OS Therapies Receives FDA and MHRA Feedback on OST-HER2 for Metastatic Osteosarcoma
OS Therapies Inc. announced that the FDA granted a Type C meeting to discuss clinical efficacy data endpoints for a BLA under the Accelerated Approval...
Breakthrough Clinical Results
OS Therapies Inc. announced that the FDA granted a Type C meeting to discuss clinical efficacy data endpoints for a BLA under the Accelerated Approval Program for OST-HER2 in recurrent, fully resected, pulmonary metastatic osteosarcoma, following a successful Phase 2b trial. The meeting is scheduled for December 11, 2025, to allow for biomarker data analysis. Concurrently, the MHRA granted a pre-MAA Meeting for the same program, with a rolling review process expected to begin in November 2025. The company aims to align BLA and MAA submission timing, in accordance with Project Orbis. OST-HER2 is an immunotherapy leveraging Listeria bacteria to target the HER2 protein.
Key Highlights
- FDA grants Type C meeting for OST-HER2 BLA submission discussion.
- MHRA grants pre-MAA meeting for OST-HER2.
- OST-HER2 is in Phase 2b clinical trial for recurrent, fully resected, pulmonary metastatic osteosarcoma.
- Company aims to align BLA and MAA submission timing.
Incidence and Prevalence
Latest Estimates of Osteosarcoma Incidence and Prevalence
Osteosarcoma is the most common primary bone malignancy, originating from primitive bone-forming mesenchymal cells. As a rare tumor, bone sarcomas represent only 0.2% of all cancers.
Incidence Rates
Recent epidemiological data shows varying incidence rates across different age groups:
- For ages 0-14 years: 4.0 (3.5-4.6) per million persons per year
- For ages 0-19 years: 5.0 (4.6-5.6) per million persons per year
A 2022 study reported an overall incidence of 1.56 cases per 1,000,000 per year for osteosarcoma.
Demographic Variations
Age Distribution
Osteosarcoma exhibits a bimodal age distribution with: - First peak during adolescence (10-14 years), coinciding with pubertal growth spurt - Second peak in adults older than 65 years, often representing a second malignancy frequently related to Paget's disease - Approximately 25% of cases occur in adults between 20 and 59 years old
Racial Differences
Significant racial variations exist in childhood and adolescent osteosarcoma incidence: - Blacks: 6.8 per million per year - Hispanics: 6.5 per million per year - Caucasians: 4.6 per million per year
Gender Differences
There is a notable gender disparity in incidence: - Males: 5.4 per million persons per year - Females: 4.0 per million persons per year
Anatomical Distribution
Osteosarcoma predominantly affects: - Femur: 42% (75% in distal femur) - Tibia: 19% (80% in proximal tibia) - Humerus: 10% (90% in proximal humerus) - Skull or jaw: 8% - Pelvis: 8%
Survival Rates
The overall 5-year survival rate for osteosarcoma is 68%, without significant gender difference. A study from Saudi Arabia (2022) reported a three-year survival rate of 82.30% for bone sarcomas collectively.
Death rates for osteosarcoma have been declining by approximately 1.3% per year.
Comparative Incidence
Among childhood cancers, osteosarcoma ranks eighth in general incidence (2.4%), following: 1. Leukemia (30%) 2. Brain and other nervous system cancers (22.3%) 3. Neuroblastoma (7.3%) 4. Wilms tumor (5.6%) 5. Non-Hodgkin lymphoma (4.5%) 6. Rhabdomyosarcoma (3.1%) 7. Retinoblastoma (2.8%)
In a 2022 study of primary bone sarcomas, osteosarcoma was the most common bone tumor (55%), followed by Ewing's sarcoma (35.5%) and chondrosarcoma (9.5%).
Adult osteosarcoma patients generally have worse outcomes than pediatric patients, though it remains unclear whether age itself is a poor prognostic factor or if there are inherent differences in tumor biology between age groups.
Study Design Parameters
Osteosarcoma Study Design Parameters and Endpoints
Study Designs
Most osteosarcoma research relies on retrospective analyses examining patient data from various databases. Sample sizes demonstrate significant variation, ranging from smaller cohorts (16-98 patients) to large database analyses (517-4,430 patients). Notable examples include a study of 517 patients with metastatic osteosarcoma from the SEER database (2020) and analysis of 4,430 patients from the National Cancer Database (2022).
Methodologies
Researchers employ diverse analytical approaches including:
- Immunohistochemical staining against CD31 and VEGF as angiogenic markers
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Robust statistical analyses featuring:
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Chi-square tests with Yates' test
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Kaplan-Meier analyses for survival estimation
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Log-rank tests for survival distribution comparisons
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Multivariate Cox proportional hazard regression
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ROC curves for predictive model assessment
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Advanced computational methods such as:
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CIBERSORTX algorithm for tumor infiltrating immune cell quantification
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Non-negative matrix factorization (NMF) for patient stratification
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Support vector machine (SVM) tools and LASSO method for predictive modeling
- Molecular techniques including RT-qPCR for expression verification
Primary Endpoints
The most frequently utilized primary endpoints include:
- Overall survival (OS) - predominant primary endpoint
- Disease-free survival (DFS) for non-metastatic patients
- Progression-free survival (PFS) for metastatic patients
- Cancer-specific survival
Secondary Endpoints/Parameters
Studies frequently assess additional parameters:
- Expression of biomarkers (VEGF, CD31)
- Tumor microenvironment characteristics
- Immune cell infiltration patterns
- Metastasis formation
- Response to chemotherapy
- Tumor site and stage as prognostic indicators
- Risk score models based on genetic signatures
Key Findings
Research has yielded several significant insights:
- Extremity primary tumors demonstrate superior survival rates compared to non-extremity tumors
- Primary tumor surgery significantly extends survival for extremity osteosarcoma but not for pelvis/spine cases
- F-FDG PET and PET/CT provide accurate diagnosis, staging and recurrence monitoring
- Tumor infiltrating immune cells (TIICs) correlate closely with prognosis
- Surgical excision remains the strongest predictor of survival
- Despite advances in tumor management, no improvement in survival rates was observed from 2004 to 2015
- Distant metastases, increasing age, male sex, and axial location serve as poor prognostic indicators
- Novel molecular classifications and gene signatures offer promising approaches for prognosis prediction and therapeutic target identification
Company drugs in pipeline
OS Therapies Inc. Drug Pipeline
Based on a thorough review of available information, there is insufficient data to determine which specific indications OS Therapies Inc. has drugs in its development pipeline for.
The company appears to be focused on osteosarcoma research and potential treatments, as suggested by its name, but no specific details about their drug candidates, clinical trials, or development pipeline can be confirmed.
Without verified information about OS Therapies Inc.'s specific drug development activities, it would be inappropriate to make claims about: - Their current pipeline - Indications being targeted - Development stages of any potential drug candidates - Therapeutic approaches being pursued
For accurate information about OS Therapies Inc.'s drug pipeline, it would be advisable to consult the company's official website, press releases, or regulatory filings where they would disclose their development programs and targeted indications.
