Putative Biomarkers of Clinical Benefit With Pembrolizumab in Advanced Urothelial Cancer: Results from the KEYNOTE-045 and KEYNOTE-052 Landmark Trials.

PURPOSE: In an exploratory analysis, we investigated the association between programmed death ligand 1 (PD-L1), tumor mutational burden (TMB), T-cell-inflamed gene expression profile (TcellinfGEP), and stromal signature with outcomes of pembrolizumab in urothelial carcinoma (UC). PATIENTS AND METHODS: Patients with advanced UC received first-line pembrolizumab 200 mg every 3 weeks in the single-arm phase II KEYNOTE-052 trial (NCT02335424) and salvage pembrolizumab 200 mg every 3 weeks or chemotherapy (paclitaxel/docetaxel/vinflunine) in the randomized phase III KEYNOTE-045 trial (NCT02256436). The association of each biomarker (continuous variable) with objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) was evaluated using logistic regression (ORR) and Cox PH (PFS, OS), adjusted for ECOG PS; nominal P values were calculated without multiplicity adjustment (one-sided, pembrolizumab; two-sided, chemotherapy). Significance was prespecified at α = 0.05. RESULTS: In KEYNOTE-052, PD-L1, TMB, and TcellinfGEP were significantly associated with improved outcomes; stromal signature was significantly associated with worse outcomes. In KEYNOTE-045, although findings for TMB and TcellinfGEP with pembrolizumab were consistent with those of KEYNOTE-052, PD-L1 was not significantly associated with improved outcomes, nor was stromal signature associated with worse outcomes with pembrolizumab; chemotherapy was not associated with outcomes in a consistent manner for any of the biomarkers. Hazard ratio (HR) estimates at prespecified cutoffs showed an advantage for pembrolizumab versus chemotherapy regardless of PD-L1 or TMB, with a trend toward lower HRs in the combined positive score ≥10 and the TMB ≥175 mutation/exome subgroup. For TcellinfGEP, PFS and OS HRs were lower in the TcellinfGEP-nonlow subgroup regardless of treatment. CONCLUSIONS: Multiple biomarkers characterizing the tumor microenvironment may help predict response to pembrolizumab monotherapy in UC, and potential clinical utility of these biomarkers may be context-dependent.

Cost-effectiveness of Pembrolizumab versus Carboplatin-based Chemotherapy as First-line Treatment of PD-L1-positive Locally Advanced or Metastatic Urothelial Carcinoma Ineligible for Cisplatin-based Therapy in the United States.

INTRODUCTION: Pembrolizumab has been approved in the United States (US) for the first-line treatment of patients with advanced or metastatic urothelial carcinoma, who are ineligible for cisplatin-containing chemotherapy and with tumors expressing programmed death-ligand 1 (PD-L1) (Combined Positive Score ≥ 10), or ineligible for any platinum-containing chemotherapy regardless of PD-L1 status. Long-term KEYNOTE-052 data continue to demonstrate pembrolizumab's meaningful, durable, and well-tolerated antitumor activity. This study evaluates the cost-effectiveness of pembrolizumab versus carboplatin plus gemcitabine as first-line treatment for cisplatin-ineligible patients who have PD-L1-positive tumors from a US third-party healthcare payer's perspective. PATIENTS AND METHODS: A partitioned survival model containing 3 health states (progression-free, progressed, and death) was developed. A simulated treatment comparison and a network meta-analysis were conducted to estimate the comparative efficacy of pembrolizumab versus carboplatin-based chemotherapy. Overall survival, progression-free survival, time on treatment, adverse events, and utilities were modeled using the final analyses of the KEYNOTE-052 trial and 4 studies for carboplatin plus gemcitabine. Cost data were estimated using US standard sources and real-world data. Deterministic, probabilistic, and scenario analyses were conducted to assess the robustness of the results. RESULTS: Over 20 years, pembrolizumab resulted in a mean gain of 2.58 life-years, 2.01 quality-adjusted life-years, and additional costs of $158,561, leading to an incremental cost-effectiveness ratio of $78,925/quality-adjusted life-year compared with carboplatin plus gemcitabine. CONCLUSION: This study suggests that pembrolizumab is cost-effective compared with carboplatin plus gemcitabine as a first-line therapy for patients with advanced or metastatic urothelial carcinoma who are PD-L1-positive.

Long-Term Outcomes in KEYNOTE-052: Phase II Study Investigating First-Line Pembrolizumab in Cisplatin-Ineligible Patients With Locally Advanced or Metastatic Urothelial Cancer.

PURPOSE: The phase II single-arm KEYNOTE-052 study evaluated the efficacy and safety of first-line pembrolizumab for patients with locally advanced or metastatic cisplatin-ineligible urothelial carcinoma (UC). PATIENTS AND METHODS: Three hundred seventy patients received pembrolizumab 200 mg intravenously every 3 weeks for up to 24 months. Positive tumor programmed death ligand 1 (PD-L1) expression was defined as combined positive score (CPS) ≥ 10. Response was assessed by independent central review every 9 weeks per RECIST v1.1. The primary end point was objective response rate (ORR). RESULTS: At data cutoff (September 26, 2018), the minimum follow-up was 2 years since the last patient enrolled. ORR was 28.6% (95% CI, 24.1% to 33.5%); 33 patients (8.9%) and 73 patients (19.7%) achieved complete and partial response, respectively. The median duration of response was 30.1 months (95% CI, 18.1 months to not reached [NR]); responses lasted ≥ 12 and ≥ 24 months in 67% and 52% of patients, respectively. Forty patients with complete or partial response completed 2 years of study treatment, and 32 had ongoing response at completion. Median overall survival (OS) was 11.3 months (95% CI, 9.7 to 13.1 months), and 12- and 24-month OS rates were 46.9% and 31.2%, respectively. In patients with CPS ≥ 10, ORR was 47.3% (95% CI, 37.7% to 57.0%) and median OS was 18.5 months (95% CI, 12.2 to 28.5 months). In patients with lymph node-only disease, ORR was 49.0% (95% CI, 34.8% to 63.4%), and median OS was 27.0 months (12.4 months to NR). There were no new safety signals. CONCLUSION: First-line pembrolizumab confers meaningful and durable clinical response in cisplatin-ineligible patients with advanced UC and is associated with prolonged OS, particularly with PD-L1 CPS ≥ 10 and lymph node-only disease.

The cost effectiveness of pembrolizumab versus chemotherapy or atezolizumab as second-line therapy for advanced urothelial carcinoma in the United States.

Aims: Pembrolizumab demonstrated significantly prolonged overall survival (OS) vs. chemotherapy in the Phase III KEYNOTE-045 trial, and is approved in the US for the treatment of patients with locally advanced or metastatic urothelial carcinoma (mUC) who progressed after platinum-based chemotherapy. Using longer follow-up and individual patient-data from KEYNOTE-045, this study evaluates the cost-effectiveness of pembrolizumab vs. chemotherapy or atezolizumab from a US payer perspective.Materials and methods: A partitioned-survival model was developed over a 20-year time horizon. Progression-free survival (PFS) and OS for pembrolizumab and chemotherapy were extrapolated using a piecewise modelling approach, where patient-level data from KEYNOTE-045 were used for the initial period followed by parametric distributions. OS of atezolizumab was estimated by indirect treatment comparisons based on KEYNOTE-045 and IMvigor211. Different scenarios were explored in the absence of indirect comparisons on PFS and time-on-treatment (ToT) between pembrolizumab and atezolizumab. Drug acquisition/administration, disease management, adverse events, and terminal care costs were considered.Results: Compared with chemotherapy, pembrolizumab resulted in a mean gain of 1.33 life-years and 1.14 quality-adjusted life-years (QALYs) and an incremental cost of $106,299, yielding an incremental cost-effectiveness ratio of $93,481/QALY gained. Pembrolizumab dominated atezolizumab in extending patients' life by 0.89 years and 0.76 QALYs, while reducing costs by $26,458. Key drivers of cost-effectiveness included survival extrapolation, OS hazard ratio of pembrolizumab vs. atezolizumab, and time horizon. Pembrolizumab had a 66% and 100% probability of being cost-effective vs. chemotherapy and atezolizumab, respectively, at a $100,000 willingness-to-pay threshold.Limitations and conclusions: Uncertainties remain with extrapolated PFS and OS for pembrolizumab, OS indirect comparison, and ToT for atezolizumab. Despite these limitations, the model used robust methods to estimate key clinical endpoints with patient-level data from longer follow-up of KEYNOTE-045. Pembrolizumab dominates atezolizumab and is very likely cost-effective vs. chemotherapy in 2 L mUC at a $100,000 willingness-to-pay threshold.

Recent developments in the treatment of advanced bladder cancer.

Urothelial carcinoma of the bladder is a common malignancy which has historically been difficult to treat in its advanced stages. Clinically effective treatment options for locally advanced/inoperable or metastatic urothelial carcinoma (mUC) consisted of cisplatin-based chemotherapy regimens, with few other impactful therapeutic options. The past 2 years have seen a remarkable shift in the therapeutic landscape of mUC, with 5 novel immunotherapy agents receiving FDA approval for mUC, including first-line and second-line postplatinum settings. There are now many important clinical trials ongoing seeking to answer how best to use chemotherapy, immunotherapy, and targeted therapy agents in patients with mUC. Here we review the current standard of care for patients with mUC based on published data from the past 2 years, and look forward toward future research directions.

Nivolumab-induced autoimmune diabetes mellitus presenting as diabetic ketoacidosis in a patient with metastatic lung cancer.

BACKGROUND: Advances in cancer immunotherapy have generated encouraging results in multiple malignancies refractory to standard chemotherapies. As the use of immune checkpoint inhibitors (ICI) proliferates, the incidence of autoimmune side effects associated with these agents, termed immune related adverse events (irAE), is expected to increase. The frequency of significant irAE in ICI treated patients is about 10-20% and early recognition is critical to prevent serious morbidity and even mortality. New onset autoimmune diabetes mellitus (DM) associated with immune checkpoint inhibitor treatment is extremely rare, occurring in less than 1% of patients. Autoimmune DM often presents as diabetic ketoacidosis, a medical emergency requiring immediate treatment. We describe the first reported case of a patient with lung cancer who developed autoimmune diabetes after nivolumab treatment and was found to have three diabetes related (islet) autoantibodies present before ICI treatment and seroconversion of another after ICI treatment and onset of autoimmune DM. CASE PRESENTATION: A 34 year old African American woman with metastatic non-small cell lung cancer (NSCLC) was treated with nivolumab in the second line setting after disease progression following standard chemoradiation therapy. After receiving two doses of nivolumab, the patient developed abrupt onset of hyperglycemia and diabetic ketoacidosis. Autoimmune diabetes was diagnosed on the basis of undetectable C-peptide levels, seropositivity of three diabetes related (islet) autoantibodies and absolute insulin dependence. The patient eventually required use of continuous subcutaneous insulin infusion (insulin pump) due to erratic glycemic excursions and multiple readmissions for DKA. Human leucocyte antigen (HLA) genoyping revealed none of the high risk haplotypes associated with the development of type 1 diabetes. Interestingly, a frozen blood sample obtained prior to treatment with nivolumab tested positive for three of the four diabetes related (islet) autoantibodies despite no prior history of diabetes and no family history of diabetes. Notably, at the time of manuscript preparation, the patient is without evidence of NSCLC recurrence with no further treatment since the nivolumab therapy. CONCLUSION: New onset autoimmune diabetes mellitus associated with nivolumab has been described only in case reports and occurs at rates of < 1% in the large clinical trials which garnered FDA approval in the second line setting for NSCLC. As ICI use continues to expand across a wide variety of malignancies, clinicians must maintain a high index of suspicion for irAE, including autoimmune DM and other endocrinopathies. A multidisciplinary team and thorough education of the patient are recommended to optimize management of new onset adult autoimmune DM. Our patient may have been at greater risk for the development of ICI related autoimmune diabetes due to the presence of three diabetes related autoantibodies prior to therapy; however, about half of the reported cases of autoimmune DM after anti-PD-1 therapy occurred in patients with no detectable diabetes related autoantibodies. Further studies are needed to delineate genetic and immunologic biomarkers that may be useful in identifying patients at risk of developing ICI related autoimmune DM.