diagnosed with advanced NSCLC from 2016 to 2020, who received frontline immunotherapy-based treatment. The data cutoff was August 31, 2022; data analysis was conducted from October 2022 to January 2023.

Exposures

Treatment discontinuation at 2 years (between 700 and 760 days, fixed duration) vs continued treatment beyond 2 years (greater than 760 days, indefinite duration).

Main Outcomes and Measures

Overall survival from 760 days was analyzed using Kaplan-Meier methods. Multivariable Cox regression that adjusted for patient-specific and cancer-specific factors was used to compare survival beyond 760 days between the fixed-duration group and the indefinite-duration group.

Results

Of 1091 patients in the analytic cohort who were still on ICI treatment at 2 years after exclusion criteria for death and progression were applied, 113 patients (median [IQR] age, 69 [62-75] years; 62 [54.9%] female; 86 [76.1%] White) were in the fixed-duration group, and 593 patients (median [IQR] age, 69 [62-76] years; 282 [47.6%] female; 414 [69.8%] White) were in the indefinite-duration group. Patients in the fixed-duration group were more likely to have a history of smoking (99% vs 93%; P = .01) and be treated at an academic center (22% vs 11%; P = .001). Two-year overall survival from 760 days was 79% (95% CI, 66%-87%) in the fixed-duration group and 81% (95% CI, 77%-85%) in the indefinite-duration group. There was no statistically significant difference in overall survival between patients in the fixed-duration and indefinite-duration groups, either on univariate (hazard ratio [HR] 1.26; 95% CI, 0.77-2.08; P = .36) or multivariable (HR 1.33; 95% CI, 0.78-2.25; P = .29) Cox regression. Approximately 1 in 5 patients discontinued immunotherapy at 2 years in the absence of progression.

Conclusions and Relevance

In a retrospective clinical cohort of patients with advanced NSCLC who were treated with immunotherapy and were progression-free at 2 years, approximately only 1 in 5 discontinued treatment. The lack of statistically significant overall survival advantage for the indefinite-duration cohort on adjusted analysis provides reassurance to patients and clinicians who wish to discontinue immunotherapy at 2 years.

Association Between Availability of Molecular Genotyping Results and Overall Survival in Patients With Advanced Nonsquamous Non-Small-Cell Lung Cancer

PURPOSE

Current guidelines recommend molecular genotyping for patients newly diagnosed with metastatic nonsquamous (mNSq) non-small-cell lung cancer (NSCLC). The association between availability of molecular genotyping before first line (1L) therapy and overall survival (OS) is not known.

METHODS

We conducted a real-world cohort study using electronic health records in patients newly diagnosed with mNSq NSCLC. Cox proportional-hazards multivariable regression models were constructed to examine the association between OS and test result availability before 1L therapy, adjusting for covariates. Additional analyses were conducted to assess the consistency and strength of the relationship. Multivariable logistic regression models were used to examine the association between concurrent tissue and plasma testing (v tissue alone) and result availability.

RESULTS

Three hundred twenty-six patients were included, 80% (261/326) with results available before 1L (available testing group), and 20% (65/326) without results available (unavailable testing group). With 14.2-month median follow-up, patients in the available testing group had significantly longer OS relative to the unavailable testing group (adjusted hazard ratio, 0.43; 95% CI, 0.30 to 0.62; P < .0001). The adjusted odds of availability of results before 1L therapy was higher with concurrent tissue and plasma testing (v tissue testing alone; adjusted odds ratio, 2.06; 95% CI, 1.09 to 3.90; P = .026).

CONCLUSION

Among patients with mNSq NSCLC in a real-world cohort, availability of molecular genotyping results before 1L therapy was associated with significantly better OS. Concurrent tissue and plasma testing was associated with a higher odds of availability of results before 1L therapy. These findings warrant renewed attention to the completion of molecular genotyping before 1L therapy.

A Phase II Open-Label Trial of Binimetinib and Hydroxychloroquine in Patients With Advanced KRAS-Mutant Non-Small Cell Lung Cancer

BACKGROUND

In RAS-mutant tumors, combined MEK and autophagy inhibition using chloroquine demonstrated synthetic lethality in preclinical studies. This phase II trial evaluated the safety and activity of the MEK inhibitor binimetinib combined with hydroxychloroquine (HCQ) in patients with advanced KRAS-mutant non-small cell lung cancer (NSCLC).

METHODS

Eligibility criteria included KRAS-mutant NSCLC, progression after first-line therapy, ECOG PS 0-1, and adequate end-organ function. Binimetinib 45 mg was administered orally (p.o.) bid with HCQ 400 mg p.o. bid. The primary endpoint was objective response rate (ORR). A Simon's 2-stage phase II clinical trial design was used, with an α error of 5% and a power β of 80%, anticipating an ORR of 30% to proceed to the 2-stage expansion.

RESULTS

Between April 2021 and January 2022, 9 patients were enrolled to stage I: median age 64 years, 44.4% females, 78% smokers. The best response was stable disease in one patient (11.1%). The median progression free survival (PFS) was 1.9 months, and median overall survival (OS) was 5.3 months. Overall, 5 patients (55.6%) developed a grade 3 adverse event (AE). The most common grade 3 toxicity was rash (33%). Pre-specified criteria for stopping the trial early due to lack of efficacy were met.

CONCLUSION

The combination of B + HCQ in second- or later-line treatment of patients with advanced KRAS-mutant NSCLC did not show significant antitumor activity. (ClinicalTrials.gov Identifier: NCT04735068).

Abstract 2166: Analysis of ctDNA next generation sequencing (NGS) for predicting response to amivantamab and lazertinib among patients with EGFR-mutant NSCLC after progression on osimertinib and platinum-based chemotherapy (CHRYSALIS-2 Cohort A)

Background: Among post-osimertinib (osi), chemotherapy-naïve patients (pts) treated with amivantamab (ami) and lazertinib (laz) in CHRYSALIS Cohort E, NGS of baseline ctDNA and tumor tissue revealed pts with identified EGFR/MET-based resistance (eg, EGFR C797S or MET amplification) were slightly more likely to respond versus those without EGFR/MET-based resistance (ORR=47% vs 29%), but about half of responders had unknown resistance mechanisms (Bauml JCO 2021; 39:15_suppl, 9006). In CHRYSALIS-2 Cohort A (NCT04077463), ami + laz demonstrated an ORR of 33% in the post-osi and platinum-based chemotherapy population (Shu JCO 2022; 40:16_suppl, 9006). This analysis investigated whether EGFR/MET-dependent resistance by ctDNA correlated with response.

Methods: Cohort A examined ami + laz in EGFR exon19del or L858R mutated advanced NSCLC whose disease progressed on osi as well as platinum-based chemotherapy. ORR was verified through blinded independent central review. Plasma samples were collected prior to treatment; ctDNA was analyzed by Guardant360.

Results: A total of 162 pts were enrolled; of these, 110 (68%) had analyzable ctDNA data, with most common mutations observed in EGFR and TP53. Twenty-eight (25%) pts had resistance categorized as EGFR/MET-dependent and 31 (28%) as EGFR/MET-independent; no genetic resistance mechanism was identified in 51 (46%). The ORR

was 29% and 26% in EGFR/MET-dependent and independent pts, respectively. ORR in pts with an unknown resistance mechanism was 39% (Table).

Conclusions: Among pts who progressed on osi and platinum-based chemotherapy, genetic profiling of osi resistance by ctDNA did not predict response, with many responders having unknown resistance mechanisms. These results suggest alternative biomarker approaches are needed to identify pts most likely to benefit from ami + laz.

Table. ORR by type of resistance mechanism Resistance mechanism n PR ORRa EGFR/MET-dependentb 28 8 29% EGFR/MET-independent 31 8 26% Unknown 51 20 39% All patients 110 36 33% aResponses were assessed by blinded independent central review per RECIST v1.1. bIncludes co-occurring ‘independent’ resistance mechanisms. EGFR, epidermal growth factor receptor; MET, mesenchymal epithelial transition factor; ORR, objective response rate; PR, partial response.

Citation Format: Rachel E. Sanborn, Saiama N. Waqar, Byoung Chul Cho, Benjamin Besse, Koichi Goto, Yongsheng Wang, Se-Hoon Lee, Melina E. Marmarelis, Yuichiro Ohe, Dong-Wan Kim, Antonio Calles, Joel Neal, Christina S. Baik, Pasi A. Janne, Joshua C. Curtin, Bharvin Patel, Mike Gormley, S. Martin Shreeve, Joshua M. Bauml, Roland E. Knoblauch, James Chih-Hsin Yang. Analysis of ctDNA next generation sequencing (NGS) for predicting response to amivantamab and lazertinib among patients with EGFR-mutant NSCLC after progression on osimertinib and platinum-based chemotherapy (CHRYSALIS-2 Cohort A) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2166.

Utilization and factors precluding receipt of checkpoint inhibitor consolidation for stage III NSCLC in a large U.S. academic health system

OBJECTIVES

We sought to determine the proportion of patients with stage III non-small cell lung cancer (NSCLC) who initiate consolidation durvalumab or other immune checkpoint inhibitors (ICIs) after concurrent chemoradiotherapy (cCRT), as well as reasons for nonreceipt and prognostic implications.

MATERIALS AND METHODS

We retrospectively identified consecutive patients with unresectable stage III NSCLC treated with definitive cCRT between October 2017 and December 2021 within a large US academic health system. Patients either received consolidation ICIs (ICI group) or did not (no-ICI group). Baseline characteristics and overall survival (OS) of the groups were assessed. Factors predictive of ICI nonreceipt were evaluated using logistic regression.

RESULTS

Of 333 patients who completed cCRT, 229 (69%) initiated consolidation ICIs; 104 (31%) did not. Reasons for ICI nonreceipt included progressive disease post-cCRT (N = 31, 9%), comorbidity or intercurrent illness (N = 25, 8%), cCRT toxicity (N = 23, 7%; 19/23 pneumonitis), and EGFR/ALK alteration (N = 14, 4%). The no-ICI group had worse performance status and a higher rate of baseline pulmonary comorbidity. Larger planning target volume was associated with post-cCRT progressive disease, and higher lung radiation dose with cCRT toxicity. Median OS was 16 months in the no-ICI group and 34.4 months in the ICI group. In the no-ICI group, OS was superior among those with EGFR/ALK alterations (median 44.5 months) and worst among those with progressive disease (median 5.9 months, P < 0.001).

CONCLUSION

31% of patients who completed cCRT for stage III NSCLC did not receive consolidation ICIs. Survival amongst these patients is poor, especially for those with progressive disease post-cCRT.

Chemoimmunotherapy vs. Immunotherapy for First Line Treatment of Advanced Non-small Cell Lung Cancer With a PD-L1 Expression ≥50% or ≥90

BACKGROUND

Evidence about the comparative effectiveness of chemoimmunotherapy vs. immunotherapy alone in patients with advanced non-small cell lung cancer (aNSCLC) and high PD-L1 expression (≥50%) or very high PD-L1 expression (≥90%) is limited because of the lack of head-to-head clinical trials.

OBJECTIVE

To compare survival in aNSCLC patients receiving first-line chemoimmunotherapy vs. immunotherapy in both the PD-L1 expression ≥50% or ≥90% subgroups, accounting for potential confounders that may influence physician decision-making.

METHODS

This cohort study used a nationwide electronic health record derived database to identify newly diagnosed cases of aNSCLC patients with PD-L1 expression of ≥50% who initiated first-line systemic therapy between October 2016 and October 2021. The exposure of interest was first-line therapy with chemoimmunotherapy or immunotherapy among patients with PD-L1 expression ≥50% or ≥90%. Survival was assessed using Kaplan-Meier curves and Cox regression. Propensity score-based inverse probability of weighting (IPW) was used to control for confounding. Because of nonproportionality of hazards, we estimated hazard ratios over the first 6 months and after 6 months for the overall cohort, and over the first 12 months and after 12 months for a subgroup of persons with a PD-L1 expression ≥90%.

RESULTS

We identified 3086 subjects who met inclusion criteria, of whom 32% received chemoimmunotherapy and 68% received immunotherapy alone. Chemoimmunotherapy was associated with no survival advantage vs. immunotherapy alone during the entire follow-up period (IPW-adjusted Hazard Ratio [aHR] 0.98, 95% CI, 0.86-1.12), but was associated with a survival benefit during the first 6 months (aHR 0.74, 95% CI, 0.61-0.90). Similarly, in the subgroup of patients with a PD-L1 expression ≥90%, chemoimmunotherapy was associated with no overall survival advantage during the entire follow-up period (aHR 0.99, 95% CI, 0.87-1.22), but was associated with a survival benefit during the first 12 months (aHR 0.74, 95% CI, 0.57-0.97).

CONCLUSION

Chemoimmunotherapy was not associated with an overall benefit over immunotherapy alone, although was associated with an early survival advantage in both the overall cohort and the subgroup of patients with a PD-L1 expression ≥90%. Future studies should focus on identifying the characteristics of higher risk patients that may benefit from the addition of chemotherapy.

Clinical Outcomes Associated With Pembrolizumab Monotherapy Among Adults With Diffuse Malignant Peritoneal Mesothelioma

Importance

Diffuse malignant peritoneal mesothelioma (DMPM) represents a rare and clinically distinct entity among malignant mesotheliomas. Pembrolizumab has activity in diffuse pleural mesothelioma but limited data are available for DMPM; thus, DMPM-specific outcome data are needed.

Objective

To evaluate outcomes after the initiation of pembrolizumab monotherapy in the treatment of adults with DMPM.

Design, Setting, and Participants

This retrospective cohort study was conducted in 2 tertiary care academic cancer centers (University of Pennsylvania Hospital Abramson Cancer Center and Memorial Sloan Kettering Cancer Center). All patients with DMPM treated between January 1, 2015, and September 1, 2019, were retrospectively identified and followed until January 1, 2021. Statistical analysis was performed between September 2021 and February 2022.

Exposures

Pembrolizumab (200 mg or 2 mg/kg every 21 days).

Main Outcomes and Measures

Median progression-free survival (PFS) and median overall survival (OS) were assessed using Kaplan-Meier estimates. The best overall response was determined using RECIST (Response Evaluation Criteria in Solid Tumors) criteria, version 1.1. The association of disease characteristics with partial response was evaluated using the Fisher exact test.

Results

This study included 24 patients with DMPM who received pembrolizumab monotherapy. Patients had a median age of 62 years (IQR, 52.4-70.6 years); 14 (58.3%) were women, 18 (75.0%) had epithelioid histology, and most (19 [79.2%]) were White. A total of 23 patients (95.8%) received systemic chemotherapy prior to pembrolizumab, and the median number of lines of prior therapy was 2 (range, 0-6 lines). Of the 17 patients who underwent programmed death ligand 1 (PD-L1) testing, 6 (35.3%) had positive tumor PD-L1 expression (range, 1.0%-80.0%). Of the 19 evaluable patients, 4 (21.0%) had a partial response (overall response rate, 21.1% [95% CI, 6.1%-46.6%]), 10 (52.6%) had stable disease, and 5 (26.3%) had progressive disease (5 of 24 patients [20.8%] were lost to follow-up). There was no association between a partial response and the presence of a BAP1 alteration, PD-L1 positivity, or nonepithelioid histology. With a median follow-up of 29.2 (95% CI, 19.3 to not available [NA]) months, the median PFS was 4.9 (95% CI, 2.8-13.3) months and the median OS was 20.9 (95% CI, 10.0 to NA) months from pembrolizumab initiation. Three patients (12.5%) experienced PFS of more than 2 years. Among patients with nonepithelioid vs epithelioid histology, there was a numeric advantage in median PFS (11.5 [95% CI, 2.8 to NA] vs 4.0 [95% CI, 2.8-8.8] months) and median OS (31.8 [95% CI, 8.3 to NA] vs 17.5 [95% CI, 10.0 to NA] months); however, this did not reach statistical significance.

Conclusions and Relevance

The results of this retrospective dual-center cohort study of patients with DMPM suggest that pembrolizumab had clinical activity regardless of PD-L1 status or histology, although patients with nonepithelioid histology may have experienced additional clinical benefit. The partial response rate of 21.0% and median OS of 20.9 months in this cohort with 75.0% epithelioid histology warrants further investigation to identify those most likely to respond to immunotherapy.

A Multicenter Retrospective Chart Review of Clinical Outcomes Among Patients With KRAS G12C Mutant Non-Small Cell Lung Cancer

BACKGROUND

On May 28, 2021, the United States Food and Drug Administration (FDA) granted accelerated approval to sotorasib for second-line or later treatment of patients with locally advanced or metastatic KRAS G12C mutant non-small cell lung cancer (NSCLC). This was the first FDA-approved targeted therapy for this patient population. Due to a paucity of real world data describing clinical outcomes in patients with locally advanced or metastatic KRAS G12C mutated NSCLC in the second-line or later, we sought to compile a large, academic medical center-based historical dataset to clarify clinical outcomes in this patient population.

MATERIALS AND METHODS

The clinical outcomes of 396 patients with stage IV (n = 268, 68%) or recurrent, metastatic (n = 128, 32%) KRAS G12C mutant NSCLC were evaluated in this multicenter retrospective chart review conducted through the Academic Thoracic Oncology Medical Investigator's Consortium (ATOMIC). Patients treated at 13 sites in the United States and Canada and diagnosed between 2006 and 2020 (30% 2006-2015, 70% 2016-2020) were included. Primary outcomes included real-world PFS (rwPFS) and overall survival (OS) from time of stage IV or metastatic diagnosis, with particular interest in patients treated with second-line docetaxel-containing regimens, as well as clinical outcomes in the known presence or absence of STK11 or KEAP1 comutations.

RESULTS

Among all patients with stage IV or recurrent, metastatic KRAS G12C mutant NSCLC (n = 201 with KRAS G12C confirmed prior to first line systemic therapy), the median first-line rwPFS was 9.3 months (95% CI, 7.3-11.8 months) and median OS was 16.8 months (95% CI, 12.7-22.3 months). In this historical dataset, first line systemic therapy among these 201 patients included platinum doublet alone (44%), PD-(L)1 inhibitor monotherapy (30%), platinum doublet chemotherapy plus PD-(L)1 inhibitor (18%), and other regimens (8%). Among patients with documented second-line systemic therapy (n = 123), the second-line median rwPFS was 8.3 months (95% CI, 6.1-11.9 months), with median rwPFS 4.6 months (95% CI, 1.4-NA) among 10 docetaxel-treated patients (9 received docetaxel and 1 received docetaxel plus ramucirumab). Within the total study population, 49 patients (12%) had a co-occurring STK11 mutation and 3 (1%) had a co-occurring KEAP1 mutation. Among the 49 patients with a co-occurring KRAS G12C and STK11 mutation, median rwPFS on first-line systemic therapy (n = 23) was 6.0 months (95% CI, 4.7-NA), and median OS was 14.0 months (95% CI, 10.8-35.3 months).

CONCLUSION

In this large, multicenter retrospective chart review of patients with KRAS G12C mutant NSCLC we observed a relatively short median rwPFS of 4.6 months among 10 patients with KRAS G12C mutant NSCLC treated with docetaxel with or without ramucirumab in the second-line setting, which aligns with the recently reported CodeBreak 200 dataset.

Very high PD-L1 expression as a prognostic indicator of overall survival among patients with advanced non-small cell lung cancer receiving anti-PD-(L)1 monotherapies in routine practice

PURPOSE

Programmed death or ligand-1 (PD-(L)1) pathway inhibitors confer improved survival as the first-line treatment for advanced non-small cell lung cancer (aNSCLC) in patients with PD-L1 expression (PD-L1 + e ≥ 50%) compared to platinum-doublet chemotherapy and have become a standard therapy. Some recent evidence suggests that among aNSCLC patients with PD-L1 + e of ≥50% receiving pembrolizumab monotherapy, very high levels of PD-L1 + e (≥90%) may be associated with better outcomes. We sought to assess whether very high PD-L1 + e (≥90%) compared to high PD-L1 + e (50%-89%) is associated with an overall survival benefit in aNSCLC patients receiving anti-PD-(L)1 monotherapies.

METHODS

We conducted a single-site retrospective cohort study of aNSCLC patients who initiated PD-(L)1 inhibitor monotherapy as the first-line treatment from October 24, 2016, to August 25, 2021, and had a PD-L1 + e ≥ 50%. The primary outcome was overall survival, measured from the start of the first-line PD-(L)1 inhibitor monotherapy (index date) to date of death or last confirmed activity prior to the cohort exit date. Propensity score-based inverse probability weighting (IPW) was used to control for confounding in Kaplan-Meier curves and Cox proportional hazard regression analysis.

RESULTS

One hundred sixty-six patients with aNSCLC receiving PD-(L)1 inhibitor monotherapy met inclusion criteria. 54% were female, 90% received pembrolizumab, median age was 68 years, 70% had non-squamous cell carcinoma, 94% had a history of smoking, 29% had a KRAS mutation, and 37% had very high PD-L1 + e. Unweighted covariates at cohort entry were similar between groups (absolute standardized mean differences [SMDs] <0.1) except for race (SMD = 0.2); age at therapy initiation (SMD = 0.13); smoking status (SMD = 0.13), and BRAF mutation status (SMD = 0.11). After weighting, baseline covariates were well balanced (all absolute SMDs <0.1). In the weighted analysis, having a very high PD-L1 + e was associated with lower mortality (weighted hazard ratio 0.57, 95% CI 0.36-0.90) and longer median survival: 3.85 versus 1.49 years.

CONCLUSIONS

Very high PD-L1 + e (≥90%) was associated with an overall survival benefit over high PD-L1 + e (50%-89%) in patients receiving the first-line PD-(L)1 inhibitor monotherapy in a model controlling for potential confounders. These findings should be confirmed in a larger real-world data set.

A single-center retrospective cohort study of perioperative systemic chemotherapy in diffuse malignant peritoneal mesothelioma

Background

Diffuse malignant peritoneal mesothelioma (DMPM) is a rare variant of malignant mesothelioma, representing 10–15% of malignant mesothelioma cases. The preferred therapeutic approach is cytoreductive surgery (CRS) accompanied by hyperthermic intraperitoneal chemotherapy (HIPEC); the role of systemic chemotherapy is not well established. While some limited retrospective studies report worse outcomes with neoadjuvant chemotherapy, our institution has favored the use of neoadjuvant chemotherapy for symptom relief and surgical optimization. The aim of our study was to assess the outcomes of patients receiving neoadjuvant chemotherapy, compared to those receiving adjuvant or no perioperative chemotherapy.

Patients and methods

We conducted a single-center retrospective cohort study of treatment-naïve, non-papillary DMPM patients seen at our institution between 1/1/2009 and 9/1/2019. We explored the effect of type of systemic therapy on clinical outcomes and estimated median overall survival (mOS) using Kaplan-Meier curves. Hazard ratios (HR) calculated by Cox proportional hazard model were used to estimate effect of the exposures on overall survival.

Results

47 patients were identified with DMPM (median age at diagnosis 61.2 years, 76.6% epithelioid histology, 74.5% white race, 55.3% known asbestos exposure). CRS was performed in 53.2% of patients (25/47); 76.0% of surgical patients received HIPEC (19/25). The majority received systemic chemotherapy (37/47, 78.7%); among patients receiving both CRS and chemotherapy, neoadjuvant chemotherapy was more common than adjuvant chemotherapy (12 neoadjuvant, 8 adjuvant). Overall mOS was 84.1 months. Among neoadjuvant patients, 10/12 underwent surgery, and 2 were lost to follow-up; the majority (9/10) had clinically stable or improved disease during the pre-operative period. There were numerical more issues with chemotherapy with the adjuvant patients (4/8: 2 switches in platinum agent, 2 patients stopped therapy) than with the neoadjuvant patients (2/10: 1 switch in platinum agent, 1 delay due to peri-procedural symptoms). Neoadjuvant chemotherapy was not associated with worse mOS compared to adjuvant chemotherapy (mOS NR vs 95.1 mo, HR 0.89, 95% CI 0.18–4.5, p = 0.89).

Conclusions

When used preferentially, the use of neoadjuvant chemotherapy in DMPM patients was not associated with worse outcomes compared to adjuvant chemotherapy. It was well-tolerated and did not prevent surgical intervention.

Impact of telemedicine adoption on accessibility and time to treatment in patients with thoracic malignancies during the COVID-19 pandemic

Background

To ensure safe delivery of oncologic care during the COVID-19 pandemic, telemedicine has been rapidly adopted. However, little data exist on the impact of telemedicine on quality and accessibility of oncologic care. This study assessed whether conducting an office visit for thoracic oncology patients via telemedicine affected time to treatment initiation and accessibility.

Methods

This was a retrospective cohort study of patients with thoracic malignancies seen by a multidisciplinary team during the first surge of COVID-19 cases in Philadelphia (March 1 to June 30, 2020). Patients with an index visit for a new phase of care, defined as a new diagnosis, local recurrence, or newly discovered metastatic disease, were included.

Results

240 distinct patients with thoracic malignancies were seen: 132 patients (55.0%) were seen initially in-person vs 108 (45.0%) via telemedicine. The majority of visits were for a diagnosis of a new thoracic cancer (87.5%). Among newly diagnosed patients referred to the thoracic oncology team, the median time from referral to initial visit was significantly shorter amongst the patients seen via telemedicine vs. in-person (median 5.0 vs. 6.5 days, p < 0.001). Patients received surgery (32.5%), radiation (24.2%), or systemic therapy (30.4%). Time from initial visit to treatment initiation by modality did not differ by telemedicine vs in-person: surgery (22 vs 16 days, p = 0.47), radiation (27.5 vs 27.5 days, p = 0.86, systemic therapy (15 vs 13 days, p = 0.45).

Conclusions

Rapid adoption of telemedicine allowed timely delivery of oncologic care during the initial surge of the COVID19 pandemic by a thoracic oncology multi-disciplinary clinic.

Comparative effectiveness of second-line immune checkpoint inhibitor therapy versus chemotherapy for malignant pleural mesothelioma

OBJECTIVES

Second-line immune checkpoint inhibition (ICI) was recently shown to have a survival advantage over placebo in malignant pleural mesothelioma (MPM), but the survival comparison to chemotherapy in patients with MPM receiving routine clinical care is unknown. Our objective was to examine the effectiveness of second-line ICI versus chemotherapy on overall survival (OS) outcomes in real-world patients with advanced MPM.

MATERIALS AND METHODS

We performed a multicenter retrospective cohort study of real-world adult patients with advanced MPM who received first-line platinum-based chemotherapy and at least two total lines of systemic therapy. Patients received either second-line chemotherapy (gemcitabine and/or vinorelbine) or ICI therapy (pembrolizumab or nivolumab ± ipilimumab). The primary outcome was OS, defined as the time from second-line therapy initiation to death or end of the observation period. We used Kaplan-Meier methods and Cox proportional hazards modeling with adjustment for relevant patient demographic and clinical variables to compare OS between the two second-line treatment groups.

RESULTS

Of the 176 patients with MPM, the median age was 75 years (IQR: 69-79.5 years), and most were white (77%), male (74%), and had epithelioid histology (67%). Thirty-five percent (61) received second-line chemotherapy and 65% (115) ICI therapy (80 pembrolizumab, 31 nivolumab, and 4 nivolumab + ipilimumab). Treatment with ICI was associated with significantly longer median OS compared to chemotherapy (8.7 vs 5.0 months, p=0.001; adjusted hazard ratio: 0.52, 95% CI: 0.34-0.81). The estimated 12-month OS probability was 36.7% (95% CI: 27.6%-45.8%) and 15.6% (95% CI: 7.7%-26.1%) in the ICI and chemotherapy groups, respectively.

CONCLUSION

In this "real-world" population of patients with MPM, treatment with ICI was associated with improved OS outcomes compared to chemotherapy in the second-line setting, in contrast with a recent clinical trial. Our findings suggest that ICI may benefit patients with advanced MPM and progression after initial platinum-based chemotherapy.

Immune Checkpoint Inhibitor Uptake in Real-World Patients With Malignant Pleural Mesothelioma

INTRODUCTION

Since the July 2017 National Comprehensive Cancer Network (NCCN) malignant pleural mesothelioma (MPM) guideline revision recommended second-line immune checkpoint inhibitors (ICIs), studies have suggested a greater response to ICI among patients with nonepithelioid MPM. Nevertheless, little is known regarding adoption of ICI in routine practice and if uptake differs by histologic subtype. Our objectives were to evaluate the real-world uptake of second-line ICI among patients with MPM and to reveal its association with histologic subtype.

METHODS

This was a multicenter, retrospective cohort study of real-world patients with MPM receiving at least two lines of systemic therapy between 2011 and 2019. We found the uptake of second-line ICI over time and evaluated the association between histologic subtype and ICI use, adjusting for relevant patient demographic and clinical factors.

RESULTS

Among the 426 patients with MPM in our cohort, 310 had epithelioid and 116 nonepithelioid histologic subtype. The median age was 73 years (interquartile range: 67-78). Overall, 144 patients (33.8%) received second-line ICI and 282 (66.2%) traditional chemotherapy. ICI uptake began in early 2015 before the NCCN guideline revision and increased rapidly to 2019. After the 2017 NCCN guideline revision, patients with nonepithelioid MPM histologic subtypes had more than 3 times the odds of receiving second-line ICI (OR = 3.26; 95% confidence interval: 1.41-7.54).

CONCLUSIONS

Among real-world patients with MPM, second-line ICI uptake began over two years before the 2017 NCCN guideline recommendations and was associated with nonepithelioid histologic subtype after contemporary studies suggested increased clinical benefit in this population, reflecting prompt integration of scientific discovery into clinical practice.

Systemic Therapy for Mutation-Driven NSCLC

Lung cancer is the leading cause of cancer deaths worldwide, and patients with nonsmall cell lung cancer have traditionally had a poor prognosis. An improved understanding of targetable oncogenic molecular alterations has led to a growing number of effective and first-line therapies in targeted patient populations. This review provides an overview of systemic therapy options available for patients with mutation-driven nonsmall cell lung cancer, as well as a discussion of data regarding safety when combined with radiation therapy.

Abstract P17: Effect of telemedicine adoption on accessibility and time to treatment in patients with thoracic malignancies during the COVID-19 pandemic

Introduction: To ensure safe delivery of oncologic care in the COVID-19 pandemic, telemedicine has been rapidly adopted. We assessed accessibility and time to treatment initiation for thoracic oncology patients seen via telemedicine or in-person during the initial phase of the COVID-19 pandemic. Methods: We conducted a retrospective cohort study of patients with thoracic malignancies seen within a multidisciplinary team at the University of Pennsylvania Health System (UPHS) during the first surge of COVID-19 cases in Philadelphia (March 1 to June 30, 2020). Patients with an index visit for a new phase of care, defined as a new diagnosis, local recurrence, or newly discovered metastatic disease were included. Patients who did not receive subsequent oncologic care within the UPHS were excluded. Dates of referral, index visit, and treatment initiation were abstracted from the electronic medical record (EMR). Patients were divided into groups based on index visit type (in-person vs. telemedicine). Comparisons of time to care between groups were evaluated using the Wilcoxon rank-sum test. Results: Between March 1 and June 30, 2020, 241 distinct thoracic oncology patients were seen for a new phase of care and managed with surgery (n=78, 32.4%), radiation (including concurrent chemoradiation) (n=59, 24.5%), or systemic therapy (n=73, 30.3%). The majority of visits were for a diagnosis of a new thoracic cancer (87.1%). 133 patients (55.2%) were seen in-person and 108 (44.8%) were seen via telemedicine. Baseline characteristics of patients seen via telemedicine vs in-person were well balanced. As expected, the proportion of telemedicine to in-person visit types changed with the local phase of the pandemic with an initial increase of telemedicine during the lockdown period and a decrease during the re-opening phase. A higher proportion of visits were conducted via telemedicine when receiving systemic therapy or radiation as compared to surgery. Among patients with new diagnoses (n=210), the median time from referral to initial visit was significantly shorter amongst the patients seen via telemedicine vs. in-person (4.5 vs. 6.0 days, p=0.006), though only 67.1% had referral dates reported in the EMR. Time-to-treatment stratified by treatment modality received did not differ by type of initial visit (median values in-person vs. telemedicine: surgery 16 vs. 22 days, p= 0.48; radiation 26.5 vs. 28 days, p=0.90; systemic therapy 13.5 vs. 14 days, p=0.49). A sensitivity analysis limited to new diagnoses only (210/241) confirmed the same results. Conclusions: Rapid adoption of telemedicine sustained timely delivery of oncologic care during the initial surge of the COVID19 pandemic across a thoracic oncology multi-disciplinary clinic. While the full impact of telemedicine on long term clinical outcomes remains to be determined, faster times from referral to initial visit in the telemedicine group provide preliminary evidence that telemedicine could sustain or improve accessibility to oncologic care, especially during current and future pandemics.

Citation Format: Vivek U. Nimgaonkar, Abigail T. Berman, Peter Gabriel, John Kucharczuk, Lawrence N. Shulman, Charu Aggarwal, Melina E. Marmarelis. Effect of telemedicine adoption on accessibility and time to treatment in patients with thoracic malignancies during the COVID-19 pandemic [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2021 Feb 3-5. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(6_Suppl):Abstract nr P17.

Next-generation Sequencing of Cerebrospinal Fluid: How Can a Liquid be Like a Solid?

The APOLLO investigators showed that next-generation sequencing of cerebrospinal fluid can reveal molecular alterations-how should this affect our management approach?See related article by Xing et al., p. 6168.

Management of Lung Cancer During the COVID-19 Pandemic

Coronavirus disease 2019 (COVID-19) has had a devastating impact around the world. With high rates of transmission and no curative therapies or vaccine yet available, the current cornerstone of management focuses on prevention by social distancing. This includes decreased health care contact for patients. Patients with lung cancer are a particularly vulnerable population, where the risk of mortality from cancer must now be balanced by the potential risk of a life-threatening infection. In these unprecedented times, a collaborative and multidisciplinary approach is required to streamline but not compromise care. We have developed guidelines at our academic cancer center to standardize management of patients with lung cancer across our health care system and provide guidance to the larger oncology community. We recommend that general principles of lung cancer treatment continue to be followed in most cases where delays could result in rapid cancer progression. We recognize that our recommendations may change over time based on clinical resources and the evolving nature of the COVID-19 pandemic. In principle, however, treatment paradigms must continue to be individualized, with careful consideration of risks and benefits of continuing or altering lung cancer-directed therapy.

Impact of KRAS and TP53 Co-Mutations on Outcomes After First-Line Systemic Therapy Among Patients With STK11-Mutated Advanced Non-Small-Cell Lung Cancer

PURPOSE

The STK11 gene encodes a serine/threonine protein kinase that regulates cell polarity and functions as a tumor suppressor. Patients with non-small-cell lung cancer (NSCLC) and STK11 mutations often have other co-mutations. We evaluated the impact of KRAS and TP53 co-mutations on outcomes after first-line systemic therapy for patients with metastatic or recurrent NSCLC that harbors STK11 mutations.

METHODS

We conducted a retrospective review of patients with metastatic NSCLC and STK11 mutations treated at the University of Pennsylvania. STK11 mutations were identified through next-generation sequencing (NGS) in tissue or plasma. Cox proportional hazard models were used to determine the relationship between STK11 co-mutations and survival outcomes. The Kaplan-Meier method was used to estimate overall survival (OS) and progression-free survival (PFS).

RESULTS

From February 2013 to December 2016, samples from 1,385 patients with NSCLC were analyzed by NGS; of these, 77 patients (6%) harbored an STK11 mutation (n = 56, tissue; n = 21, plasma). Of the 62 patients included, 18 had an STK11 mutation alone, 19 had STK11/KRAS, 18 had STK11/TP53, and seven had STK11/KRAS/TP53. Patients with STK11/KRAS co-mutations had a worse median PFS (2.4 months) compared with STK11 alone (5.1 months; log-rank P = .048), STK11/TP53 (4.3 months; log-rank P = .043), and STK11/KRAS/ TP53 (13 months; log-rank P = .03). Patients with STK11/KRAS co-mutation experienced shorter median OS (7.1 months) compared with STK11 alone (16.1 months; log-rank P < .001), STK11/TP53 (28.3 months; log-rank P < .001), and STK11/KRAS/TP53 (22 months; log-rank P = .025).

CONCLUSION

Among patients with advanced NSCLC and STK11 mutations treated with first-line systemic therapy, co-mutation with KRAS was associated with significantly worse PFS and OS. By contrast, co-mutation of STK11 with TP53 conferred a better prognosis.

Abstract 783: Impact of KRAS and TP53 co-mutations on outcomes following 1st-line therapy among patients with LKB1/STK11 mutated stage IV NSCLC

* Authors E. M. B. and M. E. M. contributed equally

Introduction: LKB1/STK11 is a tumor suppressor and a negative regulator of mTOR signaling. NSCLC patients with STK11 mutations (MT) commonly also have other co-mutations. We evaluated the impact of STK11 MT on outcomes following chemotherapy for metastatic NSCLC, and the role of common co-existing MTs in KRAS and TP53.

Methods: We conducted a retrospective review of patients (pts) with NSCLC and STK11 MT treated at the University of Pennsylvania. STK11 MT was identified through next generation sequencing (NGS) in tissue or using the Guardant 360TM platform for plasma. Four treatment groups were analyzed: STK11 alone (A), and 3 co-MT groups: STK11/KRAS (B), STK11/TP53 (C), and STK11/KRAS/TP53 (D). Chi-square analysis was used to assess differences in baseline characteristics between the MT groups. Cox proportional hazard models (HR) were used to determine the relationship of STK11 co-MT to survival. Kaplan-Meier analysis was used to estimate overall survival (OS) and progression-free survival (PFS).

Results: Between 2/14/13 and 12/1/16, 77 pts with STK11 MT who received systemic therapy were identified (56 tissue, 21 plasma): median age at diagnosis 66 yrs, 51.5% male, 85% ECOG PS of 0 or 1, 94% of pts received 1st-line chemotherapy. There were no significant differences in baseline characteristics among mutation groups. Pts with STK11/KRAS had a worse median PFS and OS vs. pts with STK11 alone (Table 1). Pts with STK11/TP53 had a significantly better OS compared to STK11/KRAS patients.

Conclusion: Among STK11 mutant NSCLC pts treated with chemotherapy, co-MT with KRAS was associated with a significantly worse PFS and OS compared to patients with STK11 alone. By contrast, co-MT with TP53 conferred a better prognosis. These results warrant further validation in a larger study.

Table 1: Outcomes by mutation statusA:STK11alone n=16 (24.2%)B:STK11/KRAS n=21 (31.8%)C:STK11/TP53 n=18 (27.3%)D:STK11/KRAS/TP53 n=11 (16.7%)Median PFS5.3 mo2.4 mo*9.9mo4.9 moMedian OS13.1 mo6.9 mo**22.2 mo***13.9 mo*compared to A, HR 2.8, 95% CI 1.1 to 6.9, p = 0.026**compared to A, HR 6.4, 95% CI 2.4 to 17.3, p&lt;0.001***compared to B, HR 0.12, 95% CI 0.04 to 0.31, p&lt;0.001

Citation Format: Erin M. Bange, Melina E. Marmarelis, Wei-Ting Hwang, Yu-Xiao Yang, Jeffrey C. Thompson, Joshua Bauml, Christine A. Ciunci, Evan W. Alley, Tracey L. Evans, Jennifer J. Morrissette, Roger B. Cohen, Corey J. Langer, Erica L. Carpenter, Charu Aggarwal. Impact of KRAS and TP53 co-mutations on outcomes following 1st-line therapy among patients with LKB1/STK11 mutated stage IV NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 783.

Diagnostic Comparison of CT Scans and Colonoscopy for Immune-Related Colitis in Ipilimumab-Treated Advanced Melanoma Patients

Colitis can be a life-threatening toxicity for patients treated with immune checkpoint blockade antibodies. With the anticipated widespread use of these reagents, the timely and accurate diagnosis of immune-related colitis becomes increasingly important. To better understand the clinical presentation of colitis from ipilimumab and to assess the use of CT scans of the abdomen/pelvis as a diagnostic tool, we retrospectively analyzed patients with advanced melanoma who received ipilimumab at our institution. Ninety nine (33%) of 303 patients developed diarrhea during therapy, and 46 patients (15%) received corticosteroids for colitis. Of the patients with diarrhea, 48 (48%) underwent colonoscopy and 46 (46%) underwent both CT and colonoscopy. In the 34 patients (34%) with a CT and biopsy, CT was highly predictive of colitis on biopsy (positive predictive value 96%), and the absence of CT findings was predictive of a negative biopsy (negative likelihood ratio 0.2). In patients who had symptoms and CT evaluation, CT was highly predictive of the need for steroids to reach resolution of symptoms (positive predictive value 92%, positive likelihood ratio 7.3). We conclude that CT is a fast, reliable, and noninvasive mode of diagnosing colitis, whereas colonoscopy and biopsy may not be needed to establish that diagnosis. Cancer Immunol Res; 5(4); 286-91. ©2017 AACR.

Combination Immunotherapy in Non-small Cell Lung Cancer

PURPOSE OF REVIEW

Checkpoint blockade has changed the treatment landscape in non-small cell lung cancer (NSCLC), but single-agent approaches are effective for only a select subset of patients. Here, we will review the evidence for combination immunotherapies in NSCLC and the clinical data evaluating the efficacy of this approach.

RECENT FINDINGS

Clinical trials evaluating combination PD-1 and CTLA-4 blockade as well as PD-1 in combination with agents targeting IDO1, B7-H3, VEGF, and EGFR show promising results. Additional studies targeting other immune pathways like TIGIT, LAG-3, and cellular therapies are ongoing. Combination immunotherapy has the potential to improve outcomes in NSCLC. Data from early clinical trials is promising and reveals that these agents can be administered together safely without a significant increase in toxicity. Further studies are needed to evaluate their long-term safety and efficacy and to determine appropriate patient selection.

Tumor control with PD-1 inhibition in a patient with concurrent metastatic melanoma and renal cell carcinoma

Blockade of the immunological checkpoint programmed death 1 (PD-1) using monoclonal antibodies has shown robust anti-tumor activity across a broad range of solid and hematological malignancies including melanoma and renal cell carcinoma (RCC). Characteristic markers such as the presence of tumor infiltrating lymphocytes, PD-L1 status, and mutational load may be equally or even more important in predicting clinical benefit from PD-1 pathway blockade than tumor histology. This case of a patient with concurrent metastatic melanoma and metastatic RCC, both of which were controlled for more than a year after a single dose of the anti-PD-1 antibody pembrolizumab, illustrates the potential to simultaneously treat distinct immunogenic tumors with anti-PD-1 agents.

Activity of the heat shock protein 90 inhibitor ganetespib in melanoma

Heat shock protein 90 (HSP90) is involved in the regulation of diverse biological processes such as cell signaling, proliferation and survival, and has been recently recognized as a potential target for cancer therapy. Ganetespib is a potent ATP competitive inhibitor of HSP90. Ganetespib downregulated the expression of multiple signal transducing molecules including EGFR, IGF-1R, c-Met, Akt, B-RAF and C-RAF, resulting in pronounced decrease in phosphorylation of Akt and Erk1/2 in a panel of five cutaneous melanoma cell lines including those harboring B-RAF and N-RAS mutations. Ganetespib exhibited potent antiproliferative activity on all five of these cell lines, with IC50 values between 37.5 and 84 nM. Importantly, Ganetespib is active on B-RAF mutated melanoma cells that have acquired resistance to B-RAF inhibition. Ganetespib induced apoptosis and cell cycle arrest at G1 and/or G2/M phase. Ganetespib induced cell cycle arrest was accompanied by altered expression of cyclin-dependent kinase inhibitor (CDKI) p21^Cip1 and p27^Kip1, cyclins B1, D1 and E, and/or cyclin-dependent kinases 1, 2 and 4. HSP90 is functionally important for melanoma cells and HSP90 inhibitors such as ganetespib could potentially be effective therapeutics for melanoma with various genetic mutations and acquired resistance to B-RAF inhibition.