Lack of Association Between Radiographic Tumor Burden and Efficacy of Immune Checkpoint Inhibitors in Advanced Lung Cancer

Highly variable timing renders immunotherapy efficacy and toxicity impractical biomarkers of one another in clinical practice

Background

A useful clinical biomarker requires not only association but also a consistent temporal relationship. For instance, chemotherapy-induced neutropenia and epidermal growth-factor inhibitor-related acneiform rash both occur within weeks of treatment initiation, thereby providing information prior to efficacy assessment. Although immune checkpoint inhibitor (ICI)-associated immune-related adverse events (irAE) have been associated with therapeutic benefit, irAE may have delayed and highly variable onset. To determine whether ICI efficacy and irAE could serve as clinically useful biomarkers for predicting each other, we determined the temporal relationship between initial efficacy assessment and irAE onset in a diverse population treated with ICI.

Methods

Using two-sided Fisher exact and Cochran-Armitage tests, we determined the relative timing of initial efficacy assessment and irAE occurrence in a cohort of 155 ICI-treated patients (median age 68 years, 40% women).

Results

Initial efficacy assessment was performed a median of 50 days [interquartile range (IQR) 39-59 days] after ICI initiation; median time to any irAE was 77 days (IQR 28-145 days) after ICI initiation. Median time to first irAE was 42 days (IQR 20-88 days). Overall, 58% of any irAE and 47% of first irAE occurred after initial efficacy assessment. For clinically significant (grade ≥2) irAE, 60% of any and 53% of first occurred after initial efficacy assessment. The likelihood of any future irAE did not differ according to response (45% for complete or partial response vs. 47% for other cases; P=1). In landmark analyses controlling for clinical and toxicity follow-up, patients demonstrating greater tumor shrinkage at initial efficacy assessment were more likely to develop future grade ≥2 (P=0.05) and multi-organ (P=0.02) irAE.

Conclusions

In contrast to that seen with chemotherapy and molecularly targeted therapies, the temporal relationship between ICI efficacy and toxicity is complex and bidirectional. In practice, neither parameter can be routinely relied on as a clinical biomarker to predict the other.

Prognostic impact of radiological tumor burden in patients with metastatic urothelial carcinoma treated with pembrolizumab

PURPOSE

Radiological tumor burden has been reported to be prognostic in many malignancies in the immunotherapy era, yet whether it is prognostic in patients with metastatic urothelial carcinoma (mUC) treated with pembrolizumab remains uninvestigated. We sought to assess the predictive and prognostic value of radiological tumor burden in patients with mUC.

METHODS

We performed a retrospective analysis of 308 patients with mUC treated with pembrolizumab. Radiological tumor burden was represented by baseline tumor size (BTS) and baseline tumor number (BTN). Optimal cut-off value of BTS was determined as 50 mm using the Youden index (small BTS: n = 194, large BTS: n = 114). Overall (OS), cancer-specific (CSS), progression-free survival (PFS), and objective response rate (ORR) were compared. Non-linear associations between BTS and OS and CSS were evaluated using restricted cubic splines.

RESULTS

Patients with large BTS were less likely to have undergone the surgical resection of the primary tumor (P = 0.01), and more likely to have liver metastasis (P < 0.001) and more metastatic lesions (P < 0.001). On multivariable analyses controlling for the effects of confounders (resection of primary tumor, metastatic site, number of metastases and lactate dehydrogenase level), large BTS and high BTN were independently associated with worse OS (HR 1.52; P = 0.015, and HR 1.69; P = 0.018, respectively) and CSS (HR 1.59; P = 0.01, and HR 1.66; P = 0.031, respectively), but not PFS. Restricted cubic splines revealed BTS was correlated with OS and CSS in linear relationships. Additionally, large BTS was significantly predictive of lower ORR and complete response rate on univariable analyses (P = 0.041 and P = 0.032, respectively), but its association disappeared on multivariable analyses.

CONCLUSION

Radiological tumor burden has independent prognostic value with a linear relationship in pembrolizumab-treated patients with mUC and might help drive the earlier introduction of second-line pembrolizumab and/or switching to subsequent therapies.

Nivolumab or Atezolizumab in the Second-Line Treatment of Advanced Non-Small Cell Lung Cancer? A Prognostic Index Based on Data from Daily Practice

BACKGROUND

The efficacy of nivolumab and atezolizumab in advanced pre-treated NSCLC was documented in prospective trials. We aim to confirm the benefits and indicate predictive factors for immunotherapy in daily practice.

METHODS

This study was a retrospective analysis. The median PFS and OS were estimated using the Kaplan-Meier method. The log-rank test was used for comparisons. Multivariate analyses were performed using the Cox regression method.

RESULTS

A total of 260 patients (ECOG 0-1) with advanced NSCLC (CS III-IV) were eligible to receive nivolumab or atezolizumab as second-line treatment. Median PFS and OS were three months (95% confidence interval [CI] 2.57-3.42) and 10 months (95% CI 8.03-11.96), respectively, for the overall population. The median OS for the atezolizumab arm was eight months (95% CI 5.89-10.1), while for the nivolumab group, it was 14 months (95% CI 10.02-17.97) (p = 0.018). The sum of all measurable changes >100.5 mm (p = 0.007; HR = 1.003, 95% CI 1.001-1.005), PLT > 281.5 G/l (p < 0.001; HR = 1.003, 95% CI 1.001-1.003) and bone metastases (p < 0.004; HR = 1.58, 95% CI 1.04-2.38) were independent negative prognostic factors for OS in multivariate analysis. Based on preliminary analyses, a prognostic index was constructed to obtain three prognostic groups. Median OS in the subgroups was 16 months (95% CI 13.3-18.7), seven months (95% CI 4.83-9.17) and four months (95% CI 2.88-5.13), respectively (p < 0.001).

CONCLUSIONS

Nivolumab and atezolizumab provided clinical benefit in real life. Clinical and laboratory factors may help to identify subgroups likely to benefit. The use of prognostic indices may be valuable in clinical practice.

Esophageal stenosis as an independent factor of poor prognosis in patients with ESCC treated with definitive chemoradiotherapy

Aim: To evaluate the clinical outcome and elucidate the prognostic factors in patients with esophageal squamous cell carcinoma (ESCC) treated with definitive chemoradiotherapy (CRT). Patients: Data for patients newly diagnosed with ESCC receiving definitive CRT at our institution between 2012 and 2018 were retrospectively reviewed. Results: A total of 201 patients were included. Severe stenosis after radiotherapy was an independent factor relevant to prognosis. Maximal esophageal wall thickness, short-term responses, severe stenosis at diagnosis and a high neutrophil-to-lymphocyte ratio were independent risk factors for the occurrence of severe stenosis after radiotherapy. Conclusion: Severe stenosis after radiotherapy is a useful predictive indicator in patients with ESCC receiving definitive CRT. Further studies are needed to verify these findings.

The efficacy of immune checkpoint inhibitors in thoracic malignancies

The advent of immune checkpoint inhibitors (ICIs) has rapidly transformed the treatment paradigm for multiple cancer types, including thoracic malignancies. In advanced non-small cell lung cancer (NSCLC), ICIs have shifted treatment paradigm and improved overall survival reaching almost one-third of patients alive at 5 years. ICIs therapies have also modified the therapeutic strategy in first-line setting in metastatic small-cell lung cancer (SCLC) patients as well as in malignant pleural mesothelioma (MPM) improving the overall survival compared with standard treatment. This phenomenon is of huge relevance as both SCLC and MPM were considered orphan diseases without any significant improvement in the therapeutic strategy in the first-line setting during the last 15 years. In this review, we aim to review the efficacy of ICI in thoracic malignancies either in monotherapy or in combination, according to predictive biomarkers, and to the US Food and Drug Administration and the European Medicines Agency approvals of treatment strategies. We address the efficacy of these agents, especially in NSCLC according to PD-L1 expression and histologic subtype.

Tumour burden and efficacy of immune-checkpoint inhibitors

Accumulating evidence suggests that a high tumour burden has a negative effect on anticancer immunity. The concept of tumour burden, simply defined as the total amount of cancer in the body, in contrast to molecular tumour burden, is often poorly understood by the wider medical community; nonetheless, a possible role exists in defining the optimal treatment strategy for many patients. Historically, tumour burden has been assessed using imaging. In particular, CT scans have been used to evaluate both the number and size of metastases as well as the number of organs involved. These methods are now often complemented by metabolic tumour burden, measured using the more recently developed 2-deoxy-2-[¹⁸F]-fluoro-D-glucose (FDG)-PET/CT. Serum-based biomarkers, such as lactate dehydrogenase, can also reflect tumour burden and are often also correlated with a poor response to immune-checkpoint inhibitors. Other circulating markers (such as circulating free tumour DNA and/or circulating tumour cells) are also attracting research interest as surrogate markers of tumour burden. In this Review, we summarize evidence supporting the utility of tumour burden as a biomarker to guide the use of immune-checkpoint inhibitors. We also describe data and provide perspective on the various tools used for tumour burden assessment, with a particular emphasis on future therapeutic strategies that might address the issue of inferior outcomes among patients with cancer with a high tumour burden.

CEA and CYFRA 21-1 as prognostic biomarker and as a tool for treatment monitoring in advanced NSCLC treated with immune checkpoint inhibitors

Aims:

To assess prognostic value of pre-therapy carcinoembryonic antigen (CEA) and cytokeratin-19 fragments (CYFRA 21-1) blood levels in non-small cell lung cancer (NSCLC) patients treated with immune-checkpoint inhibitors (ICIs) and their early change as predictor of benefit.

Materials and methods:

This is a retrospective cohort study including patients with stage IIIB–IV NSCLC who received anti PD-1/PD-L1 in first or advanced lines of therapy in two institutions. A control cohort of patients treated only with chemotherapy has been enrolled as well.

Results:

A total of 133 patients treated with nivolumab or atezolizumab were included in the test set, 74 treated with pembrolizumab first line in the validation set and 89 in the chemotherapy only cohort. CYFRA 21-1 >8 ng/mL was correlated with overall survival (OS) in the test set, validation set and in univariate and multivariate analysis (pooled cohort hazard ratio (HR) 1.90, 95% confidence interval (CI) 1.24–2.93, p 0.003). Early 20% reduction after the third cycle was correlated with OS for CEA (HR 0.12; 95% CI 0.04–0.33; p < 0.001), and for CYFRA 21-1 (HR 0.19; 95% CI 0.07–0.55; p 0.002)

Conclusions:

CYFRA 21-1 pre-therapy assessment provides clinicians with relevant prognostic information about patients treated with ICI. CEA and CYFRA 21-1 repeated measures could be useful as an early marker of benefit.