Discontinuation of immune checkpoint inhibitor (ICI) above 18 months of treatment in real-life patients with advanced non-small cell lung cancer (NSCLC): INTEPI, a multicentric retrospective study

Treatment Effect Waning in Immuno-oncology Health Technology Assessments: A Review of Assumptions and Supporting Evidence with Proposals to Guide Modelling

Treatment effect waning (TEW) refers to the attenuation of treatment effects over time. Assumptions of a sustained immuno-oncologic treatment effect have been a source of contention in health technology assessment (HTA). We review how TEW has been addressed in HTA and in the wider scientific literature. We analysed company submissions to English language HTA agencies and summarised methods and assumptions used. We subsequently reviewed TEW-related work in the ISPOR Scientific Presentations Database and conducted a targeted literature review (TLR) for evidence of the maintenance of immuno-oncology (IO) treatment effects post-treatment discontinuation. We found no standardised approach adopted by companies in submissions to HTA agencies, with immediate TEW most used in scenario analyses. Independently fitted survival models do however suggest TEW may often be implicitly modelled. Materials in the ISPOR scientific database suggest gradual TEW is more plausible than immediate TEW. The TLR uncovered evidence of durable survival in patients treated with IOs but no evidence that directly addresses the presence or absence of TEW. Our HTA review shows the need for a consistent and appropriate implementation of TEW in oncology appraisals. However, the TLR highlights the absence of direct evidence on TEW in literature, as TEW is defined in terms of relative treatment effects-not absolute survival. We propose a sequence of steps for analysts to use when assessing whether a TEW scenario is necessary and appropriate to present in appraisals of IOs.

Overall Survival, Treatment Duration, and Rechallenge Outcomes With ICI Therapy for Recurrent or Metastatic HNSCC

Importance

Immune checkpoint inhibition (ICI) is a frontline treatment for recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC), but questions remain surrounding optimal duration of therapy, benefits and risks of ICI rechallenge, and efficacy in first vs subsequent lines of therapy.

Objectives

To estimate survival in US patients receiving ICI-based treatment for R/M HNSCC, compare outcomes associated with treatment discontinuation vs continuation at 1 or 2 years, and assess outcomes after immunotherapy rechallenge.

Design, Setting, and Participants

This retrospective, population-based cohort study included adult patients in the Flatiron Health nationwide oncology database treated with immunotherapy for R/M HNSCC from 2015 to 2023. Data cutoff was August 31, 2023; data analysis was conducted from December 2023 to February 2024.

Exposures

Treatment continuation vs discontinuation at 1 and 2 years; rechallenge with ICI after at least a 60-day period off ICI therapy without intervening systemic treatment (immediate rechallenge), or with intervening systemic treatment (delayed rechallenge).

Main Outcomes and Measures

Overall survival (OS) from ICI initiation was analyzed using the Kaplan-Meier method. Cox multivariable regression was used to examine associations of key variables (line of therapy, human papillomavirus [HPV] status, Eastern Cooperative Oncology Group [ECOG] performance status) with survival.

Results

The cohort included 4549 patients with R/M HNSCC who received ICI-containing therapy (median [IQR] age, 66 [59-72] years; 3551 [78.1%] male; 56 [1.2%] Asian, 260 [5.7%] Black or African American, 3020 [66.4%] White, 1213 [26.7%] other or unknown race; 3226 [70.9%] ECOG performance status 0 or 1). There were 3000 patients (65.9%) who received ICI in frontline and 1207 (26.5%) in second line; 3478 patients (76.5%) received ICI monotherapy. Median (IQR) OS was 10.9 (4.1-29.1) months and was longer in patients who received ICI in frontline therapy (12.2 [4.8-32.0] vs 8.7 [3.2-22.4] months), had HPV-positive cancer (16.6 [6.5-43.9] vs 8.8 [3.5-24.0] months), and had ECOG performance status 0 or 1 (13.5 [5.2-33.9] vs 5.5 [2.0-13.7] months). There were no survival differences on adjusted analysis between patients who stopped vs those who continued ICI at 1 or 2 years. Median (IQR) OS after ICI rechallenge was 15.7 (13.7-21.9) months in the immediate rechallenge group and 9.9 (3.7-18.1) months in the delayed rechallenge group.

Conclusions and Relevance

In this large cohort study of patients with R/M HNSCC receiving ICI-based therapy, survival estimates closely mirrored clinical trial results, both in frontline and later-line settings. Discontinuation of ICI in long-term responders at 1 or 2 years may be a reasonable strategy that does not appear to compromise survival. ICI rechallenge was associated with clinical benefit in a subset of patients.

Progression-Free Survival and Treatment-Free Interval in Head and Neck Cancer with Long-Term Response to Nivolumab: Timing of Active Discontinuation

The optimal timing for actively discontinuing immune checkpoint inhibitor therapy in long-term responders with recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) remains unresolved. We conducted a retrospective study of 246 patients with R/M HNSCC treated with nivolumab to determine the optimal timing to actively discontinue nivolumab therapy. We examined the point at which progression-free survival (PFS) plateaued in all cases. We compared the prognosis of 19 (7.7%) ongoing cases and 227 (92.3%) discontinued cases and analyzed treatment duration and treatment-free interval (TFI). The 6-year overall survival was 11.8% (median, 12.1), and the 6-year PFS was 15.3% (median, 3.0). The PFS curve remained stable for 3 years. The median duration of nivolumab treatment was 2.9 months (range 0.03-81.9): Ongoing group, 41.8 (5.6-81.9); Decision group, 36.8 (4.0-70.1); Toxicity group, 30.6 (2.8-64.8); and progressive disease group, 2.0 (0.03-42.9). TFI in the Decision group was 15.1 months (0.6-61.6) and 30.6 months (2.8-64.8) in the Toxicity group. Long-term responses in R/M HNSCC patients treated with nivolumab are rare but gradually increasing. For this patient group, our best estimate of the optimal time to end treatment is 3 years, as the PFS in this study reached a plateau at that timepoint.

Outcomes of patients with advanced solid tumors who discontinued immune-checkpoint inhibitors: a systematic review and meta-analysis

Background

The outcome of patients with metastatic tumors who discontinued immune checkpoint inhibitors (ICIs) not for progressive disease (PD) has been poorly explored. We performed a meta-analysis of all studies reporting the clinical outcome of patients who discontinued ICIs for reasons other than PD.

Methods

We searched PubMed, Embase and Scopus databases, from the inception of each database to December 2023, for clinical trials (randomized or not) and observational studies assessing PD-(L)1 and CTLA-4 inhibitors in patients with metastatic solid tumors who discontinued treatment for reasons other than PD. Each study had to provide swimmer plots or Kaplan-Meier survival curves enabling the reconstruction of individual patient-level data on progression-free survival (PFS) following the discontinuation of immunotherapy. The primary endpoint was PFS from the date of treatment discontinuation overall and according to tumor histotype, type of treatment and reason of discontinuation. The Combersure's method was used to estimate meta-analytical non-parametric summary survival curves assuming random effects at study level.

Findings

Thirty-six studies (2180 patients) were included. The pooled median PFS (mPFS) was 24.7 months (95% CI, 18.8-30.6) and the PFS-rate at 12, 24, and 36 months was respectively 69.8% (95% CI, 63.1-77.3), 51.0% (95% CI, 43.4-59.8) and 34.0% (95% CI, 27.0-42.9). Univariable analysis showed that the mPFS was significantly longer for patients with melanoma (43.0 months), as compared with non-small cell lung cancer (NSCLC, 13.5 months) and renal cell carcinoma (RCC, 10.0 months; between-strata comparison test p-value < 0.001); for patients treated with anti-PD-(L)1 + anti-CTLA-4 as compared with anti-PD-(L)1 monotherapy (44.6 versus 19.9 months; p-value < 0.001), and in NSCLC when the reason of treatment discontinuation was elective as compared with toxicity onset (19.6 versus 4.8 months; p-value = 0.003). The multivariable analysis confirmed these differences.

Interpretation

The long-term outcome of patients who stopped ICIs for reasons other than PD was substantially affected by clinicopathological features: PFS after treatment discontinuation was longer in patients with melanoma, and/or treated with anti-PD-(L)1 + anti-CTLA-4, and shorter in patients with RCC or in those patients with NSCLC who stopped treatment for toxicity onset.

Funding

The Italian Ministry of University and Research (PRIN 2022Y7HHNW).

Non-Small Cell Lung Cancer Metastatic Without Oncogenic Alterations

This overview provides a thorough review of current treatment approaches for first-line management of nononcogenic addicted non-small cell lung cancer. We also address pertinent clinical decision-making queries encountered in everyday practice, such as the optimal treatment strategy for PD-L1-high patients, predictive factors for response to immune checkpoint inhibitors (ICI) both in terms of patient and cancer characteristics, the potential benefits of dual checkpoint blockade, and the unresolved issue of safe discontinuation strategies for long-term responders. Around one in five patients falls into this latter category while the majority develop either primary or acquired resistance to ICI-based first-line therapy, necessitating effective subsequent lines of treatment. Docetaxel, with or without combination of antiangiogenic agents, serves as the backbone of treatment, although evidence in the post-ICI setting is limited. Given that an inflamed tumor microenvironment (TME) is crucial for ICI responses, targeting the TME in cases of acquired resistance alongside continued ICI administration appears rational, although clinical trials so far have failed to confirm this hypothesis. Antibody-drug conjugates have emerged as a promising treatment modality, offering the potential for reduced toxicity and improved efficacy by targeting specific cancer antigens. Moreover, several chemotherapy-free approaches are currently under investigation for treatment-naïve patients, including alternative ICI and drugs targeting epitopes on both cancer and immune cells.

Clinical perspectives on serum tumor marker use in predicting prognosis and treatment response in advanced non-small cell lung cancer

The optimal positioning and usage of serum tumor markers (STMs) in advanced non-small cell lung cancer (NSCLC) care is still unclear. This review aimed to provide an overview of the potential use and value of STMs in routine advanced NSCLC care for the prediction of prognosis and treatment response. Radiological imaging and clinical symptoms have shown not to capture a patient's entire disease status in daily clinical practice. Since STM measurements allow for a rapid, minimally invasive, and safe evaluation of the patient's tumor status in real time, STMs can be used as companion decision-making support tools before start and during treatment. To overcome the limited sensitivity and specificity associated with the use of STMs, tests should only be applied in specific subgroups of patients and different test characteristics should be defined per clinical context in order to answer different clinical questions. The same approach can similarly be relevant when developing clinical applications for other (circulating) biomarkers. Future research should focus on the approaches described in this review to achieve STM test implementation in advanced NSCLC care.

The efficacy of immune checkpoint inhibitors following discontinuation for long-term response or toxicity in advanced or metastatic non-small-cell lung cancers: A retrospective study

Background and Aims

The treatment of metastatic non-small-cell lung cancer (NSCLC) has been revolutionized by the arrival of immune checkpoint inhibitors (ICI). For patients without immune related adverse events (irAEs), it is recommended to continue the treatment as long as it provides clinical benefit or until unacceptable toxicity appears. The aim of our study was to evaluate survival data among patients with advanced or metastatic NSCLC following ICI discontinuation for reasons of long-term response or toxicity (irAEs).

Methods

We included all patients with advanced or metastatic NSCLC treated with nivolumab and pembrolizumab at the Centre Jean Perrin, Clermont-Ferrand, France (January 1, 2016 to May 31, 2019). We focused on two groups in this study population: "Voluntary treatment discontinuation" (medical decision as a result of long-term response and patient decision) and "Treatment discontinuation due to toxicity" (irAEs). The primary endpoint was to evaluate the postdiscontinuation outcomes of these two groups: progression-free survival (PFS) and overall survival (OS), and rechallenge in the "voluntary discontinuation" group.

Results

The final analysis concerned 146 patients, including 10 (7%) in the "discontinuation due to toxicity" group, 11 (8%) in the "voluntary discontinuation" group, 100 (68%) who discontinued treatment as a result of progression and 25 (17%) whose treatment was still on-going. The median PFS in the "discontinuation due to toxicity" group was not reached, and in the "voluntary discontinuation" group (n = 11) was 37 months (p = 0.4), versus 2 months in the progression group (p < 0.001). The median OS in "discontinuation due to toxicity," and in the "voluntary discontinuation" groups was not reached (p = 0.5), versus 10 months in the progression group (p < 0.001).

Conclusion

Treatment discontinuation following long-term response to ICI treatment showed sustained response and long-term survival after discontinuation. The incidence of irAEs was associated with better long-term survival, even after ICI discontinuation.

What is the optimal duration, dose and frequency for anti-PD1 therapy of non-small cell lung cancer?

Over the past decade, immune checkpoint inhibitors (ICIs) have transformed the management of multiple malignancies including lung cancer. However, the optimal use of these agents in terms of duration, dose and administration frequency remains unknown. Focusing on anti-PD1 agents nivolumab and pembrolizumab in the context of non-small cell lung cancer, we argue that several lines of evidence suggest current administration regimens of these drugs may result in overtreatment with potentially important implications for cost, quality of life and toxicity. This review summarizes evidence for the scope to optimize anti-PD1 regimens, the limitations of existing data and potential approaches to solve these problems including with a novel multi-arm clinical trial design implemented in the recently opened REFINE-Lung study.

Discontinuation of anti‑programmed cell death protein 1 immune checkpoint inhibition after complete remission in head and neck squamous cell carcinoma: A case report and literature review

Programmed cell death protein 1 (PD-1) inhibition plays a central role in the current treatment of recurrent or metastatic head and neck squamous cell carcinoma (R/M-HNSCC). Some patients achieve a durable response, and even complete remission (CR) is possible, though it occurs rarely. In cases of durable CR, there are no guidelines regarding a possible discontinuation of immunotherapy. Since clinical experience on this issue is limited, the present study reported on a case of a durable CR following discontinuation of PD-1 inhibition in R/M-HNSCC and additionally presented an overview on the current literature. The present study reported on a case of CR of recurrent oropharyngeal cancer after four cycles of PD-1 monotherapy with Nivolumab. The therapy was discontinued after overall 46 cycles. Even after 3 more years of follow-up, there was no sign of tumor recurrence. Overall, according to reports from the literature, CR seems to be an indicator for durable disease control after therapy discontinuation. Since data on therapy termination is rare, decisions about when to stop successful immunotherapy in R/M-HNSCC have to be made individually for each patient.

Immune checkpoint inhibitors in non-small cell lung cancer - When should we dare to stop treatment?

Over the last years, the emergence of immune checkpoint inhibitors (ICI) has revolutionized the treatment of non-small cell lung cancer (NSCLC). Patients in a palliative setting with previously very poor prognosis may now show remarkable responses over years. Yet, ICI therapy is very cost-intensive and involves frequent contacts with healthcare resources. Some of the early trial protocols restricted ICI treatment duration to two years. Now follow-up data of these studies is available and reveal the possibility of a persistent response after two or more years without further treatment for patients having successfully completed two years of therapy. May we now dare to think (and speak) of cure in the palliative setting? Does it mean we can stop ICI therapy after an initial two-year treatment? In this review, we try to improve confidence in clinical decision-making for this patient group. To this end, trials with a restricted treatment duration of two years and other data considering potential ICI discontinuation in responding patients were evaluated. Up to 25% of patients successfully complete an initial two-year course of ICI. Within this group about 40-46% of patients are alive at five years without further treatment with five-year survival rates of up to 83%. Data on ICI rechallenge are scarce, yet it does not seem to provide the same level of efficacy as at first exposure. At present there are no established biomarkers to help with decision-making. Possible future (bio-)markers, such as PD-L1, mutations, circulating tumor DNA (ctDNA) or Positron emission tomography (PET) need to be evaluated further in a prospective setting. In conclusion, we propose that the concept of discontinuing ICI therapy in patients with tumor response has to be seriously taken into consideration as it may be of benefit to our patients and health care systems.

Immunotherapy in Urothelial Cancer: Stop When Achieving a Response, Restart upon Disease Progression

BACKGROUND

Since there is no clear consensus on optimal treatment duration of PD-(L)1 targeting checkpoint inhibitors in the setting of urothelial cancer (UC) patients, even patients with durable responses are often treated up to 2 years. It is questionable whether this is necessary and whether quality of life improves when treatment is discontinued earlier and restarted when necessary.

METHODS

We collected available data from locally advanced or metastatic UC patients within the Netherlands between September 2017 and December 2019 treated with first or second-line pembrolizumab, to evaluate treatment duration, reasons for discontinuation, subsequent treatments and survival outcomes.

RESULTS

Data were available from 74 patients: 85% (63/74) of patients had a treatment duration of 12 months or shorter, and in seven out of them, treatment was discontinued for another reason than progressive disease. Two patients (3%) had a treatment duration between 12 and 24 months, and eight patients (11%) completed 24 months of treatment. Survival at data cut-off (1 July 2020) with a median follow-up of 35 months was 100% in patients with partial or complete response (6/7 patients) and treatment duration ≤ 12 months, and 100% in patients treated for 24 months. In total, three patients were re-treated with pembrolizumab upon progressive disease during follow-up.

CONCLUSIONS

In patients who reach partial or complete response during treatment with a PD-(L)1 targeting checkpoint inhibitor, early discontinuation of treatment with pembrolizumab and restart if necessary seems to be reasonable with preserved favorable outcomes. This article should drive further efforts to optimize the treatment duration for patients who respond to treatment with pembrolizumab.

Treatment-free survival after discontinuation of immune checkpoint inhibitors in mNSCLC: a systematic review and meta-analysis

Background

Recent research has suggested that patients with metastatic non-small cell lung cancer (mNSCLC) can achieve ongoing response after discontinuation of immune checkpoint inhibitor (ICI), but the best time to discontinue and the factors influencing efficacy remain unknown.

Method

A systematic search was performed for prospective clinical trials in patients with mNSCLC treated with ICIs published up to July 10, 2022. Eligible studies reported treatment-free survival (TFS) after discontinuation of ICI in partial objective responders. We calculated objective response rate (ORR) and TFS using random-effects models with respective 95% confidence intervals (Cis), and performed subgroup analyses to discuss the specific associations between ORR and TFS and the associated influencing factors.

Results

Across the 26 cohorts (3833 patients) included, the weighted mean ORR for all patients was 29.30% (95% CI 24.28% to 34.57%), with ICI plus chemotherapy (48.83%, 95% CI 44.36% to 53.30%) significantly higher than monotherapy (23.40%, 95% CI 18.53% to 28.62%). 395 patients were all patients who were complete or partial responders in the study, 194 discontinued ICI treatment, and nearly 35.5% achieved a durable response. No significant differences in TFS were found between subgroups according to the ICI regimen classification. Four cohorts of patients who completed 35 courses of treatment showed high levels of pooled TFS at 6 (80.18%, 95% CI 53.03% to 97.87%) and 12 months (66.98%, 95% CI 46.90% to 84.47%). Three cohorts of patients discontinued ICI treatment due to treatment-related adverse events (TRAEs) with the TFS rates at 6 (76.98%, 95% CI 65.79% to 86.65%) and 12 months (64.79%, 95% CI 50.20% to 78.19%).

Conclusion

Patients with mNSCLC were able to achieve ongoing responses after discontinuation of ICI. In conclusion, the results of this meta-analysis indicate that different treatment regimens, different drugs or different treatment durations may have an impact on TFS.

Immune checkpoint activity regulates polycystic kidney disease progression

Innate and adaptive immune cells modulate the severity of autosomal dominant polycystic kidney disease (ADPKD), a common kidney disease with inadequate treatment options. ADPKD has parallels with cancer, in which immune checkpoint inhibitors have been shown to reactivate CD8+ T cells and slow tumor growth. We have previously shown that in PKD, CD8+ T cell loss worsens disease. This study used orthologous early-onset and adult-onset ADPKD models (Pkd1 p.R3277C) to evaluate the role of immune checkpoints in PKD. Flow cytometry of kidney cells showed increased levels of programmed cell death protein 1 (PD-1)/cytotoxic T lymphocyte associated protein 4 (CTLA-4) on T cells and programmed cell death ligand 1 (PD-L1)/CD80 on macrophages and epithelial cells in Pkd1RC/RC mice versus WT, paralleling disease severity. PD-L1/CD80 was also upregulated in ADPKD human cells and patient kidney tissue versus controls. Genetic PD-L1 loss or treatment with an anti-PD-1 antibody did not impact PKD severity in early-onset or adult-onset ADPKD models. However, treatment with anti-PD-1 plus anti-CTLA-4, blocking 2 immune checkpoints, improved PKD outcomes in adult-onset ADPKD mice; neither monotherapy altered PKD severity. Combination therapy resulted in increased kidney CD8+ T cell numbers/activation and decreased kidney regulatory T cell numbers correlative with PKD severity. Together, our data suggest that immune checkpoint activation is an important feature of and potential novel therapeutic target in ADPKD.

Assessing the Performance of a Novel Stool-Based Microbiome Test That Predicts Response to First Line Immune Checkpoint Inhibitors in Multiple Cancer Types

The intestinal microbiome is by now an undebatable key player in the clinical outcome of ICI therapies. However, no microbiome profiling method to aid therapy decision is yet validated. We conducted a multi-centric study in patients with stage III/IV melanoma, NSCLC, or RCC receiving ICI treatment. The stool microbiome profile of 63 patients was analyzed with BiomeOne^®, a microbiome-based algorithm that anticipates whether a patient will achieve clinical benefit with ICIs prior to therapy initiation. Classification of patient samples as Rs and NRs was achieved with a sensitivity of 81% and a specificity of 50% in this validation cohort. An ICI-favorable response was characterized by an intestinal microbiome rich in bacteria such as Oscillospira sp., Clostridia UCG-014, Lachnospiraceae UCG-010 sp., Prevotella copri, and a decrease in Sutterella sp., Lactobacillales, and Streptococcus sp. Patients who developed immune-related adverse events (irAEs) had an overall increased microbial diversity and richness, and a stool microbiome depleted in Agathobacter. When compared with the programmed death-ligand 1 (PD-L1) expression test in the subcohort of NSCLC patients (n = 38), BiomeOne^® exhibited a numerically higher sensitivity (78.6%) in identifying responders when compared with the PD-L1 test (67.9%). This study provides an evaluation of BiomeOne^®, the first microbiome-based test for prediction of ICI response, to achieve market authorization. Validation with further indications and expansion to other microbiome-based interventions will be essential to bring microbiome-based diagnostics into standard clinical practice.

Short-course treatment after complete response to pembrolizumab in metastatic urothelial bladder cancer: a case series

Background: The optimal duration of treatment for metastatic patients who achieve a complete response with immune checkpoint inhibitors is unknown. Methods: The outcome for six metastatic bladder cancer patients who received short course of pembrolizumab is reported. Results: A median number of seven cycles of pembrolizumab was given. After a median follow-up of 38 months, progressive disease was confirmed in three patients. All patients relapsed in lymph nodes and underwent pembrolizumab rechallenge: one achieved a complete response, another a partial response. Conclusion: Our case series paves the way for discontinuation of pembrolizumab in patients who achieve a complete response since three out of six patients remain free of disease after 3-year follow-up. Prospective studies are required to confirm our results.

Discontinuation of Immune Checkpoint Inhibitor due to irAEs in NSCLC Patients With EGFR Mutation

BACKGROUND/AIM

Immune checkpoint inhibitors (ICIs) have revolutionized advanced non-small cell lung cancer (NSCLC) treatment. Even patients with epidermal growth factor receptor (EGFR)-mutated NSCLC may choose an ICI after failure of EGFR-tyrosine kinase inhibitor treatment. ICI-mediated immune-related adverse events (irAEs) may prompt NSCLC patients to discontinue their treatment. This study evaluated the effect of ICI treatment discontinuation on the prognosis of patients with EGFR-mutated NSCLC.

PATIENTS AND METHODS

We performed a retrospective study that reviewed the clinical courses of patients with EGFR-mutated NSCLC treated with ICI therapy from February 2016 to February 2022. 'Discontinuation' was defined as failure to receive at least two treatment courses of ICI due to grade 2 irAEs (grade 1 in the lung) or higher in patients responding to ICI.

RESULTS

During the study period, 13 of 31 patients discontinued ICI therapy due to irAEs. Survival from the initiation of ICI therapy was significantly longer in patients who discontinued ICI therapy compared with those who did not discontinue. In uni- and multivariate analyses, 'discontinuation' was a favourable factor. There was no significant difference in survival from ICI initiation between patients with grade 3 or higher irAEs and those with grade 2 or lower irAEs.

CONCLUSION

In this patient cohort, discontinuation of ICI therapy due to irAEs did not adversely affect prognosis in patients with EGFR-mutant NSCLC. Our results suggest that when treating patients with EGFR-mutant NSCLC with ICIs, chest physicians should consider discontinuing ICI with close monitoring.

Challenges and knowledge gaps with immune checkpoint inhibitors monotherapy in the management of patients with non-small-cell lung cancer: a survey of oncologist perceptions

BACKGROUND

Immune checkpoint-inhibitors (ICIs) are changing outcomes in different cancer settings, notably for patients with non-small-cell lung cancer (NSCLC). There are, however, still important gaps of evidence for clinical practice when using these novel treatments. In this study, we assessed physicians' opinion and experience on challenges for clinical practice with ICIs monotherapy in NSCLC.

METHODS

A survey was conducted on experienced physicians treating patients with NSCLC with ICIs. Two rounds of pilot tests were carried out for validation among a group of experts. Topics under analysis were in relation to treatment of elderly populations, performance status, brain metastases, use of steroids or antibiotics, the effects of gut microbiome, autoimmune diseases, human immunodeficiency virus infection, solid organ transplants, use of anti-programmed cell death protein 1 versus anti-programmed death-ligand 1 drugs, atypical tumour responses, predictors of response, duration of treatment and a final open question on additional relevant challenges.

RESULTS

Two hundred and twenty-one answers were collected, including 106 (48%) valid answers from experts for final analysis (physicians who have treated at least 20 patients with NSCLC with ICIs). The vast majority agreed that the selected topics in this study are important challenges ahead and more evidence is needed. Moreover, predictors of response, treating brain metastasis, shorter duration of treatment, the effects of gut microbiome and concomitant use of steroids were voted the most important topics to be further addressed in prospective clinical research.

CONCLUSIONS

This survey contributed to understanding which are the main challenges for clinical practice with ICIs monotherapy in NSCLC. It can also contribute to guide further clinical research, considering the opinions and experience of those who regularly treat NSCLC patients with ICIs.

The lung, the niche, and the microbe: Exploring the lung microbiome in cancer and immunity

The lung is a complex and unique organ system whose biology is strongly influenced by environmental exposure, oxygen abundance, connection to extrapulmonary systems via a dense capillary network, and an array of immune cells that reside in the tissue at steady state. The lung also harbors a low biomass community of commensal microorganisms that are dynamic during both health and disease with the capacity to modulate regulatory immune responses during diseases such as cancer. Lung cancer is the third most common cancer worldwide with the highest mortality rate amongst cancers due to the difficulty of an early diagnosis. This review discusses the current body of work addressing the interactions between the lung microbiota and the immune system, and how these two components of the pulmonary system are linked to lung cancer development and outcomes. Bringing in lessons from broader studies examining the effects of the gut microbiota on cancer outcomes, we highlight many challenges and gaps in this nascent field.

Immune-checkpoint inhibitor use in patients with cancer and pre-existing autoimmune diseases

Immune-checkpoint inhibitors (ICIs) have dramatically changed the management of advanced cancers. Designed to enhance the antitumour immune response, they can also cause off-target immune-related adverse events (irAEs), which are sometimes severe. Although the efficacy of ICIs suggests that they could have wide-ranging benefits, clinical trials of the drugs have so far excluded patients with pre-existing autoimmune disease. However, evidence is accumulating with regard to the use of ICIs in this 'at-risk' population, with retrospective data suggesting that they have an acceptable safety profile, but that there is a risk of disease flare or other irAE occurrence. The management of immunosuppressive drugs at ICI initiation in patients with autoimmune disease (or later in instances of disease flare or irAE) remains a question of particular interest in clinical practice, in which there is always a search for the balance between protecting against autoimmunity and ensuring a good tumour response. Although temporary use of immunosuppressants seems safe, prolonged use or use at ICI initiation might hamper the antitumour immune response, prompting clinicians to use the minimal efficient immunosuppressive regimen. However, a new paradigm is emerging, in which inhibitors of TNF or IL-6 could have synergistic effects with ICIs on tumour response, while also preventing severe irAEs. If confirmed, this 'decoupling' effect on toxicity and efficacy could change therapeutic practice in this field. Knowledge of the current use of ICIs in patients with pre-existing autoimmune disease, particularly with regard to the use of immunosuppressive drugs and/or biologic DMARDs, can help to guide clinical practice.

What is the optimal duration of immune checkpoint inhibitors in malignant tumors?

Immunotherapy, represented by immune checkpoint inhibitors (ICIs), has made a revolutionary difference in the treatment of malignant tumors, and considerably extended patients' overall survival (OS). In the world medical profession, however, there still reaches no clear consensus on the optimal duration of ICIs therapy. As reported, immunotherapy response patterns, immune-related adverse events (irAEs) and tumor stages are all related to the diversity of ICIs duration in previous researches. Besides, there lacks clear clinical guidance on the intermittent or continuous use of ICIs. This review aims to discuss the optimal duration of ICIs, hoping to help guide clinical work based on the literature.

Dosing Regimens of Immune Checkpoint Inhibitors: Attempts at Lower Dose, Less Frequency, Shorter Course

Immune checkpoint inhibitors (ICIs) are a revolutionary breakthrough in the field of cancer by modulating patient's own immune system to exert anti-tumor effects. The clinical application of ICIs is still in its infancy, and their dosing regimens need to be continuously adjusted. Pharmacokinetic/pharmacodynamic studies showed a significant plateau in the exposure-response curve, with high receptor occupancy and plasma concentrations achieved at low dose levels. Coupled with concerns about drug toxicity and heavy economic costs, there has been an ongoing quest to reevaluate the current ICI dosing regimens while preserving maximum clinical efficacy. Many clinical data showed remarkable anticancer effects with ICIs at the doses far below the approved regimens, indicating the possibility of dose reduction. Our review attempts to summarize the clinical evidence for ICIs regimens with lower-dose, less-frequency, shorter-course, and provide clues for further ICIs regimen optimization.