Immune-related adverse events requiring hospitalization in patients with lung cancer: implications and insights.

BACKGROUND: Immune checkpoint inhibitors (ICI) are associated with a distinct spectrum of toxicities. Data on irAE hospitalization rates and clinical course of patients with thoracic malignancies are lacking. METHODS: Patients with advanced thoracic malignancy treated with ICI (2/2016 to 6/2021) were retrospectively identified. Demographic and clinical data of confirmed irAE hospitalizations were extracted from the medical record and a descriptive analysis was performed. RESULTS: From February 2016 to June 2021, 1312 patients with thoracic malignancy received ICI (monotherapy, combination with 2nd ICI or other agents) with 102 patients (7.7%) hospitalized for irAEs. Treatment intent was first-line therapy in most patients (N = 50, 49%) with 9% (n = 9) receiving adjuvant ICI (N = 9). Sixty patients (59%) received ICI alone, 32% (N = 33) chemo plus immunotherapy, and 7% (N = 7) dual ICI. The median age on admission was 68 years. The median time between ICI initiation and admission was 64 days (1-935 days). Pneumonitis (32.3%; 33/102) was the most frequent indication for admission followed by gastroenterocolitis (19.6%; 20/102), hepatitis (12.7%; 13/102), myo/pericarditis (9.8%; 10/102), and endocrinopathies (9.8%; 10/102). Multi-organ toxicity occurred in 36% (N = 37) of patients. Overall, 85.2% (87/102) of patients received systemic corticosteroids and 17.6% (18/102) required additional lines of immunosuppression. The median length of hospitalization stay was 7 days (2-28 days) with a 25.5% (n = 26) readmission rate within 60 days and an 11.8% (n = 12) in house mortality rate. CONCLUSIONS: Severe irAE requiring inpatient admission, although infrequent, results in considerable morbidity, mortality, and healthcare utilization. Pneumonitis was the most common irAE requiring inpatient management in our patient population with a significant risk of mortality despite the use of guideline-directed systemic immunosuppression. This study highlights the continued need for collaborative efforts amongst medical specialties for improving the diagnostic and therapeutic management of patients with irAEs.

Toxicities from BRAF and MEK Inhibitors: Strategies to Maximize Therapeutic Success.

PURPOSE OF REVIEW: This report highlights several of the recent therapeutic advancements in the treatment of BRAF-mutant tumors, discusses the most common adverse events observed with BRAF-targeted agents, and suggests strategies to manage and mitigate treatment-related toxicities. RECENT FINDINGS: BRAF and MEK inhibitors represent a significant advancement in the treatment of BRAF-mutated malignancies with data across tumor types demonstrating the anti-tumor efficacy of dual MAPK inhibition. Although these agents have a reasonable toxicity profile, variable side effects across organ systems can develop. The discovery of activating BRAF mutations and subsequent development of BRAF and MEK inhibitors has transformed the treatment algorithms of BRAF-mutant malignancies. With increased application of these targeted regimens, identification and prompt management of their unique adverse events are crucial.

The case for adjuvant BRAF-targeted therapy versus adjuvant anti-PD-1 therapy for patients with resected, high-risk melanoma.

The development of highly effective BRAF-targeted therapy and immune checkpoint inhibition for patients with advanced metastatic melanoma has transformed the treatment of this disease. More recently, these advances have moved into the resected, high-risk stage II and III settings. For patients with resected, BRAF-mutant stage III melanoma, there are no head-to-head data to support the use of BRAF-targeted therapy (specifically the combination of dabrafenib and trametinib) with either single-agent nivolumab or pembrolizumab. Because the relapse-free and distant metastasis-free survivals are similar in a cross-trial comparison, it is not clear what the best option for these patients is. In this piece, the authors argue on behalf of and against both approaches. PLAIN LANGUAGE SUMMARY: Two types of therapy exist for patients diagnosed with melanoma who have completed surgery and remain at high risk for tumor recurrence: (1) drugs that target the BRAF mutation (found in ∼50% of patients) and (2) immunotherapy. There are no data showing that either approach is better than the other, so the choice of which therapy is best for an individual patient can be challenging. In this article, we make arguments for and against each option.

Dose-escalation trial of combination dabrafenib, trametinib, and AT13387 in patients with BRAF-mutant solid tumors.

BACKGROUND: Combination BRAF and MEK inhibitor therapy is an active regimen in patients who have BRAF V600E-mutated tumors; however, the clinical efficacy of this therapy is limited by resistance. Preclinically, the addition of heat shock protein 90 (HSP90) inhibition improves the efficacy of BRAF inhibitor therapy in both BRAF inhibitor-sensitive and BRAF inhibitor-resistant mutant cell lines. METHODS: Cancer Therapy Evaluation Program study 9557 (ClinicalTrials.gov identifier NCT02097225) is a phase 1 study that was designed to assess the safety and efficacy of the small-molecule HSP90 inhibitor, AT13387, in combination with dabrafenib and trametinib in BRAF V600E/K-mutant solid tumors. Correlative analyses evaluated the expression of HSP90 client proteins and chaperones. RESULTS: Twenty-two patients with metastatic, BRAF V600E-mutant solid tumors were enrolled using a 3 + 3 design at four dose levels, and 21 patients were evaluable for efficacy assessment. The most common tumor type was colorectal cancer (N = 12). Dose-limiting toxicities occurred in one patient at dose level 3 and in one patient at dose level 4; specifically, myelosuppression and fatigue, respectively. The maximum tolerated dose was oral dabafenib 150 mg twice daily, oral trametinib 2 mg once daily, and intravenous AT13387 260 mg/m2 on days 1, 8, and 15. The best response was a partial response in two patients and stable disease in eight patients, with an overall response rate of 9.5% (90% exact confidence interval [CI], 2%-27%), a disease control rate of 47.6% (90% CI, 29%-67%), and a median overall survival of 5.1 months (90% CI, 3.4-7.6 months). There were no consistent proteomic changes associated with response or resistance, although responders did have reductions in BRAF expression, and epidermal growth factor receptor downregulation using HSP90 inhibition was observed in one patient who had colorectal cancer. CONCLUSIONS: HSP90 inhibition combined with BRAF/MEK inhibition was safe and produced evidence of modest disease control in a heavily pretreated population. Additional translational work may identify tumor types and resistance mechanisms that are most sensitive to this approach.

The Effect of Advances in Lung-Cancer Treatment on Population Mortality.

BACKGROUND: Lung cancer is made up of distinct subtypes, including non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC). Although overall mortality from lung cancer has been declining in the United States, little is known about mortality trends according to cancer subtype at the population level because death certificates do not record subtype information. METHODS: Using data from Surveillance, Epidemiology, and End Results (SEER) areas, we assessed lung-cancer mortality and linked deaths from lung cancer to incident cases in SEER cancer registries. This allowed us to evaluate population-level mortality trends attributed to specific subtypes (incidence-based mortality). We also evaluated lung-cancer incidence and survival according to cancer subtype, sex, and calendar year. Joinpoint software was used to assess changes in incidence and trends in incidence-based mortality. RESULTS: Mortality from NSCLC decreased even faster than the incidence of this subtype, and this decrease was associated with a substantial improvement in survival over time that corresponded to the timing of approval of targeted therapy. Among men, incidence-based mortality from NSCLC decreased 6.3% annually from 2013 through 2016, whereas the incidence decreased 3.1% annually from 2008 through 2016. Corresponding lung cancer-specific survival improved from 26% among men with NSCLC that was diagnosed in 2001 to 35% among those in whom it was diagnosed in 2014. This improvement in survival was found across all races and ethnic groups. Similar patterns were found among women with NSCLC. In contrast, mortality from SCLC declined almost entirely as a result of declining incidence, with no improvement in survival. This result correlates with limited treatment advances for SCLC in the time frame we examined. CONCLUSIONS: Population-level mortality from NSCLC in the United States fell sharply from 2013 to 2016, and survival after diagnosis improved substantially. Our analysis suggests that a reduction in incidence along with treatment advances - particularly approvals for and use of targeted therapies - is likely to explain the reduction in mortality observed during this period.

Lymphocyte-activation gene 3 in non-small-cell lung carcinomas: correlations with clinicopathologic features and prognostic significance.

Lymphocyte-activation gene 3 (LAG-3) modulates the tumor microenvironment through immunosuppressive effects. Its associations with clinicopathologic parameters and prognostic significance in non-small-cell lung carcinomas remain unclear. We examined LAG-3 expression in 368 resected non-small-cell lung carcinomas (including 218 adenocarcinomas and 150 squamous-cell carcinomas) using tissue microarrays, with normalization to CD8+ T-cell count (LAG-3/CD8 index), and correlated LAG-3, CD8, and LAG-3/CD8 index with clinicopathologic features, molecular status, and survival. LAG-3 expression in the immune cells (ranged 0.35-540.1 cells/mm²) was identified in 92% of non-small-cell lung carcinomas. In adenocarcinomas and squamous-cell carcinomas, LAG-3 expression correlated with CD8+ T-cell count and PD-L1 expression. In adenocarcinomas, high LAG-3 expression (defined as >median) was additionally associated with smoking history, high T stage, aggressive pathologic features (solid-predominant histologic pattern, lymphovascular invasion, and nodal metastasis), and lack of EGFR mutation. In the entire resected tumor cohort and in adenocarcinomas, high LAG-3 and LAG-3/CD8 index were each associated with worse overall survival. In squamous-cell carcinomas, high CD8 was associated with better overall survival. In an exploratory analysis of pretreatment samples from advanced non-small-cell lung carcinoma patients treated with pembrolizumab, high CD8 was predictive of improved overall and progression-free survival, while high LAG-3, but not high LAG-3/CD8 index, was associated with improved progression-free survival. In conclusion, the clinicopathologic correlations and prognostic impact of LAG-3 in non-small-cell lung carcinoma are histotype-dependent, highlighting differences in the immune microenvironment between adenocarcinomas and squamous-cell carcinomas. The predictive impact of LAG-3 warrants further investigation.

Temporal Trends in Inpatient Oncology Census Before and During the COVID-19 Pandemic and Rates of Nosocomial COVID-19 Among Patients with Cancer at a Large Academic Center.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted health care systems. However, to date, the trend of hospitalizations in the oncology patient population has not been studied, and the frequency of nosocomial spread to patients with cancer is not well understood. The objectives of this study were to evaluate the impact of COVID-19 on inpatient oncology census and determine the nosocomial rate of COVID-19 in patients with cancer admitted at a large academic center. MATERIALS AND METHODS: Medical records of patients with cancer diagnosed with COVID-19 and admitted were reviewed to evaluate the temporal trends in inpatient oncology census during pre-COVID-19 (January 2019 to February 2020), COVID-19 (March to May 2020), and post-COVID-19 surge (June to August 2020) in the region. In addition, nosocomial infection rates of SARS-CoV-2 were reviewed. RESULTS: Overall, the daily inpatient census was steady in 2019 (median, 103; range, 92-118) and until February 2020 (median, 112; range, 102-114). However, there was a major decline from March to May 2020 (median, 68; range, 57-104), with 45.4% lower admissions during April 2020. As the COVID-19 surge eased, the daily inpatient census over time returned to the pre-COVID-19 baseline (median, 103; range, 99-111). One patient (1/231, 0.004%) tested positive for SARS-CoV-2 13 days after hospitalization, and it is unclear if it was nosocomial or community spread. CONCLUSION: In this study, inpatient oncology admissions decreased substantially during the COVID-19 surge but over time returned to the pre-COVID-19 baseline. With aggressive infection control measures, the rates of nosocomial transmission were exceedingly low and should provide reassurance to those seeking medical care, including inpatient admissions when medically necessary. IMPLICATIONS FOR PRACTICE: The COVID-19 pandemic has had a major impact on the health care system, and cancer patients are a vulnerable population. This study observes a significant decline in the daily inpatient oncology census from March to May 2020 compared with the same time frame in the previous year and examines the potential reasons for this decline. In addition, nosocomial rates of COVID-19 were investigated, and rates were found to be very low. These findings suggest that aggressive infection control measures can mitigate the nosocomial infection risk among cancer patients and the inpatient setting is a safe environment, providing reassurance.

Temporal Trends and Outcomes Among Patients Admitted for Immune-Related Adverse Events: A Single-Center Retrospective Cohort Study from 2011 to 2018.

BACKGROUND: The aim of this study was to characterize severe immune-related adverse events (irAEs) seen among hospitalized patients and to examine risk factors for irAE admissions and clinically relevant outcomes, including length of stay, immune checkpoint inhibitor (ICI) discontinuation, readmission, and death. METHODS: Patients who received ICI therapy (ipilimumab, pembrolizumab, nivolumab, atezolizumab, durvalumab, avelumab, or any ICI combination) at Massachusetts General Hospital (MGH) and were hospitalized at MGH following ICI initiation between January 1, 2011, and October 24, 2018, were identified using pharmacy and hospital admission databases. Medical records of all irAE admissions were reviewed, and specialist review with defined criteria was performed. Demographic data, relevant clinical history (malignancy type and most recent ICI regimen), and key admission characteristics, including dates of admission and discharge, immunosuppressive management, ICI discontinuation, readmission, and death, were collected. RESULTS: In total, 450 admissions were classified as irAE admissions and represent the study's cohort. Alongside the increasing use of ICIs at our institution, the number of patients admitted to MGH for irAEs has gradually increased every year from 9 in 2011 to 92 in 2018. The hospitalization rate per ICI recipient has declined over that same time period (25.0% in 2011 to 8.5% in 2018). The most common toxicities leading to hospitalization in our cohort were gastrointestinal (30.7%; n = 138), pulmonary (15.8%; n = 71), hepatic (14.2%; n = 64), endocrine (12.2%; n = 55), neurologic (8.4%; n = 38), cardiac (6.7%; n = 30), and dermatologic (4.4%; n = 20). Multivariable logistic regression revealed statistically significant increases in irAE admission risk for CTLA-4 monotherapy recipients (odds ratio [OR], 2.02; p < .001) and CTLA-4 plus PD-1 combination therapy recipients (OR, 1.88; p < .001), relative to PD-1/PD-L1 monotherapy recipients, and patients with multiple toxicity had a 5-fold increase in inpatient mortality. CONCLUSION: This study illustrates that cancer centers must be prepared to manage a wide variety of irAE types and that CTLA-4 and combination ICI regimens are more likely to cause irAE admissions, and earlier. In addition, admissions for patients with multi-organ involvement is common and those patients are at highest risk of inpatient mortality. IMPLICATIONS FOR PRACTICE: The number of patients admitted to Massachusetts General Hospital for immune-related adverse events (irAEs) has gradually increased every year and the most common admissions are for gastrointestinal (30.7%), pulmonary (15/8%), and hepatic (14.2%) events. Readmission rates are high (29% at 30 days, 49% at 180 days) and 64.2% have to permanently discontinue immune checkpoint inhibitor therapy. Importantly, multiple concurrent toxicities were seen in 21.6% (97/450) of irAE admissions and these patients have a fivefold increased risk of inpatient death.

Severe Neurological Toxicity of Immune Checkpoint Inhibitors: Growing Spectrum.

Expanding use of immune-checkpoint inhibitors (ICIs) underscores the importance of accurate diagnosis and timely management of neurological immune-related adverse events (irAE-N). We evaluate the real-world frequency, phenotypes, co-occurring immune-related adverse events (irAEs), and long-term outcomes of severe, grade III to V irAE-N at a tertiary care center over 6 years. We analyze how our experience supports published literature and professional society guidelines. We also discuss these data with regard to common clinical scenarios, such as combination therapy, ICI rechallenge and risk of relapse of irAE-N, and corticosteroid taper, which are not specifically addressed by current guidelines and/or have limited data. Recommendations for management and future irAE-N reporting are outlined. ANN NEUROL 2020;87:659-669.

Multi-detector computed tomography (MDCT)-based severity score as a prognostic tool in patients with suspected immune checkpoint inhibitor therapy associated colitis.

OBJECTIVE: This study aimed to assess MDCT as a diagnostic and prognostic tool in patients with suspected immune checkpoint inhibitor (ICI)-related colitis. MATERIALS AND METHODS: This retrospective cohort study included patients receiving ICIs at three hospitals between 2015 and 2019 who underwent both abdominopelvic MDCT and endoscopic biopsy to workup suspected ICI-related colitis. Two radiologists independently reviewed MDCT images for signs of colitis based on pre-defined features. Diagnostic performance of MDCT was calculated and categorical variables between treatment subgroups were compared. Logistic regression was used to develop proposed MDCT criteria for diagnosis and MDCT severity score based on a combination of MDCT features of colitis to predict the patient outcomes in ICI-related colitis. RESULTS: A total of 118 MDCT scans from 108 patients were evaluated for suspected colitis, with 72 confirmed ICI-related colitis cases. Sensitivity, specificity, PPV, and NPV of MDCT for diagnosis of ICI-related colitis was 81% (58/72), 52 % (24/46), 73% (58/80), and 63% (24/38), respectively. Small bowel involvement was visualized in 25% of cases with ICI-related colitis (18/72). In melanoma patients presenting with diarrhea grade ≥ 2 (n = 40), MDCT had the best diagnostic performance for ICI-related colitis (specificity = 80% [8/10], PPV = 92% [23/25]). MDCT severity scores predicted intravenous steroid use (OR 10.3, p = 0.004), length of stay > 7 days (OR 9.0, p < 0.001), and endoscopic mucosal ulceration (OR 4.7, p = 0.02). CONCLUSION: MDCT is a useful diagnostic and prognostic tool for evaluating patients with immune checkpoint inhibitor-related colitis. An MDCT-based severity score enables assessment of disease severity and predicts outcome. KEY POINTS: • MDCT is useful for the diagnosis of colitis in patients receiving immune checkpoint inhibitor (ICI) therapy, and an MDCT-based severity score allows for prognostication of patient outcomes. • MDCT yielded moderate sensitivity (81%) for diagnosis of ICI-related colitis but limited specificity (52%). However, in symptomatic melanoma patients (grade 2-4 diarrhea) with a high pretest probability, MDCT proved useful for diagnosis with a high PPV (92%). • For ICI-related colitis, our proposed MDCT severity score has prognostic value in predicting intravenous steroid use, prolonged length of stay during inpatient admission (> 7 days), and endoscopic mucosal ulceration.

Thermal Ablation, Embolization, and Selective Internal Radiation Therapy Combined with Checkpoint Inhibitor Cancer Immunotherapy: Safety Analysis.

PURPOSE: To describe interventional oncology therapies combined with immune checkpoint inhibitor (ICI) therapy targeting the programmed death 1 pathway in patients with different neoplasms. MATERIALS AND METHODS: This was a retrospective cohort study of patients who underwent tumor-directed thermal ablation, embolization, or selective internal radiation therapy (SIRT) between January 1, 2011, and May 1, 2019, and received anti-programmed death 1/PD-L1 agents ≤ 90 days before or ≤ 30 days after the interventional procedure. Immune-related adverse events (irAEs) and procedural complications ≤ 90 days after the procedure were graded according to the Common Terminology Criteria for Adverse Events version 5.0. The study included 65 eligible patients (49% female; age 63 years ± 11.1). The most common tumors were metastatic melanoma (n = 28) and non-small cell lung cancer (NSCLC) (n = 12). Patients underwent 78 procedures (12 patients underwent > 1 procedure), most frequently SIRT (35.9%) and cryoablation (28.2%). The most common target organs were liver (46.2%), bone (24.4%), and lung (9.0%). Most patients received ICI monotherapy with pembrolizumab (n = 30), nivolumab (n = 22), and atezolizumab (n = 6); 7 patients received ipilimumab and nivolumab. RESULTS: Seven (10.8%) patients experienced an irAE (71.4% grade 1-2), mostly affecting the skin. Median time to irAE was 33 days (interquartile range, 19-38 days). Five irAEs occurred in patients with melanoma, and no irAEs occurred in patients with NSCLC. Management required corticosteroids (n = 3) and immunotherapy discontinuation (n = 1); all irAEs resolved to grade ≤ 1. There were 4 intraprocedural and 32 postprocedural complications (77.8% grade < 3). No grade 5 irAEs and/or procedural complications occurred. CONCLUSIONS: No unmanageable or unanticipated toxicities occurred within 90 days after interventional oncology therapies combined with ICIs.

Immune-Related Adverse Events (irAEs): Diagnosis, Management, and Clinical Pearls.

PURPOSE OF REVIEW: While immune checkpoint inhibitor (ICI) therapy has improved melanoma patient outcomes, it has also resulted in the rise of unique immune-related adverse events (irAEs). Here, we review and synthesize irAE management recommendations from several oncological societies into a streamlined format to aid in diagnosis and management. We also include clinical pearls highlighting several recent research studies in this field. RECENT FINDINGS: Knowledge of immunotherapy toxicity has continually evolved, and several major oncologic societies have recently released new or updated guidelines. Keeping up with the evolving field of immunotherapy and related toxicities is crucial, because ICI use, in combination with other agents, will only continue to increase and likely result in new and different patterns of irAEs. Providing clear and concise references for clinicians will help ensure proper irAE evaluation and management going forward. We present one such reference here, covering management of common and/or serious irAEs.

Tolerance and efficacy of BRAF plus MEK inhibition in patients with melanoma who previously have received programmed cell death protein 1-based therapy.

BACKGROUND: Combined BRAF and MEK inhibition (BRAF-MEK) is a standard therapy for patients with BRAF V600-mutant melanoma, but to the authors' knowledge, the tolerance, adverse event (AE) profile, and efficacy have not been well defined in the post-programmed cell death protein 1 (PD-1) setting. METHODS: Patients with BRAF V600-mutant melanoma who received combined BRAF-MEK after prior PD-1-based therapy were assembled from 4 tertiary care centers in the United States and Australia. Dose modification was defined as a treatment break, dose reduction, or intermittent dosing. Rates of hospitalization and discontinuation due to AEs were collected, and overall survival (OS) was calculated using Kaplan-Meier methods from the time of the initiation of BRAF-MEK therapy. RESULTS: A total of 78 patients were identified as having received a BRAF-MEK regimen at a median of 34 days after the last dose of PD-1-based therapy. The majority of patients (86%) received the combination of dabrafenib and trametinib. Approximately 80% of patients had American Joint Committee on Cancer M1c or M1d disease. Sixty-five regimens (83%) had ≥1 dose modification. The median time to the first dose modification was 14 days; 86% occurred within 90 days and 71% involved pyrexia. Dose modifications were more common in patients receiving BRAF-MEK <90 days after the last dose of PD-1 and who were not receiving steroids. Of the dose modifications, 25 (31%) led to an AE-related hospitalization. Among 55 BRAF-naive patients, the median time receiving BRAF-MEK therapy was 5.8 months and the median OS was 15.6 months. CONCLUSIONS: The majority of patients receiving BRAF-MEK inhibition after PD-1 therapy require dose interruptions, and a significant minority require hospitalization for AEs. In this higher risk population, the median time receiving therapy and OS may be inferior to those presented in published phase 3 trials.

Differential expression of PD-L1 and IDO1 in association with the immune microenvironment in resected lung adenocarcinomas.

Like programmed cell death ligand 1 (PD-L1), indoleamine 2,3-dioxygenase 1 (IDO1) is known to exert immunosuppressive effects and be variably expressed in human lung cancer. However, IDO1 expression has not been well studied in lung adenocarcinoma. PD-L1 and IDO1 expression was evaluated in 261 resected lung adenocarcinomas using tissue microarrays and H-scores (cutoff: 5). We compared IDO1 and PD-L1 expression with clinical features, tumor-infiltrating lymphocytes, HLA class I molecule expression, molecular alterations, and patient outcomes. There was expression of PD-L1 in 89 (34%) and IDO1 in 74 (29%) cases, with co-expression in 49 (19%). Both PD-L1 and IDO1 were significantly associated with smoking, aggressive pathologic features, and abundant CD8+ and T-bet+ (Th1 marker) tumor-infiltrating lymphocytes. PD-L1 expression was also associated with preserved HLA class I molecule expression (p = 0.002). Compared to PD-L1+/IDO1+ and PD-L1+ only cases, significantly fewer IDO1+ only cases had abundant CD8+ and T-bet+ tumor-infiltrating lymphocytes (p < 0.001, respectively). PD-L1 expression was significantly associated with EGFR wild-type (p < 0.001) and KRAS mutants (p = 0.021), whereas isolated IDO1 expression was significantly associated with EGFR mutations (p = 0.007). As for survival, PD-L1 was a significant predictor of decreased progression-free and overall survival by univariate but not multivariate analysis, while IDO1 was not associated with progression-free or overall survival. Interestingly, there was a significant difference in the 5-year progression-free and overall survival (p = 0.004 and 0.038, respectively), where cases without PD-L1 or IDO1 expression had the longest survival, and those with PD-L1 alone had the shortest survival. While PD-L1+/-IDO1 expression is observed in association with HLA class I expression, cytotoxic T lymphocyte/Th1 microenvironments, EGFR wild-type, and KRAS mutations, isolated IDO1 expression does not demonstrate these associations, suggesting that IDO1 may serve a distinct immunosuppressive role in lung adenocarcinomas. Thus, further investigation of IDO1 may demonstrate its role as a potential biomarker for patients who undergo anti-PD-1/PD-L1 therapy.

What to Do When Anti-PD-1 Therapy Fails in Patients With Melanoma.

Monotherapy with immune checkpoint inhibitors, specifically those targeting programmed death 1 (PD-1), has revolutionized the treatment of metastatic melanoma: approximately 40% of patients achieve a partial or complete response, many of which are durable. However, a subset of patients who initially respond to therapy will progress, leaving the majority of patients in need of an effective second-line approach. While some standard therapies exist, there has been robust interest in utilizing targeted immunotherapy combinations in this population to overcome primary or acquired resistance. Other approaches include treatment with anti-PD-1 agents beyond progression; targeting oligometastatic disease with surgery, radiation, and/or intratumor injections; and the use of other approved systemic therapies. This review summarizes the current available treatment strategies for patients with advanced melanoma when PD-1-directed therapy is not enough.

Immunomodulatory effects of current cancer treatment and the consequences for follow-up immunotherapeutics.

Recent advances in the use of immunotherapy have led to historic advancements in the field of oncology. Checkpoint inhibitors have demonstrated significant effectiveness against a broadening range of cancers. However, despite the success of antibodies against the immune regulators, CTLA4 and PD-L1/PD-1, only a subset of patients will have a durable response to these therapies, which implies that a broader view of cancer immunity is required. It is becoming increasingly apparent that combination therapy to target multiple events in the cancer-immunity cycle is needed and could potentially extend the benefit of immunotherapy to a larger population. In this review, we discuss the current status of immunotherapy and highlight the use of combination therapy to prime the tumor microenvironment and thereby improve treatment effect.