Genetic diversity of Coxsackievirus A21 associated with sporadic cases of acute respiratory infections in Malaysia

Clinical and Genomic Epidemiology of Coxsackievirus A21 and Enterovirus D68 in Homeless Shelters, King County, Washington, USA, 2019-2021

Congregate homeless shelters are disproportionately affected by infectious disease outbreaks. We describe enterovirus epidemiology across 23 adult and family shelters in King County, Washington, USA, during October 2019-May 2021, by using repeated cross-sectional respiratory illness and environmental surveillance and viral genome sequencing. Among 3,281 participants >3 months of age, we identified coxsackievirus A21 (CVA21) in 39 adult residents (3.0% [95% CI 1.9%-4.8%] detection) across 7 shelters during October 2019-February 2020. We identified enterovirus D68 (EV-D68) in 5 adult residents in 2 shelters during October-November 2019. Of 812 environmental samples, 1 was EV-D68-positive and 5 were CVA21-positive. Other enteroviruses detected among residents, but not in environmental samples, included coxsackievirus A6/A4 in 3 children. No enteroviruses were detected during April 2020-May 2021. Phylogenetically clustered CVA21 and EV-D68 cases occurred in some shelters. Some shelters also hosted multiple CVA21 lineages.

Development of a robust cell-based potency assay for a coxsackievirus A21 oncolytic virotherapy

Oncolytic viruses (OV) are part of a burgeoning field of investigational oncolytic therapy (OT), in which lytic viruses dissolve advanced tumors productively and specifically. One such OT is a Coxsackievirus A21 (CVA21) based OV that is currently under clinical evaluation. A tissue culture infectious dose (TCID50) assay was used for CVA21 potency release and stability testing in early clinical development. The titer measured in this method was an extrapolated value from cytopathic effect (CPE) observed during the serial dilution but doesn't represent direct viral killing of cells. Moreover, the assay was not deemed to be optimal to carry into late phase clinical development due to limitations in assay precision, turn-around time, and sample throughput. To address these points, we developed a plaque assay to measure viral plaque forming units to measure the potency value for drug substance (DS), drug product (DP) and virus seed (master and working) stocks. In this manuscript, we describe the steps taken to develop this plaque assay for the late-stage clinical development, which include the assay qualification, validation, and robustness protocols, and describe statistical methods for data analysis. Moreover, the method was validated for linearity, accuracy, precision, and specificity. Furthermore, the plaque assay quantifies OV infectivity with better precision (32% vs 58%), with higher sample throughput (22 samples/week vs 3 samples/week) and shorter assay turnaround time (4 days vs 7 days) than the TCID50 method. This assay development strategy can provide guidance for the development of robust cell-based potency methods for OVs and other infectious viral products.

Phase 1b study of intravenous coxsackievirus A21 (V937) and ipilimumab for patients with metastatic uveal melanoma

PURPOSE

No standard of care therapy exists for patients with metastatic uveal melanoma who are not HLA-A2:01 positive. The phase 1b, open-label CLEVER study (NCT03408587) evaluated V937 in combination with ipilimumab in patients with uveal melanoma.

METHODS

Adults with advanced uveal melanoma and liver metastases received up to 8 cycles of intravenous V937 (1 × 109 TCID50 per infusion; infusions on days 1, 3, 5, and 8 [cycle 1], then every 3 weeks [Q3W] thereafter [cycles 2-8]) and 4 cycles of intravenous ipilimumab 3 mg/kg Q3W (beginning at cycle 1 day 8). The primary endpoint was safety. Secondary endpoints included objective response rate and progression-free survival (PFS) per immune-related Response Evaluation Criteria in Solid Tumors (irRECIST).

RESULTS

Eleven patients were enrolled (median age, 65.0 years) and received a median of 6 injections of V937 and 3.5 infusions of ipilimumab. The best overall response was stable disease in 3 patients and progressive disease in 8 patients. All patients exhibited progression per irRECIST, with a 9% irPFS rate at week 26. Ten patients had treatment-related AEs, the most frequent of which were diarrhea (55%), fatigue (45%), and myalgia (36%). Two grade 3 AEs (diarrhea, n = 2) were considered related to ipilimumab; neither was related to V937.

CONCLUSION

Although the combination of V937 with ipilimumab had a manageable safety profile, meaningful clinical benefit was not observed in patients with uveal melanoma and liver metastases.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03408587 (January 24, 2018).