Abstract
TPS3128
Background: Coxsackievirus A21 (CVA21: CAVATAK) is a naturally occurring "common cold" virus. CVA21 displays potent oncolytic activity against both in vitro cultures of cancer cells and against in vivo xenografts of human cancers in mouse models of melanoma, prostate cancer, breast cancer and multiple myeloma, all which exhibit high surface ICAM-1 expression, which is used for viral entry. In mouse human melanoma xenograft CVA21 challenge models, progeny virus released from infected cells is capable of targeting adjacent cells, entering the systemic circulation, and destroying micro-metastatic foci. In a phase 1 study, two intralesional injections of CVA21 were shown to reduce or stabilize the growth of injected melanoma lesions. Methods: The CALM study investigates the efficacy and safety of intratumoral CVA21 in approximately 63 pts with treated or untreated unresectable Stage IIIC-IVM1c melanoma. Pts are treated with up to 3 x 10
8
TCID
50
intratumorally on study days 1, 3, 5 and 8 and then every three weeks for a further 6 injections. Key eligibility criteria are ≥ 18 yrs old, ECOG 0-1, and at least 1 injectable cutaneous, sc, or nodal tumor >1.0 cm. The primary endpoint is irPFS at 6 months following tx; secondary endpoints include durable response rate and OS. A 2-stage Simon’s minimax design will be employed. Based on data from previous trials and literature, a target overall irPFS at 6 months of 22.5% versus a projected rate of 10% in the target population is selected. With an alpha level of 5% and 80% of power, a total of 54 evaluable patients will be required to test the null hypothesis that the true irPFS rate is <10% versus the alternative hypothesis that the true irPFS rate is at least 22.5%. Thirty-five patients will be treated at Stage I. If 3 or more objective responses (CR or PR) are achieved by modified RECIST 1.1 criteria in the first 35 patients, then the study will complete enrollment. Results: Currently, 21 patients have been enrolled on the study and treated with CVA21 injections. The treatment has been well tolerated. The Stage I interim efficacy endpoint of > 3 objective responses has been achieved, and the second stage of the study is proceeding with a planned enrollment of a total of 63 patients. Clinical trial information: NCT01227551.