June 3, 2026
Source: Press Release, Prague, Basel & Boston
• First-in-human study of SOT106 to be initiated in second half of 2026, advancing a differentiated LRRC15 ADC toward early clinical signal;
SOTIO Biotech, a clinical-stage biopharmaceutical company owned by PPF Group, today announced that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation (ODD) to SOT106 for the treatment of osteosarcoma, reinforcing its potential as a targeted therapy for this high unmet need population.
SOT106 is a next-generation antibody-drug conjugate (ADC) targeting leucine-rich repeat-containing 15 (LRRC15), a clinically validated target broadly expressed across sarcoma subtypes and in tumor associated stroma. The program is designed to deliver an early and actionable clinical signal, with expansion potential across multiple solid tumors. Preclinical data demonstrate strong anti-tumor activity in both soft tissue and osteosarcoma models and favorable tolerability supporting a high therapeutic index. SOTIO expects to initiate a first-in-human clinical trial of SOT106 in the second half of 2026.
“Orphan Drug Designation for SOT106 underscores both the urgent need for new treatment options in osteosarcoma and the strength of our ADC platform,” said Radek Spisek, M.D., Ph.D., chief executive officer of SOTIO. “Osteosarcoma is a devastating disease that has seen little therapeutic innovation over the past four decades. Treatment continues to rely on intensive chemotherapy regimens associated with significant toxicities and limited long-term benefit. We are encouraged by this recognition from the FDA and look forward to advancing SOT106 into the clinic later this year.”
Sarcomas are a diverse group of cancers arising in bones and soft tissues and comprising more than 70 distinct subtypes. Their rarity and biological heterogeneity have made therapeutic innovation challenging, including the development of targeted approaches such as ADCs. Patients today are primarily treated with a combination of surgery, radiation and/or chemotherapy, yet outcomes remain poor for patients with aggressive, recurrent or metastatic disease. This need is especially clear in osteosarcoma, the most common bone cancer in children and adolescents, where a significant number of patients require amputation of the affected limb.
ODD provides several incentives to support the development of therapies for rare diseases and areas of high unmet need, including the potential for seven years of market exclusivity upon approval, waivers of certain regulatory fees, and enhanced interaction with and guidance from the U.S. FDA throughout the development process.
