Ki-67 Proliferation Index Is Associated With Tumor Grade and Survival in Pleural Epithelioid Mesotheliomas

Pleural epithelioid mesothelioma (PEM) is divided into low and high grades based on nuclear atypia, mitoses, and necrosis in the tumor. Assessing mitoses and nuclear atypia tend to be labor-intensive with limited reproducibility. Ki-67 proliferation index was shown to be a prognostic factor in PEM, but its performance has not been directly correlated with tumor grade or mitotic score. This study evaluated the potential of Ki-67 index as a surrogate of tumor grade. We also compared the predictability of mitoses and Ki-67 index for overall survival (OS). Ninety-six PEM samples from 85 patients were identified from the surgical pathology file during 2000-2021 at our institution, and all glass slides were reviewed by 2 pulmonary pathologists to confirm the diagnosis and assign the tumor grade. Digital image analysis (DIA) was done for Ki-67 index. The agreement on tumor grading between 2 reviewers was moderate (kappa value = 0.47). The correlation between mitotic count (average count by 2 reviewers) and Ki-67 index was 0.65. The areas under the curve for predicting tumor grade by mitotic score and Ki-67 index were 0.84 and 0.74 (reviewer 1) and 0.85 and 0.81 (reviewer 2), respectively. High Ki-67 index and mitoses were significantly associated with poor OS ( P =0.03 and 0.0005, using 30% and 10/2 mm 2 as cutoffs, respectively). In conclusion, Ki-67 index by DIA was associated with tumor grade as well as mitotic count, and its predictability for OS was comparable to that of mitotic score, thus being a potential surrogate for tumor grade.

Pegargiminase Plus First-Line Chemotherapy in Patients With Nonepithelioid Pleural Mesothelioma: The ATOMIC-Meso Randomized Clinical Trial

Importance

Arginine deprivation using ADI-PEG20 (pegargiminase) combined with chemotherapy is untested in a randomized study among patients with cancer. ATOMIC-Meso (ADI-PEG20 Targeting of Malignancies Induces Cytotoxicity-Mesothelioma) is a pivotal trial comparing standard first-line chemotherapy plus pegargiminase or placebo in patients with nonepithelioid pleural mesothelioma.

Objective

To determine the effect of pegargiminase-based chemotherapy on survival in nonepithelioid pleural mesothelioma, an arginine-auxotrophic tumor.

Design, Setting, and Participants

This was a phase 2-3, double-blind randomized clinical trial conducted at 43 centers in 5 countries that included patients with chemotherapy-naive nonepithelioid pleural mesothelioma from August 1, 2017, to August 15, 2021, with at least 12 months' follow-up. Final follow-up was on August 15, 2022. Data analysis was performed from March 2018 to June 2023.

Intervention

Patients were randomly assigned (1:1) to receive weekly intramuscular pegargiminase (36.8 mg/m2) or placebo. All patients received intravenous pemetrexed (500 mg/m2) and platinum (75-mg/m2 cisplatin or carboplatin area under the curve 5) chemotherapy every 3 weeks up to 6 cycles. Pegargiminase or placebo was continued until progression, toxicity, or 24 months.

Main Outcomes and Measures

The primary end point was overall survival, and secondary end points were progression-free survival and safety. Response rate by blinded independent central review was assessed in the phase 2 portion only.

Results

Among 249 randomized patients (mean [SD] age, 69.5 [7.9] years; 43 female individuals [17.3%] and 206 male individuals [82.7%]), all were included in the analysis. The median overall survival was 9.3 months (95% CI, 7.9-11.8 months) with pegargiminase-chemotherapy as compared with 7.7 months (95% CI, 6.1-9.5 months) with placebo-chemotherapy (hazard ratio [HR] for death, 0.71; 95% CI, 0.55-0.93; P = .02). The median progression-free survival was 6.2 months (95% CI, 5.8-7.4 months) with pegargiminase-chemotherapy as compared with 5.6 months (95% CI, 4.1-5.9 months) with placebo-chemotherapy (HR, 0.65; 95% CI, 0.46-0.90; P = .02). Grade 3 to 4 adverse events with pegargiminase occurred in 36 patients (28.8%) and with placebo in 21 patients (16.9%); drug hypersensitivity and skin reactions occurred in the experimental arm in 3 patients (2.4%) and 2 patients (1.6%), respectively, and none in the placebo arm. Rates of poststudy treatments were comparable in both arms (57 patients [45.6%] with pegargiminase vs 58 patients [46.8%] with placebo).

Conclusions and Relevance

In this randomized clinical trial of arginine depletion with pegargiminase plus chemotherapy, survival was extended beyond standard chemotherapy with a favorable safety profile in patients with nonepithelioid pleural mesothelioma. Pegargiminase-based chemotherapy as a novel antimetabolite strategy for mesothelioma validates wider clinical testing in oncology.

Trial Registration

ClinicalTrials.gov Identifier: NCT02709512.

Pralsetinib in patients with RET fusion-positive non-small-cell lung cancer: A plain language summary of the ARROW study

WHAT IS THIS SUMMARY ABOUT?

This is a summary of a research study called ARROW, which tested a medicine called pralsetinib in patients with non-small cell lung cancer (NSCLC), thyroid cancer, and other advanced solid tumours caused by a change in a gene called RET. For the purposes of this summary, only patients with NSCLC with a change in RET called fusion (RET fusion+) are highlighted.

WHAT WERE THE RESULTS?

In total, 281 patients with RET fusion+ NSCLC had taken part in this study across the USA, Europe, and Asia. Patients were asked to take four pills (adding up to 400 mg) of pralsetinib each day and were checked for any changes in their tumours, as well as for any side effects. After an average of 8 months of treatment with pralsetinib, 72% of previously untreated patients and 59% of patients who had previously received chemotherapy had considerable shrinkage of their tumours. Among 10 patients with tumours which had spread to the brain (all of whom had received previous treatments), 70% had their tumours shrink greatly in the brain after treatment with pralsetinib. On average, patients lived with little to no tumour growth for 16 months. In previously untreated patients, the most common severe side effects that were considered related to pralsetinib treatment were decreased white blood cells (neutrophils and lymphocytes), increased blood pressure, and an increase in a blood protein called creatine phosphokinase. In previously treated patients, the severe side effects were decreased white blood cells (neutrophils, lymphocytes, and leukocytes), increased blood pressure, and low levels of red blood cells. In both untreated and previously treated patients, the most common severe side effects that required hospital attention were lung inflammation/swelling causing shortness of breath (pneumonitis) and lung infection (pneumonia).

WHAT DO THE RESULTS MEAN?

Overall, the ARROW study showed that pralsetinib was effective in shrinking tumours in patients with RET fusion+ NSCLC regardless of previous treatment history. The recorded side effects were expected in patients receiving this type of medicine. Clinical Trial Registration: NCT03037385 (ARROW) (ClinicalTrials.gov).

Pralsetinib in Patients with Advanced/Metastatic Rearranged During Transfection (RET)-Altered Thyroid Cancer: Updated Efficacy and Safety Data from the ARROW Study

Background: Rearranged during transfection (RET) alterations are targetable oncogenic drivers in thyroid cancer. Primary data from the open-label, phase 1/2 ARROW study demonstrated clinical activity and manageable safety with pralsetinib, a selective RET inhibitor, in patients with advanced/metastatic RET-altered thyroid cancer. We present an updated analysis with more patients and longer follow-up. Methods: Adult patients with advanced/metastatic RET-mutant medullary thyroid cancer (MTC) or RET fusion-positive thyroid cancer who initiated oral pralsetinib at 400 mg once daily were included. Primary endpoints were overall response rate (ORR) by blinded independent central review (per RECIST v1.1) and safety. Secondary endpoints included duration of response (DoR), progression-free survival (PFS), and overall survival. Responses were assessed in three cohorts of patients with baseline measurable disease: patients with RET-mutant MTC who had received prior cabozantinib and/or vandetanib (C/V), treatment-naïve patients with RET-mutant MTC, and patients with previously treated RET fusion-positive thyroid cancer. Patient-reported outcomes (PROs) were an exploratory endpoint. Results: As of October 18, 2021, the measurable disease population comprised of 61 patients with RET-mutant MTC and prior C/V, 62 treatment-naïve patients with RET-mutant MTC, and 22 patients with RET fusion-positive thyroid cancer who had received prior systemic therapy, including radioactive iodine. The ORR was 55.7% [confidence interval; 95% CI: 42.4-68.5] in patients with RET-mutant MTC and prior C/V, 77.4% [95% CI: 65.0-87.1] in treatment-naïve patients with RET-mutant MTC, and 90.9% [95% CI: 70.8-98.9] in patients with previously treated RET fusion-positive thyroid cancer. Median DoR and median PFS were both 25.8 months in patients with RET-mutant MTC and prior C/V, not reached in treatment-naïve patients with RET-mutant MTC, and 23.6 and 25.4 months, respectively, in patients with previously treated RET fusion-positive thyroid cancer. In the RET-altered thyroid cancer safety population (N = 175), 97.1% of patients reported a treatment-related adverse event (TRAE); these led to discontinuation in 5.7% and dose reduction in 52.6% of patients. There was one death (0.6%) due to a TRAE. PROs improved or remained stable after pralsetinib treatment. Conclusions: In this updated analysis of the ARROW study, pralsetinib continued to show deep and durable clinical activity and a manageable safety profile in patients with advanced/metastatic RET-altered thyroid cancer. Clinical Trial Registration: NCT03037385.

The Timing, Trajectory, and Incidence of Immune-Related Adverse Events in NSCLC Treated With Atezolizumab

Introduction

Immune-related adverse events (irAEs) due to immune checkpoint inhibitors can have complicated clinical courses. We comprehensively evaluated the timing, trajectory, and incidence of both single and multiple irAEs for NSCLC treated with atezolizumab.

Methods

Data were pooled from 2457 patients who participated in the IMpower130, IMpower132, and IMpower150 clinical trials investigating the use of atezolizumab in metastatic NSCLC as part of a chemoimmunotherapy regimen. Longitudinal irAE data with landmark analysis, time-to-onset, changes in grading severity, and occurrence of multiple events were summarized.

Results

In general, 1557 patients were treated with atezolizumab and 900 patients were in the control groups. Median follow-up was 32.3 and 23.5 months, respectively. In the atezolizumab group, 753 patients (48.4%) experienced at least one irAE. In the control group, 289 patients (32.1%) experienced at least one nonimmune adverse event that was attributed to an irAE. In the atezolizumab group, the most common irAEs were rash, hepatitis, and hypothyroidism. Furthermore, 13% of the patients experienced two irAEs and 4% experienced three irAEs. Within 5 months of treatment, the cumulative incidence for any irAE was 39.2%. Median time-to-onset varied from 1 to 10 months based on the specific irAE. Grade 1 to 2 irAEs increased in severity for 33% of the patients.

Conclusions

We identified dynamic clinical patterns for irAEs in patients treated with atezolizumab, including variations in time-to-onset, incidence of multiple irAEs, and frequency of irAEs increasing in severity. These results can guide clinical management and future reporting of adverse events to enable comprehensive longitudinal analyses.

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.

Clinical and molecular characterization of long-term survivors with extensive-stage small cell lung cancer treated with first-line atezolizumab plus carboplatin and etoposide

OBJECTIVES

In the Phase I/III IMpower133 study, first-line atezolizumab plus carboplatin and etoposide (CP/ET) treatment for extensive-stage small cell lung cancer (ES-SCLC) significantly improved overall survival (OS) and progression-free survival versus placebo plus CP/ET. We explored patient and disease characteristics associated with long-term survival in IMpower133, and associations of differential gene expression and SCLC-A (ASCL1-driven), SCLC-N (NEUROD1-driven), SCLC-P (POU2F3-driven), and SCLC-inflamed (SCLC-I) transcriptional subtypes with long-term survival.

MATERIALS AND METHODS

Patients with previously untreated ES-SCLC were randomized 1:1 to four 21-day cycles of CP/ET with atezolizumab or placebo. Long-term survivors (LTS) were defined as patients who lived ≥ 18 months post randomization. A generalized linear model was used to evaluate the odds of living ≥ 18 months. Differential gene expression was analyzed using RNA-sequencing data in LTS and non-LTS. OS was assessed by T-effector and B-cell gene signature expression. Distribution of SCLC transcriptional subtypes was assessed in LTS and non-LTS.

RESULTS

More LTS were in the atezolizumab arm (34%) than in the placebo arm (20%). The odds ratio for living ≥ 18 months in the atezolizumab arm versus the placebo arm was 2.1 (P < 0.03). Enhanced immune-related signaling was seen in LTS in both arms. Exploratory OS analyses showed atezolizumab treatment benefit versus placebo across T-effector and B-cell gene signature expression subgroups. A higher proportion of LTS than non-LTS in both arms had the SCLC-I subtype; this difference was particularly pronounced in the atezolizumab arm.

CONCLUSION

These exploratory analyses suggest that long-term survival is more likely with atezolizumab than placebo in ES-SCLC, confirming the treatment benefit of the IMpower133 regimen.

CLINICALTRIAL

gov Identifier: NCT02763579.

Real-World Outcomes With Lurbinectedin in Second-Line Setting and Beyond for Extensive Stage Small Cell Lung Cancer

BACKGROUND

Lurbinectedin has emerged as a potential treatment option for relapsed small cell lung cancer (SCLC). While clinical trials have demonstrated its efficacy and safety, real-world data are limited. This study aimed to evaluate the safety and efficacy of lurbinectedin in a real-world setting, focusing on its use as a second-line agent and beyond in SCLC patients.

METHODS

A retrospective analysis was conducted on 90 patients who received lurbinectedin between June 2020 and June 2022 within the Mayo Clinic Health System. Of these, 50 patients received lurbinectedin as a second-line agent, and 14 patients received it as a third-line or later agent. The primary outcomes assessed were overall survival (OS), progression-free survival (PFS), and treatment-related adverse events.

RESULTS

Lurbinectedin was generally well tolerated in this real-world cohort, with a median OS of 5.1 months in the second-line cohort and 5.6 months in the third-line or later cohort. Median PFS was 2.1 months in the second-line cohort and 3.4 months in the third-line or later cohort. Adverse events were manageable, with the most common being neutropenia, anemia, fatigue, and febrile neutropenia. No treatment-related deaths or grade 5 toxicities were reported.

CONCLUSION

This real-world study provides valuable insights into the safety and efficacy of lurbinectedin in relapsed SCLC. Lurbinectedin demonstrated modest efficacy and a comparable safety profile to that observed in clinical trials. However, outcomes for relapsed SCLC remain suboptimal, particularly for patients with a shorter chemotherapy-free interval and central nervous system metastases.

Amivantamab plus Chemotherapy in NSCLC with EGFR Exon 20 Insertions

BACKGROUND

Amivantamab has been approved for the treatment of patients with advanced non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) exon 20 insertions who have had disease progression during or after platinum-based chemotherapy. Phase 1 data showed the safety and antitumor activity of amivantamab plus carboplatin-pemetrexed (chemotherapy). Additional data on this combination therapy are needed.

METHODS

In this phase 3, international, randomized trial, we assigned in a 1:1 ratio patients with advanced NSCLC with EGFR exon 20 insertions who had not received previous systemic therapy to receive intravenous amivantamab plus chemotherapy (amivantamab-chemotherapy) or chemotherapy alone. The primary outcome was progression-free survival according to blinded independent central review. Patients in the chemotherapy group who had disease progression were allowed to cross over to receive amivantamab monotherapy.

RESULTS

A total of 308 patients underwent randomization (153 to receive amivantamab-chemotherapy and 155 to receive chemotherapy alone). Progression-free survival was significantly longer in the amivantamab-chemotherapy group than in the chemotherapy group (median, 11.4 months and 6.7 months, respectively; hazard ratio for disease progression or death, 0.40; 95% confidence interval [CI], 0.30 to 0.53; P<0.001). At 18 months, progression-free survival was reported in 31% of the patients in the amivantamab-chemotherapy group and in 3% in the chemotherapy group; a complete or partial response at data cutoff was reported in 73% and 47%, respectively (rate ratio, 1.50; 95% CI, 1.32 to 1.68; P<0.001). In the interim overall survival analysis (33% maturity), the hazard ratio for death for amivantamab-chemotherapy as compared with chemotherapy was 0.67 (95% CI, 0.42 to 1.09; P = 0.11). The predominant adverse events associated with amivantamab-chemotherapy were reversible hematologic and EGFR-related toxic effects; 7% of patients discontinued amivantamab owing to adverse reactions.

CONCLUSIONS

The use of amivantamab-chemotherapy resulted in superior efficacy as compared with chemotherapy alone as first-line treatment of patients with advanced NSCLC with EGFR exon 20 insertions. (Funded by Janssen Research and Development; PAPILLON ClinicalTrials.gov number, NCT04538664.).

Salvage therapy expands highly cytotoxic and metabolically fit resilient CD8+ T cells via ME1 up-regulation

Patients with advanced cancers who either do not experience initial response to or progress while on immune checkpoint inhibitors (ICIs) receive salvage radiotherapy to reduce tumor burden and tumor-related symptoms. Occasionally, some patients experience substantial global tumor regression with a rebound of cytotoxic CD8+ T cells. We have termed the rebound of cytotoxic CD8+ T cells in response to salvage therapy as T cell resilience and examined the underlying mechanisms of resilience. Resilient T cells are enriched for CX3CR1+ CD8+ T cells with low mitochondrial membrane potential, accumulate less reactive oxygen species (ROS), and express more malic enzyme 1 (ME1). ME1 overexpression enhanced the cytotoxicity and expansion of effector CD8+ T cells partially via the type I interferon pathway. ME1 also increased mitochondrial respiration while maintaining the redox state balance. ME1 increased the cytotoxicity of peripheral lymphocytes from patients with advanced cancers. Thus, preserved resilient T cells in patients rebound after salvage therapy and ME1 enhances their resiliency.

Improved Survival Outcomes in Patients With MET-Dysregulated Advanced NSCLC Treated With MET Inhibitors: Results of a Multinational Retrospective Chart Review

BACKGROUND

We evaluated the disease and patient characteristics, treatment, and MET testing patterns, predictive biomarkers and survival outcomes in patients with MET-dysregulated metastatic non-small-cell lung cancer (NSCLC) in a real-world setting.

PATIENTS AND METHODS

This was a multinational, retrospective, noninterventional chart review study. Data from medical records of patients with advanced/metastatic EGFR wild-type, MET-dysregulated NSCLC (December 2017-September 2018) were abstracted into electronic data collection forms.

RESULTS

Overall, 211 patient charts were included in this analysis; 157 patients had MET exon 14 skipping mutations (METex14; with or without concomitant MET amplification) and 54 had MET amplification only. All patients were tested for METex14, whereas MET amplification was evaluated in 168 patients. No overlap was reported between MET dysregulation and ALK, ROS1 or RET rearrangements, or HER2 exon 20 insertions. Overall, 56 of 211 patients (26.5%) received MET inhibitor (METi) therapy in any treatment-line setting (31.2% in the METex14 cohort; 13% in the MET-amplified only cohort). In the METex14 cohort, median OS in patients receiving METi was 25.4 months versus 10.7 months in patients who did not (HR [95% CI]: 0.532 [0.340-0.832]; P = .0055). In the MET-amplified only cohort, median OS was 20.6 months in patients treated with METi compared with 7.6 months in those without METi (HR [95% CI]: 0.388 [0.152-0.991]; P = .0479).

CONCLUSIONS

MET alterations in NSCLC typically occur in the absence of other oncogenic driver mutations and are associated with poor survival outcomes. Notably, METi therapies are associated with improved survival outcomes in patients with MET-dysregulated NSCLC.

Time from immune checkpoint inhibitor to sotorasib use correlates with risk of hepatotoxicity in non-small cell lung cancer: A brief report

INTRODUCTION

We evaluated the risk factors and outcomes for patients who experienced hepatotoxicity after use of sotorasib in KRAS G12C mutated NSCLC.

METHODS

Retrospective review of medical records of patients with KRAS G12C mutated NSCLC who received sotorasib between May 28th, 2021, and December 31st, 2021 across all Mayo Clinic sites, with follow up until December 31st, 2022.

RESULTS

Thirty-one patients received sotorasib as standard of care treatment. Grade 3 or higher hepatoxicity was seen in 32% (10/31) patients presenting at a median of 51 days (range, 27-123) of sotorasib initiation. Baseline demographics were comparable between patients with and without ≥grade 3 hepatotoxicity, except for presence of CNS metastases and time from prior immune checkpoint inhibitor (ICI) treatment. Improvement in liver tests was observed in all patients after stopping sotorasib, and it was restarted at a lower dose in 8 patients. Despite dose reduction, hepatotoxicity requiring sotorasib discontinuation occurred in 2 patients. Twenty-eight of 31 patients had received prior ICI. Median time from prior ICI therapy was 69 days (range, 4-542). Rates of ≥grade 3 hepatoxicity were 75% (3/4), 64% (7/11) and 0% (0/13) for patients who received ICI within 30 days, 31-90 days and >90 days. None of the 3 patients without prior ICI exposure developed hepatoxicity. The median PFS and OS were 3.9 months and 9.9 months respectively.

CONCLUSION

One-third of patients developed grade 3 or higher sotorasib induced hepatotoxicity. Risk of hepatotoxicity was higher in patients who received sotorasib within 90 days of ICI treatment.

Epigenomics may begin to explain in vitro differential response to hypomethylating agents in MMR-D hypermethylated endometrial cancer

This work examines differences in chromatin accessibility, methylation, and response to DNA hypomethylating agents between mismatch repair-deficient and non-mismatch repair-deficient endometrial cancer. Next-generation sequencing of a stage 1B, grade 2 endometrioid endometrial cancer tumor revealed microsatellite instability and a variant of unknown significance in POLE along with global and MLH1 hypermethylation. Inhibition of viability by decitabine in the study and comparison tumors was minimal, as shown by an inhibitory effect of 0 and 17.9, respectively. Conversely, the inhibitory effect of azacitidine on the study tumor was more pronounced, at 72.8 versus 41.2. In vitro, mismatch repair-deficient endometrial cancer with MLH1 hypermethylation respond better to DNA methyltransferase inhibition by azacytidine (DNA/RNA inhibition), than to decitabine (DNA-only inhibition). Additional large studies are needed to substantiate our findings.

A Novel Humanized PD-1/PD-L1 Mouse Model Permits Direct Comparison of Antitumor Immunity Generated by Food and Drug Administration-Approved PD-1 and PD-L1 Inhibitors

Seven different anti-PD-1 and PD-L1 mAbs are now widely used in the United States to treat a variety of cancer types, but no clinical trials have compared them directly. Furthermore, because many of these Abs do not cross-react between mouse and human proteins, no preclinical models exist in which to consider these types of questions. Thus, we produced humanized PD-1 and PD-L1 mice in which the extracellular domains of both mouse PD-1 and PD-L1 were replaced with the corresponding human sequences. Using this new model, we sought to compare the strength of the immune response generated by Food and Drug Administration-approved Abs. To do this, we performed an in vivo T cell priming assay in which anti-PD-1/L1 therapies were given at the time of T cell priming against surrogate tumor Ag (OVA), followed by subsequent B16-OVA tumor challenge. Surprisingly, both control and Ab-treated mice formed an equally robust OVA-specific T cell response at the time of priming. Despite this, anti-PD-1/L1-treated mice exhibited significantly better tumor rejection versus controls, with avelumab generating the best protection. To determine what could be mediating this, we identified the increased production of CX3CR1+PD-1+CD8+ cytotoxic T cells in the avelumab-treated mice, the same phenotype of effector T cells known to increase in clinical responders to PD-1/L1 therapy. Thus, our model permits the direct comparison of Food and Drug Administration-approved anti-PD-1/L1 mAbs and further correlates successful tumor rejection with the level of CX3CR1+PD-1+CD8 + T cells, making this model a critical tool for optimizing and better utilizing anti-PD-1/L1 therapeutics.

Perioperative Immune Checkpoint Inhibition in Early-Stage Non-Small Cell Lung Cancer: A Review

Importance

Although cancer-related mortality continues to decline, lung cancer remains the No. 1 cause of cancer deaths in the US. Almost half of the patients with non-small cell lung cancer (NSCLC) are diagnosed with early-stage, local or regional disease and are at high risk of recurrence within 5 years of diagnosis.

Observations

Immune checkpoint inhibitors (ICIs) have improved outcomes for patients with metastatic NSCLC and have recently been tested in multiple clinical trials to determine their efficacy in the neoadjuvant or adjuvant setting for patients with local or regional disease. The landscape for perioperative ICIs in lung cancer is evolving rapidly, with recently reported and soon to mature clinical trials; however, the recent data highlight the potential of ICIs to increase response rates and decrease rates of relapse in early stages of lung cancer. Concurrently, novel applications of cell-free DNA may guide perioperative management strategies.

Conclusions and Relevance

This article reviews the various approaches of incorporating perioperative use of immunotherapeutic agents for the treatment of early stages of NSCLC.

Clinical Utility Validation of an Automated Ultrarapid Gene Fusion Assay for NSCLC

Introduction

Gene rearrangements are frequent oncologic drivers in NSCLC, and many are suitable for treatment with Food and Drug Administration-approved or experimental targeted therapies. We evaluated the accuracy, specimen acceptance profile, and limits of detection of a rapid fusion assay (Idylla GeneFusion Assay), a commercially available ultrarapid molecular assay, for its clinical utility.

Methods

A collection of 97 specimens which had previously undergone next-generation sequencing testing were analyzed using the rapid fusion assay. Accuracy was evaluated by sensitivity and specificity compared with the next-generation sequencing results. The performance characteristics were tested by using a variety of different clinically relevant specimen types. Limits of detection were assessed by evaluating different input of tumor percentage and material amount.

Results

The rapid fusion assay was found to have 100% sensitivity in detecting fusions of ALK, ROS1, RET, NTRK1, and MET exon 14 skipping and 83% sensitivity for NTRK2/3 fusions. There were 100% specificity in detecting fusions of ROS1, RET, NTRK2/3, and MET exon 14 skipping and 98% specificity for ALK. Testing was successful with formalin-fixed paraffin-embedded biopsy and surgical tissues, cell blocks from fine-needle aspiration and pleural fluid (down to 5% tumor content, 18 mm2 tissue scraped), cytology smears (≥300 cells), and previously extracted RNA (minimal 20 ng).

Conclusions

The rapid fusion assay is quick, accurate, and versatile, allowing reliable detection of ALK, ROS1, RET fusions, and MET exon 14 skipping in NSCLC, and NTRK fusions. Rapid molecular testing may expedite treatment with appropriate targeted therapies.

Uncertainty-informed deep learning models enable high-confidence predictions for digital histopathology

A model's ability to express its own predictive uncertainty is an essential attribute for maintaining clinical user confidence as computational biomarkers are deployed into real-world medical settings. In the domain of cancer digital histopathology, we describe a clinically-oriented approach to uncertainty quantification for whole-slide images, estimating uncertainty using dropout and calculating thresholds on training data to establish cutoffs for low- and high-confidence predictions. We train models to identify lung adenocarcinoma vs. squamous cell carcinoma and show that high-confidence predictions outperform predictions without uncertainty, in both cross-validation and testing on two large external datasets spanning multiple institutions. Our testing strategy closely approximates real-world application, with predictions generated on unsupervised, unannotated slides using predetermined thresholds. Furthermore, we show that uncertainty thresholding remains reliable in the setting of domain shift, with accurate high-confidence predictions of adenocarcinoma vs. squamous cell carcinoma for out-of-distribution, non-lung cancer cohorts.

The Evolving Therapeutic Landscape for Malignant Pleural Mesothelioma

PURPOSE OF REVIEW

For patients with malignant pleural mesothelioma, prognosis is poor with extremely low 5-year survival rates and limited therapeutic options. Here, we review the current treatment landscape for mesothelioma and highlight promising future therapeutic directions.

RECENT FINDINGS

Evolving frontline therapeutic options for mesothelioma include VEGF inhibition in combination with chemotherapy and dual immune checkpoint inhibition, with synergisms between the therapies and response prediction via biomarkers also being explored. Evolving experimental treatments for mesothelioma include PARP and ALK inhibitors, dendritic and CAR T-cell therapies, anti-mesothelin vaccines, and oncolytic viral therapies, representing timely advances in the field. The therapeutic landscape for malignant pleural mesothelioma is evolving and preferred treatment in the frontline and later settings will likely evolve with it. However, this does not preclude the evidence for including multi-modal therapies spanning angiogenesis and immune checkpoint inhibitors, and biomarker utilization, in current clinical trials and management.

Trials, tribunals, and opportunities for lung cancer KRASG12C brain metastases

The activity of KRAS inhibitors against brain metastases is relatively unexplored. The recent work on pre-clinical models and preliminary data from the ongoing KRYSTAL-1 phase 1b clinical trial support the potential of adagrasib (MRTX849) to penetrate the central nervous system (CNS) and provide control of KRASG12C brain metastases.

Lower Exome Sequencing Coverage of Ancestrally African Patients in The Cancer Genome Atlas

BACKGROUND

In the United States, cancer disproportionately impacts Black and African American individuals. Identifying genetic factors underlying cancer disparities has been an important research focus and requires data that are equitable in both quantity and quality across racial groups. It is widely recognized that DNA databases quantitatively underrepresent minorities. However, the differences in data quality between racial groups have not been well studied.

METHODS

We compared the qualities of germline and tumor exomes between ancestrally African and European patients in The Cancer Genome Atlas of 7 cancers with at least 50 self-reported Black patients in the context of sequencing depth, tumor purity, and qualities of germline variants and somatic mutations.

RESULTS

Germline and tumor exomes from ancestrally African patients were sequenced at statistically significantly lower depth in 6 out of the 7 cancers. For 3 cancers, most ancestrally European exomes were sequenced in early sample batches at higher depth, whereas ancestrally African exomes were concentrated in later batches and sequenced at much lower depth. For the other 3 cancers, the reasons of lower sequencing coverage of ancestrally African exomes remain unknown. Furthermore, even when the sequencing depths were comparable, African exomes had disproportionally higher percentages of positions with insufficient coverage, likely because of the known European bias in the human reference genome that impacted exome capture kit design.

CONCLUSIONS

Overall and positional lower sequencing depths of ancestrally African exomes in The Cancer Genome Atlas led to underdetection and lower quality of variants, highlighting the need to consider epidemiological factors for future genomics studies.

Exploring the safety, effect on the tumor microenvironment, and efficacy of itacitinib in combination with epacadostat or parsaclisib in advanced solid tumors: a phase I study

BACKGROUND

This phase I multicenter study was designed to evaluate the safety, tolerability, efficacy, and translational effects on the tumor microenvironment of itacitinib (Janus-associated kinase 1 (JAK1) inhibitor) in combination with epacadostat (indoleamine 2,3-dioxygenase 1 (IDO1) inhibitor) or parsaclisib (phosphatidylinositol 3-kinase δ (PI3Kδ) inhibitor).

METHODS

Patients with advanced or metastatic solid tumors were enrolled and received itacitinib (100-400 mg once a day) plus epacadostat (50-300 mg two times per day; group A), or itacitinib (100-400 mg once a day) plus parsaclisib or parsaclisib monotherapy (0.3-10 mg once a day; group B).

RESULTS

A total of 142 patients were enrolled in the study. The maximum tolerated dose was not reached for either the combination of itacitinib plus epacadostat (n=47) or itacitinib plus parsaclisib (n=90). One dose-limiting toxicity of serious, grade 3 aseptic meningitis was reported in a patient receiving itacitinib 300 mg once a day plus parsaclisib 10 mg once a day, which resolved when the study drugs were withdrawn. The most common treatment-related adverse events among patients treated with itacitinib plus epacadostat included fatigue, nausea, pyrexia, and vomiting, and for patients treated with itacitinib plus parsaclisib were fatigue, pyrexia, and diarrhea. In the itacitinib plus epacadostat group, no patient had an objective response. Among patients receiving itacitinib 100 mg once a day plus parsaclisib 0.3 mg once a day, three achieved partial response for an objective response rate (95% CI) of 7.1% (1.50 to 19.48). Treatment with itacitinib plus epacadostat demonstrated some increase in tumor CD8⁺ T cell infiltration and minor changes in six plasma proteins, whereas treatment with itacitinib plus high-dose parsaclisib resulted in downregulation of 20 plasma proteins mostly involved in immune cell function, with no observed change in intratumoral CD8⁺ T cell infiltration.

CONCLUSION

Adverse events with JAK1 inhibition combined with either IDO1 or PI3Kδ inhibition were manageable, but the combinations demonstrated limited clinical activity or enhancement of immune activation in the tumor microenvironment.

TRIAL REGISTRATION NUMBER

NCT02559492.

Tumor Junction Burden and Antigen Presentation as Predictors of Survival in Mesothelioma Treated With Immune Checkpoint Inhibitors

INTRODUCTION

The favorable outcomes with immunotherapy for mesothelioma were somewhat unexpected because this tumor has a low tumor mutation burden which has been associated with benefit in other cancers. Because chromosomal rearrangements are common in mesothelioma and have neoantigenic potential, we sought to determine whether they are associated with survival in patients treated with immunotherapy.

METHODS

Pleural biopsies of mesothelioma after at least one line of therapy were obtained from patients (n = 44) before treatment with nivolumab alone (NCT29908324) or in combination with ipilimumab (NCT30660511). RNA and whole-genome sequencing were performed to identify the junctions resulting from chromosomal rearrangements and antigen processing and presentation gene set expression. Associations with overall survival (OS) were estimated using Cox models. An OS cutoff of 1.5 years was used to distinguish patients with and without durable benefit for use in receiving operating characteristic curves.

RESULTS

Although tumor junction burdens were not predictive of OS, we identified significant interactions between the junction burdens and multiple antigen processing and presentation gene sets. The "regulation of antigen processing and presentation of peptide antigen" gene set revealed an interaction with tumor junction burden and was predictive of OS. This interaction also predicted 1.5-year or greater survival with an area under the receiving operating characteristic curve of 0.83. This interaction was not predictive of survival in a separate cohort of patients with mesothelioma who did not receive immune checkpoint inhibitors.

CONCLUSIONS

Analysis of structural variants and antigen presentation gene set expression may facilitate patient selection for immune checkpoint inhibitors.

New Era for Malignant Pleural Mesothelioma: Updates on Therapeutic Options

Malignant pleural mesothelioma (MPM) is a rare malignancy with few treatment options. Recent advances have led to US Food and Drug Administration approvals and changes in the standard of care with a novel biomedical device approved for use with platinum-pemetrexed, and also for immunotherapy agents to be included as a frontline treatment option in unresectable disease. Although predictive biomarkers for systemic therapy are not currently in use in clinical practice, it is essential to correctly identify the MPM histology to determine an optimal treatment plan. Patients with nonepithelioid MPM may have a greater magnitude of benefit to dual immunotherapy checkpoint inhibitors and this regimen should be preferred in the frontline setting for these patients. However, all patients with MPM can derive benefit from immunotherapy treatments, and these agents should ultimately be used at some point during their treatment journey. There are ongoing studies in the frontline unresectable setting that may further define the frontline therapy space, but a critical area of research will need to focus on the immunotherapy refractory population. This review article will describe the new developments in the areas of biology with genomics and chromothripsis, and also focus on updates in treatment strategies in radiology, surgery, radiation, and medical oncology with cellular therapies. These recent innovations are generating momentum to find better therapies for this disease.

Correlation of Somatostatin Receptor 2 Expression, 68Ga-DOTATATE PET Scan and Octreotide Treatment in Thymic Epithelial Tumors

Somatostatin receptor 2 (SSTR2) has been shown to be expressed in a subset of neuroendocrine tumors and carcinomas and plays a role in imaging studies and guiding therapy. Patients with tumors expressing SSTR2 may be successfully treated with somatostatin inhibitors or radiolabeled somatostatin analogues. We studied SSTR2 expression in TET and correlated it with 68Ga-DOTATATE PET/CT or 68Ga-DOTATATE PET/MR results and treatment outcome. An institutional database of TET was searched for thymoma, thymic carcinoma, and thymic neuroendocrine tumor (TNET) with available resection specimens. Cases were subtyped (2021 WHO classification) and staged (8^th AJCC/UICC staging). A section was stained with anti-SSTR2 antibody (clone UMB1). Percent tumor cells with membranous staining was recorded if present in ≥1% of tumor cells. Medical records were searched for 68Ga-DOTATATE PET scans and treatment. Statistical analysis was performed. Eighty patients (1969-2021) with a median age of 61.3 years (range, 19.1-87.3) (37 males, 46.3%) had thymic carcinoma (N=33), TNET (N=7), or thymoma (N=40). SSTR2 expression was identified in 29 (of 80, 36.3%) TET including 2/2 (100%) small cell carcinomas, 2/5 (40.0%) atypical carcinoid tumors, 16/23 (69.6%) squamous cell carcinomas, 2/2 (100%) lymphoepithelial carcinomas, 1/1 (100%) adenosquamous carcinoma, and 6/40 (15.0%) thymomas. SSTR2 expression in ≥50% of tumor cells (vs 1-49%) was associated with younger age (p=0.023) and shorter recurrence/metastasis-free survival (p=0.007). 68Ga-DOTATATE PET scans (N=9) revealed a Krenning score of 3 in patients with atypical carcinoid tumor, small cell carcinoma, and squamous cell carcinoma (N=1 each) with SSTR2 expression in 95, 100, and 5% of tumor cells, respectively. Scans with Krenning scores of ≤2 (N=5) were seen in tumors with no SSTR2 expression in 80% of cases and a single atypical carcinoid tumor with SSTR2 expression in 10% of tumor cells. One scan resulted as "increased uptake" was in a patient with no SSTR2 expression. In conclusion, 68Ga-DOTATATE PET scans correlated with SSTR2 expression in TET in most patients and appeared to be useful to identify patients with TET who may be amenable to treatment with somatostatin analogues. Larger studies including more patients with 68Ga-DOTATATE PET scans are necessary to independently and prospectively validate our findings.

NKG7 Is a T-cell-Intrinsic Therapeutic Target for Improving Antitumor Cytotoxicity and Cancer Immunotherapy

Cytotoxic CD8⁺ T cells (CTL) are a crucial component of the immune system notable for their ability to eliminate rapidly proliferating malignant cells. However, the T-cell intrinsic factors required for human CTLs to accomplish highly efficient antitumor cytotoxicity are not well defined. By evaluating human CD8⁺ T cells from responders versus nonresponders to treatment with immune checkpoint inhibitors, we sought to identify key factors associated with effective CTL function. Single-cell RNA-sequencing analysis of peripheral CD8⁺ T cells from patients treated with anti-PD-1 therapy showed that cells from nonresponders exhibited decreased expression of the cytolytic granule-associated molecule natural killer cell granule protein-7 (NKG7). Functional assays revealed that reduced NKG7 expression altered cytolytic granule number, trafficking, and calcium release, resulting in decreased CD8⁺ T-cell-mediated killing of tumor cells. Transfection of T cells with NKG7 mRNA was sufficient to improve the tumor-cell killing ability of human T cells isolated from nonresponders and increase their response to anti-PD-1 or anti-PD-L1 therapy in vitro. NKG7 mRNA therapy also improved the antitumor activity of murine tumor antigen-specific CD8⁺ T cells in an in vivo model of adoptive cell therapy. Finally, we showed that the transcription factor ETS1 played a role in regulating NKG7 expression. Together, our results identify NKG7 as a necessary component for the cytotoxic function of CD8⁺ T cells and establish NKG7 as a T-cell-intrinsic therapeutic target for enhancing cancer immunotherapy.See related article by Li et al., p. 154.

Repurposing Ceritinib Induces DNA Damage and Enhances PARP Inhibitor Responses in High-Grade Serous Ovarian Carcinoma

PARP inhibitors (PARPi) have activity in homologous recombination (HR) repair-deficient, high-grade serous ovarian cancers (HGSOC). However, even responsive tumors develop PARPi resistance, highlighting the need to delay or prevent the appearance of PARPi resistance. Here, we showed that the ALK kinase inhibitor ceritinib synergizes with PARPis by inhibiting complex I of the mitochondrial electron transport chain, which increases production of reactive oxygen species (ROS) and subsequent induction of oxidative DNA damage that is repaired in a PARP-dependent manner. In addition, combined treatment with ceritinib and PARPi synergized in HGSOC cell lines irrespective of HR status, and a combination of ceritinib with the PARPi olaparib induced tumor regression more effectively than olaparib alone in HGSOC patient-derived xenograft (PDX) models. Notably, the ceritinib and olaparib combination was most effective in PDX models with preexisting PARPi sensitivity and was well tolerated. These findings unveil suppression of mitochondrial respiration, accumulation of ROS, and subsequent induction of DNA damage as novel effects of ceritinib. They also suggest that the ceritinib and PARPi combination warrants further investigation as a means to enhance PARPi activity in HGSOC, particularly in tumors with preexisting HR defects. SIGNIFICANCE: The kinase inhibitor ceritinib synergizes with PARPi to induce tumor regression in ovarian cancer models, suggesting that ceritinib combined with PARPi may be an effective strategy for treating ovarian cancer.

Synergistic combination of cytotoxic chemotherapy and cyclin-dependent kinase 4/6 inhibitors in biliary tract cancers

BACKGROUND AND AIMS

Biliary tract cancers (BTCs) are uncommon, but highly lethal, gastrointestinal malignancies. Gemcitabine/cisplatin is a standard-of-care systemic therapy, but has a modest impact on survival and harbors toxicities, including myelosuppression, nephropathy, neuropathy, and ototoxicity. Whereas BTCs are characterized by aberrations activating the cyclinD1/cyclin-dependent kinase (CDK)4/6/CDK inhibitor 2a/retinoblastoma pathway, clinical use of CDK4/6 inhibitors as monotherapy is limited by lack of validated biomarkers, diffident preclinical efficacy, and development of acquired drug resistance. Emerging studies have explored therapeutic strategies to enhance the antitumor efficacy of CDK4/6 inhibitors by the combination with chemotherapy regimens, but their mechanism of action remains elusive.

APPROACH AND RESULTS

Here, we report in vitro and in vivo synergy in BTC models, showing enhanced efficacy, reduced toxicity, and better survival with a combination comprising gemcitabine/cisplatin and CDK4/6 inhibitors. Furthermore, we demonstrated that abemaciclib monotherapy had only modest efficacy attributable to autophagy-induced resistance. Notably, triplet therapy was able to potentiate efficacy through elimination of the autophagic flux. Correspondingly, abemaciclib potentiated ribonucleotide reductase catalytic subunit M1 reduction, resulting in sensitization to gemcitabine.

CONCLUSIONS

As such, these data provide robust preclinical mechanistic evidence of synergy between gemcitabine/cisplatin and CDK4/6 inhibitors and delineate a path forward for translation of these findings to preliminary clinical studies in advanced BTC patients.

SATB2 Is Expressed in a Subset of Pulmonary and Thymic Neuroendocrine Tumors

OBJECTIVES

To evaluate SATB2 expression and prognostic implications in a large cohort of thoracic neuroendocrine tumors.

METHODS

Surgical pathology files (1995-2017) and an institutional thymic epithelial tumor database (2010-2020) were searched for resected neuroendocrine tumors. Cases were stained with SATB2 (clone EP281). Percent SATB2-positive tumor cells and expression intensity were scored.

RESULTS

In the lung, SATB2 was expressed in 5% or more of tumor cells in 29 (74.4%) of 39 small cell carcinomas and 9 (22.5%) of 40 atypical and 26 (40.6%) of 64 typical carcinoid tumors. SATB2 percent tumor cell expression and intensity were higher in small cell carcinomas than in carcinoid tumors (both P < .001, respectively). After adjusting for tumor subtype, SATB2 expression did not correlate with outcome. In the thymus, four (100%) of four atypical carcinoid tumors and one large cell neuroendocrine carcinoma but no small cell carcinoma (n = 2) expressed SATB2 in 5% or more of tumor cells.

CONCLUSIONS

SATB2 (clone EP281) is expressed in a large subset of pulmonary and thymic neuroendocrine tumors and therefore does not appear to be a useful marker to identify the origin of neuroendocrine tumors. Validation studies are needed, specifically including thymic neuroendocrine tumors, as the expression pattern might be different in those tumors.

Outcomes With Pembrolizumab Monotherapy in Patients With Programmed Death-Ligand 1-Positive NSCLC With Brain Metastases: Pooled Analysis of KEYNOTE-001, 010, 024, and 042

Introduction

We retrospectively evaluated outcomes in patients with programmed death-ligand 1 (PD-L1)–positive non–small-cell lung cancer (NSCLC) to determine whether baseline (i.e., at study enrollment) brain metastases were associated with the efficacy of pembrolizumab versus chemotherapy.

Methods

We pooled data for patients with previously treated or untreated PD-L1‒positive (tumor proportion score [TPS], ≥1%) advanced or metastatic NSCLC in KEYNOTE-001 (NCT01295827), KEYNOTE-010 (NCT01905657), KEYNOTE-024 (NCT02142738), and KEYNOTE-042 (NCT02220894). Patients received pembrolizumab (2 mg/kg, 10 mg/kg, or 200 mg every 3 wk or 10 mg/kg every 2 wk); chemotherapy was a comparator in all studies except KEYNOTE-001. All studies included patients with previously treated, stable brain metastases.

Results

A total of 3170 patients were included, 293 (9.2%) with and 2877 (90.8%) without baseline brain metastases; median (range) follow-up at data cutoff was 12.9 (0.1‒43.7) months. Pembrolizumab improved overall survival versus chemotherapy in patients with or without baseline brain metastases: benefit was seen in patients with PD-L1 TPS ≥50% (0.67 [95% confidence intervals (CI): 0.44‒1.02] and 0.66 [95% CI: 0.58‒0.76], respectively) and PD-L1 TPS ≥1% (0.83 [95% CI: 0.62‒1.10] and 0.78 [95% CI: 0.71‒0.85], respectively). Progression-free survival was improved, objective response rates were higher, and duration of response was longer with pembrolizumab versus chemotherapy regardless of brain metastasis status. The incidence of treatment-related adverse events with pembrolizumab versus chemotherapy was 66.3% versus 84.4% in patients with brain metastases and 67.2% versus 88.3% in those without.

Conclusions

Pembrolizumab monotherapy improved outcomes and was associated with fewer adverse events than chemotherapy in patients with treatment-naive and previously treated PD-L1‒positive advanced/metastatic NSCLC regardless of the presence of baseline treated, stable brain metastases.

Heterogeneity of PD-L1 expression between invasive and lepidic components of lung adenocarcinomas

The dynamics of PD-L1 expression are poorly understood over the development of lung adenocarcinomas from pre-invasive lesions to fully invasive carcinomas. Given the importance of PD-L1 expression for the selection of patients to receive immunotherapy in the metastatic setting and possibly in the neoadjuvant setting, we sought to evaluate the agreement of PD-L1 expression in invasive and lepidic components of resected tumor specimens. We stained 86 adenocarcinomas for PD-L1 using the SP263 clone. We assessed the agreement of PD-L1 expression by tumor cells and immune cells between lepidic and invasive components. When both lepidic and invasive components were considered, PD-L1 positive immune cells and tumor cells were observed in 50 (58.1%) and 18 (20.9%) samples, respectively, using a ≥ 1% PD-L1 expression cutoff. Using a ≥ 1% cutoff for PD-L1 expression, positively stained tumor cells were observed in 11 (13%) lepidic and 15 (17%) invasive patterns, with agreement in 76 (88%) specimens and disagreement in 10 (12%) specimens (ĸ = 0.549). At ≥ 1% PD-L1 expression cutoff, PD-L1 positive immune cells were observed in 31 (35%) lepidic and 32 (37%) invasive patterns with an agreement of PD-L1 expression in 49 (57%) specimens and disagreement in 37 (43%) specimens (ĸ = 0.073). In our study of early stage adenocarcinomas of the lung, there was poor agreement in PD-L1 expression between paired invasive and lepidic components of tumors. Our data suggest that the non-invasive tumor components may not be as immunostimulatory as the invasive components, resulting in less adaptive expression of PD-L1.

A phase I/II study of rovalpituzumab tesirine in delta-like 3-expressing advanced solid tumors

Delta-like protein 3 (DLL3) is highly expressed in solid tumors, including neuroendocrine carcinomas/neuroendocrine tumors (NEC/NET). Rovalpituzumab tesirine (Rova-T) is a DLL3-targeting antibody-drug conjugate. Patients with NECs and other advanced DLL3-expressing tumors were enrolled in this phase I/II study (NCT02709889). The primary endpoint was safety. Two hundred patients were enrolled: 101 with NEC/NET (large-cell NEC, gastroenteropancreatic NEC, neuroendocrine prostate cancer, and other NEC/NET) and 99 with other solid tumors (melanoma, medullary thyroid cancer [MTC], glioblastoma, and other). The recommended phase II dose (RP2D) was 0.3 mg/kg every 6 weeks (q6w) for two cycles. At the RP2D, grade 3/4 adverse events included anemia (17%), thrombocytopenia (15%), and elevated aspartate aminotransferase (8%). Responses were confirmed in 15/145 patients (10%) treated at 0.3 mg/kg, including 9/69 patients (13%) with NEC/NET. Rova-T at 0.3 mg/kg q6w had manageable toxicity, with antitumor activity observed in patients with NEC/NET, melanoma, MTC, and glioblastoma.

Pralsetinib for patients with advanced or metastatic RET-altered thyroid cancer (ARROW): a multi-cohort, open-label, registrational, phase 1/2 study

BACKGROUND

Oncogenic alterations in RET represent important therapeutic targets in thyroid cancer. We aimed to assess the safety and antitumour activity of pralsetinib, a highly potent, selective RET inhibitor, in patients with RET-altered thyroid cancers.

METHODS

ARROW, a phase 1/2, open-label study done in 13 countries across 71 sites in community and hospital settings, enrolled patients 18 years or older with RET-altered locally advanced or metastatic solid tumours, including RET-mutant medullary thyroid and RET fusion-positive thyroid cancers, and an Eastern Co-operative Oncology Group performance status of 0-2 (later limited to 0-1 in a protocol amendment). Phase 2 primary endpoints assessed for patients who received 400 mg once-daily oral pralsetinib until disease progression, intolerance, withdrawal of consent, or investigator decision, were overall response rate (Response Evaluation Criteria in Solid Tumours version 1.1; masked independent central review) and safety. Tumour response was assessed for patients with RET-mutant medullary thyroid cancer who had received previous cabozantinib or vandetanib, or both, or were ineligible for standard therapy and patients with previously treated RET fusion-positive thyroid cancer; safety was assessed for all patients with RET-altered thyroid cancer. This ongoing study is registered with clinicaltrials.gov, NCT03037385, and enrolment of patients with RET fusion-positive thyroid cancer was ongoing at the time of this interim analysis.

FINDINGS

Between Mar 17, 2017, and May 22, 2020, 122 patients with RET-mutant medullary and 20 with RET fusion-positive thyroid cancers were enrolled. Among patients with baseline measurable disease who received pralsetinib by July 11, 2019 (enrolment cutoff for efficacy analysis), overall response rates were 15 (71%) of 21 (95% CI 48-89) in patients with treatment-naive RET-mutant medullary thyroid cancer and 33 (60%) of 55 (95% CI 46-73) in patients who had previously received cabozantinib or vandetanib, or both, and eight (89%) of nine (95% CI 52-100) in patients with RET fusion-positive thyroid cancer (all responses confirmed for each group). Common (≥10%) grade 3 and above treatment-related adverse events among patients with RET-altered thyroid cancer enrolled by May 22, 2020, were hypertension (24 patients [17%] of 142), neutropenia (19 [13%]), lymphopenia (17 [12%]), and anaemia (14 [10%]). Serious treatment-related adverse events were reported in 21 patients (15%), the most frequent (≥2%) of which was pneumonitis (five patients [4%]). Five patients [4%] discontinued owing to treatment-related events. One (1%) patient died owing to a treatment-related adverse event.

INTERPRETATION

Pralsetinib is a new, well-tolerated, potent once-daily oral treatment option for patients with RET-altered thyroid cancer.

FUNDING

Blueprint Medicines.

Pralsetinib for RET fusion-positive non-small-cell lung cancer (ARROW): a multi-cohort, open-label, phase 1/2 study

BACKGROUND

Oncogenic alterations in RET have been identified in multiple tumour types, including 1-2% of non-small-cell lung cancers (NSCLCs). We aimed to assess the safety, tolerability, and antitumour activity of pralsetinib, a highly potent, oral, selective RET inhibitor, in patients with RET fusion-positive NSCLC.

METHODS

ARROW is a multi-cohort, open-label, phase 1/2 study done at 71 sites (community and academic cancer centres) in 13 countries (Belgium, China, France, Germany, Hong Kong, Italy, Netherlands, Singapore, South Korea, Spain, Taiwan, the UK, and the USA). Patients aged 18 years or older with locally advanced or metastatic solid tumours, including RET fusion-positive NSCLC, and an Eastern Cooperative Oncology Group performance status of 0-2 (later limited to 0-1 in a protocol amendment) were enrolled. In phase 2, patients received 400 mg once-daily oral pralsetinib, and could continue treatment until disease progression, intolerance, withdrawal of consent, or investigator decision. Phase 2 primary endpoints were overall response rate (according to Response Evaluation Criteria in Solid Tumours version 1·1 and assessed by blinded independent central review) and safety. Tumour response was assessed in patients with RET fusion-positive NSCLC and centrally adjudicated baseline measurable disease who had received platinum-based chemotherapy or were treatment-naive because they were ineligible for standard therapy. This ongoing study is registered with ClinicalTrials.gov, NCT03037385, and enrolment of patients with treatment-naive RET fusion-positive NSCLC was ongoing at the time of this interim analysis.

FINDINGS

Of 233 patients with RET fusion-positive NSCLC enrolled between March 17, 2017, and May 22, 2020 (data cutoff), 92 with previous platinum-based chemotherapy and 29 who were treatment-naive received pralsetinib before July 11, 2019 (efficacy enrolment cutoff); 87 previously treated patients and 27 treatment-naive patients had centrally adjudicated baseline measurable disease. Overall responses were recorded in 53 (61%; 95% CI 50-71) of 87 patients with previous platinum-based chemotherapy, including five (6%) patients with a complete response; and 19 (70%; 50-86) of 27 treatment-naive patients, including three (11%) with a complete response. In 233 patients with RET fusion-positive NSCLC, common grade 3 or worse treatment-related adverse events were neutropenia (43 patients [18%]), hypertension (26 [11%]), and anaemia (24 [10%]); there were no treatment-related deaths in this population.

INTERPRETATION

Pralsetinib is a new, well-tolerated, promising, once-daily oral treatment option for patients with RET fusion-positive NSCLC.

FUNDING

Blueprint Medicines.

A Phase Ib/II Study of Pepinemab in Combination with Avelumab in Advanced Non-Small Cell Lung Cancer

PURPOSE

The CLASSICAL-Lung clinical trial tested the combination of pepinemab, an IgG4 humanized mAb targeting semaphorin 4D, with the PD-L1 inhibitor avelumab to assess the effects of coupling increased T-cell infiltration and reversal of immune suppression via pepinemab with sustained T-cell activation via checkpoint inhibition.

PATIENTS AND METHODS

This phase Ib/II, single-arm study was designed to evaluate the safety, tolerability, and efficacy of pepinemab in combination with avelumab in 62 patients with advanced non-small cell lung cancer (NSCLC), including immunotherapy-naïve (ION) patients and patients whose tumors progressed following anti-PD-1/L1 monotherapy (IOF). The main objectives were to evaluate safety/tolerability, establish a recommended phase 2 dose (RP2D), obtain a preliminary evaluation of antitumor activity, and investigate candidate biomarker activity.

RESULTS

The combination was well tolerated with no major safety signals identified. Pepinemab, 10 mg/kg with avelumab, 10 mg/kg, every 2 weeks, was selected as the RP2D. Among 21 evaluable ION patients, 5 patients experienced partial responses (PR), 4 patients evidenced clinical benefit ≥1 year, and the disease control rate (DCR) was 81%. Notably, overall response rate with the combination therapy was higher than previously reported for single-agent avelumab in the PD-L1-negative/low population. Among 29 evaluable IOF patients, the combination resulted in a DCR of 59%, including 2 PR and 7 patients with durable clinical benefit of ≥23 weeks. Biomarker analysis of biopsies demonstrated increased CD8 T-cell density correlating with RECIST response criteria.

CONCLUSIONS

The combination of pepinemab with avelumab was well tolerated in NSCLC and showed signs of antitumor activity in immunotherapy-resistant and PD-L1-negative/low tumors.

First-line nivolumab plus ipilimumab in unresectable malignant pleural mesothelioma (CheckMate 743): a multicentre, randomised, open-label, phase 3 trial

BACKGROUND

Approved systemic treatments for malignant pleural mesothelioma (MPM) have been limited to chemotherapy regimens that have moderate survival benefit with poor outcomes. Nivolumab plus ipilimumab has shown clinical benefit in other tumour types, including first-line non-small-cell lung cancer. We hypothesised that this regimen would improve overall survival in MPM.

METHODS

This open-label, randomised, phase 3 study (CheckMate 743) was run at 103 hospitals across 21 countries. Eligible individuals were aged 18 years and older, with previously untreated, histologically confirmed unresectable MPM, and an Eastern Cooperative Oncology Group performance status of 0 or 1. Eligible participants were randomly assigned (1:1) to nivolumab (3 mg/kg intravenously once every 2 weeks) plus ipilimumab (1 mg/kg intravenously once every 6 weeks) for up to 2 years, or platinum plus pemetrexed chemotherapy (pemetrexed [500 mg/m² intravenously] plus cisplatin [75 mg/m² intravenously] or carboplatin [area under the concentration-time curve 5 mg/mL per min intravenously]) once every 3 weeks for up to six cycles. The primary endpoint was overall survival among all participants randomly assigned to treatment, and safety was assessed in all participants who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT02899299, and is closed to accrual.

FINDINGS

Between Nov 29, 2016, and April 28, 2018, 713 patients were enrolled, of whom 605 were randomly assigned to either nivolumab plus ipilimumab (n=303) or chemotherapy (n=302). 467 (77%) of 605 participants were male and median age was 69 years (IQR 64-75). At the prespecified interim analysis (database lock April 3, 2020; median follow-up of 29·7 months [IQR 26·7-32·9]), nivolumab plus ipilimumab significantly extended overall survival versus chemotherapy (median overall survival 18·1 months [95% CI 16·8-21·4] vs 14·1 months [12·4-16·2]; hazard ratio 0·74 [96·6% CI 0·60-0·91]; p=0·0020). 2-year overall survival rates were 41% (95% CI 35·1-46·5) in the nivolumab plus ipilimumab group and 27% (21·9-32·4) in the chemotherapy group. Grade 3-4 treatment-related adverse events were reported in 91 (30%) of 300 patients treated with nivolumab plus ipilimumab and 91 (32%) of 284 treated with chemotherapy. Three (1%) treatment-related deaths occurred in the nivolumab plus ipilimumab group (pneumonitis, encephalitis, and heart failure) and one (<1%) in the chemotherapy group (myelosuppression).

INTERPRETATION

Nivolumab plus ipilimumab provided significant and clinically meaningful improvements in overall survival versus standard-of-care chemotherapy, supporting the use of this first-in-class regimen that has been approved in the USA as of October, 2020, for previously untreated unresectable MPM.

FUNDING

Bristol Myers Squibb.

Updated Overall Survival and PD-L1 Subgroup Analysis of Patients With Extensive-Stage Small-Cell Lung Cancer Treated With Atezolizumab, Carboplatin, and Etoposide (IMpower133)

IMpower133 (ClinicalTrials.gov identifier: NCT02763579), a randomized, double-blind, phase I/III study, demonstrated that adding atezolizumab (anti-programmed death-ligand 1 [PD-L1]) to carboplatin plus etoposide (CP/ET) for first-line (1L) treatment of extensive-stage small-cell lung cancer (ES-SCLC) resulted in significant improvement in overall survival (OS) and progression-free survival (PFS) versus placebo plus CP/ET. Updated OS, disease progression patterns, safety, and exploratory biomarkers (PD-L1, blood-based tumor mutational burden [bTMB]) are reported.

BRCA1/MAD2L1 Deficiency Disrupts the Spindle Assembly Checkpoint to Confer Vinorelbine Resistance in Mesothelioma

Mesothelioma is a universally lethal cancer lacking effective therapy. The spindle poison vinorelbine exhibits clinical activity in the relapsed setting, and in preclinical models requires BRCA1 to initiate apoptosis. However, the mechanisms underlying this regulation and the clinical implications have not been explored. Here, we show that BRCA1 silencing abrogated vinorelbine-induced cell-cycle arrest, recruitment of BUBR1 to kinetochores, and apoptosis. BRCA1 silencing led to codepletion of MAD2L1 at the mRNA and protein levels consistent with its status as a transcriptional target of BRCA1 Silencing of MAD2L1 phenocopied BRCA1 and was sufficient to confer resistance to vinorelbine. This was recapitulated in cell lines selected for resistance to vinorelbine, which acquired loss of both BRCA1 and MAD2L1 expression. Following ex vivo vinorelbine in 20 primary tumor explants, apoptotic response rate was 59% in BRCA1/MAD2L1-positive explants compared with 0% in BRCA1/MAD2L1-negative explants. In 48 patients, BRCA1 and/or MAD2L1 loss of expression was not prognostic; however, in a subset of patients treated with vinorelbine, survival was shorter for patients lacking BRCA1/MAD2L1 expression compared with double-positive patients (5.9 vs. 36.7 months, P = 0.03). Our data implicate BRCA1/MAD2L1 loss as a putative predictive marker of resistance to vinorelbine in mesothelioma and warrant prospective clinical evaluation.

Optimizing clinical cytology touch preparations for next generation sequencing

Intraoperative diagnosis is routinely performed on cytology touch preparations (TPs) from core needle biopsies (CNBs). Current interest promotes their utility as an important source of patient tissue for clinical genomic testing. Herein we present whole genome structural variant analysis (SVA) from mate-pair sequencing (MPseq) and whole exome sequencing (WES) mutation calling in DNA directly whole genome amplified (WGA) from TPs. Chromosomal copy changes and somatic DNA junction detection from MPseq of TPs were highly consistent with associated CNBs and bulk resected tissues in all cases. While increased frequency coverage noise from limitations of amplification of limited sample input was significant, this was effectively compensated by natural tumor enrichment during the TP process, which also enhanced variant detection and loss of heterozygosity evaluations from WES. This novel TP methodology enables expanded utility of frequently limited CNB for both clinical and research genomic testing.

Correlation of novel ALKATI with ALK immunohistochemistry and clinical outcomes in metastatic melanoma

AIMS

Recently, a novel isoform of anaplastic lymphoma kinase, with alternative transcription initiation (ALKATI ), has been described in melanoma and is susceptible to targeted ALK-inhibitor therapy. Clinical outcomes of patients with ALKATI mutated melanoma as well as correlation with immunohistochemical (IHC) methods have not yet been described.

METHODS AND RESULTS

Clinicopathological characteristics were abstracted for 324 patients with metastatic melanoma (MM). IHC, fluorescence in-situ hybridisation and RNA-based digital molecular analysis assays were performed on archival tissue from 173 stage III and 192 stage IV tumours. ALKATI was identified in 12.7 and 4.8% stage III and IV tumours, respectively. Discrete presentations of the ALKATI are seen: isolated ALKATI (n = 20) and mixed ALKATI (combined ALKATI and ALKWT ; n = 7). Isolated ALKWT expression (n = 4) was seen with no ALK fusions. Stage III patients showed improved survival with ALKATI expression compared to those with ALKWT or no expression [5-year survival 80, 95% confidence interval (CI) = 57-100% versus 43%, 95% CI = 34-55%, P = 0.013]. Clinicopathological characteristics were not statistically significant. Strong diffuse cytoplasmic staining of ALK IHC (n = 12) has a sensitivity of 52.2%, specificity 100%, PPV of 100% and NPV of 92.5% of detecting isolated ALKATI .

CONCLUSION

Presence of ALKATI is a good prognostic indicator in MM. ALK IHC and digital molecular analysis can be incorporated into MM evaluation to identify patients with ALKATI for targeted therapy.

A Population-based Study of Immunotherapy-related Toxicities in Lung Cancer

BACKGROUND

Population-level data regarding incidences of immune-related adverse events (irAEs) are lacking. This study evaluated the frequencies of irAEs among patients with non-small-cell lung cancer (NSCLC) who received immune checkpoint inhibitors.

PATIENTS AND METHODS

Administrative claims data from a large United States commercial insurance database (OptumLabs Data Warehouse) were used to retrospectively identify patients with NSCLC between January 1, 2015 and December 31, 2017 who received a programmed death-ligand 1/programmed cell death protein-1 (PD(L)-1) inhibitor. Cumulative risks for irAEs were estimated at 1, 3, 6, 9, and 12 months after initiation of a PD-(L)1 inhibitor. Additionally, associations between patient characteristics and frequency of irAEs were investigated utilizing multivariate logistic modeling.

RESULTS

The risk of developing any irAE was 52.5% (95% confidence interval, 49.9%-55.2%) after 12 months in 3164 patients with NSCLC who initiated a PD-(L)1 inhibitor (median age, 69.0 years; 1763 [55.7%] males; 1401 [44.3%] females). Cumulative risks of irAEs increased over time: pneumonitis was recorded in 2.5% of patients 1 month after initiation of treatment, and increased to 14.3% after 9 months. Risks of hypophysitis and pericarditis were 3.6% and 1.7% at 9 months, respectively. Patients who received PD-(L)1 inhibitors in the first line had lower frequencies of irAEs (hazard ratio, 0.77; 95% confidence interval, 0.67-0.87).

CONCLUSION

Our findings suggest that the frequencies of some irAEs may be higher than the rates reported in the pivotal trials that led to United States Food and Drug Administration approvals for PD-(L)1 inhibitors. These real-world data refine provider and patient expectations for outcomes in a broader population beyond what is observed in clinical trials.

Therapeutic plasma exchange clears circulating soluble PD-L1 and PD-L1-positive extracellular vesicles

Background

Trans-acting programmed death-ligand 1 (PD-L1) derives from malignant cells in three known forms. High levels of secreted splice variant PD-L1 (sPD-L1), ADAM10/ADAM17-shed sPD-L1, and PD-L1-positive extracellular vesicles (evPD-L1) each predict poor prognosis and limited response to PD-(L)1 checkpoint inhibitors in cancer. To our knowledge, no clinical intervention has reduced any of these circulating forms of extracellular PD-L1. Here, we explore therapeutic plasma exchange (TPE) as a treatment to reduce circulating extracellular PD-L1.

Results

In patients with melanoma, sPD-L1 levels above 0.277 ng/mL predicted inferior overall survival. In patients undergoing TPE for non-malignant indications, each TPE session removed a mean 70.8% sPD-L1 and 73.1% evPD-L1 detectable in plasma. TPE also reduced total and ADAM10-positive extracellular vesicles.

Conclusion

Here, we report the first known clinical intervention to remove either sPD-L1 or evPD-L1 from plasma in vivo. TPE reduces plasma sPD-L1 and evPD-L1 in vivo and may have a role in treatment with immunotherapy. TPE may also prove useful in patients with other extracellular vesicle-related conditions.