Chemotherapy reinforces anti-tumor immune response and enhances clinical efficacy of immune checkpoint inhibitors

New evidence suggests that the clinical success of chemotherapy is not merely due to tumor cell toxicity but also arises from the restoration of immunosurveillance, which has been immensely neglected in previous preclinical and clinical researches. There is an urgent need for novel insights into molecular mechanisms and regimens that uplift the efficacy of immunotherapy since only a minority of cancer patients are responsive to immune checkpoint inhibitors (ICIs). Recent findings on combination therapy of chemotherapy and ICIs have shown promising results. This strategy increases tumor recognition and elimination by the host immune system while reducing immunosuppression by the tumor microenvironment. Currently, several preclinical studies are investigating molecular mechanisms that give rise to the immunomodulation by chemotherapeutic agents and exploit them in combination therapy with ICIs in order to achieve a synergistic clinical activity. In this review, we summarize studies that exhibit the capacity of conventional chemotherapeutics to elicit anti-tumor immune responses, thereby facilitating anti-tumor activities of the ICIs. In conclusion, combining chemotherapeutics with ICIs appears to be a promising approach for improving cancer treatment outcomes.

Association of Programmed Cell Death Ligand 1 Expression Status With Receipt of Immune Checkpoint Inhibitors in Patients With Advanced Non-Small Cell Lung Cancer

IMPORTANCE

Initial approval for immune checkpoint inhibitors (ICIs) for treatment of advanced non-small cell lung cancer (NSCLC) was limited to patients with high levels of programmed cell death ligand 1 (PD-L1) expression. However, in the period after approval, it is not known how new evidence supporting efficacy of these treatments in patients with low or negative PD-L1 expression was incorporated into real-world practice.

OBJECTIVE

To evaluate the association between PD-L1 testing and first-line ICI use.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study (January 1, 2011, to December 31, 2018) used a deidentified nationwide electronic health record-derived database reflecting real-world care at more than 280 US community and academic cancer clinics (approximately 800 sites of care). Patients included those with advanced NSCLC without other identifiable variations diagnosed in the period after the US Food and Drug Administration's initial first-line approval of ICIs for patients with high PD-L1 expression (≥50%).

EXPOSURE

First-line ICI treatment.

MAIN OUTCOMES AND MEASURES

Patterns of PD-L1 testing and first-line ICI treatment among all patients and patients stratified by tumor histologic type (squamous vs nonsquamous).

RESULTS

A total of 45 631 patients (mean [SD] age, 68.4 [9.6] years; 21 614 [47.4%] female) with advanced NSCLC were included in the study. PD-L1 testing increased from 468 (7.2%) in 2015 to 4202 (73.2%) in 2018. Within a subset of 7785 patients receiving first-line treatment in the period after first-line approval of pembrolizumab, those who received PD-L1 testing had a greater odds of receiving an ICI (odds ratio, 2.11; 95% CI, 1.89-2.36). Among patients with high PD-L1 expression (≥50%), 1541 (83.5%) received first-line ICI treatment; 776 patients (40.3%) with low PD-L1 expression (1%-49%) and 348 (32.3%) with negative PD-L1 expression (0%) also received ICIs. In addition, 755 untested patients (32.8%) were treated with a first-line ICI. The proportion of patients who received ICIs without PD-L1 testing increased during the study period (59 [17%] in quarter 4 of 2016 to 141 [53.8%] in quarter 4 of 2018).

CONCLUSIONS AND RELEVANCE

In this study, use of first-line ICI treatment increased among patients with advanced NSCLC with negative, low, or untested PD-L1 expression status in 2016 through 2018. These findings suggest that national practice was rapidly responsive to new clinical evidence rather than adhering to regulatory guidance in place at the time.

Amplifying Outcomes: Checkpoint Inhibitor Combinations in First-Line Non-Small Cell Lung Cancer

PURPOSE

Lung cancer is one of the most common types of cancer, resulting in approximately 1.8 million deaths worldwide. Immunotherapy using checkpoint inhibitors has become standard of care in advanced non-small cell lung cancer (NSCLC), and there is increasing interest in further improving outcomes through combination with other therapeutics. This systematic review evaluates emerging phase III data on the efficacy and safety of checkpoint inhibitor combinations as first-line treatment for advanced NSCLC.

MATERIALS AND METHODS

Published and presented literature was searched using the key search terms "non-small cell lung cancer" AND "checkpoint-inhibitors" (OR respective aliases) AND phase III trials. Seven randomized phase III clinical trials reporting outcomes on checkpoint inhibitor combinations in first-line advanced NSCLC were identified.

RESULTS

Four first-line trials reported outcomes for checkpoint inhibitor combinations in nonsquamous NSCLC. Pembrolizumab-chemotherapy, atezolizumab-chemotherapy, and atezolizumab-bevacizumab-chemotherapy showed significantly improved overall survival compared with controls in patients with advanced nonsquamous epidermal growth factor receptor-negative (EGFR-)/ anaplastic lymphoma kinase gene (ALK)- NSCLC. Two trials reported outcomes for squamous NSCLC, with pembrolizumab-chemotherapy reporting significantly improved overall survival (OS) compared with chemotherapy. The combination of nivolumab-ipilimumab in all-comer histology failed to improve OS compared with histology appropriate chemotherapy in patients regardless of their tumor mutational burden status. Based on improved survival and safety, either pembrolizumab monotherapy or pembrolizumab-chemotherapy administered based on PD-L1 status and histology is a preferred treatment option. Outcomes for atezolizumab-bevacizumab-chemotherapy in EGFR+/ALK+ patients are promising and require further exploration.

CONCLUSION

First-line checkpoint inhibitors added to standard therapies improve overall survival for nonsquamous EGFR-/ALK- and squamous advanced NSCLC.

IMPLICATIONS FOR PRACTICE

Single-agent immune checkpoint inhibitors are now standard of care for advanced non-small cell lung cancer (NSCLC), and emerging data show that combining these agents with established chemotherapy further improves outcomes. The phase III KEYNOTE-189 and IMPower-130 trials showed significantly improved survival using this strategy for nonsquamous NSCLC, and the phase III KEYNOTE-407 trial showed similar results in squamous disease. Checkpoint inhibitor combinations are therefore an important new treatment option for first-line NSCLC. Programmed death ligand-1 expression may inform the use of checkpoint inhibitor combination therapy, and overall tumor mutation burden is also an emerging biomarker for this new treatment strategy.

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.

Pembrolizumab plus chemotherapy for first-line treatment of metastatic nonsquamous non-small-cell lung cancer: a network meta-analysis

Aim: A systematic review and network meta-analysis were conducted to evaluate the efficacy of pembrolizumab + pemetrexed + platinum relative to other regimens in metastatic nonsquamous non-small-cell lung cancer (NSq-NSCLC). Patients & methods: Eligible studies evaluated first-line regimens in NSq-NSCLC patients without known targetable mutations. Relative treatment effects were synthesized with random effects proportional hazards Bayesian network meta-analyses. Results: The hazard ratio (HR) for overall survival (OS) for pembrolizumab + pemetrexed + platinum was statistically significant over all platinum-doublet (HR range: 0.42–0.61), platinum-doublet + bevacizumab (HR range: 0.44–0.53) and platinum-doublet + atezolizumab regimens (HR range: 0.56–0.62). Additionally, pembrolizumab + pemetrexed + platinum numerically improved OS over atezolizumab + paclitaxel + carboplatin + bevacizumab (HR: 0.65; 95% credible interval: 0.43, 1.01). Pembrolizumab + pemetrexed + platinum had 95.6% probability of being the best treatment regimen for OS. Conclusion: Pembrolizumab + pemetrexed + platinum is likely the most efficacious first-line regimen for metastatic NSq-NSCLC.

Choosing wisely first line immunotherapy in non-small cell lung cancer (NSCLC): what to add and what to leave out

Immunotherapy has dramatically changed the therapeutic scenario in treatment naïve advanced non-small cell lung cancer (NSCLC). While single agent pembrolizumab has become the standard therapy in patients with PD-L1 expression on tumor cells ≥ 50%, the combination of pembrolizumab or atezolizumab and platinum-based chemotherapy has emerged as an effective first line treatment regardless of PD-L1 expression both in squamous and non-squamous NSCLC without oncogenic drivers. Furthermore, double immune checkpoint inhibition has shown promising results in treatment naïve patients with high tumor mutational burden (TMB). Of note, the presence of both negative PD-L1 expression and low TMB may identify a subgroup of patients who has little benefit from immunotherapy combinations and for whom the best treatment option may still be platinum-based chemotherapy. To date, first-line single agent immune checkpoint blockade has demonstrated limited activity in EGFR mutated NSCLC and the combination of immunotherapy and targeted agents has raised safety concerns in both EGFR and ALK positive NSCLC patients. Finally, in EGFR mutated or ALK rearranged NSCLC, atezolizumab in combination with platinum-based chemotherapy and bevacizumab is emerging as a potential treatment option upon progression to first line tyrosine kinase inhibitors.

Enhancing antitumor response by combining immune checkpoint inhibitors with chemotherapy in solid tumors

BACKGROUND

Cancer immunotherapy has changed the standard of care for a subgroup of patients with advanced disease. Immune checkpoint blockade (ICB) in particular has shown improved survival compared with previous standards of care for several tumor types. Although proven to be successful in more immunogenic tumors, ICB is still largely ineffective in patients with tumors that are not infiltrated by immune cells, the so-called cold tumors.

PATIENTS AND METHODS

This review describes the effects of different chemotherapeutic agents on the immune system and the potential value of these different types of chemotherapy as combination partners with ICB in patients with solid tumors. Both preclinical data and currently ongoing clinical trials were evaluated. In addition, we reviewed findings regarding different dosing schedules, including the effects of an induction phase and applying metronomic doses of chemotherapy.

RESULTS

Combining ICB with other treatment modalities may lead to improved immunological conditions in the tumor microenvironment and could thereby enhance the antitumor immune response, even in tumor types that are so far unresponsive to ICB monotherapy. Chemotherapy, that was originally thought to be solely immunosuppressive, can exert immunomodulatory effects which may be beneficial in combination with immunotherapy. Each chemotherapeutic drug impacts the tumor microenvironment differently, and in order to determine the most suitable combination partners for ICB it is crucial to understand these mechanisms.

CONCLUSION

Preclinical studies demonstrate that the majority of chemotherapeutic drugs has been shown to exert immunostimulatory effects, either by inhibiting immunosuppressive cells and/or activating effector cells, or by increasing immunogenicity and increasing T-cell infiltration. However, for certain chemotherapeutic agents timing, dose and sequence of administration of chemotherapeutic agents and ICB is important. Further studies should focus on determining the optimal drug combinations, sequence effects and optimal concentration-time profiles in representative preclinical models.

To do or not to do: A concise update of current clinical controversies in immune checkpoint blockade

Although programmed death-ligand 1 is currently the best available biomarker for first-line therapy with pembrolizumab for patients with non-small cell lung cancer and is a required companion test approved by the US Food and Drug Administration, programmed death-ligand 1 testing is an option (as a complementary test) for patients treated with nivolumab, atezolizumab, and durvalumab. Programmed death-ligand 1 expression is continuously variable and dynamic in the tumor microenvironment. Due to the complex molecular and cellular interactions involved in immune response, a single biomarker may not be sufficient to predict response to cancer immunotherapy. Integration of multiple tumor, immune response, and genomic parameters is likely to influence the future interpretation of biomarker-based treatment outcomes. This article, in a case-based format, concisely summarizes most up-to-date evidence in answering some commonly seen clinical controversies of cancer immunotherapy, in terms of (i) the predictive value of programmed death-ligand 1 as a biomarker; (ii) whether the use of steroids with checkpoint inhibitors will decrease efficacy of the latter; (iii) selection of patients for cancer immunotherapy based on immune-based response criteria, and (iv) whether the use of influenza vaccine with checkpoint inhibitors is considered safe. Until more robust, long-term prospective clinical data are available, these discussions may serve as a starting point for pharmacists to gain timely and effective management of these realistic issues.

Perspectives in immunotherapy: meeting report from the Immunotherapy Bridge (29-30 November, 2017, Naples, Italy)

Immunotherapy represents the third important wave in the history of the systemic treatment of cancer after chemotherapy and targeted therapy and is now established as a potent and effective treatment option across several cancer types. The clinical success of anti-cytotoxic T-lymphocyte-associated antigen (CTLA)-4, first, and anti-programmed death (PD)-1/PD-ligand (L)1 agents in melanoma and other cancers a few years later, has encouraged increasing focus on the development of other immunotherapies (e.g. monoclonal antibodies with other immune targets, adoptive cell transfer, and vaccines), with over 3000 immuno-oncology trials ongoing, involving hundreds of research institutes across the globe. The potential use of these different immunotherapeutic options in various combinations with one another and with other treatment modalities is an area of particular promise. The third Immunotherapy Bridge meeting (29-30 November, 2017, Naples, Italy) focused on recent advances in immunotherapy across various cancer types and is summarised in this report.

Heuristic value-based framework for lung cancer decision-making

Heuristics and the application of fast-and-frugal trees may play a role in establishing a clinical decision-making framework for value-based oncology. We determined whether clinical decision-making in oncology can be structured heuristically based on the timeline of the patient's treatment, clinical intuition, and evidence-based medicine. A group of 20 patients with advanced non-small cell lung cancer (NSCLC) were enrolled into the study for extensive treatment analysis and sequential decision-making. The extensive clinical and genomic data allowed us to evaluate the methodology and efficacy of fast-and-frugal trees as a way to quantify clinical decision-making. The results of the small cohort will be used to further advance the heuristic framework as a way of evaluating a large number of patients within registries. Among the cohort whose data was analyzed, substitution and amplification mutations occurred most frequently. The top five most prevalent genomic alterations were TP53 (45%), ALK (40%), LRP1B (30%), CDKN2A (25%), and MYC (25%). These 20 cases were analyzed by this clinical decision-making process and separated into two distinctions: 10 straightforward cases that represented a clearer decision-making path and 10 complex cases that represented a more intricate treatment pathway. The myriad of information from each case and their distinct pathways was applied to create the foundation of a framework for lung cancer decision-making as an aid for oncologists. In late-stage lung cancer patients, the fast-and-frugal heuristics can be utilized as a strategy of quantifying proper decision-making with limited information.