Clinical trials in cancer theranostics with potential near-term impact on clinical practice

Theranostics has its roots with the first radioiodine therapy for thyroid diseases in about 80 years ago. More recently the field has experienced a remarkable renascence with the regulatory approval of paired imaging and radiopharmaceutical therapy agents in gastroenteropancreatic neuroendocrine tumours and metastatic castration-resistant prostate cancer that are now employed in routine clinical practice. The momentum is strong for identification and testing of new theranostic agents for use in various cancers and finding new clinical indications of the available agents. There are currently numerous preclinical, first-in-human studies, large-scale prospective registries, and clinical trials including randomized trials underway in cancer theranostics that target a variety of germane biological targets. The results of these investigations, if successful, will undoubtedly impact the future of cancer management which is anticipated to improve patient outcome. Multi-targeted theranostics may also provide opportunities for synergistic efficacy to tackle the inherent complexities driven by the heterogeneity of cancer. In this article, we review the currently active recruiting phase 2 and phase 3 clinical trials in cancer theranostics that are targeted to the prostate-specific membrane antigen, gastrin-releasing peptide receptor, and fibroblast activation protein, with the anticipated potential near-term (<5 years) impact on clinical practice.