Citations

TPS3172 Background: Bladder cancer is a leading cause of cancer death in the United States. Over 90% of bladder cancer cases are urothelial carcinomas (UC) that may present as a non-muscle-invasive (NMIBC) or muscle-invasive disease (MIBC). Standard of care for NMIBC includes transurethral resection of bladder tumor (TURBT), intravesical chemotherapy and immunotherapy with Bacillus Calmette-Guerin (BCG). Patients (pts) with high-grade BCG-refractory NMIBC or MIBC undergo RC, which involves complete bladder removal and pelvic lymphadenectomy. RC severely impacts quality of life with significant morbidity. Oncolytic viruses are showing promise in UC, and MV-NIS has proven efficacy in other tumor types. MV-NIS is an investigational oncolytic measles virus with an excellent safety profile, irrespective of route of administration (n > 100). MV-NIS-related adverse events are limited to infusion reactions and transient CBC changes, and little local toxicity is anticipated with intravesical therapy. Clinical efficacy of this oncolytic may be related to absence of measles immunity. Based on this, the clinical strategy for MV-NIS is focused on targeting immune-privileged sites via intra-tumoral or intravesical routes, alone or in combination with checkpoint inhibitors. We hypothesize that intravesical therapy with oncolytic MV-NIS can improve clinical outcomes for (a) BCG refractory NMIBC pts to avoid or delay the need for RC; and (b) MIBC pts undergoing RC. Methods: This study is enrolling pts undergoing RC who are ineligible to receive neoadjuvant chemotherapy. The trial has 2 stages to (a) determine the safety and tolerability of intravesical MV-NIS, and (b) assess preliminary efficacy. Part (a) includes 4-24 pts in a timing cohort with doses administered at increasing durations (1-4 weeks) prior to RC to establish safety of a single MV-NIS dose. Part (b) includes an expansion cohort (n = 12) to evaluate the safety and efficacy of 2 intravesical doses of MV-NIS at 2-week intervals prior to RC. Safety is assessed using NCI-CTCAE V5 and Clavien-Dindo grading of operative complications. The efficacy endpoint is pathologic stage at time of RC (pT0 rate), which can be compared to pre-study TURBT stage. Additional exploratory studies include PK and PD analyses in urine, blood and tumor. Enrollment is ongoing at 2 Mayo Clinic sites (Rochester, MN and Jacksonville, FL) and the study has now progressed from the timing cohort into the expansion cohort. Clinical trial information: NCT03171493 .

TPS3161 Background: VV1 is an oncolytic vesicular stomatitis virus engineered to express human IFNβ to enhance cellular anti-tumor immune responses and tumor selectivity, and the human sodium iodide symporter (NIS) for virus tracking by SPECT imaging. Cancer cells are often hyporesponsive to IFNβ, enabling the efficient spread of VV1 and resulting in increased oncolysis. Differently from other oncolytic viruses, VV1 is suitable for both intra-tumoral (IT) and/or intra-venous (IV) administration. Despite considerable anti-tumor activity with checkpoint inhibitors (CPI) among some malignancies, long term survival and overall cures remain elusive. Prior Ph 1 studies have shown significant anti-tumor activity among several malignancies when VV1 was administered either as monotherapy or in combination with a CPI, despite progression on prior CPI monotherapy. Furthermore, pre- and post-treatment biopsy evaluations after VV1 treatment have demonstrated T cell infiltration and inflammation in both IT injected and non-injected lesions. Among IV treated patients (pts), IFNβ was detectable in the serum correlating with viral replication, making it an effective biomarker. C is a high-affinity potent human IgG4 anti-PD-1 monoclonal antibody. Though approved for use in cutaneous squamous cell carcinoma, C has shown anti-tumor activity, similar to other CPI, in several other indications. Therefore, VV1 and C could be an attractive combination for the immunotherapy for several solid tumors. This study represents the first clinical evaluation of VV1 in combination with C in pts with advanced solid tumors. Methods: The Ph 2 Simon 2 stage five-arm study of IV administration VV1 in combination with IV C will enroll pts with advanced NSCLC, HCC, melanoma & endometrial cancer. Enrolled pts with NSCLC & melanoma will be recent CPI-progressors, whereas enrolled HCC & endometrial cancer will be CPI-naïve. The study’s objectives include assessment of preliminary anti-tumor activity, safety, & immuno-regulatory activity of the combination. Pts will receive IV VV1 once on D1 and IV C once every 3 weeks until confirmed disease progression or intolerable toxicity. Pts enrolled in one melanoma cohort will also receive IT VV1 administered to palpable lesions. Response will be assessed every 9 weeks per RECIST v1.1. The null hypothesis of each cohort’s ORR will be tested versus a one-sided alternative yielding a Type I error rate of 5% and power of 80%. Cohorts will be expanded based on signal of activity. Clinical trial information: NCT .

3090 Background: VV1 (Voyager V1) is derived from VSV, an RNA virus with low human seroprevalence, engineered to replicate selectively in and kill human cancer cells. In Part 1 of this study, we demonstrated the safety of intratumoral VV1 and dose-response, using serum IFNβ as a biomarker; we observed viral replication in tumor and concomitant lymphocyte/neutrophil trafficking (SITC 2018). 2 other studies suggested greater efficacy and higher IFNβ levels with IV administration. Longer infusion durations were reported to mitigate infusion reactions (IRRs) for another oncolytic. Methods: We studied 3 different infusion durations of VV1 monotherapy at the recommended phase 2 IV dose (1.7 x 1010 TCID50) in patients with advanced solid tumors. Endpoints included safety, preliminary anti-tumor activity, viral titers, IFNβ PD and shedding. Patients received IV VV1 once on D1 and were monitored for DLT over 21 days with efficacy assessments every 6 weeks. IRRs were classified using Lee 2014 criteria for CRS as either constitutional symptoms only (G1) or involving hypotension (G2). Results: 18 patients were treated at 30, 60 and 180-minute durations (n = 7, 5 and 6, respectively). No DLTs, deaths or G3-4 related IRR AEs were observed. Most pts were female (67%), white (100%), with ECOG PS 0 (61%) and median 4 lines of prior systemic therapy (range 1-14) for colorectal (CRC; 56%), squamous cell carcinoma (11%), pheochromocytoma (11%), sarcoma (11%) or other (11%) cancers. The table shows results (number of patients) by infusion duration. Conclusions: There was no difference in safety between the 3 infusion durations, while efficacy and PD markers suggested better anti-tumor effect with 30-minute infusion. VV1 is safe for caregivers, with no viral shedding. Part 3 of this study will now treat CRC patients with VV1 in combination with a checkpoint inhibitor (avelumab). A 5-arm phase 2 basket study in combination with cemiplimab is proceeding with 30-minute infusions. Clinical trial information: NCT02923466 . [Table: see text]

3022 Background: Axi-cel is a US and EU-approved autologous anti-CD19 chimeric antigen receptor (CAR) T cell therapy for pts with relapsed/refractory large B cell lymphoma after ≥ 2 prior therapies. In ZUMA-1 (NCT02348216), the objective response rate was 83% (58% complete response rate; Locke et al. Lancet Oncol. 2019). T cell-related biology (Immunosign 21; Immunoscore) measured pretreatment in the tumor microenvironment (TME) was associated with response to axi-cel (Rossi et al. AACR 2018. #LB-016; Rossi et al. AACR 2019. #CT153). This expanded analysis characterized the pretreatment TME immune contexture and examined associations between immune cell subsets and response. Methods: In ZUMA-1, pts received axi-cel at a target dose of 2.0 × 106 CAR T cells/kg. Archival pretreatment tumor biopsy samples were analyzed by multiplex immunohistochemistry (Brightplex). Two panels were developed and applied to assess T cell (CD3, CD8, FoxP3, PD-1, LAG-3, TIM-3) and myeloid cell (CD11b, CD14, CD15, LOX1, S100A9, CD68) subsets (n = 14 total). The association between T cell and myeloid cell subset density, prespecified immune scores (Immunosign 21; Immunoscore), and objective response was evaluated. T test values were based on Brightplex analysis. Results: Pretreatment tumor biopsy samples from 18 pts were analyzed (14 objective responders and 4 nonresponders). The pretreatment TME comprised all major myeloid and T cell subsets, with diverse distribution across samples analyzed. The median TME density of monocytes (CD11b+ CD15− CD14+; 1215 cells/mm2) and macrophages (CD68+; 530 cells/mm2) was greater than that of the total CD8+ T cell subset (312 cells/mm2). The pretreatment Immunosign 21 and Immunoscore scores associated positively with the density of all major T cell subsets and some myeloid subsets. The density of activated CD8+ T cells (PD-1+ LAG-3+/− TIM-3−) was most significantly associated with clinical response versus other T cell subsets. The density of nonactivated CD8+ T cells (PD-1− LAG-3− TIM-3−) and exhausted CD8+ T cells (PD-1+ LAG-3+ TIM-3+) were not significantly associated with response. Additional characterization of the immune contexture and correlative analysis of cell subsets will be presented. Conclusions: These results suggest that a TME associated with increased density of activated PD-1+ LAG-3+/− TIM-3− CD8+ T cells, measurable pretreatment, facilitates clinical response in pts post–axi-cel.

SUMMARY Given their malignant potential, resection of esophageal granular cell tumors (GCTs) is often undertaken, yet the optimal technique is unknown. We present a large series of dedicated endoscopic resection using band ligation (EMR-B) of esophageal GCTs. Patients diagnosed with esophageal GCTs between 2002 and 2019 were identified using a prospectively collected pathology database. Endoscopic reports were reviewed, and patients who underwent dedicated EMR-B of esophageal GCTs were included. Medical records were queried for demographics, findings, adverse events, and follow-up. We identified 21 patients who underwent dedicated EMR-B for previously identified esophageal GCT. Median age was 39 years; 16 (76%) were female. Eight (38%) had preceding signs or symptoms, potentially attributable to the GCT. Upon endoscopic evaluation, 12 (57%) were found in the distal esophagus. Endoscopic ultrasound was used in 15 cases (71%). Median lesion size was 7 mm, interquartile range 4 mm—8 mm. The largest lesion was 12 mm. A total of 20 (95%) had en bloc resection confirmed with pathologic examination. The only patient with tumor extending to the resection margin underwent surveillance endoscopy that showed no residual tumor. No patients experienced bleeding, perforation, or stricturing in our series. No patients have had known recurrence of their esophageal GCT. EMR-B of esophageal GCT achieves complete histopathologic resection with minimal adverse events. EMR-B is safe and effective and seems prudent compared with observation for what could be an aggressive and malignant tumor. EMR-B should be considered first-line therapy when resecting esophageal GCT up to 12 mm in diameter.

Abstract Allogeneic hematopoietic cell transplantation (HCT) is the only curative therapy for myelofibrosis (MF). In this large multicenter retrospective study, overall survival (OS) in MF patients treated with allogeneic HCT (551 patients) and without HCT (non-HCT) (1377 patients) was analyzed with Cox proportional hazards model. Survival analysis stratified by the Dynamic International Prognostic Scoring System (DIPSS) revealed that the first year of treatment arm assignment, due to upfront risk of transplant-related mortality (TRM), HCT was associated with inferior OS compared with non-HCT (non-HCT vs HCT: DIPSS intermediate 1 [Int-1]: hazard ratio [HR] = 0.26, P < .0001; DIPSS-Int-2 and higher: HR, 0.39, P < .0001). Similarly, in the DIPSS low-risk MF group, due to upfront TRM risk, OS was superior with non-HCT therapies compared with HCT in the first-year post treatment arm assignment (HR, 0.16, P = .006). However, after 1 year, OS was not significantly different (HR, 1.38, P = .451). Beyond 1 year of treatment arm assignment, an OS advantage with HCT therapy in Int-1 and higher DIPSS score patients was observed (non-HCT vs HCT: DIPSS-Int-1: HR, 2.64, P < .0001; DIPSS-Int-2 and higher: HR, 2.55, P < .0001). In conclusion, long-term OS advantage with HCT was observed for patients with Int-1 or higher risk MF, but at the cost of early TRM. The magnitude of OS benefit with HCT increased as DIPSS risk score increased and became apparent with longer follow-up.

Increasing data support the importance of preexisting host immune response and neoantigen burden for determining response to immune checkpoint inhibitors (ICIs). In lung cancer and melanoma, tumor mutational burden (TMB) has emerged as an independent biomarker for ICI response. However, the significance of TMB in breast cancer, particularly in the context of PD-L1 negativity, remains unclear. This report describes a patient with HER2-negative breast cancer with high TMB and an apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like (APOBEC) trinucleotide signature; her disease was refractory to multiple lines of treatments but achieved durable complete response using ICIs and capecitabine. Additional analysis of the tumor revealed a low amount of stromal tumor-infiltrating lymphocytes (sTILs) and PD-L1 negativity, reflecting a poor preexisting host immune response. In collaboration with Foundation Medicine, comprehensive genomic profiling from 14,867 patients with breast cancer with the FoundationOne test was evaluated. Using the cutoff of ≥10 mutations/megabase (mut/Mb) for high TMB, PD-L1 positivity and TMB-high populations were not significantly overlapping (odds ratio, 1.02;P=.87). Up to 79% of TMB-high tumors with >20 mut/Mb were PD-L1–negative. Our study highlights that despite having low TILs and PD-L1 negativity, some patients may still experience response to ICIs.

Abstract Genetic variants that define two distinct haplotypes at the TMEM106B locus have been implicated in multiple neurodegenerative diseases and in healthy brain ageing. In frontotemporal dementia (FTD), the high expressing TMEM106B risk haplotype was shown to increase susceptibility for FTD with TDP-43 inclusions (FTD-TDP) and to modify disease penetrance in progranulin mutation carriers (FTD-GRN). To elucidate the biological function of TMEM106B and determine whether lowering TMEM106B may be a viable therapeutic strategy, we performed brain transcriptomic analyses in 8-month-old animals from our recently developed Tmem106b−/− mouse model. We included 10 Tmem106b+/+ (wild-type), 10 Tmem106b+/− and 10 Tmem106−/− mice. The most differentially expressed genes (153 downregulated and 60 upregulated) were identified between Tmem106b−/− and wild-type animals, with an enrichment for genes implicated in myelination-related cellular processes including axon ensheathment and oligodendrocyte differentiation. Co-expression analysis also revealed that the most downregulated group of correlated genes was enriched for myelination-related processes. We further detected a significant loss of OLIG2-positive cells in the corpus callosum of Tmem106b−/− mice, which was present already in young animals (21 days) and persisted until old age (23 months), without worsening. Quantitative polymerase chain reaction revealed a reduction of differentiated but not undifferentiated oligodendrocytes cellular markers. While no obvious changes in myelin were observed at the ultrastructure levels in unchallenged animals, treatment with cuprizone revealed that Tmem106b−/− mice are more susceptible to cuprizone-induced demyelination and have a reduced capacity to remyelinate, a finding which we were able to replicate in a newly generated Tmem106b CRISPR/cas9 knock-out mouse model. Finally, using a TMEM106B HeLa knock-out cell line and primary cultured oligodendrocytes, we determined that loss of TMEM106B leads to abnormalities in the distribution of lysosomes and PLP1. Together these findings reveal an important function for TMEM106B in myelination with possible consequences for therapeutic strategies aimed at lowering TMEM106B levels.

Abstract Glioblastomas are the most common form of malignant primary brain tumor and an important cause of morbidity and mortality. In recent years there have been important advances in understanding the molecular pathogenesis and biology of these tumors, but this has not translated into significantly improved outcomes for patients. In this consensus review from the Society for Neuro-Oncology (SNO) and the European Association of Neuro-Oncology (EANO), the current management of isocitrate dehydrogenase wildtype (IDHwt) glioblastomas will be discussed. In addition, novel therapies such as targeted molecular therapies, agents targeting DNA damage response and metabolism, immunotherapies, and viral therapies will be reviewed, as well as the current challenges and future directions for research.

Context.— Autopsy rates have decreased dramatically despite providing important clinical information to medical practices and social benefits to decedents' families. Objective.— To assess the impact of an institutional Office of Decedent Affairs (ODA), a direct communication link between pathology and decedents' families, on hospital autopsy consent rates, autopsy-related communication, practitioner views, and next-of-kin experiences. Design.— A before and after study involving all hospital decedents whose deaths did not fall within the jurisdiction of the medical examiner's office from 2013 to 2018. A pathology-run ODA launched in May 2016 to guide next-of-kin through the hospital death process (including autopsy-related decisions) and serve as the next-of-kin's contact for any subsequent autopsy-related communication. Critical care and hematology/oncology practitioners were assessed for their autopsy-related views and decedents' next-of-kin were assessed for their autopsy-related experiences. Autopsy consent rates for non–medical examiner hospital deaths, autopsy-related communication rates, practitioner views on the role and value of autopsy, and next-of-kin autopsy experiences and decisions factors were compared prior to and after ODA launch. Results.— Autopsy consent rates significantly increased from 13.2% to 17.3% (480 of 3647 deaths versus 544 of 3148 deaths; P < .001). There were significant increases in the rate of autopsy-related discussions and bereavement counseling provided to decedents' families. Practitioner views on the positive role of autopsy for any hospital death and those with advanced stage cancer also significantly increased. Next-of-kin indicated more consistent autopsy-related discussions with the potential benefits of autopsy discussed becoming key decision factors. Conclusions.— An ODA improves hospital autopsy consent rates, autopsy-related communication, providers' autopsy-related views, and next-of-kins autopsy experiences.