Efficacy and safety of bispecific antibodies vs. immune checkpoint blockade combination therapy in cancer: a real-world comparison

Emerging tumor immunotherapy methods encompass bispecific antibodies (BSABs), immune checkpoint inhibitors (ICIs), and adoptive cell immunotherapy. BSABs belong to the antibody family that can specifically recognize two different antigens or epitopes on the same antigen. These antibodies demonstrate superior clinical efficacy than monoclonal antibodies, indicating their role as a promising tumor immunotherapy option. Immune checkpoints are also important in tumor immunotherapy. Programmed cell death protein-1 (PD-1) is a widely acknowledged immune checkpoint target with effective anti-tumor activity. PD-1 inhibitors have demonstrated notable therapeutic efficacy in treating hematological and solid tumors; however, more than 50% of patients undergoing this treatment exhibit a poor response. However, ICI-based combination therapies (ICI combination therapies) have been demonstrated to synergistically increase anti-tumor effects and immune response rates. In this review, we compare the clinical efficacy and side effects of BSABs and ICI combination therapies in real-world tumor immunotherapy, aiming to provide evidence-based approaches for clinical research and personalized tumor diagnosis and treatment.

Immunotherapy in Small Cell Lung Cancer Treatment: a Promising Headway for Future Perspective

OPINION STATEMENT

Despite advancements in clinical research, both prognosis and treatment for SCLC patients are still in the nascent stage. SCLC is a fatal disease with high tumor mutational burden and is strongly associated with exposure to tobacco. This leads to the development of potential neo-antigens, inhibition of immune responses, and development of paraneoplastic disorders. Surgery, radiation, and chemotherapy are widely accepted treatments for cancer globally, and most recently, immunotherapy has now become the "fourth pillar" of SCLC treatment. Various immune checkpoint pathways regulate the activation of T cells at multiple stages during an immune response. T cell checkpoint inhibitors such as anti-PD1 (pembrolizumab, nivolumab), anti-PDL1, and anti-CTLA-4 (tremelimumab, ipilimumab) have potential to show anti-cancer activity along with the promise to prolong survival in patients with SCLC. Treatment with the CTLA-4-specific antibodies can restore the immune response by increasing the accumulation and survival of T-cells whereas monoclonal antibodies block either PD-1 or its ligands that prevent downregulation of effector T-cell, which enables the T-cells to mediate the death of tumor cells. Furthermore, monoclonal antibody in combination with chemotherapy has attained quite a focus to enhance the survival of SCLC patients. Apart from this, various immunotherapeutic approaches have been evaluated in the clinical trials for SCLC patients such as TLR9 agonist, anti-CD47, anti-ganglioside therapy, and anti-Notch signaling. The current review focuses on the rationale as well as on the clinical studies of immunotherapy in SCLC along with the clinical end results of certain immunotherapeutic agents and novel therapeutic combinations in SCLC patients.

Efficacy of Immune Checkpoint Inhibitors against Advanced or Metastatic Neuroendocrine Neoplasms: A Systematic Review and Meta-Analysis

We performed a systematic review and meta-analysis of the treatment efficacy of immune checkpoint inhibitors (ICIs) in advanced/metastatic neuroendocrine neoplasms (NENs). MEDLINE and EMBASE were searched to identify studies that provide data on treatment response and/or survival outcomes of advanced/metastatic NEN patients treated with ICIs. The overall response rate (ORR) was pooled using a random-effects model. Meta-regression was performed to explore factors influencing the ORR. Individual patient data (IPD) meta-analysis of survival was performed using stratified Cox regression. Ten studies (464 patients) were included. The overall pooled ORR was 15.5% (95% confidence interval (CI), 9.5-24.3%), and it varied according to the primary site (thoracic, 24.7%; gastro-entero-pancreatic, 9.5%), tumor differentiation (poorly differentiated, 22.7%; well-differentiated, 10.4%), and drug regimen (combination, 25.3%; monotherapy, 10.1%). All these variables significantly influenced the ORR. Tumor differentiation was associated with both overall survival and progression-free survival (hazard ratio of poorly differentiated tumors, 4.2 (95% CI, 2.0-8.7) and 2.6 (95% CI, 1.6-4.4), respectively). Thus, the treatment efficacy of ICIs for advanced/metastatic NENs varied according to primary site, tumor differentiation, and drug regimen. Poorly differentiated NENs showed a better ORR than well-differentiated NENs but had a negative impact on survival.

Immune Checkpoints OX40 and OX40L in Small-Cell Lung Cancer: Predict Prognosis and Modulate Immune Microenvironment

Background

OX40 and OX40 ligand (OX40L), as essential immune checkpoint (IC) modulators, are highly correlated with cancer immunity regulation as well as tumor microenvironment (TME). Immunotherapy showed outstanding advantages in small-cell lung cancer (SCLC) therapy. However, functions and clinical significance of OX40 and OX40L in SCLC were not clear yet.

Materials and Methods

SCLC samples of 143 patients were collected for immunohistochemistry (IHC) or whole-exome sequencing (WES). We comprehensively explored the expression and mutation of OX40/OX40L in SCLC, and systematically linked OX40/OX40L with TME.

Results

The expression of OX40/OX40L on tumor cells and tumor-infiltrating lymphocytes (TILs) was found in the IHC cohort and verified in other cohorts with SCLC tissues and cell lines. The results showed co-expression patterns among OX40/OX40L, other ICs, and T-cell markers. The WES data suggested that OX40/OX40L mutation is rare in SCLC (<5%). Patients with positive OX40 protein expression on TILs showed substantially higher recurrence-free survival than those with negative expression (p=0.009). The external dataset also indicated that high OX40/OX40L expression was correlated with better prognosis [overall survival: OX40, p<0.001; OX40L, p=0.019]. Importantly, activation of immunity and high infiltration of CD4(+) and CD8(+) T cells were observed in the high OX40/OX40L expression group.

Conclusions

Collectively, this work highlighted the significance of OX40 and OX40L in prognosis and TME cell infiltration characterization of SCLC. Evaluating the OX40/OX40L-expression levels of individual patients with SCLC might contribute to guiding more precise therapy.

Small Cell Lung Cancer, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Small Cell Lung Cancer (SCLC) provide recommended management for patients with SCLC, including diagnosis, primary treatment, surveillance for relapse, and subsequent treatment. This selection for the journal focuses on metastatic (known as extensive-stage) SCLC, which is more common than limited-stage SCLC. Systemic therapy alone can palliate symptoms and prolong survival in most patients with extensive-stage disease. Smoking cessation counseling and intervention should be strongly promoted in patients with SCLC and other high-grade neuroendocrine carcinomas. The "Summary of the Guidelines Updates" section in the SCLC algorithm outlines the most recent revisions for the 2022 update, which are described in greater detail in this revised Discussion text.

Safety, Efficacy, and Pharmacodynamics of Tremelimumab Plus Durvalumab for Patients With Unresectable Hepatocellular Carcinoma: Randomized Expansion of a Phase I/II Study

This phase I/II study evaluated tremelimumab (anticytotoxic T-lymphocyte–associated antigen-4 monoclonal antibody) and durvalumab (antiprogrammed death ligand-1 monoclonal antibody) as monotherapies and in combination for patients with unresectable hepatocellular carcinoma (HCC), including a novel regimen featuring a single, priming dose of tremelimumab (ClinicalTrials.gov identifier: NCT02519348).

Evidence to Date: Evaluating Pembrolizumab in the Treatment of Extensive-Stage Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) is an aggressive subtype of lung cancer characterized by a rapid initial response and early development of resistance to systemic therapy and radiation. The management of SCLC significantly changed for the first time in decades with the introduction of immune checkpoint inhibitors. Pembrolizumab, a humanized IgG4 isotype antibody, targets the programmed cell death protein 1 (PD-1) pathway to restore anti-tumor immunity. Prospective trials of pembrolizumab in patients with previously treated SCLC showed significant durability of responses. These results led to the U.S. Food and Drug Administration (FDA) granting pembrolizumab accelerated approval as second- or third-line monotherapy for patients with extensive-stage (ES) SCLC. In a recent clinical trial that included patients with previously untreated ES-SCLC, pembrolizumab in combination with platinum/etoposide met its progression-free survival endpoint, but overall survival (OS) did not cross the threshold for superiority. With the therapeutic landscape for SCLC rapidly evolving, we review prior experience and future directions of pembrolizumab in ES-SCLC.

Immunotherapy for the treatment of metastatic small cell lung cancer: Focus on pembrolizumab

AREAS COVERED

The current evidence on the role of pembrolizumab for patients with extensive SCLC is reviewed in this article. Particularly, preclinical and clinical data from phase I/II and III clinical trials, which evaluate the efficacy and toxicity of pembrolizumab for these patients, are summarized based on PubMed/MEDLINE search and relevant articles. In addition, future perspectives on the emerging role of immunotherapy for SCLC are highlighted in light of potentially useful biomarkers.

EXPERT COMMENTARY

Pembrolizumab shows an excellent toxicity profile in recent studies, and significantly prolonged progression-free survival (PFS) but not overall survival (OS) in the phase III clinical trial KN604, in contrast to atezolizumab and durvalumab. The latter two agents have already been approved and incorporated in the daily clinical practice. Further research should be conducted so that phase III clinical trials can validate the potential clinical benefit of this checkpoint inhibitor in combination with other active agents and establish its role in the metastatic setting of SCLC.

Effect of immunotherapy on overall survival in limited-stage small cell lung carcinoma: a national cancer database analysis

Background:

While immune-based therapies have been approved for extensive-stage small cell lung cancer, there is limited data on the efficacy of immunotherapy in patients with limited-stage disease.

Methods:

We used the National Cancer Database to first evaluate factors associated with the inclusion of immunotherapy as part of the initial therapeutic course in patients diagnosed with limited-stage small cell lung cancer (LS-SCLC). Consequently, we evaluated the impact of this immunotherapy on 2-year and 5-year overall survival (OS). We did this by performing 1:1 matching for controls that did not receive immunotherapy, and comparing survival between cohorts using the Kaplan–Meier method.

Results:

A total of 98 patients with LS-SCLC received immunotherapy as part of their initial therapeutic regimen. Age and facility type were the only significant predictors of the use of immunotherapy. There was no statistically significant difference between matched case-control cohorts in median OS (p = 0.985), 2-year OS (p = 0.747), and 5-year OS (p = 0.934).

Conclusion:

In this study using a large national database, we found that the inclusion of immunotherapy as part of the initial systemic therapy regimen was not significantly associated with improved OS in a cohort of LS-SCLC patients.

Old but gold: the role of drug combinations in improving response to immune check-point inhibitors in thoracic malignancies beyond NSCLC

The introduction of immune checkpoint inhibitors (ICIs) in non-oncogene addicted non-small cell lung cancer (NSCLC) has revolutionized the treatment scenario and led to a meaningful improvement in patient prognosis. Disappointingly, the success of ICI therapy in NSCLC has not been fully replicated in other thoracic malignancies as small cell lung cancer (SCLC), malignant pleural mesothelioma (MPM), and thymic epithelial tumors (TETs), due to the peculiar biological features of these disease and to the difficulties in the conduction of well-designed, biomarker-driven clinical trials. Therefore, combination strategies of ICIs plus conventional therapies (either chemotherapy, alternative ICIs or targeted agents) have been implemented. Although first approvals of ICI therapy have been recently granted in SCLC and MPM (in combination with chemotherapy and different ICIs), results remain somewhat modest and limited to a small proportion of patients. This work reviews the trial results of ICI therapy in mesothelioma, SCLC, and TETs and discusses the potential of combining ICIs with old drugs.

Real World Analysis of Small Cell Lung Cancer Patients: Prognostic Factors and Treatment Outcomes

In this observational study, we assessed treatment patterns and prognostic factors in patients with small cell lung cancer (SCLC) in a large state-mandated healthcare organization in Israel. Methods: All incident cases with histologically confirmed SCLC who initiated systemic anti-cancer treatment between 2011 and 2017 were identified. Treatment patterns and overall survival (OS) were evaluated for each line of therapy. Results: A total of 235 patients were identified (61% male, median age 64 years, 95% ever smokers, 64% had extensive stage). The first-line treatment was platinum-etoposide regimen for 98.7% of the cohort. The second and third-line regimen were given to 43% and 12% of patients, respectively. Mean OS for extensive and limited stage patients was 9.1 and 23.5 months respectively. In a multivariable model, increased risk for mortality was observed among patients with an ECOG performance status (PS) of 2 compared to a PS of 0-1 for the extensive stage patients (Hazard ratio (HR) = 1.63, 95% confidence ratios (CI): 1.00-2.65); and for males compared to females for the limited stage patients (HR = 2.17; 95% CI: 1.12-4.20). Regarding all 2nd line patients in a multivariable model incorporating relevant confounding factors, demonstrated a significantly better outcome with platinum-based regimens compared to topotecan. Median survival after initiation of 2nd line in platinum-sensitive patients was longer (p = 0.056) for those re-challenged with platinum-based regimen (n = 7): 6.8mo (6.1-not reported (NR)), compared with those switched to a different treatment (n = 27): 4.5 mo (2.6-6.6) for extensive stage patients, and a non-significant difference was also observed for limited stage patients. Conclusion: To our knowledge, this is one of the largest real-world studies of SCLC patients. OS for SCLC patients was similar to that reported in clinical trials. PS for extensive stage patients and sex for limited stage patients were significant correlates of prognosis. Re-challenge of the platinum-based doublet was associated with longer OS compared to switching treatment in extensive stage patients.

Combination therapy: Future directions of immunotherapy in small cell lung cancer

Small cell lung cancer (SCLC), an aggressive and devastating malignancy, is characterized by rapid growth and early metastasis. Although most patients respond to first-line chemotherapy, the majority of patients rapidly relapse and have a relatively poor prognosis. Fortunately, immunotherapy, mainly including antibodies that target the cytotoxic T lymphocyte antigen-4 (CTLA-4), checkpoints programmed death-1 (PD-1), and programmed death-ligand 1 (PD-L1) to block immune regulatory checkpoints on tumor cells, immune cells, fibroblasts cells and endothelial cells, has achieved the milestone in several solid tumors, such as melanoma and non-small-cell lung carcinomas (NSCLC). In recent years, immunotherapy has made progress in the treatment of patients with SCLC, while its response rate is relatively low to monotherapy. Interestingly, the combination of immunotherapy with other therapy, such as chemotherapy, radiotherapy, and targeted therapy, preliminarily achieve greater therapeutic effects for treating SCLC. Combining different immunotherapy drugs may act synergistically because of the complementary effects of the two immune checkpoint pathways (CTLA-4 and PD-1/PD-L1 pathways). The incorporation of chemoradiotherapy in immunotherapy may augment antitumor immune responses because chemoradiotherapy can enhance tumor cell immunogenicity by rapidly inducing tumor lysis and releasing tumor antigens. In addition, since immunotherapy drugs and the molecular targets drugs act on different targets and cells, the combination of these drugs may achieve greater therapeutic effects in the treatment of SCLC. In this review, we focused on the completed and ongoing trials of the combination therapy for immunotherapy of SCLC to find out the rational combination strategies which may improve the outcomes for SCLC.

Galectin-9-based immune risk score model helps to predict relapse in stage I-III small cell lung cancer

Background

For small cell lung cancer (SCLC) therapy, immunotherapy might have unique advantages to some extent. Galectin-9 (Gal-9) plays an important role in antitumor immunity, while little is known of its function in SCLC.

Materials and methods

By mean of immunohistochemistry (IHC), we tested the expression level of Gal-9 and other immune markers on both tumor cells and tumor-infiltrating lymphocytes (TILs) in 102 surgical-resected early stage SCLC clinical samples. On the basis of statistical analysis and machine learning results, the Gal-9-based immune risk score model was constructed and its predictive performance was evaluated. Then, we thoroughly explored the effects of Gal-9 and immune risk score on SCLC immune microenvironment and immune infiltration in different cohorts and platforms.

Results

In the SCLC cohort for IHC, the expression level of Gal-9 on TILs was statistically correlated with the levels of program death-1 (p=0.001), program death-ligand 1 (PD-L1) (p<0.001), CD3 (p<0.001), CD4 (p<0.001), CD8 (p<0.001), and FOXP3 (p=0.047). High Gal-9 protein expression on TILs indicated better recurrence-free survival (30.4 months, 95% CI: 23.7–37.1 vs 39.4 months, 95% CI: 31.6–47.3, p=0.009). The immune risk score model which consisted of Gal-9 on TILs, CD4, and PD-L1 on TILs was established and validated so as to differentiate high-risk or low-risk patients with SCLC. The prognostic predictive performance of immune risk score model was better than single immune biomarker (area under the curve 0.671 vs 0.621–0.644). High Gal-9-related enrichment pathways in SCLC were enriched in immune system diseases and rheumatic disease. Furthermore, we found that patients with SCLC with low immune risk score presented higher fractions of activated memory CD4 T cells than patients with high immune risk score (p=0.048).

Conclusions

Gal-9 is markedly related to tumor-immune microenvironment and immune infiltration in SCLC. This study emphasized the predictive value and promising clinical applications of Gal-9 in stage I–III SCLC.

In Search of the Long-Desired 'Copernican Therapeutic Revolution' in Small-Cell Lung Cancer

Small-cell lung cancer has defied our scientific community for decades. Chemotherapy has been the mainstay treatment for small-cell lung cancer (SCLC) and unlike its counterpart, non-small cell lung cancer, no significant therapeutic breakthroughs have been made since the 1970s. Among the reasons for this slow-paced therapeutic development, one that stands out is the distinctive and almost universal loss of function of the tumour suppressor genes TP53 and RB1 in this disease, for which pharmacological activation has yet to be achieved, despite having been highly sought after. Although no molecularly targeted approach has been approved for clinical practice thus far, several strategies are currently exploring the potential to drug the tumour's "Achilles heel" that stems from essential pathways regulating DNA-damage response. Most recently, we have witnessed newfound reasons to hope, as the combination of immunotherapy and systemic chemotherapy has improved survival outcomes, representing the first landmark achievement in decades and a new standard of care for patients with extensive disease SCLC. However, continuous efforts are still needed towards a better understanding of the molecular pathways that singularise this tumour to eventually identify the predictive biomarkers that might result in the development of a more rational therapeutic approach, including the use of immunotherapy combinations. In this review we aim to uncover critical aspects of the immune microenvironment and biology of SCLC and provide an overview of the current and future landscape of promising therapeutic opportunities. The challenge still stands, but regardless, we are living in exciting times to finally check SCLC off the "bucket list" of our scientific community.

Immunotherapy in Small Cell Lung Cancer

Simple Summary

Small cell lung cancer (SCLC) accounts for about 15% of lung cancers and it has limited therapeutic options and poor prognosis. There has been no real progress for over 30 years in the treatment of this aggressive tumor type and platinum based chemotherapy represented the cornerstone of therapy. Immune checkpoint inhibitors are the first agents in the last decades to determine an improvement in outcomes of patients with extensive stage (ES) SCLC patients. In the IMpower 133 and CASPIAN studies, the addition of atezolizumab or durvalumab, respectively, to first-line chemotherapy produced a significant improvement in overall survival with an acceptable safety profile in previously untreated patients with ES-SCLC, leading to a new standard of care. This review summarizes the main results observed with checkpoint inhibitors in SCLC, discussing the critical issues related to the use of novel checkpoint inhibitors and the future research with immunotherapy agents in SCLC.

Abstract

Small-cell lung cancer (SCLC) is an aggressive tumor type with limited therapeutic options and poor prognosis. Chemotherapy regimens containing platinum represent the cornerstone of treatment for patients with extensive disease, but there has been no real progress for 30 years. The evidence that SCLC is characterized by a high mutational burden led to the development of immune-checkpoint inhibitors as single agents or in combination with chemotherapy. Randomized phase III trials demonstrated that the combination of atezolizumab (IMpower-133) or durvalumab (CASPIAN) with platinum-etoposide chemotherapy improved overall survival of patients with extensive disease. Instead, the KEYNOTE-604 study demonstrated that the addition of pembrolizumab to chemotherapy failed to significantly improve overall survival, but it prolonged progression-free survival. The safety profile of these combinations was similar with the known safety profiles of all single agents and no new adverse events were observed. Nivolumab and pembrolizumab single agents showed anti-tumor activity and acceptable safety profile in Checkmate 032 and KEYNOTE 028/158 trials, respectively, in patients with SCLC after platinum-based therapy and at least one prior line of therapy. Future challenges are the identification predictive biomarkers of response to immunotherapy in SCLC and the definition of the role of immunotherapy in patients with limited stage SCLC, in combination with radiotherapy or with other biological agents.

Opportunities and obstacles of targeted therapy and immunotherapy in small cell lung cancer

Small cell lung cancer (SCLC) is an aggressive malignant tumour which accounts for approximately 13-15% of all newly diagnosed lung cancer cases. To date, platinum-based chemotherapy are still the first-line treatments for SCLC. However, chemotherapy resistance and systemic toxicity limit the long-term clinical outcome of first-line treatment in SCLC. Recent years, targeted therapy and immunotherapy have made great breakthrough in cancer therapy, and researchers aim to exploit both as a single agent or in combination with chemotherapy to improve the survival of SCLC patients, but limited effectiveness and the adverse events remain the major obstacles in the treatment of SCLC. To overcome these challenges for SCLC therapies, prevention and early diagnosis for this refractory disease is very important. At the same time, we should reveal more information about the pathogenesis of SCLC and the mechanism of drug resistance. Finally, new treatment strategies should also be taken into considerations, such as repurposing drug, optimising of targets, combination therapy strategies or prognostic biomarkers to enhance therapeutic effects and decrease the adverse events rates in SCLC patients. This article will review the molecular biology characteristics of SCLC and discuss the opportunities and obstacles of the current therapy for SCLC patients.

Update on the Biology, Management, and Treatment of Small Cell Lung Cancer (SCLC)

Small-cell lung cancer (SCLC) accounts for 13-15% of all new lung cancer cases in the US. The tumor has a tendency to disseminate early resulting in 80-85% of patients being diagnosed with extensive disease (ES-SCLC). Chemotherapy has provided SCLC patients considerable survival benefits over the past three decades. Nonetheless, most patients relapse and rarely survive beyond 2 years. Despite consistent overall response rates of ≥50%, until recently, median survival times and 2-year survivals only ranged between 7-10 months and 10-20%, respectively. Several chemotherapy agents possess activity against SCLC, both, as single agents and in combinations but etoposide-platinum emerged as the preferred first line regimen. Upon relapse, many patients remain candidates for additional therapy. However, the sensitivity of relapsed SCLC to further therapies is markedly reduced and dependent upon the level and duration of response to the initial treatment (platinum-sensitive vs. resistant relapse). Multiple factors suggest a therapeutic role for immunotherapy in SCLC: SCLC has been associated with immune-mediated paraneoplastic processes (cerebellar degeneration, limbic encephalitis, and Lambert-Eaton syndrome) and patients presenting with these paraneoplastic syndromes have shown more favorable outcomes, suggesting an underlying immune response mechanism.Comprehensive genomic profiling of SCLC indicates that the majority lack functional p53 (90%) and Rb1 (65%). These universal genetic aberrations facilitate poor genomic stability, thus perpetuating the generation of tumor associated antigens, amenable to targeting with immunotherapy.SCLC has one of the highest mutational loads, likely a reflection of the myriad of insults inflicted by smoking-related carcinogens. The relationship between tumor mutational load and response to immune checkpoint inhibitors has been established in multiple solid tumors, including preliminary results in relapsed SCLC. In this manuscript, we review the early (some failed and discontinued, some partly successful, and still ongoing) attempts to incorporate immunotherapy (particularly vaccine based approaches) to the treatment of SCLC, and the latest attempts (mostly incorporating the use of checkpoint inhibitors), including those with favorable but preliminary results (CheckMate 032, Keynote 028 and 158), and those with more definitive positive (iMpower 133 and CASPIAN) and negative (CheckMate 331 and 451) results.

Phase 2 study of NAB-paclitaxel in SensiTivE and refractory relapsed small cell lung cancer (SCLC) (NABSTER TRIAL)

BACKGROUND

Despite sensitivity to first-line chemotherapy, most small-cell lung cancer (SCLC) patients relapse. In this setting, topotecan demonstrated modest activity with significant toxicity. Paclitaxel was also active. This study was designed to evaluate activity and safety of nab-paclitaxel in relapsed SCLC.

METHODS

In this multicentre prospective Phase 2 trial, patients with refractory or sensitive SCLC progressed to first-line platinum-based chemotherapy received nab-paclitaxel 100 mg/smq on days 1, 8, 15 every 4 weeks up to six cycles, progressive disease or intolerable toxicity. Primary endpoint was investigator-assessed objective tumour response. Secondary endpoints were toxicity, progression-free survival (PFS) and overall survival (OS).

RESULTS

Of the 68 patients treated, partial response was 8% in the refractory cohort and 14% in the sensitive cohort. Most common toxicities of any grade were fatigue (54%), anaemia (38%), neutropenia (29%), leukopenia (26%) and diarrhoea (21%). Median PFS was similar in both refractory (1.8 months) and sensitive cohorts (1.9 months), while median OS was longer in sensitive one (6.6 versus 3.6 months).

CONCLUSIONS

Although nab-paclitaxel has shown some modest anti-tumour activity in relapsed SCLC, associated with a favourable toxicity profile, the primary end-point of the study was not met.

CLINICAL TRIAL REGISTRATION

Clinical Trial registration number is ClinicalTrials.gov Identifier: NCT03219762.

Systemic Therapy of Extensive Stage Small Cell Lung Cancer in the Era of Immunotherapy

OPINION STATEMENT

In March 2019, the FDA approved the use of the anti-programmed death ligand 1 (PD-L1) antibody atezolizumab, as a first-line treatment option in combination with platinum-etoposide (PE) for patients with extensive stage small cell lung cancer (ED SCLC) based upon the results of the IMpower133 trial. More recently, the FDA approved the anti-PD-L1 antibody durvalumab in March 2020 , also in the frontline setting for SCLC based upon the results of the CASPIAN trial. Both these trials demonstrated a small, but significant overall survival (OS) benefit with the addition of a PD-L1 antibody to standard chemotherapy in the treatment of ED SCLC, thereby altering the treatment paradigm for this aggressive disease. Previously, the FDA had approved the anti-PD1 antibodies nivolumab and pembrolizumab as single-agent third-line treatment options based upon encouraging phase 1/2 data in patients with relapsed SCLC who had not received prior immunotherapy (IO). Despite these recent advances, the overall benefit of IO in SCLC remains somewhat disappointing in comparison with the results seen in non-small cell lung cancer (NSCLC). To date, no reliable biomarkers exist to predict responsiveness to IO in SCLC, and the utility of second- or third-line immunotherapy is questionable in patients who have received IO as part of first-line treatment. There has also been minimal success in identifying targetable mutations in SCLC. Novel approaches include combination approaches with IO, including PARP inhibitors and CDK inhibitors. Few ongoing trials, however, have enrolled patients who have received frontline immunotherapy given the only recent change in standard of care. Consequently, the results of current trials evaluating second- and third-line therapies need to be interpreted and translated into clinical practice with caution. The most significant challenge in SCLC remains the identification of molecular targets for which drugs can be developed that can improve survival over the current standard of care.

Prevalence of CD8+ cytotoxic lymphocytes in human neoplasms

PURPOSE

Immune checkpoint inhibitors have recently been approved by the US FDA as first and/or second line therapy in a subset of cancer types. Recent evidence suggests that the quantity of tumor infiltrating lymphocytes (TILs) influences the likelihood of response to immune checkpoint inhibitors. Here, we set out to assess the density of CD8+ lymphocytes in a wide range of different cancer types and subtypes.

METHODS

The density of CD8+ lymphocytes was compared across different cancer types using tissue microarrays (TMAs) composed of up to 50 tumor samples each from 84 different cancer types and subtypes. In total 2652 cancers and 608 normal tissues were successfully analyzed by CD8 immunohistochemistry followed by automated image analysis of digitized slides.

RESULTS

We found that the median CD8+ lymphocyte counts ranged from 6 cells/mm2 in pleomorphic adenoma up to 1573 cells/mm2 in Hodgkin's lymphoma. The CD8 counts were generally lower in normal tissues compared to cancer tissues. Blood vessels of the spleen were the only non-lymphatic tissue staining positive for CD8. Tumor types approved for checkpoint inhibitor therapy, including malignant melanoma (81), muscle invasive urothelial carcinoma (119), small cell lung cancer (120), clear cell renal cell cancer (153), squamous cell carcinoma (189) and adenocarcinoma of the lung (328) as well as Hodgkin's lymphoma (1573) were all ranking among the upper half of our list. Comparably high CD8 densities (median cells/mm2) were also found in several rare and aggressive cancer types including Merkel cell carcinoma (70), angiosarcoma (95), anaplastic thyroid cancer (156) and embryonal carcinoma of the testis (186). In 73 of the 84 analyzed cancer types, the highly variable CD8 counts occasionally exceeded the average CD8 count of tumors for which checkpoint inhibitors have been approved.

CONCLUSION

These data support the concept that among most tumor types at least some individual cancers may benefit from treatment with immune checkpoint inhibitors.

Immunotherapy - new perspective in lung cancer

Lung carcinoma is associated with a high mortality worldwide, being the leading cause of cancer death. It is mainly classified into squamous non-small cell lung cancer (NSCLC), non-squamous NSCLC, and small cell lung cancer. However, such malignancy has been increasingly subdivided into histological and molecular subtypes to guide treatment. Therapies can be used in adjuvant and palliative settings. Regarding immunotherapy, it has been widely tested in both first or subsequent palliative lines. In this sense, drugs such as pembrolizumab, nivolumab, atezolizumab, ipilimumab, avelumab, and durvalumab have been assessed in large studies. Some of these trials have also studied these medicines in adjuvant and in maintenance therapy. In recent years, advances in immunotherapy have raised the hope that the unfavorable prognosis observed in several affected individuals can be changed. Immunotherapy has increased the overall survival in squamous NSCLC, non-squamous NSCLC, and small cell lung cancer. However, it has added to the oncology practice some side effects that are unusual in standard chemotherapy and require special clinical support. In order to show how immunotherapy is being applied in the treatment of lung carcinoma, we reviewed the main studies in adjuvant and palliative scenarios. What is the better scheme? What is the better combination? What is the better dose? When should we use immunotherapy? Does programmed cell death ligand 1 expression significantly interfere in immunotherapy efficiency? Some of these questions have already been answered, while others require more investigations.

Outcomes with immune checkpoint inhibitors for relapsed small-cell lung cancer in a Swiss cohort

OBJECTIVES

Early clinical trials showed promising outcomes with immune-checkpoint inhibitors (ICI) in a subset of patients with relapsed small-cell lung carcinoma (SCLC). The aim of this retrospective analysis was to assess the efficacy and safety of ICI for relapsed SCLC in a real-world patient population.

METHODS

Nine cancer centres in Switzerland contributed data to this cohort. Responses were assessed by the local investigators using standard RECIST v1.1 criteria. Progression-free survival (PFS) and overall survival (OS) were analysed by the Kaplan-Meier method. Associations between potential predictive markers and survival endpoints were probed by Cox proportional hazards.

RESULTS

Forty-five patients were included in the analysis. Median age was 63 years, 73% were males and 18% had an ECOG performance status (PS) ≥ 2. ICIs were given as second-line treatment in 60%. Twenty-four patients (53%) received ipilimumab with nivolumab. Twenty-eight patients (62%) had undergone irradiation (RT) prior to or during ICI. Overall response rate (ORR) was 29% and median PFS and OS were 2.3 and 6.5 months, respectively. Median duration of response was 9 months (95% CI 2.8-NA). Five patients maintained their response for > 6 months, all of them receiving combination treatment. There were no new safety signals.

CONCLUSION

This is the first report of "real-world" data on ICI in relapsed SCLC also including patients with poor PS. Promising durable responses were observed. No biological prognostic marker could be identified.

Choice of second-line systemic therapy in stage IV small cell lung cancer (SCLC) - A decision-making analysis amongst European lung cancer experts

OBJECTIVES

Stage IV small cell lung cancer (SCLC) is associated with short survival and progression after first-line systemic therapy frequently occurs within months. Although topotecan is approved for second-line treatment, its efficacy is limited, and treatment heterogeneity exists.

MATERIAL AND METHODS

The decision-making patterns for second line treatment of 13 European medical oncologists with expertise in SCLC were analyzed.

RESULTS

The two criteria most relevant to decision-making were the performance status and the interval of recurrence since first-line treatment. With an interval of less than 3 months since the end of first-line chemotherapy, 62 % of the experts recommended cyclophosphamide, doxorubicin and vincristine (CAV) for fit patients and 54 % recommended topotecan for unfit patients. For an interval of more than 6 months, a clear consensus for a re-challenge with a platinum doublet was achieved (92 %). However, there was no consensus on the second-line therapy with an interval of 3-6 months since the end of first-line therapy.

CONCLUSION

Real world practice may differ from recommendations in general guidelines and cannot always be directly derived from trial results as other factor such as habits, patient's preference, convenience or costs have to be factored in.

Pembrolizumab monotherapy in patients with previously treated metastatic high-grade neuroendocrine neoplasms: joint analysis of two prospective, non-randomised trials

Background

Metastatic high-grade neuroendocrine neoplasms (G3NENs) have limited treatment options after progression on platinum-based therapy. We addressed the role of Pembrolizumab in patients with previously treated metastatic G3NENs.

Methods

Two open-label, phase 2 studies enrolled patients with G3NEN (Ki-67 > 20%) to receive Pembrolizumab at 200 mg I.V. every 3 weeks. Radiographic evaluation was conducted every 9 weeks with overall response rate as the primary endpoint.

Results

Between November 2016 and May 2018, 29 patients (13 males/16 females) with G3NENs were enrolled. One patient (3.4%) had an objective response and an additional six patients (20.7%) had stable disease, resulting in a disease control rate of 24.1%. Disease control rate (DCR) at 18 weeks was 10.3% (3/29). There was no difference in the DCR, PFS or OS between the PD-L1-negative and -positive groups (p 0.56, 0.88 and 0.55, respectively). Pembrolizumab was well tolerated with only 9 grade 3, and no grade 4 events considered drug-related.

Conclusions

Pembrolizumab can be safely administered to patients with G3NENs but has limited activity as a single agent. Successful completion of our trials suggest studies in G3NENs are feasible and present an unmet need. Further research to identify active combination therapies should be considered.

Clinical trial registration number

NCT02939651 (10/20/2016).

Nivolumab Monotherapy and Nivolumab Plus Ipilimumab in Recurrent Small Cell Lung Cancer: Results From the CheckMate 032 Randomized Cohort

INTRODUCTION

Nivolumab monotherapy is approved in the United States for third-line or later metastatic small cell lung cancer based on pooled data from nonrandomized and randomized cohorts of the multicenter, open-label, phase 1/2 trial of nivolumab ± ipilimumab (CheckMate 032; NCT01928394). We report updated results, including long-term overall survival (OS), from the randomized cohort.

METHODS

Patients with small cell lung cancer and disease progression after one to two prior chemotherapy regimens were randomized 3:2 to nivolumab 3 mg/kg every 2 weeks or nivolumab 1 mg/kg plus ipilimumab 3 mg/kg every 3 weeks for four cycles followed by nivolumab 3 mg/kg every 2 weeks. Patients were stratified by number of prior chemotherapy regimens and treated until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) by blinded independent central review.

RESULTS

Overall, 147 patients received nivolumab and 96 nivolumab plus ipilimumab. Minimum follow-up for ORR/progression-free survival/safety was 11.9 months (nivolumab) and 11.2 months (nivolumab plus ipilimumab). ORR increased with nivolumab plus ipilimumab (21.9% versus 11.6% with nivolumab; odds ratio: 2.12; 95% confidence interval: 1.06-4.26; p = 0.03). For long-term OS, minimum follow-up was 29.0 months (nivolumab) versus 28.4 months (nivolumab plus ipilimumab); median (95% confidence interval) OS was 5.7 (3.8-7.6) versus 4.7 months (3.1-8.3). Twenty-four-month OS rates were 17.9% (nivolumab) and 16.9% (nivolumab plus ipilimumab). Grade 3 to 4 treatment-related adverse event rates were 12.9% (nivolumab) versus 37.5% (nivolumab plus ipilimumab), and treatment-related deaths were n =1 versus n = 3, respectively.

CONCLUSIONS

Whereas ORR (primary endpoint) was higher with nivolumab plus ipilimumab versus nivolumab, OS was similar between groups. In each group, OS remained encouraging with long-term follow-up. Toxicities were more common with combination therapy versus nivolumab monotherapy.

Nivolumab for the treatment of small cell lung cancer

Introduction: Treatment of extensive-stage SCLC is still a challenge but immunotherapy with checkpoint inhibitors is showing promising results. Nivolumab alone or in combination with ipilimumab has demonstrated a benefit in terms of response and survival in patients with pre-treated extensive-stage disease and has been approved as third-line therapy after failure of chemotherapy. However, data from two phase III trials with nivolumab are negative. In the first trial, nivolumab was administered as a single agent compared to second-line chemotherapy, while in the second it was given alone or in combination with ipilimumab as maintenance treatment after platinum-based chemotherapy.Areas covered: Our review focuses on the role of immunotherapy, and in particular nivolumab, in the treatment of SCLC, describing the results of the main trials and its future perspectives, with reference to clinical trials with other checkpoint inhibitors.Expert opinion: The future of nivolumab in the treatment of SCLC needs to be clarified with further clinical trials, in which improved patient selection and a more specific setting and/or timepoint of the disease may be identified.

Use of immunotherapy in the treatment of gastric cancer

Gastric cancer (GC) is a malignant tumor that negatively impacts human health, which typically presents in the advanced stages of disease in the majority of patients. Despite the development of combination chemotherapy, only a modest survival advantage is gained in patients with GC treated by this method. Recently, cancer immunotherapies have received considerable attention as a viable therapeutic option for GC. Specifically, the immune checkpoint inhibitors, chimeric antigen rector (CAR)-T cells and tumor vaccines, represent immunotherapies that have exhibited promising effects in the treatment of GC. A number of clinical trials have employed either immuno-oncology monotherapies or combination therapies to improve the overall survival time (OS) and objective response rate (ORR) of patients with GC. The current review presents a summary of the clinical effects of checkpoint inhibitors, including CAR-T and tumor vaccines, in the treatment of GC.

Immune Checkpoint Blockade: The New Frontier in Cancer Treatment

Immune checkpoint blockers have revolutionized cancer treatment in recent years. These agents are now approved for the treatment of several malignancies, including melanoma, squamous and non-squamous non-small cell lung cancer, renal cell carcinoma, urothelial carcinoma, and head and neck squamous cell carcinoma. Studies have demonstrated the significant impact of immunotherapy versus standard of care on patient outcomes, including durable response and extended survival. The use of immunotherapy-based combination therapy has been shown to further extend duration of response and survival. Immunotherapies function through modulation of the immune system, which can lead to immune-mediated adverse events (imAEs). These include a range of dermatologic, gastrointestinal, endocrine, and hepatic toxicities, as well as other less common inflammatory events. ImAEs are typically low grade and manageable when identified early and treated with appropriate measures. Identifying the right patient for the right therapy will become more important as new immunotherapies and immunotherapy-based combinations are approved and costs of cancer care continue to rise.

Immune checkpoint blockade in small cell lung cancer

Despite the highly immunogenic potential of small cell lung cancer (SCLC), progress in evaluating the therapeutic value of immune checkpoint agents has lagged behind that of non-small cell lung cancer. Results from a number of phase I-III clinical trials that specifically address the use of anti-PD-1, anti-PD-L1 and anti-CTLA-4 agents in SCLC have now been reported. This review will focus on the available evidence for immune checkpoint blockade in SCLC and review current biomarker strategies with the aim of providing perspective and interpretation of this data for clinical practice.

The evolving landscape of immunotherapy in small-cell lung cancer: A focus on predictive biomarkers

Small cell lung cancer (SCLC) was defined as a "recalcitrant cancer" because of its dismal prognosis and lack of outcome improvements in the last 30 years. Immunotherapy with checkpoint inhibitors revolutionized treatment in many cancer types and results from the IMpower133 study, a double-blind placebo-controlled phase III trial, showed overall survival benefit for atezolizumab when added to standard platinum-etoposide chemotherapy in first-line SCLC setting for the first time since years. Trials with other checkpoint inhibitors, e.g. pembrolizumab, durvalumab, nivolumab and ipilimumab, are ongoing in various settings, but, to date, there are no defined factors to identify patients who are more likely to benefit from such treatments. This review summarizes results of immunotherapy trials in SCLC for first-line, maintenance and further-line therapies for single-agents and combinations with checkpoint inhibitors. Predictive factors from these trials are reviewed in order to identify their clinical value, with particular emphasis on PD-L1 expression on both tumor cells and in stroma, especially in pembrolizumab-treated patients, and tumor mutational burden, for patients treated with the ipilimumab and nivolumab combination.

Current Diagnosis and Management of Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) is an aggressive disease with distinct pathological, clinical, and molecular characteristics from non-small-cell lung cancer. SCLC has high metastatic potential, resulting in a clinically poor prognosis. Early concurrent chemo-radiation is the standard of care for limited-stage SCLC (LS-SCLC). Prophylactic cranial irradiation (PCI) is recommended for patients with LS-SCLC without progression of disease after initial therapy. A combination of etoposide and cisplatin or carboplatin remains the mainstay of first-line treatment for ES-SCLC, with the addition of atezolizumab, now becoming standard. Most SCLCs initially respond to therapy but almost invariably recur. Topotecan and amrubicin (in Japan) remain the primary chemotherapy options for relapsed SCLC. Immunotherapy, including nivolumab with or without ipilimumab, is now available for refractory disease. In general, the poor prognosis of SCLC has not improved significantly for more than 3 decades. Recently, next-generation molecular profiling studies have identified new therapeutic targets for SCLC. A variety of proapoptotic agents, compounds capitalizing on DNA-repair defects, immunotherapy agents, and antibody-drug conjugates are being evaluated in SCLC, with a number of them showing early promise.

Immune Checkpoint Inhibitors in Small Cell Lung Cancer: A Partially Realized Potential

Small cell lung cancer (SCLC) is a highly lethal subtype of lung cancer that has seen few therapeutic advances, despite ongoing concerted efforts. Immunotherapy has been an effective option in other carcinogen-related cancers and has shown modest activity in SCLC. Monotherapy with the anti-PD-1 antibody nivolumab in patients with at least two prior lines of therapy was associated with a response rate of 11.9% and a median duration of response of 17.9 months, leading to accelerated approval by the Food and Drug Administration (FDA) as third-line therapy for SCLC. Second-line checkpoint inhibitors have not performed well enough to change the standard of care, and maintenance immunotherapy has not shown significant benefit. However, the incorporation of concurrent immunotherapy in the first-line treatment of SCLC has improved outcomes. The addition of the anti-PD-L1 antibody atezolizumab to standard carboplatin plus etoposide led to an improvement in progression free survival (PFS) and overall survival, the first such improvement in over 30 years leading to the approval of atezolizumab as part of first-line therapy for advanced SCLC. While these landmark approvals offer promising novel treatment options for this recalcitrant disease, more work is needed to optimize their delivery and to build upon these important advances.

Immunotherapy in Small Cell Lung Cancer

Small-cell lung cancer (SCLC) is extremely sensitive to standard treatments, including conventional cytotoxic chemotherapies and radiotherapy, and has poor prognosis and short survival. Standard therapies have reached a plateau of effectiveness and new therapeutic strategies are needed to improve SCLC patient outcomes going forward. Immunotherapy has revolutionised the treatment of solid malignancies, offering a novel way to harness the host immune system to target malignant cells in patients whose disease may no longer respond to cytotoxic therapy. This review describes the available data for the checkpoint inhibitors, such as anti-cytotoxic T-lymphocyte antigen-4 protein (CTLA-4), anti-programmed cell death-1 protein receptor (PD-1), and ligands (PD-L1 and PD-L2) alone or in combination with first-line chemotherapy or in relapsed SCLC. Several trials investigating immunotherapy in SCLC patients are ongoing and the results are awaited soon. Moreover, further immune checkpoint inhibitors directed against other targets, such as the killer-cell immunoglobulin-like receptor and lymphocyte-activation gene-3, are in clinical development. Overall, the high expectations from the oncology community are that the drugs under development will offer new and improved treatment options for SCLC patients.

Beyond chemotherapy: Emerging biomarkers and therapies as small cell lung cancer enters the immune checkpoint era

For decades, clinicians have seen no therapeutic advances for SCLC, including no FDA-approved targeted therapies; recently, immune checkpoint blockade has emerged as a promising new option for the treatment of relapsed SCLC (including recent FDA approval of nivolumab in the third-line setting) and may soon represent the frontline standard of care in combination with chemotherapy. However, we need to uncover biomarkers to guide patient selection and develop novel approaches to enhance response to immunotherapies.

2017-2018 Scientific Advances in Thoracic Oncology: Small Cell Lung Cancer

SCLC remains an aggressive, deadly cancer with only modest effect on survival from standard chemotherapy. However, with the advent of immunotherapy and comprehensive genomic and transcriptomic profiling, multiple new targets are showing promise in the clinical arena, and just recently programmed death ligand 1 inhibition has been shown to improve the efficacy of standard chemotherapy in extended-disease SCLC. Our increasing understanding of the interactions between different pathways will enable more tailored immunotherapy and targeted therapies based on specific biomarkers and rational combinations. Here we discuss the preclinical and clinical strides in 2017 and 2018 that put us on the threshold of a new era in therapeutics and will, it is hoped, translate into significant improvements in survival.

Role of Immune Checkpoint Inhibitors in Small Cell Lung Cancer

BACKGROUND

Small cell lung cancer (SCLC) accounts for approximately 13% of all lung cancer diagnoses each year. SCLC is characterized by a rapid doubling time, early metastatic spread, and an unfavorable prognosis overall.

AREAS OF UNCERTAINTY

Most patients with SCLC will respond to initial treatment; however, the majority will experience a disease recurrence and response to second-line therapies is poor. Immune checkpoint inhibitors may be an option given the success in other diseases.

DATA SOURCES

A literature search was conducted using Medline (1946-July week 1, 2017) and Embase (1996-2017 week 28) with the search terms small cell lung cancer combined with nivolumab or ipilimumab or pembrolizumab or atezolizumab or tremelimumab or durvalumab. Five clinical trials, including extended follow-up for 2, that evaluated immune checkpoint inhibitors in limited stage or extensive stage SCLC were included.

RESULTS

In 2 phase 2 trials, ipilimumab was added to upfront chemotherapy. In both trials, an improvement in progression-free survival was seen. Toxicity, when combined with a platinum and etoposide, was significant. In a confirmatory phase 3 trial, ipilimumab did not prolong overall survival when added to first-line chemotherapy. Overall, response rates were similar between the placebo and ipilimumab groups. A phase 1/2 trial evaluated nivolumab alone or in combination with ipilimumab in recurrent SCLC. Results revealed that nivolumab monotherapy and the combination of nivolumab and ipilimumab were relatively safe and had antitumor activity. Pembrolizumab has been evaluated in a multicohort, phase 1b trial. Preliminary data showed a durable response in the second-line setting.

CONCLUSION

Given the lack of overall survival data and significant toxicity associated with the combination of ipilimumab with first-line chemotherapy, this treatment is not a reasonable option at this time. Nivolumab alone or in combination with ipilimumab is a valid option for recurrent SCLC.

Analysis of topoisomerase I expression and identification of predictive markers for efficacy of topotecan chemotherapy in small cell lung cancer

Background

We evaluated topoisomerase I (TOPO1) expression in patients with small cell lung cancer (SCLC) and identified predictive factors for the efficacy of second‐line topotecan chemotherapy.

Methods

We retrospectively evaluated the records of SCLC patients treated in our department from January 2007 to December 2016 who received second‐line topotecan chemotherapy. Patients with archived tumor samples were enrolled. TOPO1 expression levels were evaluated by immunohistochemistry, and the relationships between TOPO1 expression, clinical factors, chemotherapy efficacy, and survival were analyzed.

Results

Of the 78 patients enrolled, 67 showed TOPO1 expression (85.9%). Patients were divided into strong (n = 43) or weak (n = 35) expression groups based on staining intensity. Disease control rates for topotecan were 39.5% and 14.3% in the strong and weak groups, respectively (P = 0.014). Second‐line median progression‐free survival was 2.2 and 2.0 months (P = 0.057), and median overall survival was 8.1 and 6.0 months (P = 0.199) in the strong and weak positive groups, respectively. Patients were also divided into sensitive (n = 47) and refractory (n = 31) disease groups according to the duration from the onset of first‐line therapy to relapse. Median second‐line progression‐free survival was 2.2 and 1.8 months in the sensitive and refractory relapse groups, respectively (P = 0.005).

Conclusions

TOPO1 expression was prevalent in SCLC patients. Strong expression was associated with an elevated disease control rate after second‐line topotecan chemotherapy. Patients with sensitive disease that relapsed after first‐line chemotherapy had better survival than refractory patients who received second‐line topotecan chemotherapy.

Lung Cancers: Molecular Characterization, Clonal Heterogeneity and Evolution, and Cancer Stem Cells

Lung cancer causes the largest number of cancer-related deaths in the world. Most (85%) of lung cancers are classified as non-small-cell lung cancer (NSCLC) and small-cell lung cancer (15%) (SCLC). The 5-year survival rate for NSCLC patients remains very low (about 16% at 5 years). The two predominant NSCLC histological phenotypes are adenocarcinoma (ADC) and squamous cell carcinoma (LSQCC). ADCs display several recurrent genetic alterations, including: KRAS, BRAF and EGFR mutations; recurrent mutations and amplifications of several oncogenes, including ERBB2, MET, FGFR1 and FGFR2; fusion oncogenes involving ALK, ROS1, Neuregulin1 (NRG1) and RET. In LSQCC recurrent mutations of TP53, FGFR1, FGFR2, FGFR3, DDR2 and genes of the PI3K pathway have been detected, quantitative gene abnormalities of PTEN and CDKN2A. Developments in the characterization of lung cancer molecular abnormalities provided a strong rationale for new therapeutic options and for understanding the mechanisms of drug resistance. However, the complexity of lung cancer genomes is particularly high, as shown by deep-sequencing studies supporting the heterogeneity of lung tumors at cellular level, with sub-clones exhibiting different combinations of mutations. Molecular studies performed on lung tumors during treatment have shown the phenomenon of clonal evolution, thus supporting the occurrence of a temporal tumor heterogeneity.

Phase II Study of Maintenance Pembrolizumab in Patients with Extensive-Stage Small Cell Lung Cancer (SCLC)

OBJECTIVE

The aim of this study was to assess the efficacy of maintenance pembrolizumab in patients with extensive-stage SCLC after treatment with platinum and etoposide.

METHODS

Patients with extensive-stage SCLC with a response or stable disease after induction chemotherapy were eligible. Pembrolizumab at a dose of 200 mg administered intravenously every 3 weeks was initiated within 8 weeks of the last cycle of chemotherapy. The primary end point of the study was progression-free survival (PFS) from study registration, with overall survival (OS) as a key secondary end point. Available tumor tissue was assessed for expression of programmed death ligand 1 (PD-L1) both in the tumor cells and in the surrounding stroma. Blood for circulating tumor cells was collected before the first, second, and third cycles of pembrolizumab.

RESULTS

Of the 45 patients enrolled, 56% were male and 22% had treated brain metastases. The median PFS was 1.4 months (95% confidence interval [CI]: 1.3-2.8), with a 1-year PFS of 13%. The median OS was 9.6 months (95% CI: 7.0-12), with a 1-year OS of 37%. Of the 30 tumors that could be assessed, three had PD-L1 expression (≥1%) in the tumor cells. A total of 20 tumors could be assessed for PD-L1 expression in the stroma. The median PFS in the eight patients with tumors positive for expression of PD-L1 at the stromal interface was 6.5 months (95% CI: 1.1-12.8) compared with 1.3 months (95% CI: 0.6-2.5) in 12 patients with tumors negative for this marker. No unexpected toxicities were observed.

CONCLUSION

Maintenance pembrolizumab did not appear to improve median PFS compared with the historical data. However, the 1-year PFS rate of 13% and OS rate of 37% suggest that a subset of patients did benefit from pembrolizumab.

Pan-cancer adaptive immune resistance as defined by the Tumor Inflammation Signature (TIS): results from The Cancer Genome Atlas (TCGA)

The Tumor Inflammation Signature (TIS) is an investigational use only (IUO) 18-gene signature that measures a pre-existing but suppressed adaptive immune response within tumors. The TIS has been shown to enrich for patients who respond to the anti-PD1 agent pembrolizumab. To explore this immune phenotype within and across tumor types, we applied the TIS algorithm to over 9000 tumor gene expression profiles downloaded from The Cancer Genome Atlas (TCGA). As expected based on prior evidence, tumors with known clinical sensitivity to anti-programmed cell death protein 1 (PD-1) blockade had higher average TIS scores. Furthermore, TIS scores were more variable within than between tumor types, and within each tumor type a subset of patients with elevated scores was identifiable although with different prevalence associated with each tumor type, the latter consistent with the observed clinical responsiveness to anti PD-1 blockade. Notably, TIS scores only minimally correlated with mutation load in most tumors and ranking tumors by median TIS score showed differing association to clinical sensitivity to PD-1/PD-1 ligand 1 (PD-L1) blockade than ranking of the same tumors by mutation load. The expression patterns of the TIS algorithm genes were conserved across tumor types yet appeared to be minimally prognostic in most cancers, consistent with the TIS score serving as a pan-cancer measurement of the inflamed tumor phenotype. Characterization of the prevalence and variability of TIS will lead to increased understanding of the immune status of untreated tumors and may lead to improved indication selection for testing immunotherapy agents.

Tumor Mutational Burden and Efficacy of Nivolumab Monotherapy and in Combination with Ipilimumab in Small-Cell Lung Cancer

Durable responses and encouraging survival have been demonstrated with immune checkpoint inhibitors in small-cell lung cancer (SCLC), but predictive markers are unknown. We used whole exome sequencing to evaluate the impact of tumor mutational burden on efficacy of nivolumab monotherapy or combined with ipilimumab in patients with SCLC from the nonrandomized or randomized cohorts of CheckMate 032. Patients received nivolumab (3 mg/kg every 2 weeks) or nivolumab plus ipilimumab (1 mg/kg plus 3 mg/kg every 3 weeks for four cycles, followed by nivolumab 3 mg/kg every 2 weeks). Efficacy of nivolumab ± ipilimumab was enhanced in patients with high tumor mutational burden. Nivolumab plus ipilimumab appeared to provide a greater clinical benefit than nivolumab monotherapy in the high tumor mutational burden tertile.

Current and future therapeutic approaches for the treatment of small cell lung cancer

INTRODUCTION

Small-cell lung cancer (SCLC) is a very aggressive disease characterized by a high response rate to first-line chemotherapy, but most patients relapse within 1 year with disappointing results to second-line treatments. Chemotherapy has reached a plateau of effectiveness and new therapeutic strategies are needed to change the natural history of SCLC. Areas covered: This review will focus on the current results and the future development of the therapeutic approaches for the treatment of SCLC. Expert commentary: Immunotherapy is becoming a new frontier for the management of SCLC with preliminary interesting results. To date, no targeted drugs have been approved for clinical practice but several novel agents are in an advanced stage of clinical development in SCLC.

Importance of immune monitoring approaches and the use of immune checkpoints for the treatment of diffuse intrinsic pontine glioma: From bench to clinic and vice versa (Review)

On the basis of immunological results, it is not in doubt that the immune system is able to recognize and eliminate transformed cells. A plethora of studies have investigated the immune system of patients with cancer and how it is prone to immunosuppression, due in part to the decrease in lymphocyte proliferation and cytotoxic activity. The series of experiments published following the demonstration by Dr Allison's group of the potential effect of anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) paved the way for a new perception in cancer immunotherapy: Immune checkpoints. Several T cell-co-stimulatory molecules including cluster of differentiation (CD)28, inducible T cell co-stimulatory, 4-1BB, OX40, glucocorticoid-induced tumor necrosis factor receptor-related gene and CD27, and inhibitory molecules including T cell immunoglobulin and mucin domain-containing-3, programmed cell death-1 (PD-1), programmed cell death ligand-1 (PD-L1), V-domain immunoglobulin suppressor of T cells activation, T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain, and B and T lymphocyte attenuator have been described in regulating T cell functions, and have been demonstrated to be essential targets in immunotherapy. In preclinical studies, glioblastoma multiforme, a high-grade glioma, the monotherapy targeting PD-1/PD-L1 and CTLA-4 resulted in increased survival times. An improved understanding of the pharmacodynamics and immune monitoring on glioma cancers, particularly in diffuse intrinsic pontine glioma (DIPG), an orphan type of cancer, is expected to have a major contribution to the development of novel therapeutic approaches. On the basis of the recent preclinical and clinical studies of glioma, but not of DIPG, the present review makes a claim for the importance of investigating the tumor microenvironment, the immune response and the use of immune checkpoints (agonists or antagonists) in preclinical/clinical DIPG samples by immune monitoring approaches and high-dimensional analysis. Evaluating the potential predictive and correlative biomarkers in preclinical and clinical studies may assist in answering certain crucial questions that may be useful to improve the clinical response in patients with DIPG.