Novel Viral Immunotherapy SuperNova Gains FDA Fast Track Designation for Sarcoma

CLD-201 (SuperNova), a novel stem cell–based oncolytic virus therapy, has received FDA Fast Track designation for soft tissue sarcoma—marking a pivotal step in its clinical development. Backed by IND clearance, CLD-201 is set to enter Phase 1 trials targeting sarcoma, triple-negative breast cancer, and head and neck cancer, addressing significant unmet needs in advanced solid tumors.

Calidi Biotherapeutics has announced that its investigational therapy, CLD-201 (SuperNova)—an allogeneic adipose stem cell–loaded oncolytic virus—has received Fast Track designation from the U.S. Food and Drug Administration (FDA) for the treatment of soft tissue sarcoma. This group of cancers remains difficult to treat and is associated with limited therapeutic options.

“FDA IND clearance and Fast Track designation represents an important milestone in the development of CLD-201,” said Dr. Guy Travis Clifton, Chief Medical Officer at Calidi. “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.”

A New Class of Therapy: Stem Cell + Oncolytic Virus

CLD-201 represents a first-in-class therapeutic platform combining two powerful biological tools: adipose-derived mesenchymal stem cells (AD-MSCs) and an engineered oncolytic vaccinia virus. The AD-MSCs act as a delivery vehicle, shielding the virus from rapid clearance by the immune system and enhancing viral amplification within the tumor microenvironment. This dual mechanism is designed to maximize tumor cell lysis while triggering a robust anti-tumor immune response.

Preclinical models have demonstrated the enhanced potency and efficacy of this strategy, supporting its potential to target not only soft tissue sarcoma but also other aggressive solid tumors.

Regulatory Momentum: Fast Track and IND Clearance

The FDA’s decision offers several advantages to Calidi, including more frequent engagement with the agency, eligibility for priority review, and the possibility of accelerated approval.

This news follows the recent clearance of Calidi’s Investigational New Drug (IND) application for CLD-201 on April 17, 2025, paving the way for the launch of a first-in-human Phase 1 clinical trial. The upcoming study will be an open-label, multicenter investigation to assess the safety, tolerability, and preliminary efficacy of CLD-201 in patients with advanced soft tissue sarcoma, triple-negative breast cancer, and head and neck cancers.