David Michael Gill

PD-1 checkpoint inhibition: Toxicities and management

PURPOSE With the recent approval of 5 PD-1/PD-L1 inhibitors for a number of malignancies, PD-1 axis inhibition is drastically changing the treatment landscape of immunotherapy in cancer. As PD-1/PD-L1 are involved in peripheral immune tolerance, inhibition of this immune checkpoint has led to novel immune-related adverse events including colitis, hepatitis, pneumonitis, rash, and endocrinopathies among many others. MATERIALS AND METHODS In this seminar, we will analyze the incidence of immune-related adverse events for nivolumab, pembrolizumab, atezolizumab, durvalumab, and avelumab. Then, we will discuss the specific management of the most common immune-mediated adverse events including colitis, hepatitis, pneumonitis, rash, endocrinopathies, nephritis, and neurologic toxicities. RESULTS Immune-related adverse events are frequently treated with immunosuppressive medication such as steroids and mycofenolate mofetil. CONCLUSIONS There are specific immune-related adverse events which are frequently seen by the treating oncologist from checkpoint inhibitors. It is essential to understand the recommended treatment options to minimize toxicity and mortality from this important class of anti-neoplastic therapies.

Systemic Immunotherapy for Urothelial Cancer: Current Trends and Future Directions

Urothelial cancer of the bladder, renal pelvis, ureter, and other urinary organs is the fifth most common cancer in the United States, and systemic platinum-based chemotherapy remains the standard of care for first-line treatment of advanced/metastatic urothelial carcinoma (UC). Until recently, there were very limited options for patients who are refractory to chemotherapy, or do not tolerate chemotherapy due to toxicities and overall outcomes have remained very poor. While the role of immunotherapy was first established in non-muscle invasive bladder cancer in the 1970s, no systemic immunotherapy was approved for advanced disease until the recent approval of a programmed death ligand-1 (PD-L1) inhibitor, atezolizumab, in patients with advanced/metastatic UC who have progressed on platinum-containing regimens. This represents a significant milestone in this disease after a void of over 30 years. In addition to atezolizumab, a variety of checkpoint inhibitors have shown a significant activity in advanced/metastatic urothelial carcinoma and are expected to gain Food and Drug Administration (FDA) approval in the near future. The introduction of novel immunotherapy agents has led to rapid changes in the field of urothelial carcinoma. Numerous checkpoint inhibitors are being tested alone or in combination in the first and subsequent-line therapies of metastatic disease, as well as neoadjuvant and adjuvant settings. They are also being studied in combination with radiation therapy and for non-muscle invasive bladder cancer refractory to BCG. Furthermore, immunotherapy is being utilized for those ineligible for first-line platinum-based chemotherapy. This review outlines the novel immunotherapy agents which have either been approved, or are currently being investigated in clinical trials in UC.

Independent Validation of Effect of HSD3B1 Genotype on Response to Androgen-Deprivation Therapy in Prostate Cancer

Independent Validation of Effect of HSD3B1 Genotype on Response to Androgen-Deprivation Therapy in Prostate Cancer Substantial advances have been made in the development of therapeutic biomarkers in various cancers, but not in prostate cancer. A germline inherited polymorphic variant (1245A→C) in the HSD3B1 gene was recently reported to correlate with shorter duration of response to androgendeprivation therapy (ADT) in hormone-sensitive prostate cancer (HSPC).1 The HSD3B1 gene encodes the enzyme 3βhydroxysteroid dehydrogenase-1 (3βHSD1), which catalyzes adrenal androgen precursors into dihydrotestosterone, the most potent androgen.2,3 In the study by Hearn et al,1 presence of 1 or more variant alleles of the HSD3B1 (1245C) was associated with decreased progression-free survival (PFS) compared with the absence of any variant alleles in 3 cohorts of men with prostate cancer treated with ADT: 2 cohorts with post-prostatectomy biochemical recurrence, and 1 cohort with metastatic HSPC (mHSPC) (total, n = 443). In the present analysis, we provide, to our knowledge, the first independent validation of these results, which have the potential to introduce the first predictive biomarker of response to therapy for this patient population.

Neutrophil-lymphocyte ratio as a predictive biomarker for response to high dose interleukin-2 in patients with renal cell carcinoma

BackgroundImmunotherapy with high-dose interleukin-2 (HD-IL2) results in long-term survival in some metastatic renal cell carcinoma (mRCC) patients but has significant acute toxicities. Biomarkers predicting response to therapy are needed to better select patients most likely to benefit. NLR (absolute neutrophil count (ANC)/absolute lymphocyte count (ALC)) is a prognostic and predicative biomarker in various malignancies. The goal was to determine whether NLR can predict response to HD-IL2 in this setting.MethodsPatients with clear cell mRCC treated with HD-IL2 were identified from an institutional database from 2003–2012. Baseline variables for the assessment of IMDC risk criteria, and neutrophil and lymphocyte count, were collected. Best response criteria were based on RECIST 1.0. Wilcoxon rank-sum test was used to evaluate the association of continuous baseline variables with disease control. NLR was stratified by ≤4 or >4. Progression free survival (PFS) and overall survival (OS) were estimated with the Kaplan-Meier method and Cox proportional hazard models assessed associations of NLR with survival.ResultsIn 71 eligible patients, median NLR in those with an objective response (n = 14, 20%) was 2.3 vs 3.4 in those without (n = 57, 80%, p = 0.02). NLR ≤4 was associated with improved progression free and overall survival. After adjustment for IMDC risk criteria, NLR remained a significant predictor of OS (ANC/ALC ≤4 vs >4, HR 0.41, 95% CI 1.09-5.46, p = 0.03; ANC/ALC continuous variable per unit change in NLR, HR 1.08, 95% CI 1.01-1.14, p = 0.03).ConclusionsIn this discovery set, NLR predicts overall survival in patients treated with HD-IL2 in mRCC, and may allow better patient selection in this setting. Data needs validation in an independent cohort.

Correlation of genomic alterations assessed by next-generation sequencing (NGS) of tumor tissue DNA and circulating tumor DNA (ctDNA) in metastatic renal cell carcinoma (mRCC): Potential clinical implications

Introduction Tumor tissue and circulating tumor DNA (ctDNA) next-generation sequencing (NGS) testing are frequently performed to detect genomic alterations (GAs) to help guide treatment in metastatic renal cell carcinoma (mRCC), especially after progression on standard systemic therapy. Our objective was to assess if GAs detected by ctDNA NGS are different from those detected by tumor tissue NGS, specifically in patients with mRCC, and if these platforms are interchangeable or complimentary. Results When controlling for genes tested by both platforms, the median mutation rate for ctDNA was similar to tissue (median 3.0 vs. 1.0, p = 0.14). However, the concordance rate between the two platforms was only 8.6%. When comparing GAs by molecular pathway, GAs in tumor tissue were more common for the DNA repair and epigenetic pathways. Materials and Methods Results of NGS testing from tumor tissue and ctDNA from 19 sequential mRCC patients were compared. GAs in each were statistically evaluated using the Wilcoxon signed-rank test. The Fischers exact test was used to compare the incidence of mutations in selected molecular pathways. Conclusions When controlling for genes tested by both platforms, similar number of GAs were detected by both tissue and ctDNA based NGS. However, there was discordance in the type of GAs detected suggesting that ctDNA NGS may be more reflective of dynamic tumor genomic heterogeneity. Hence, these two platforms may be considered complementary to each other, rather than interchangeable, for assessment of tumor GAs to guide selection of targeted clinical trial therapies.

The future of immune checkpoint cancer therapy after PD-1 and CTLA-4

The adaptive immune system plays an important role in eradicating malignant cells. Co-stimulatory and co-inhibitory signals to T cells though immune checkpoint receptors are involved in tumorigenesis and metastasis. Exploitation of immune checkpoint inhibitors, PD-1 and CTLA-4, with monoclonal antibodies has created impressive clinical responses. Many other immune checkpoint co-inhibitors and co-stimulators exist, including the B7 superfamily and tumor necrosis factor receptors superfamily. Here, we will examine co-inhibitors and co-stimulators beyond PD-1 and CTLA-4 that are being investigated in active clinical trials. We will review the immunology and preclinical studies that support investigation of these targets. Finally, we will briefly discuss the potential for immunotherapy to be combined with other treatment modalities.

Incidence of Immune-Related Adverse Events with Program Death Receptor-1- and Program Death Receptor-1 Ligand-Directed Therapies in Genitourinary Cancers

Program death receptor-1 (PD-1) and program death receptor-1 ligand (PD-L1) inhibitors are increasingly being used in the clinic to treat a growing number of malignancies, including many genitourinary (GU) malignancies. These immune-based therapies have demonstrated a distinct toxicity profile compared to traditional chemotherapy and the targeted therapies directed at the vascular endothelial growth factor pathway or the mammalian target of rapamycin pathway. Autoimmune toxicity targeting the skin, gastrointestinal tract, or the endocrine organs are some of the more common adverse events (AEs) noted with these therapies. Here in, we report the results of a systematic review of the incidence of toxicities in GU cancers reported in the phase II or phase III clinical trials using single-agent PD-1 or PD-L1 inhibitors. Overall, the rate of serious (grades 3–4) AEs was noted in approximately 15% of patients. The AEs noted were similar between all the agents tested, highlighting the overall class effect of these therapies. The incidence in GU cancers is similar to those seen in other malignancies. Given the widespread and high volume real-world use of these agents, it is important for oncologists to be familiar with these side effects to minimize the risks for patients while undergoing therapy.

Activin Receptor Inhibitors—Dalantercept

Development of anti-angiogenic therapy including the vascular endothelial growth factor (VEGF) antibodies and VEGF-tyrosine kinase receptors has been a major landmark in cancer therapy leading improvement in survival in several cancers. While anti-angiogenic therapy is effective in some settings, resistance often develops owing to evasive, alternative pathways. Novel targets for anti-angiogenic therapy are urgently required to provide treatment alternatives in patients whose tumors are unresponsive to approved anti-angiogenic agents; one such pathway is the bone morphogenetic proteins (BMP 9 and BMP 10) that activate the type I activin receptor-like kinase-1 (ALK1), which has been implicated in the development of functional vasculature. Dalantercept (ACE-041) is a novel anti-angiogenic agent, which is a soluble form of ALK1, and acts as a ligand trap for BMP 9 and BMP 10, inhibiting their interaction with ALK1, which further disrupts the process of vascular development. This review will discuss the preclinical and clinical development of dalantercept as a novel anti-angiogenic therapy in treating a variety of cancers and its distinct safety profile compared to other anti-VEGF agents. We will also discuss the ongoing and completed studies of dalantercept, including combination studies with other VEGF-directed therapies.

Everolimus Versus Temsirolimus in Metastatic Renal Cell Carcinoma After Progression With Previous Systemic Therapies

BACKGROUND Everolimus is an approved agent for use after disease progression with vascular endothelial growth factor receptor-tyrosine kinase inhibitors (VEGFR-TKIs) in patients with metastatic renal cell carcinoma. With recently published trials showing efficacy of nivolumab and cabozantinib in the second-line therapy setting, the use of everolimus will likely move to the third- or fourth-line therapy setting. Temsirolimus has occasionally been used instead of everolimus for many reasons, including financial considerations, assurance of patient compliance given its intravenous administration, its toxicity profile, patient performance status, and patient or physician preference. However, efficacy of everolimus and temsirolimus in this setting have not been compared in a randomized trial. The results from retrospective studies have been inconsistent. MATERIALS AND METHODS We identified patients treated with a first-line VEGFR-TKI for metastatic renal cell carcinoma and then treated with either everolimus or temsirolimus on progression from the databases of 2 large academic cancer centers. Progression-free survival (PFS) and overall survival (OS) were assessed from the initiation of second-line treatment using the Kaplan-Meier method. RESULTS A total of 90 patients received either everolimus (n = 59; 66%) or temsirolimus (n = 31; 34%) after progression during first-line VEGFR-TKI therapy. The patient and disease characteristics were similar in both groups. The median PFS was not different, but OS was superior with everolimus compared with temsirolimus (24.2 months vs. 12.1 months; hazard ratio, 0.58; P = .047). CONCLUSION Our results bolster existing guidelines supporting everolimus over temsirolimus as salvage therapy after previous systemic therapies.

Immunotherapy of advanced renal cell carcinoma: Current and future therapies

ABSTRACT Previously a malignancy with few therapeutic options, metastatic renal cell carcinoma (mRCC) treatment is rapidly evolving. Although cytokine therapies (interferon-a, interleukin-2) have been used less frequently over the past decade, recent approval of an immune checkpoint inhibitor, nivolumab, has led to a resurgence in immune therapy for mRCC. With greater understanding of the complex and dynamic interaction between the tumor and the immune system, numerous new immunotherapies are being studied for mRCC. In this article, we review the mechanism of action, clinical outcomes and toxicity profiles of both clinically approved and selected investigational immunotherapies. Either alone or in combination, these novel agents are encouraging for the future of mRCC therapy.