CLD-201 Receives FDA Fast Track Designation Targeting Sarcoma

The investigational allogeneic adipose stem cell-loaded oncolytic virus, CLD-201 (SuperNova), has been granted fast track designation by the US FDA for the treatment of soft tissue sarcoma. This designation aims to expedite the development and review process for CLD-201, a therapy designed to address a significant unmet medical need in oncology.¹

The fast track designation, a program designed to facilitate the development and accelerate the review of drugs that treat serious conditions and fill an unmet medical need, signals the FDA's recognition of CLD-201's potential in sarcoma.^1,2 This status will enable more frequent interactions between Calidi Biotherapeutics, the sponsor, and the FDA throughout the development process, potentially leading to eligibility for priority review and accelerated approval, contingent on future clinical data.

“FDA [investigational new drug] clearance and fast track designation represent an important milestone in the development of CLD-201. This designation underscores the unmet medical need in sarcoma and provides scientific and regulatory validation of CLD-201. We believe CLD-201 has the potential to provide durable and transformational treatment to patients with sarcoma as well as patients with other advanced tumor types. We want to thank the FDA for its support and partnership and look forward to continued collaboration with the agency,” said Guy Travis Clifton, MD, chief medical officer of Calidi Biotherapeutics, in a press release.¹

CLD-201 is an innovative therapeutic candidate comprising adipose-derived mesenchymal stem cells loaded with an oncolytic vaccinia virus. This unique stem-cell loading strategy is designed to shield the oncolytic virus from immune system clearance, allowing for enhanced viral amplification within the stem cells. This mechanism is intended to increase the potency of the viral therapy, promote immune activation, and ultimately lead to enhanced anti-tumor efficacy, as observed in preclinical animal models.

The forthcoming phase 1 clinical trial will be a first-in-human, open-label, multicenter study. This trial aims to evaluate the safety, tolerability, and preliminary efficacy of CLD-201 across several advanced solid tumor types, including sarcoma, triple-negative breast cancer, and head and neck squamous cell carcinoma. The inclusion of multiple tumor types in the initial study phase suggests the broad potential applicability of this oncolytic viral platform beyond soft tissue sarcoma.

Soft tissue sarcomas are a heterogeneous group of rare cancers that originate in the soft tissues of the body, such as muscle, fat, fibrous tissue, blood vessels, or nerves. Treatment for advanced or metastatic soft tissue sarcoma remains challenging, often involving surgery, radiation therapy, and chemotherapy, with limited durable responses. The development of novel therapeutic approaches, such as oncolytic viruses, represents a significant area of research to improve patient outcomes in this difficult-to-treat population.

Calidi Biotherapeutics' broader strategy revolves around its proprietary Redtail platform, which focuses on developing targeted therapies capable of delivering genetic medicines to distal sites of disease. This platform leverages advanced enveloped technology designed to evade immune detection, allowing for systemic delivery of viral vectors. The company aims for these virotherapies to effectively reach tumor sites, induce tumor lysis, and deliver potent gene therapies to metastatic locations. Beyond CLD-201, the Redtail platform's lead candidate, currently in IND-enabling studies, targets non-small cell lung cancer, ovarian cancer, and other tumor types with high unmet medical needs. Additionally, Calidi is developing other clinical-stage protected virotherapies for intratumoral and localized administration, focusing on injectable cancer indications. The Fast Track designation for CLD-201 highlights the potential of this innovative approach in addressing complex oncologic challenges.

REFERENCES:

1. Calidi Biotherapeutics Receives FDA Fast Track Designation for CLD-201 (SuperNova), a First-In-Class Stem-Cell Loaded Viral Therapy for the Treatment of Patients with Soft Tissue Sarcoma. News release. Calidi Biotherapeutics. July 29, 2025. Accessed July 30, 2025. https://tinyurl.com/2jzfnzjc

2. Fast Track. US FDA. Updated August 13, 2024. Accessed July 30, 2025. https://tinyurl.com/y748ywj9