Anti-PD-1 elicits regression of undifferentiated pleomorphic sarcomas with UV-mutation signatures

Undifferentiated pleomorphic sarcoma (UPS), an aggressive soft-tissue sarcoma of adults, has been characterized by low tumor mutational burden (TMB) and high copy number alterations. Clinical trials of programmed death-1 (PD-1) blockade in UPS have reported widely varying efficacy. We describe two patients with recurrent scalp UPS that experienced clinical benefit from PD-1 blockade. These tumors had high TMB with a UV-induced mutational pattern. Analysis of additional head and neck UPS cases identified five out of seven tumors with high TMB and an ultraviolet (UV) mutational signature. Head and neck UPS tumors also had increased programmed death-ligand 1 (PD-L1) expression and CD8+ T cell infiltration as compared with UPS tumors arising from other sites. In summary, we found that UPS tumors of the head and neck, but not elsewhere, have a PD-L1+, T-cell-inflamed tumor microenvironment and high TMB, suggesting that these tumors represent a distinct genetic subgroup of UPS for which immune checkpoint inhibitor therapy might be effective.

Immune-mediated ototoxicity associated with immune checkpoint inhibitors in patients with melanoma

Immune checkpoint inhibitors (ICIs) are associated with a range of organ-specific toxicities known as immune-related adverse events (irAEs). Immune-mediated ototoxicity from ICIs is poorly described. Herein, we describe the clinical presentation, diagnostic evaluation and management of six ICI-treated patients who developed immune-mediated ototoxicity, identified by a multidisciplinary immune-related toxicity team. This is the largest case series to date and identifies bilateral high-frequency hearing loss and tinnitus as the most common reported symptoms and can be associated with abnormal speech reception thresholds and word recognition ability on audiogram in select patients. We propose multidisciplinary evaluation of patients with suspected otologic irAEs including referral to otolaryngology, audiometry evaluation±magnetic resonance imaging for evaluation of suspected immune-mediated ototoxicity.

Abstract A14: Meta-analysis improves identification of microbiome associations with antitumor response in melanoma, lung, and kidney cancer patients treated with checkpoint inhibitors

While immune checkpoint inhibitors (ICIs) have revolutionized the treatment of many cancers by producing durable antitumor responses, only 10-30% of treated patients respond and the ability to predict response to treatment remains elusive. Preliminary studies suggest the gut microbiome may be a novel biomarker for tumor response rates, including high alpha-diversity and a few specific bacterial species that associate with improved tumor responses to ICIs in melanoma, renal cell cancer (RCC), and non-small cell lung cancer (NSCLC). Despite these reports, the specific bacteria or bacterial communities helpful or harmful to ICI responses have been inconsistent across study populations and various malignancies, and further correlation with immune and mutational biomarkers is limited or lacking. We hypothesized that, by use of a larger sample size and a consistent computational approach, we would derive a clearer microbial profile that correlated with immunotherapeutic outcomes in more than one cancer type and in response to ICIs that target different immune checkpoints. To test this hypothesis, we have reanalyzed the available raw 16S rRNA amplicon and metagenomic sequencing data across five recently published studies (n=303) using Resphera Insight v2.2 and MetaPhlAn2, respectively, for taxonomic assignment. We used pathway prediction algorithms (PICRUSt) to examine functional characteristics enriched among responders and nonresponders, as well as effect of antibiotic usage and virulence factors using multiple reference databases. Our results confirm signals reported in each study, though some bacteria reported initially were not statistically significant after correction for false discovery rate. Likely, in part, because our analysis allows for comparison of individual species across cohorts, we were able to identify new bacterial signatures associated with clinical response or nonresponse. Further, these new results enabled us to re-evaluate and develop response and nonresponse indicator indexes. When our composite index was compared to an index assembled from the literature, some improvement occurred in a sensitivity and specificity analysis. Moreover, while lower alpha-diversity has been associated with disease states and higher alpha-diversity with healthy states, we found that alpha-diversity was not consistently predictive of response or nonresponse to ICIs. In summary, this bioinformatics platform improves on existing pipelines by standardizing critical preprocessing and downstream analysis tools, enabling comprehensive evaluations of taxonomic and functional signals across sequencing datasets. These analyses allow for identification of novel bacterial signatures associated with clinical responses that could potentially be used as biomarkers in patients undergoing treatment with checkpoint inhibitors. Results from these analyses will be validated in subsequent analyses of ICI therapy and clinical outcomes in our ongoing prospective cohorts.

Citation Format: Fyza T. Shaikh, James R. White, Joell G. Gills, Jarushka Naidoo, Evan Lipson, Drew M. Pardoll, Cynthia L. Sears. Meta-analysis improves identification of microbiome associations with antitumor response in melanoma, lung, and kidney cancer patients treated with checkpoint inhibitors [abstract]. In: Proceedings of the AACR Special Conference on the Microbiome, Viruses, and Cancer; 2020 Feb 21-24; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2020;80(8 Suppl):Abstract nr A14.

Concurrent Immune Checkpoint Inhibitors and Stereotactic Radiosurgery for Brain Metastases in Non-Small Cell Lung Cancer, Melanoma, and Renal Cell Carcinoma

PURPOSE

To characterize the effect of concurrent stereotactic radiosurgery-stereotactic radiation therapy (SRS-SRT) and immune checkpoint inhibitors on patient outcomes and safety in patients with brain metastases (BMs).

METHODS AND MATERIALS

We retrospectively identified metastatic non-small cell lung cancer, melanoma, and renal cell carcinoma patients who had BMs treated with SRS-SRT from 2010 to 2016 without prior whole-brain radiation therapy. We included SRS-SRT patients who were treated with anti-cytotoxic T-lymphocyte-associated protein 4 (ipilimumab) and anti-programmed cell death protein 1 receptor (nivolumab, pembrolizumab). Patients who were given immune checkpoint inhibitors on active or unreported clinical trials were excluded, and concurrent immune checkpoint inhibition (ICI) was defined as ICI given within 2 weeks of SRS-SRT. Patients were managed with SRS-SRT, SRS-SRT with nonconcurrent ICI, or SRS-SRT with concurrent ICI. Progression-free survival and overall survival (OS) were estimated using Kaplan-Meier survival curves, and Cox proportional hazards models were used for multivariate analysis. Logistic regression was used to identify predictors of acute neurologic toxicity, immune-related adverse events, and new BMs.

RESULTS

A total of 260 patients were treated with SRS-SRT to 623 BMs. Of these patients, 181 were treated with SRS-SRT alone, whereas 79 received SRS-SRT and ICI, 35% of whom were treated with concurrent SRS-SRT and ICI. Concurrent ICI was not associated with increased rates of immune-related adverse events or acute neurologic toxicity and predicted for a decreased likelihood of the development of ≥3 new BMs after SRS-SRT (P=.045; odds ratio, 0.337). Median OS for patients treated with SRS-SRT, SRS-SRT with nonconcurrent ICI, and SRS-SRT with concurrent ICI was 12.9 months, 14.5 months, and 24.7 months, respectively. SRS-SRT with concurrent ICI was associated with improved OS compared with SRS-SRT alone (P=.002; hazard ratio [HR], 2.69) and compared with nonconcurrent SRS-SRT and ICI (P=.006; HR, 2.40) on multivariate analysis. The OS benefit of concurrent SRS-SRT and ICI was significant in comparison with patients treated with SRS-SRT before ICI (P=.002; HR, 3.82) or after ICI (P=.021; HR, 2.64).

CONCLUSIONS

Delivering SRS-SRT with concurrent ICI may be associated with a decreased incidence of new BMs and favorable survival outcomes without increased rates of adverse events.

Abstract CT096: Clinical activity, immune and viral correlates of PD-1 blockade with pembrolizumab as first systemic therapy in patients with advanced Merkel cell carcinoma

Background: Merkel cell carcinoma (MCC) is an aggressive skin cancer linked to UV exposure and the Merkel cell polyomavirus (MCPyV). Cytotoxic chemotherapy is associated with high response rates in patients (pts) with metastatic MCC, although responses are seldom durable and median progression-free survival is only 13 weeks. MCC may be responsive to PD-1 pathway blockade as tumors often express PD-L1 and MCPyV-specific T cells express the inhibitory co-receptor PD-1.

Methods: In this open-label, phase II trial by the Cancer Immunotherapy Trials Network (NCT02267603), adults with advanced/metastatic MCC and no prior systemic therapy were enrolled. Pembrolizumab, a humanized IgG4 anti-PD-1 monoclonal antibody, was given IV every 3 weeks (2 mg/kg). Response was assessed by RECIST 1.1 every 9-12 weeks. Presence of MCPyV was assessed by measuring serum antibody titers to the MCPyV oncoprotein and/or quantifying tumor oncoprotein expression by immunohistochemistry (IHC).

Results: Twenty-six pts were treated (median duration 22 weeks, range 4 to 49 weeks as of 1/8/16 dataset). Twenty-three pts had at least one documented radiologic or clinical assessment of response. Fifteen of 23 evaluable pts (65%) responded (4 complete responses and 11 partial responses); 2 additional pts had stable disease and 6 had progressive disease as best response. Fourteen of 15 responses (93%) were ongoing at last follow-up. Ten responders had at least one follow-up evaluation with response duration ranging from 8+ to 27+ weeks beyond initial documented response. Treatment was generally well tolerated with mostly grade 1 or 2 adverse events. Two pts developed severe drug-related toxicities including grade 4 myocarditis (n = 1) and grade 4 transaminase elevation (n = 1), both of which improved with corticosteroid treatment. Both pts have ongoing tumor responses despite discontinuation of pembrolizumab. Sixteen of 26 pts (62%) were classified as having virus-positive MCC. Among the 23 evaluable pts, 9 of 14 (64%) of those with virus positive tumors responded, while 6 of 9 (67%) of pts with virus negative tumors responded. Analyses of T cells specific to MCPyV and titers of oncoprotein antibodies during therapy, as well as IHC characterization of tumor biopsies including PD-L1 expression are ongoing.

Conclusions: First-line therapy with pembrolizumab in pts with advanced MCC is associated with frequent (65%) and durable responses. Notably, the response rate was similar among pts with virus-positive and virus-negative tumors. While virus-positive tumors are known to express highly antigenic MCPyV oncoproteins, virus-negative tumors are typically UV-induced and display strikingly elevated mutational burdens generating putative neo-antigens. Thus, potentially through distinct mechanisms, both virus-positive and virus-negative MCC tumors appear to be immunogenic and frequently responsive to anti-PD-1 therapy.

Citation Format: Paul Nghiem, Shailender Bhatia, Evan Lipson, Ragini Kudchadkar, Natalie Miller, Adil Daud, Steven Fling, Philip Friedlander, Harriet Kluger, Holbrook Kohrt, Lisa Lundgren, Kim Margolin, Thomas Olencki, Sunil Reddy, Erica Shantha, William Sharfman, Elad Sharon, Michi Shinohara, John Thompson, Jennifer Yearley, Suzanne Topalian, Martin Cheever. Clinical activity, immune and viral correlates of PD-1 blockade with pembrolizumab as first systemic therapy in patients with advanced Merkel cell carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT096.

Universal interfacing system for interactive technologies in telemedicine, disabilities, rehabilitation, and education

A modular hardware and software system for human-computer interaction is described that allows for flexible, affordable interfacing of people, computers, and instruments. The approach is illustrated with an application in the disabilities area. Other application areas are outlined.

The second generation of nasal continuous positive airway pressure devices. Are they created equal?

Nasal continuous positive airway pressure (NCPAP) is considered the preferred medical treatment of obstructive sleep apnea. Because NCPAP exerts its beneficial effects by maintaining positive airway pressure, we proposed to test the ability of the newer "second generation" NCPAP machines to maintain a constant airway pressure during simulated breathing on a lung model. Each of the seven new NCPAP devices tested were examined under conditions of changing inspiratory flow, end expiratory pressure (EEP) and resistance added to the patient end of the NCPAP hose. During inspiration airway pressure fell and in expiration it increased relative to the EEP in all machines. Using the standard NCPAP hose and a breathing pattern consistent with normal breathing during sleep, the maximum decline in pressure during simulated inspiration and excess pressure during simulated expiration was -0.5 cm H2O and 0.6 cm H2O, respectively. Adding resistance, increasing inspiratory flow but not EEP exaggerated this effect. All of the machines behaved similarly in this regard. Further, the performance of the NCPAP devices did not deteriorate after 6 hours of uninterrupted operation. We conclude that the second generation NCPAP machines may be interchanged without another laboratory trial to readjust the EEP.

Restrictive chest bellows disease and frontometaphyseal dysplasia

We describe a patient with frontometaphyseal dysplasia (FMD), restrictive chest bellows disease, hypercapnic respiratory failure, and cor pulmonale. Treatment with intermittent supplemental oxygen, nocturnal nasal volume ventilation, and posture modification was successful in partial resolution of chronic hypoventilation and excessive daytime somnolence.

System analysis of Phycomyces light-growth response with Gaussian white noise and sum-of-sinusoids test stimuli

The sporangiophore (fruiting body) of the fungus Phycomyces modulates its elongation rate in response to changes in blue light intensity. This light-growth response of wild-type and behavioral mutant strains has been studied extensively by two methods of nonlinear system identification employing Gaussian white noise and sum-of-sinusoids test stimuli. Both methods are in the framework of the Wiener theory of nonlinear systems. The light-growth response is well described by the first-order Wiener G-functional; addition of the second-order functional improves the precision. The Wiener kernel of first-order resembles the light-growth response to a nonsaturating pulse stimulus. The second-order kernel indicates the nonlinear property of rectification. The kernels have been interpreted by system analysis methods in the frequency domain. A nonlinear dynamic model of the light-growth response has been developed from the kernels obtained by both methods. The model includes a nonlinear dynamic subsystem, including a squarer, followed by a linear dynamic subsystem (which, by itself, accounts for the first-order kernel). This parametric model has been used to evaluate light-growth response kernels under various conditions (viz. wavelength, temperature, and genetic strain). The kernels of single and double mutants have been analyzed jointly with a nonparametric model to reveal interactions among the products of eight genes that influence the light-growth response. The extent of interactions found suggests that these gene products function together in a molecular complex.