OS Therapies Announces Full Enrollment in PhIIb Clinical Trial AOST-2121 in Recurred, Resected Osteosarcoma with OST-HER2 (Listeria monocytogenes) for Delay or Prevention of Recurrence

ROCKVILLE, Md.--(BUSINESS WIRE)--OS Therapies, a research and clinical stage biopharmaceutical company, is extremely excited to announce Full Enrollment for its lead OST-HER2 (OST31-164) program in its ongoing clinical trial AOST-2121 (NCT04974008). The trial is being conducted at 21 Children’s Oncology Group (COG) sites across the country for patients with Osteosarcoma that had metastasized to the lungs requiring surgical removal. Historically, 80-90% of these patients would develop additional metastasis within the period of the trial. The planned number of patients have now received treatment and the few remaining slots will be allocated to patients that have already been identified. Patients continue OST-HER2 treatment for 48 weeks and then are followed for survival 2 additional years. The primary endpoints of the trial are Event Free Survival and Overall Survival.

“Several patients have completed the treatment phase of the trial and many more are undergoing treatment with OST-HER2. We hope that this treatment will reduce additional recurrences and extend the lives of all osteosarcoma patients and look forward to the outcome once all patients have completed treatment,” said Dr. Robert Petit, CMO/CSO of OS Therapies. Osteosarcoma is a rare but challenging disease for patients and their physicians, occurring primarily in teens and young adults. “Reaching thirty-nine patients enrolled is a major milestone in this trial, occurring more quickly than projected. A sincere thank you to the patients, families and healthcare providers - the Children’s Oncology Group, and the outstanding leadership of Principle Investigators Damon Reed, MD, and Kelly Bailey, MD,“ said Paul Romness, CEO of OS Therapies.

About Osteosarcoma

Osteosarcoma is a solid tumor of the bone that predominantly occurs in adolescents and young adults (AYA). Standard treatment includes surgery and chemotherapy. For patients with metastatic osteosarcoma or have recurrence after chemotherapy, the prognosis is poor.

About OS Therapies

OS Therapies Incorporated is a research and clinical-stage therapeutic company focused on the identification, development, and commercialization of treatments for Osteosarcoma (OS) and other deadly cancers in kids and adults. OS Therapies has two platform technologies: OST-HER2 and OST-TDC being developed for therapies to treat Osteosarcoma (OS) and other solid tumors including ovarian.

About OST-HER2

The OST-HER2 Lm vector platform technology has been administered to over 450 cancer patients in ongoing and completed clinical trials. AOST-2121 is a Phase IIB clinical trial intended to prevent or delay metastasis and improve Overall Survival (OS) in Osteosarcoma. OST-HER2 has already received Fast-Track, Orphan, and Rare Disease Designation (RDD). OST hopes to seek a Break-Through Designation (BTD) based on data from this Phase IIb clinical trial. OST31-164 has previously received USDA provisional approval for treatment of Osteosarcoma in canines. In a completed Phase III study in canines (n=180), early data demonstrated a clear separation of treated and untreated canine patients (p=.0007) in Overall Survival (OS) and Disease Progression.

For more information, please see the Company's website at www.ostherapies.com