Occult myocardial injury is prevalent amongst elderly patients in the hospital-at-home setting. A retrospective analysis of 213 patients

Background

Hospital-at-Home (HAH) is a valid alternative for in-hospital stay for a wide variety of clinical indications. Occult myocardial injury, associated with acute illness, mainly occurs in patients with a background of non-obstructive coronary disease. The aim of this study was to describe the prevalence of this phenomenon in our HAH population.

Methods

A retrospective description and analysis of data collected for patients admitted to the Sheba beyond's HAH services during 14 months.

Results

During a period of 14 months (7/10/21-6/12/22), blood troponin measurements were available for 213 patients (median age 78 years, 52% males) hospitalized mainly for infectious causes. The median HS (highly sensitive) troponin level was 7.7 ng/L (IQR = 13.2 ng/L) (the normal upper limit is 12 ng/L) with 31% of all patients demonstrating an abnormally increased troponin level (68/213). Of all patients, 64% had a background diagnosis of a cardiovascular disease (138/213), of whom, 49% had abnormal HS troponin levels (68/138). No patient suffered from acute cardiac function deterioration and no patient died during their hospital-at-home stay.

Conclusion

The prevalence of occult myocardial injury amongst elderly patients admitted to hospital-at-home stay for diagnoses other than myocardial infarction is relatively high but it is not associated with worse short-term clinical outcomes.

Comparison of Standard vs. Relative Risk Models to Define Candidates for Deintensification in Locoregionally Advanced P16+ Oropharyngeal Cancer

PURPOSE/OBJECTIVE(S)

Various methods to identify candidates for treatment deintensification with p16+ oropharyngeal squamous cell carcinoma (OPSCC) have been used, but the optimal approach is unknown.

MATERIALS/METHODS

Multi-institutional cohort study of 385 patients with previously untreated p16+ OPSCC undergoing definitive radiotherapy (RT) with or without systemic therapy between 2009-2020. Chemotherapy intensity was categorized as high (bolus cisplatin and/or induction chemotherapy), medium (weekly cisplatin), or low (non-cisplatin or RT alone). Standard favorable vs. unfavorable risk was defined using NRG HN005 eligibility criteria. High vs. low relative risk (RR) group was defined using the HNCIG omega score (≥ 0.80 vs. < 0.80), which quantifies the proportion of a patient's overall event risk due to cancer. We used multivariable ordinal logistic regression to estimate effects of age (yrs), sex, performance status (PS), Charlson comorbidity index (CCI), T/N (AJCC 8th), current smoking, and pack-years (> 10 vs. ≤ 10) on treatment allocation. Effects on relative event hazards were estimated using generalized competing event regression.

RESULTS

Median follow-up time was 44.2 months. Chemotherapy intensity was high in 206 (54%), medium in 108 (28%), and low in 71 (18%). 280 patients (73%) were unfavorable risk and 197 (51%) were high RR. 178 patients (46%) had discordant risk classification. On univariable analysis, significant predictors of higher intensity chemotherapy (normalized odds ratio (OR)) were CCI 0-1 (OR 1.49, 95% CI: 1.23-1.79), high omega score (OR 1.46; 1.20-1.77), decreased age (OR 1.43; 1.18-1.74), and PS 0 (OR 1.22; 1.01-1.48). Controlling for CCI, higher omega score was associated with significantly higher odds of intensive chemotherapy (OR 1.35; 1.10-1.65, but unfavorable risk (HN005 ineligibility) was not (OR 1.19; 0.98-1.44). Higher omega score was also associated with significantly higher RR for cancer recurrence (Rec) vs. competing mortality (CM) events (relative HR (rHR) 1.76; 1.12-2.75), but unfavorable risk was not (rHR 1.05; 0.63-1.75). Among patients receiving cisplatin, 50 favorable risk patients (58%) had high RR; all of their event risk was due to cancer recurrence (Table). The 110 unfavorable risk patients (48%) with low omega score had significantly lower RR for cancer events compared to the high omega score group (rHR 0.49; 0.29-0.84).

CONCLUSION

Many patients with favorable risk p16+ OPSCC have high relative risk for cancer events, which correlates with a benefit of intensive treatment. The HNCIG omega score is a strong predictor of allocation to intensive chemotherapy and may help identify candidates for deintensification.

Characterization of Antibody Repertoires in Patients with HPV-Related HNSCC Undergoing Definitive Radiation with Immunotherapy

PURPOSE/OBJECTIVE(S)

Integrating immune checkpoint inhibitor (ICI) immunotherapy agents into the definitive treatment of head and neck squamous cell carcinoma (HNSCC) has been challenging. It is apparent that understanding how these therapies affect specific components of the immune response is critical to improve outcomes. The role of B cells has been increasingly recognized, especially in HPV+ HNSCC. As antibodies are one of the chief downstream products of B cells, we sought to evaluate the antibody repertoires of patients with HPV+ HNSCC undergoing definitive radiation therapy (RT) and ICI (RT-ICI).

MATERIALS/METHODS

Serum samples from patients with p16+ HNSCC undergoing RT-ICI were collected for the KEYCHAIN clinical trial (NCT03383094). We analyzed 8 samples from 4 patients collected pre-treatment and 3 months following treatment using the HuProt Human Proteome Microarray, which samples >20,000 human proteins. Genes encoding surface proteins (GESPs) were obtained from The Cancer Surfaceome Atlas. Mutational data were obtained from AACR Project GENIE. For murine studies, C3H mice were injected with 5x105 cells of AT-84-E7-OVA syngeneic SCC into the right flank. Anti-PD-L1 ICI (aPD-L1) was given via intraperitoneal injection every 3 days for 3 doses. RT was 12 Gy in 1 fraction. Cell surface markers in lymph nodes (LNs) were analyzed by flow cytometry.

RESULTS

In total, we detected antibodies against 10959 unique antigens in the pre-treatment serum, of which 14% and 11% were shared by 3 and 4 patients, respectively. Following completion of RT-ICI, we detected antibodies against 11019 unique antigens, of which 20% and 18% were shared by 3 and 4 patients, respectively. Of these, 5824 (53%) antigens were not detected in the pre-treatment serum, and therefore represent antibodies against "newly detected" antigens. We found 777 antigens that were newly detected and shared by at least 2 patients. Analysis of these antigens revealed enrichment in pathways such as, "response to oxygen levels." We next found that 114 (14.7%) of these represented GESPs. We integrated mutational analysis of the most frequently mutated genes in >1,800 HNSCC samples and found 2/114 GESPs were shared. Using a murine model of HPV+ HNSCC, we found that treatment with RT and aPD-L1 led to the greatest frequency of germinal center (GC) B cells in tumor-draining and non-tumor-draining LNs.

CONCLUSION

In patients with p16-positive HNSCC, proteomic analysis of antibody repertoires revealed many antigens against which antibodies were formed during RT-ICI that are shared between patients. Intriguingly, GC formation, which is the nidus for B cell responses, in locoregional LNs was greatest with RT-ICI. These findings support the further investigation of B-cell mediated responses in HPV+ HNSCC.

Germline genetic biomarkers to stratify patients for personalized radiation treatment

Background

Precision medicine incorporating genetic profiling is becoming a standard of care in medical oncology. However, in the field of radiation oncology there is limited use of genetic profiling and the impact of germline genetic biomarkers on radiosensitivity, radioresistance, or patient outcomes after radiation therapy is poorly understood. In HNSCC, the toxicity associated with treatment can cause delays or early cessation which has been associated with worse outcomes. Identifying potential biomarkers which can help predict toxicity, as well as response to treatment, is of significant interest.

Methods

Patients with HNSCC who received RT and underwent next generation sequencing of somatic tumor samples, transcriptome RNA-seq with matched normal tissue samples were included. Patients were then grouped by propensity towards increased late vs. early toxicity (Group A) and those without (Group B), assessed by CTCAE v5.0. The groups were then analyzed for association of specific germline variants with toxicity and clinical outcomes.

Results

In this study we analyzed 37 patients for correlation between germline variants and toxicity. We observed that TSC2, HLA-A, TET2, GEN1, NCOR2 and other germline variants were significantly associated with long term toxicities. 34 HNSCC patients treated with curative intent were evaluated for clinical outcomes. Group A had significantly improved overall survival as well as improved rates of locoregional recurrence and metastatic disease. Specific variants associated with improved clinical outcomes included TSC2, FANCD2, and PPP1R15A, while the HLA-A and GEN1 variants were not correlated with survival or recurrence. A group of five HLA-DMA/HLA-DMB variants was only found in Group B and was associated with a higher risk of locoregional recurrence.

Conclusions

This study indicates that germline genetic biomarkers may have utility in predicting toxicity and outcomes after radiation therapy and deserve further investigation in precision radiation medicine approaches.

Lymphatic-preserving treatment sequencing with immune checkpoint inhibition unleashes cDC1-dependent antitumor immunity in HNSCC

Despite the promise of immune checkpoint inhibition (ICI), therapeutic responses remain limited. This raises the possibility that standard of care treatments delivered in concert may compromise the tumor response. To address this, we employ tobacco-signature head and neck squamous cell carcinoma murine models in which we map tumor-draining lymphatics and develop models for regional lymphablation with surgery or radiation. We find that lymphablation eliminates the tumor ICI response, worsening overall survival and repolarizing the tumor- and peripheral-immune compartments. Mechanistically, within tumor-draining lymphatics, we observe an upregulation of conventional type I dendritic cells and type I interferon signaling and show that both are necessary for the ICI response and lost with lymphablation. Ultimately, we provide a mechanistic understanding of how standard oncologic therapies targeting regional lymphatics impact the tumor response to immune-oncology therapy in order to define rational, lymphatic-preserving treatment sequences that mobilize systemic antitumor immunity, achieve optimal tumor responses, control regional metastatic disease, and confer durable antitumor immunity.

Improved Prognosis of Treatment Failure in Cervical Cancer with Nontumor PET/CT Radiomics

Radiomics has been applied to predict recurrence in several disease sites, but current approaches are typically restricted to analyzing tumor features, neglecting nontumor information in the rest of the body. The purpose of this work was to develop and validate a model incorporating nontumor radiomics, including whole-body features, to predict treatment outcomes in patients with previously untreated locoregionally advanced cervical cancer. Methods: We analyzed 127 cervical cancer patients treated definitively with chemoradiotherapy and intracavitary brachytherapy. All patients underwent pretreatment whole-body ¹⁸F-FDG PET/CT. To quantify effects due to the tumor itself, the gross tumor volume (GTV) was directly contoured on the PET/CT image. Meanwhile, to quantify effects arising from the rest of the body, the planning target volume (PTV) was deformably registered from each planning CT to the PET/CT scan, and a semiautomated approach combining seed-growing and manual contour review generated whole-body muscle, bone, and fat segmentations on each PET/CT image. A total of 965 radiomic features were extracted for GTV, PTV, muscle, bone, and fat. Ninety-five patients were used to train a Cox model of disease recurrence including both radiomic and clinical features (age, stage, tumor grade, histology, and baseline complete blood cell counts), using bagging and split-sample-validation for feature reduction and model selection. To further avoid overfitting, the resulting models were tested for generalization on the remaining 32 patients, by calculating a risk score based on Cox regression and evaluating the c-index (c-index > 0.5 indicates predictive power). Results: Optimal performance was seen in a Cox model including 1 clinical biomarker (whether or not a tumor was stage III-IVA), 2 GTV radiomic biomarkers (PET gray-level size-zone matrix small area low gray level emphasis and zone entropy), 1 PTV radiomic biomarker (major axis length), and 1 whole-body radiomic biomarker (CT bone root mean square). In particular, stratification into high- and low-risk groups, based on the linear risk score from this Cox model, resulted in a hazard ratio of 0.019 (95% CI, 0.004, 0.082), an improvement over stratification based on clinical stage alone, which had a hazard ratio of 0.36 (95% CI, 0.16, 0.83). Conclusion: Incorporating nontumor radiomic biomarkers can improve the performance of prognostic models compared with using only clinical and tumor radiomic biomarkers. Future work should look to further test these models in larger, multiinstitutional cohorts.

Adaptive replanning using cone beam CT for deformation of original CT simulation

BACKGROUND

During a course of radiation therapy, anatomical changes such as a decrease in tumour size or weight loss can trigger the need for repeating a computed tomography (CT) simulation scan in order to generate a new treatment plan. This adaptive approach requires a separate appointment for an additional CT scan which generates additional burden, cost, and radiation exposure for patients.

CASE PRESENTATION

Here, we present a case of a head and neck cancer patient who required palliative radiation for a large neck mass. During treatment, he had a remarkable response which required a replan due to rapid tumour downsizing. In this case, we used a novel technique to avoid repeating the planning CT simulation by using a mid-treatment high-quality cone beam CT (CBCT) to deform the secondary image (plan CT) of the original planning CT and generate a new adapted treatment plan.

CONCLUSION

This is the first report to our knowledge using a Halcyon CBCT to deform the original planning CT in order to generate a new radiation treatment plan, and this novel technique represents a new potential method of adaptive replanning for select patients.

Microneedle-mediated Intratumoral Delivery of Anti-CTLA-4 Promotes cDC1-dependent Eradication of Oral Squamous Cell Carcinoma with Limited irAEs

Head and neck squamous cell carcinoma (HNSCC) ranks sixth in cancer incidence worldwide and has a 5-year survival rate of only 63%. Immunotherapies-principally immune checkpoint inhibitors (ICI), such as anti-PD-1 and anti-CTLA-4 antibodies that restore endogenous antitumor T-cell immunity-offer the greatest promise for HNSCC treatment. Anti-PD-1 has been recently approved for first-line treatment of recurrent and metastatic HNSCC; however, less than 20% of patients show clinical benefit and durable responses. In addition, the clinical application of ICI has been limited by immune-related adverse events (irAE) consequent to compromised peripheral immune tolerance. Although irAEs are often reversible, they can become severe, prompting premature therapy termination or becoming life threatening. To address the irAEs inherent to systemic ICI therapy, we developed a novel, local delivery strategy based upon an array of soluble microneedles (MN). Using our recently reported syngeneic, tobacco-signature murine HNSCC model, we found that both systemic and local-MN anti-CTLA-4 therapy lead to >90% tumor response, which is dependent on CD8 T cells and conventional dendritic cell type 1 (cDC1). However, local-MN delivery limited the distribution of anti-CTLA-4 antibody from areas distal to draining lymphatic basins. Employing Foxp3-GFPDTR transgenic mice to interrogate irAEs in vivo, we found that local-MN delivery of anti-CTLA-4 protects animals from irAEs observed with systemic therapy. Taken together, our findings support the exploration of MN-intratumoral ICI delivery as a viable strategy for HNSCC treatment with reduced irAEs, and the opportunity to target cDC1s as part of multimodal treatment options to boost ICI therapy.

601 Sequencing immunotherapy before lymphatic ablation unleashes cDC1-dependent antitumor immunity in HNSCC

Background

Despite the proven efficacy of immune checkpoint inhibitor (ICI) therapy in the recurrent/metastatic setting for head and neck squamous cell carcinoma (HNSCC), clinical trials of ICI combined with curative-intent therapies have yielded equivocal results [1–4]. Collectively, this highlights gaps in our understanding of rational immune oncology (IO) treatment sequencing and suggests that the efficacy ICI may be disrupted by standard therapies, which necessarily compromise regional lymphatics.

Methods

We employ a preclinical model of tobacco-signature HNSCC to identify sequences of therapy that maximize durable response. By mapping the cervical lymphatic basins in the mouse, we define patterns of active antitumor immunosurveillance. Additionally, we establish tumors with distinct patterns of regional lymphatic drainage and develop a murine neck dissection (ND) model.

Results

We find that cervical lymphatic ablation, with ND or stereotactic body radiation therapy, in tumor bearing animals abolishes the response to ICI therapy, significantly impacting overall survival. Examination of the tumor immune microenvironment following ND reveals dramatic changes with a ten-fold increase in CD45 cells and exclusion of cytotoxic and antigen-specific lymphocytes. By examining the lymphatics removed at the time of ND, we find that conventional type I dendritic cells (cDC1s) and type I interferon (IFN-I) signaling are significantly increased, suggesting that these effectors are lost after curative-intent therapy. Depleting IFN-I or cDC1s blocks the response to ICI similar to lymphatic ablation. We find that successful primary response to ICI leads to durable immunity, conferred by systemically distributed memory T cells, not impaired by delayed ND. Lastly, we discover a rational IO treatment sequence by delivering neoadjuvant ICI followed by ND. Neoadjuvant ICI leads to complete tumor response, accumulation of nodal cDC1, and durable immunity. Surprisingly, the incidence of nodal metastasis at early timepoints reveals a similar burden of nodal disease between control and ICI-treated animals that decreases at late timepoints only with ICI treatment (44% vs 15%, n=25, p=0.033). This suggests that ICI also drives active immunosurveillance in regional, tumor-draining lymphatics, challenging the landmark findings from the definitive clinical trial demonstrating the benefit of elective versus therapeutic neck dissection for oral SCC patients with clinically negative necks.

Conclusions

This work demonstrates the necessity of preserving tumor-draining lymphatics during the tumor response to ICI therapy in HNSCC. Overall, we define rational IO treatment sequences to achieve optimal primary tumor response, durable antitumor immunity and immunosurveillance of regional metastatic disease. These findings can inform future clinical trials investigating combination IO therapy and treatment sequencing.

References

Harrington, K. J. et al. Nivolumab versus standard, single-agent therapy of investigator’s choice in recurrent or metastatic squamous cell carcinoma of the head and neck (CheckMate 141): health-related quality-of-life results from a randomised, phase 3 trial. Lancet Oncology 18, 1104–1115 (2017).

Burtness, B. et al. Pembrolizumab alone or with chemotherapy versus cetuximab with chemotherapy for recurrent or metastatic squamous cell carcinoma of the head and neck (KEYNOTE-048): a randomised, open-label, phase 3 study. Lancet (London, England) 394, 1915–1928 (2019).

Lee, N. Y. et al. Avelumab plus standard-of-care chemoradiotherapy versus chemoradiotherapy alone in patients with locally advanced squamous cell carcinoma of the head and neck: a randomised, double-blind, placebo-controlled, multicentre, phase 3 trial. Lancet Oncol 22, 450–462 (2021).

D’Cruz, A. K. et al. Elective versus Therapeutic Neck Dissection in Node-Negative Oral Cancer. New England Journal of Medicine 373, 521–529 (2015).

Hypofractionated radiation therapy as palliative management for symptomatic and local control of advanced thoracic malignancies

BACKGROUND

Radiation therapy plays an important role for symptom palliation for intrathoracic malignancies ineligible for curative-intent therapy. Limited data exists regarding the role of stereotactic body radiation therapy (SBRT) versus conformal radiation in intrathoracic tumors for palliation. We report the efficacy of hypofractionated RT (or palliative SBRT) in the symptom management and durable control of lung and non-lung intrathoracic tumors.

METHODS

We performed a retrospective review of ninety-two thoracic lesions across 76 patients who completed palliative SBRT with doses ranging 25-50 Gy in 5-10 fractions between 2009 and 2019. Symptoms (cough, chest pain, hemoptysis, shortness of breath) were assessed at consult and 1-6 months follow-up. Local control was evaluated using follow-up CT imaging via RECIST criteria. Descriptive statistics were used to evaluate symptom palliation and Kaplan-Meier method to analyze local control.

RESULTS

Of primary lung (Cohort P) lesions, 40% showed stable symptoms, 30% never developed symptoms, and 19% showed symptom relief. CT imaging 1-6 months post-SBRT showed 91% with partial response (PR) or stable disease (SD) in Cohort P and 87% with PR or SD in metastatic (Cohort M) lesions. In patients with initial PR/SD, local control until death was achieved in 71% of Cohort P and 84% of Cohort M. Of our symptomatic patients (Cohort S), 98% showed no symptom progression post-radiotherapy. All patients with hemoptysis at presentation achieved hemostasis post-radiotherapy.

CONCLUSIONS

Palliative SBRT has the advantage of higher biologic dose without protracted course for patients with limited prognosis. Patients showed significant symptom palliation and long-term local control. Palliative SBRT represents a reasonable treatment modality for incurable thoracic malignancies.

Defining the Role of Immunotherapy in the Curative Treatment of Locoregionally Advanced Head and Neck Cancer: Promises, Challenges, and Opportunities

Recent advancements in the development of immunotherapies have raised the hope for patients with locally-advanced HNSCC (LA-HNSCC) to achieve improved oncologic outcomes without the heavy burden of treatment-related morbidity. While there are several ongoing late phase clinical trials that seek to determine whether immunotherapy can be effectively employed in the definitive setting, initial results from concurrent immuno-radiotherapy therapy trials have not shown strong evidence of benefit. Encouragingly, evidence from preclinical studies and early-phase neoadjuvant studies have begun to show potential pathways forward, with therapeutic combinations and sequences that intentionally spare tumor draining lymphatics in order to maximize the synergy between definitive local therapy and immunotherapy. The intent of this review is to summarize the scientific rationale and current clinical evidence for employing immunotherapy for LA-HNSCC as well as the ongoing efforts and challenges to determine how to optimally deliver and sequence immunotherapy alongside traditional therapeutics. In both the preclinical and clinical settings, we will discuss the application of immunotherapies to both surgical and radiotherapeutic management of HNSCC.

Real-world data from a molecular tumor board demonstrates improved outcomes with a precision N-of-One strategy

Next-generation sequencing (NGS) can identify novel cancer targets. However, interpreting the molecular findings and accessing drugs/clinical trials is challenging. Furthermore, many tumors show resistance to monotherapies. To implement a precision strategy, we initiated a multidisciplinary (basic/translational/clinical investigators, bioinformaticians, geneticists, and physicians from multiple specialties) molecular tumor board (MTB), which included a project manager to facilitate obtaining clinical-grade biomarkers (blood/tissue NGS, specific immunohistochemistry/RNA expression including for immune-biomarkers, per physician discretion) and medication-acquisition specialists/clinical trial coordinators/navigators to assist with medication access. The MTB comprehensively reviewed patient characteristics to develop N-of-One treatments implemented by the treating physician's direction under the auspices of a master protocol. Overall, 265/429 therapy-evaluable patients (62%) were matched to ≥1 recommended drug. Eighty-six patients (20%) matched to all drugs recommended by MTB, including combinatorial approaches, while 38% received physician's choice regimen, generally with unmatched approach/low degree of matching. Our results show that patients who receive MTB-recommended regimens (versus physician choice) have significantly longer progression-free (PFS) and overall survival (OS), and are better matched to therapy. High (≥50%) versus low (<50%) Matching Score therapy (roughly reflecting therapy matched to ≥50% versus <50% of alterations) independently correlates with longer PFS (hazard ratio [HR], 0.63; 95% confidence interval [CI], 0.50-0.80; P < 0.001) and OS (HR, 0.67; 95% CI, 0.50-0.90; P = 0.007) and higher stable disease ≥6 months/partial/complete remission rate (52.1% versus 30.4% P < 0.001) (all multivariate). In conclusion, patients who receive MTB-based therapy are better matched to their genomic alterations, and the degree of matching is an independent predictor of improved oncologic outcomes including survival.

Abstract A30: Development of an immunogenic and radioresistant orthotopic mouse model to recapitulate the stromal barriers of pancreatic cancer

Pancreatic cancer responds poorly to systemic therapies, including immunotherapy. One of the most important factors responsible for the historically poor response rates of pancreatic cancer is the presence of highly desmoplastic immunosuppressive stroma. Elevated interstitial fluid pressures (IFP) prevent the penetration of systemic therapeutics and immune cells into pancreatic tumor tissue. It has been hypothesized that ablative techniques, such as irradiation (XRT), can overcome these barriers, but only a few studies have specifically focused on pancreatic cancer, which is relatively radioresistant, due to the lack of good preclinical models. Hence, it has become increasingly important to develop mouse models of pancreatic cancer that not only have dense desmoplastic immunosuppressive stroma but also mimic its radioresistant properties. We have developed an immunocompetent mouse model of pancreatic cancer using a cell line derived from a genetically engineered KPC mouse (LSL-KrasG12D/+; LSL-Trp53R172H/+; PDX1Cre/+; LSL-ROSA26 Luc/+). Tumor pieces from subcutaneous tumors grown on C57BL/6 mice were surgically implanted on the pancreatic tails of mice of same background to develop the orthotopic tumors. Eight days post-implantation, the IFP of these tumors were measured to be 40 +/- 16 mm Hg using a microtip pressure catheter. This pressure was higher than the IFP of normal pancreas (8-15 mm Hg) and the capillary-venous blood pressures (15-30 mmHg), which mimicked the difference between pancreatic tumor IFPs and normal tissue IFPs measured in human tumors. Further, second harmonic generation microscopy was used to study the collagen deposition in these tumors, which revealed a 16 +/- 3.2 % collagen accumulation, characteristic of a desmoplastic stroma in contrast to the 1.07 +/- 0.2% in normal pancreas. Further, flow cytometry analysis in these tumors showed an excessive infiltration of immunosuppressive CD11b+, Gr-1+ myeloid-derived suppressor cells (MDSC) that amounted to 11 +/- 2.5% of total cells in the tumor. However, the CD4+ and CD8+ populations were observed to be less than 0.1% of the total tumor, which was confirmed by immunohistochemical analyses. Mice bearing these orthotopic pancreatic tumors of mean tumor volume 58 +/- 6.4 cubic mm (n=5/group) were then subjected to increasing doses of focused XRT (0, 8, 12, and 16 Gy) using a laser-guided stereotactic small-animal X-ray irradiator with 1-mm resolution. The mean tumor volumes (in cubic mm) 14 days post XRT were 612 +/- 38.6, 780 +/- 45.8, 794 +/- 47.6, 508 +/- 40.2 for 0, 8, 12, and 16 Gy of radiation without statistically significant differences between the groups. This study shows the development of a radioresistant orthotopic mouse model of pancreatic cancer with the stromal and microenvironmental characteristic of human tumors, which can be used for the preclinical study of various stromal inhibitors and immunomodulatory agents in combination with ablation techniques.

Citation Format: Jayanth Surya Narayanan Shankara Narayanan, Suna Erdem, Phillip Dominick Sanders, Andrew Sharabi, Rebekah White. Development of an immunogenic and radioresistant orthotopic mouse model to recapitulate the stromal barriers of pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on the Evolving Landscape of Cancer Modeling; 2020 Mar 2-5; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2020;80(11 Suppl):Abstract nr A30.

Abstract 109: Myeloid Syk-PI3Kg-HIF axis inhibits anti-tumor adaptive immunity: In silico design of a “first in class” novel dual-Syk/PI3K inhibitor, SRX3207, to block the immunosuppressive tumor microenvironment

Introduction: Macrophages (MΘs) play important roles in the initiation and progression of solid tumors and in establishing an immunosuppressive tumor microenvironment (TME) that dampens effective anti-tumor immune responses in cancer. Hence, targeting signaling pathways in MΘs that promote tumor immunosuppression will provide therapeutic benefit. Syk kinase is a well-established cytoplasmic protein tyrosine kinase that has been extensively studied in adaptive immune responses, but its role in macrophage-mediated inflammatory responses and innate immune responses remains poorly understood. The role of PI3Kγ in tumor growth and immunosuppression has been recently established by our and other groups. Our current study examines whether targeting two crucial signaling entities, which promote macrophage-mediated anti-inflammatory responses viz. Syk kinase and PI3K, would maximally activate the anti-tumor immune response.

Methodology: 1) We generated myeloid-specific conditional Syk k/o mice to investigate if the deletion of Syk has any role in a) macrophage polarization in vitro and in vivo; b) tumor growth in various syngeneic mouse models including LLC, B16, CT26, and MC38 carcinoma; c) tumor immunosuppression including polarization of macrophages into immunosuppressive phenotype, infiltration of myeloid-derived suppressor cells, regulatory T cells; and d) infiltration and activation of CD8+T cells in the TME. 2) We used commercially available Syk inhibitor, R788, to study the role of Syk in the control of the aforementioned phenotypes. 3) We used computational chemistry methods to develop a novel chemotype, SRX3207, which inhibits both PI3K and Syk (with a single molecule) as a strategy for combinatorial activation of anti-cancer immunity.

Results: Our results suggest that macrophage, Syk, functions upstream of Rac2 GTPase and PI-3K to modulate integrin (αvβ3/αvβ5&α4β1)-mediated polarization of immunosuppressive macrophages and tumor growth in in vivo syngeneic tumor models. Genetic or pharmacological blockade of Syk in MΘs promotes a pro-inflammatory MΘ phenotype, restores CD8+ T cell activity, destabilizes HIF under hypoxia, and stimulates an antitumor immune response. Moreover, Syk-regulated immune response gene signature predicts survival in cancer patients. Novel dual-Syk/PI3K inhibitor, SRX3207, shows great efficacy in various syngeneic tumor models with no toxicity.

Conclusions: Our results validate the concept of combined Syk and PI3K inhibition as an effective approach to treat macrophage-driven, devastating cancers. This study will open new avenues to explore this chemotype in combination with other immuno-oncologic agents as the majority of cancer patients do not respond to single agent anti-PD1 or other checkpoint inhibitors currently in clinical use.

Citation Format: Shweta Joshi, Kevin Liu, Muamera Zulcic, Alok Singh, Timothy Pham, Christopher K. Glass, Andrew Sharabi, Guillermo A. Morales, Joseph R. Garlich, Donald Durden. Myeloid Syk-PI3Kg-HIF axis inhibits anti-tumor adaptive immunity: In silico design of a “first in class” novel dual-Syk/PI3K inhibitor, SRX3207, to block the immunosuppressive tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 109.

Heparanase is expressed in adult human osteoarthritic cartilage and drives catabolic responses in primary chondrocytes

OBJECTIVES

The chondrocytes' pericellular matrix acts as a mechanosensor by sequestering growth factors that are bound to heparan sulfate (HS) proteoglycans. Heparanase is the sole mammalian enzyme with HS degrading endoglycosidase activity. Here, we aimed to ascertain whether heparanase plays a role in modulating the anabolic or catabolic responses of human articular chondrocytes.

METHODS

Primary chondrocytes were incubated with pro-heparanase and catabolic and anabolic gene expression was analyzed by quantitative polymerase chain reaction (PCR). MMP13 enzymatic activity in the culture medium was measured with a specific fluorescent assay. Extracellular regulated kinase (ERK) phosphorylation was evaluated by Western blot. Human osteoarthritis (OA) cartilage was assessed for heparanase expression by reverse-transcriptase PCR, by Western blot and by a heparanase enzymatic activity assay.

RESULTS

Cultured chondrocytes rapidly associated with and activated pro-heparanase. Heparanase induced the catabolic genes MMP13 and ADAMTS4 and the secretion of active MMP13, and down-regulated the anabolic genes ACAN and COL2A1. PG545, a HS-mimetic, inhibited the effects of heparanase. Heparanase expression and enzymatic activity were demonstrated in adult human osteoarthritic cartilage. Heparanase induced ERK phosphorylation in cultured chondrocytes and this could be inhibited by PG545, by fibroblast growth factor 2 (FGF2) neutralizing antibodies and by a FGF-receptor inhibitor.

CONCLUSIONS

Heparanase is active in osteoarthritic cartilage and induces catabolic responses in primary human chondrocytes. This response is due, at least in part, to the release of soluble growth factors such as FGF2.

Hyperprogressors after Immunotherapy: Analysis of Genomic Alterations Associated with Accelerated Growth Rate

Purpose: Checkpoint inhibitors demonstrate salutary anticancer effects, including long-term remissions. PD-L1 expression/amplification, high mutational burden, and mismatch repair deficiency correlate with response. We have, however, observed a subset of patients who appear to be "hyperprogressors," with a greatly accelerated rate of tumor growth and clinical deterioration compared with pretherapy, which was also recently reported by Institut Gustave Roussy. The current study investigated potential genomic markers associated with "hyperprogression" after immunotherapy.Experimental Design: Consecutive stage IV cancer patients who received immunotherapies (CTLA-4, PD-1/PD-L1 inhibitors or other [investigational] agents) and had their tumor evaluated by next-generation sequencing were analyzed (N = 155). We defined hyperprogression as time-to-treatment failure (TTF) <2 months, >50% increase in tumor burden compared with preimmunotherapy imaging, and >2-fold increase in progression pace.Results: Amongst 155 patients, TTF <2 months was seen in all six individuals with MDM2/MDM4 amplification. After anti-PD1/PDL1 monotherapy, four of these patients showed remarkable increases in existing tumor size (55% to 258%), new large masses, and significantly accelerated progression pace (2.3-, 7.1-, 7.2- and 42.3-fold compared with the 2 months before immunotherapy). In multivariate analysis, MDM2/MDM4 and EGFR alterations correlated with TTF <2 months. Two of 10 patients with EGFR alterations were also hyperprogressors (53.6% and 125% increase in tumor size; 35.7- and 41.7-fold increase).Conclusions: Some patients with MDM2 family amplification or EGFR aberrations had poor clinical outcome and significantly increased rate of tumor growth after single-agent checkpoint (PD-1/PD-L1) inhibitors. Genomic profiles may help to identify patients at risk for hyperprogression on immunotherapy. Further investigation is urgently needed. Clin Cancer Res; 23(15); 4242-50. ©2017 AACR.

Hyperprogressors after Immunotherapy: Analysis of Genomic Alterations Associated with Accelerated Growth Rate

Purpose: Checkpoint inhibitors demonstrate salutary anticancer effects, including long-term remissions. PD-L1 expression/amplification, high mutational burden, and mismatch repair deficiency correlate with response. We have, however, observed a subset of patients who appear to be "hyperprogressors," with a greatly accelerated rate of tumor growth and clinical deterioration compared with pretherapy, which was also recently reported by Institut Gustave Roussy. The current study investigated potential genomic markers associated with "hyperprogression" after immunotherapy.Experimental Design: Consecutive stage IV cancer patients who received immunotherapies (CTLA-4, PD-1/PD-L1 inhibitors or other [investigational] agents) and had their tumor evaluated by next-generation sequencing were analyzed (N = 155). We defined hyperprogression as time-to-treatment failure (TTF) <2 months, >50% increase in tumor burden compared with preimmunotherapy imaging, and >2-fold increase in progression pace.Results: Amongst 155 patients, TTF <2 months was seen in all six individuals with MDM2/MDM4 amplification. After anti-PD1/PDL1 monotherapy, four of these patients showed remarkable increases in existing tumor size (55% to 258%), new large masses, and significantly accelerated progression pace (2.3-, 7.1-, 7.2- and 42.3-fold compared with the 2 months before immunotherapy). In multivariate analysis, MDM2/MDM4 and EGFR alterations correlated with TTF <2 months. Two of 10 patients with EGFR alterations were also hyperprogressors (53.6% and 125% increase in tumor size; 35.7- and 41.7-fold increase).Conclusions: Some patients with MDM2 family amplification or EGFR aberrations had poor clinical outcome and significantly increased rate of tumor growth after single-agent checkpoint (PD-1/PD-L1) inhibitors. Genomic profiles may help to identify patients at risk for hyperprogression on immunotherapy. Further investigation is urgently needed. Clin Cancer Res; 23(15); 4242-50. ©2017 AACR.

Exceptional Response to Nivolumab and Stereotactic Body Radiation Therapy (SBRT) in Neuroendocrine Cervical Carcinoma with High Tumor Mutational Burden: Management Considerations from the Center For Personalized Cancer Therapy at UC San Diego Moores Cancer Center

This article reports a patient with a rare metastatic, chemotherapy‐refractory neuroendocrine carcinoma who was treated with stereotactic body radiation therapy (SBRT) combined with anti‐programmed cell death protein 1 antibody. The novel treatment modality of SBRT combined with a checkpoint inhibitor is discussed, as well as the implications of molecular profiling and tumor mutational burden as potential predictors of response.

Neuroendocrine carcinoma of the cervix is an ultra‐rare malignancy with a poor prognosis and limited treatment options. Checkpoint blockade immunotherapy has rapidly developed into an emerging standard of care for several common disease types. Interestingly, in preclinical and retrospective clinical data, radiation therapy has been demonstrated to synergize with checkpoint inhibitors. Here we report a patient with metastatic, chemotherapy‐refractory neuroendocrine carcinoma who presented with partial bowel obstruction due to a large tumor burden. Genomic analysis demonstrated a high number of alterations on liquid biopsy (circulating tumor DNA [ctDNA]), which prompted treatment with stereotactic body radiation therapy (SBRT) combined with anti‐programmed cell death protein 1 antibody. Tissue rebiopsy and comprehensive genomic profiling confirmed high tumor mutational burden and a mismatch repair gene defect. The patient manifested near‐complete systemic resolution of disease, ongoing at 10+ months. We discuss the novel treatment modality of SBRT combined with a checkpoint inhibitor and the implications of molecular profiling and tumor mutational burden as potential predictors of response.

Key Points.

High‐grade, large‐cell neuroendocrine carcinoma of the cervix is an ultra‐rare malignancy that carries a grim prognosis.

Next‐generation sequencing may reveal key mutations in MSH2 genes amongst others. MSH2 mutations target the DNA mismatch repair process and can predispose patients to malignancies with high mutational burdens.

Immunotherapy combined with radiation therapy can elicit a significant response, both within and outside the field of radiation. The latter is termed the “abscopal” effect, perhaps mediated by radiation‐induced cross presentation of tumor antigens resulting in immune activation.

Sequencing of blood‐derived ctDNA showed a high number of alterations, and tissue sequencing confirmed a high tumor mutational burden as a consequence of a mismatch repair gene defect. This observation led to a therapeutic “match” with an anti‐ programmed cell death protein 1 antibody combined with SBRT, resulting in a durable (10+ months), near‐complete remission in a patient with advanced chemotherapy‐refractory disease.

Specificity of Genetic Biomarker Studies in Cancer Research: A Systematic Review

As genetic information becomes more readily available, there is increasing demand from both patients and providers to develop personalized approaches to cancer care. Investigators are increasingly reporting numbers of studies correlating genomic signatures and other biomarkers to survival endpoints. The extent to which cancer-specific and non-specific effects are reported in contemporary studies is unknown. In this review of 85 high-impact studies associating genetic biomarkers with cancer outcomes, 95% reported significant associations with event-free survival outcomes, yet less than half reported effects on a cancer-specific endpoint. This methodology leaves open the possibility that observed associations are unrelated to cancer.

Summary and Recommendations from the National Cancer Institute's Clinical Trials Planning Meeting on Novel Therapeutics for Non-Muscle Invasive Bladder Cancer

The NCI Bladder Cancer Task Force convened a Clinical Trials Planning Meeting (CTPM) Workshop focused on Novel Therapeutics for Non-Muscle Invasive Bladder Cancer (NMIBC). Meeting attendees included a broad and multi-disciplinary group of clinical and research stakeholders and included leaders from NCI, FDA, National Clinical Trials Network (NCTN), advocacy and the pharmaceutical and biotech industry. The meeting goals and objectives were to: 1) create a collaborative environment in which the greater bladder research community can pursue future optimally designed novel clinical trials focused on the theme of molecular targeted and immune-based therapies in NMIBC; 2) frame the clinical and translational questions that are of highest priority; and 3) develop two clinical trial designs focusing on immunotherapy and molecular targeted therapy. Despite successful development and implementation of large Phase II and Phase III trials in bladder and upper urinary tract cancers, there are no active and accruing trials in the NMIBC space within the NCTN. Disappointingly, there has been only one new FDA approved drug (Valrubicin) in any bladder cancer disease state since 1998. Although genomic-based data for bladder cancer are increasingly available, translating these discoveries into practice changing treatment is still to come. Recently, major efforts in defining the genomic characteristics of NMIBC have been achieved. Aligned with these data is the growing number of targeted therapy agents approved and/or in development in other organ site cancers and the multiple similarities of bladder cancer with molecular subtypes in these other cancers. Additionally, although bladder cancer is one of the more immunogenic tumors, some tumors have the ability to attenuate or eliminate host immune responses. Two trial concepts emerged from the meeting including a window of opportunity trial (Phase 0) testing an FGFR3 inhibitor and a second multi-arm multi-stage trial testing combinations of BCG or radiotherapy and immunomodulatory agents in patients who recur after induction BCG (BCG failure).

Abstract 635: Antigen-specific immune responses in melanoma using stereotactic radiotherapy combined with anti-PD1 checkpoint blockade

Purpose: Multiple pre-clinical studies and case reports have described potential synergy between radiotherapy and immunotherapy, including checkpoint blockade with anti-PD1 and anti-CTLA-4 antibodies. However, further understanding of how radiotherapy contributes to immune mediated cell death, especially with regards to timing and dose per fraction, is needed to guide protocols for clinical trials. Here we investigated the development of radiation induced antigen-specific immune responses (RASIR) using stereotactic image guided small animal radiotherapy combined with anti-PD1 checkpoint blockade in a B16 melanoma model.

Experimental Design: MC38 colorectal carcinoma, B16, and B16-OVA melanoma were cultured in complete RPMI media. A gamma-cell irradiator was used for in-vitro irradiation of cell suspensions. For in-vivo experiments 6-8 week old C57BL/6 mice were injected with 1x10^5 or 5x10^5 B16-OVA cells into the flank. Tumors were irradiated using a stereotactic CT guided small animal irradiator to treat a 1cmx1cm field prescribed to isocenter. For adoptive transfer experiments mice received 2x10^6 purified OT1 T-cells via retro-orbital injection. Anti-PD1 antibody was given intraperitoneally in three scheduled doses of 200ug. Cells were processed, stained, and analyzed by Flow cytometry on BD FACSCaliber or LSR II for indicated cell surface markers or intracellular cytokines.

Results: We found that irradiation with 10Gy or 20Gy increased cell surface expression of MHC Class I, CCR7, CXCR3, and FAS in MC38 colorectal carcinoma and B16 melanoma at 24 and 48 Hours. We observed in-vivo that stereotactic radiotherapy of B16-OVA melanoma tumors increased CFSE labeled proliferation and Interferon-gamma activation of adoptively transferred OT1 T-cells in the draining lymph node and spleen. 18 Gy of radiotherapy resulted in increased activation and proliferation of antigen-specific T-cells when compared to 12Gy suggesting a possible dose response. Furthermore, when radiotherapy was combined with scheduled anti-PD1 antibody there was near eradication of B16-OVA melanoma tumors accompanied by increased development of endogenous antigen-specific immune responses.

Conclusions: Radiotherapy increased expression of immunogenic cell surface markers in MC38 colorectal carcinoma and B16 melanoma. Stereotactic radiotherapy induced endogenous CD8 mediated antigen-specific immune responses when combined with scheduled anti-PD1 immunotherapy and resulted in near eradication of established B16-OVA melanoma. This study provides important pre-clinical evidence to support and guide clinical trials combining radiotherapy with anti-PD1 checkpoint blockade in melanoma. Future goals include analyzing development of RASIR using fractionated stereotactic radiotherapy with combined checkpoint blockade in multiple different tumor types.

Citation Format: Andrew Sharabi, Christopher Nirschl, Tina Ceccato, Brian Francica, Angela Alme, Thomas Nirschl, Esteban Velarde, Theodore DeWeese, Charles Drake. Antigen-specific immune responses in melanoma using stereotactic radiotherapy combined with anti-PD1 checkpoint blockade. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 635. doi:10.1158/1538-7445.AM2014-635

Current standards and future directions for prostate cancer radiation therapy

Definitive radiation therapy is a well-recognized curative treatment option for localized prostate cancer. A suitable technique, dose, target volume and the option of a combination with androgen deprivation therapy need to be considered. An optimal standard external beam radiotherapy currently includes intensity-modulated and image-guided radiotherapy techniques with total doses of ≥76-78 Gy in conventional fractionation. Protons or carbon ions are alternatives available only in specific centers. Data from several randomized studies increasingly support the rationale for hypofractionated radiotherapy. A simultaneous integrated boost with dose escalation focused on a computed tomography/PET- or MRI/magnetic resonance spectroscopy-detected malignant lesion is one option to increase tumor control, with potentially no additional toxicity. The application of a spacer is a promising concept for optimal protection of the rectal wall.