OS Therapies

Today we are proud to announce that the FDA has granted our meeting request to gain alignment on the surrogate endpoint that could support Breakthrough Therapy Designation (BTD) and Accelerated Approval of OST-HER2 in the prevention of recurrence in fully resected, lung metastatic osteosarcoma. The meeting will be in written response-only format, with the FDA’s feedback expected in mid-June, likely just in time for our keynote presentation at MIB Agents FACTOR on June 28 in Salt Lake City, UT. https://lnkd.in/eUx3dE4v OS Therapies (NYSE-A: OSTX) is a B2i Digital Featured Company. View our comprehensive profile at https://lnkd.in/eWRy5ZYe Highlights from today’s announcement include: · The FDA’s written response is scheduled for mid-June, enabling us to present our statistical analysis during the closing keynote at MIB FACTOR on June 28, 2025, at 3:30 PM MDT. · The meeting is a significant step towards our early Q3 BLA submission for Accelerated Approval, with a potential approval targeted for year-end 2025. · OST-HER2 has received Rare Pediatric Disease Designation (RPDD). If approved before September 30, 2026, we would become eligible for a Priority Review Voucher (PRV), which could be sold. Recent PRVs have fetched $150M. · Approximately half of osteosarcoma patients develop lung metastases. We believe OST-HER2 could address a market opportunity exceeding $500M in preventing recurrence. Paul Romness, CEO of OS Therapies, noted, “We remain on track for an early third quarter submission and are hopeful to receive approval by year-end 2025 in order to bring this life saving treatment to patients in early 2026.” See the full announcement: https://lnkd.in/enzizsY4... OST-HER2 is a listeria-based immunotherapy designed to stimulate an immune response against HER2-expressing cancer cells. The candidate has shown statistically significant results in a Phase 2b trial for recurrent, fully resected, lung metastatic osteosarcoma and is featured in the PBS film Shelter Me: The Cancer Pioneers, scheduled to begin streaming June 29, 2025. We are also advancing a tunable ADC platform for other cancers. Learn more about our work at https://lnkd.in/eetih6v7 and visit B2i Digital for updates. For investor-related questions, please visit OS Therapies’ Investor Relations page or email irpr@ostherapies.com. #OSTherapies #Immunotherapy #Osteosarcoma

We are pleased to announce new positive data for OST-HER2 in treating unresected osteosarcoma in dogs. The combination of OST-HER2 and palliative radiation resulted in tumor control, delayed metastases, and survival of more than 500 days in one-third of the study animals. The data suggest a potential future role for OST-HER2 as a frontline therapy in human osteosarcoma before surgery or chemotherapy. OS Therapies is a B2i Digital Featured Company. View their comprehensive profile at https://lnkd.in/eWRy5ZYe. Highlights from today’s announcement include: - In a study of 15 dogs with unresected primary osteosarcoma, treatment with OST-HER2 and palliative radiation led to tumor arrest and prolonged survival without surgery or chemotherapy. - Peer-reviewed data published in Molecular Therapy showed that strong immune responses to OST-HER2 correlated with long-term survival in dogs with resected tumors, supporting potential use in humans. - OST-HER2 was well tolerated in both studies and may represent a significant advance in controlling metastatic disease and prolonging survival. CEO Paul Romness noted, “It has been my dream since founding the Company that OST-HER2 could potentially change the standard of care in osteosarcoma, potentially limiting the need for amputation or surgical resection of the primary tumor. With today’s data, we believe we are taking the first steps towards this given that our Comparative Oncology approach, as a result of the 96% genetic homology between human and canine osteosarcoma, leads us to believe there is significant potential for this canine data to translate into humans in the treatment of frontline and primary metastatic osteosarcoma, similarly to how it has in recurrent, fully-resected, lung metastatic osteosarcoma.” We plan to pursue conditional approval from the USDA for OST-HER2's updated formulation in canine use later this year. Read the full release: https://lnkd.in/egdJScM9. Learn more about OS Therapies’ work at https://lnkd.in/eetih6v7 and visit https://lnkd.in/eQHi_ykX #OSTX

Today we announced that we have completed the acquisition of the listeria-based cancer immunotherapy assets of Advaxis Immunotherapies from Ayala Pharmaceuticals, positioning OS Therapies as the world leader in listeria-based cancer immunotherapies. OS Therapies is a B2i Digital Featured Company. View their comprehensive profile at https://lnkd.in/eWRy5ZYe The acquisition significantly expands our clinical pipeline with three new cancer immunotherapy candidates: - OST-AXAL (previously AXAL/ADXS/HPV) for Human Papilloma Virus (HPV)-associated cancers (completed 1 of 2 Phase 3 trials) - OST-503 (previously ADXS-503) for Non-Small Cell Lung Cancer (NSCLC) & Glioblastoma (positive Phase 2 data in NSCLC) - OST-PSA (previously ADXS-504/ADXS31142) for Prostate Cancer Additionally, we have added 8 un-named pre-clinical immunotherapy candidates targeting over 30 cancers. New manufacturing-based intellectual property protects the listeria-based platform and candidates into 2040. “We are thrilled to have now consolidated all of the intellectual property for the listeria cancer immunotherapy platform into OS Therapies, positioning us to fully expand it in the years ahead and improve the standard of care across cancer treatment in the years ahead,” said Paul Romness, CEO of OS Therapies. We are poised become a new commercial category of immunotherapy in oncology upon approval of its lead asset OST-HER2 to prevent recurrence in fully-resected, lung metastatic osteosarcoma, targeted for year-end 2025. Upon approval, the Company will become eligible to receive a Priority Review Voucher, currently valued at $150 million. According to Nova One Advisor, the global cancer immunotherapy market size was valued at $126 billion in 2023 and is projected to surpass around $296 billion by 2033. OS Therapies is a clinical-stage oncology company focused on identifying, developing, and commercializing a new class of immunotherapy candidates for solid tumors, beginning with osteosarcoma. The Company’s lead asset, OST-HER2, has received Rare Pediatric Disease Designation from the FDA and demonstrated positive data in a Phase 2b clinical trial. The company intends to submit a BLA Accelerated Approval request to the FDA in the third quarter of 2025. Led by CEO Paul Romness and an experienced executive team that includes Christopher Acevedo (CFO), Robert Petit (Chief Medical and Scientific Officer), John Doll (Chief of Staff), and Gerald Commissiong (Chief Business Officer), OS Therapies is focused on driving its pipeline forward to deliver potentially transformative treatments for osteosarcoma and other hard-to-treat cancers. Learn more about our work at https://lnkd.in/eetih6v7 and visit B2i Digital for updates. For investor-related questions, please visit OS Therapies’ Investor Relations page or email irpr@ostherapies.com.

#OSTherapies’ CEO Paul Romness and CBO Gerald Commissiong recently attended the premiere of director and producer Steven Latham’s latest film, “Shelter Me: The Cancer Pioneers,” which features our OST-HER2 #immunotherapy.   Steven’s film is an inspiring story that the OS Therapies team is extremely proud to be a part of. OST-HER2 is an immunotherapy that leverages the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the #HER2 protein.   The film details groundbreaking clinical trials in #comparativeoncology, in which treatments utilized for dogs with cancer are now being applied to human patients. Leading scientists from the National Cancer Institute (NCI) / The National Institutes of Health, the University of Pennsylvania, the University of Illinois Urbana-Champaign, the University of Wisconsin-Madison, and Colorado State University are all featured as well. You can see the full Steven Latham Productions film on PBS and the network’s app in May.   Learn more about “Shelter Me” here: www.shelterme.tv   Powered by Petco Love   Conrad Stanley #Osteosarcoma #OSTX $OSTX #CancerResearch #OSTHER2

We have formally requested a meeting with the FDA’s Center for Biologics Evaluation and Research (CBER) to gain alignment on clinical endpoints required for Breakthrough Therapy Designation (BTD) and Accelerated Approval via a conditional BLA for candidate OST-HER2 in the prevention or delay of recurrence of fully resected, lung metastatic osteosarcoma. This meeting follows the FDA’s feedback on a prior BTD request and represents an important step in clarifying data requirements for potential expedited review. Robert Petit, Chief Medical & Scientific Officer of OS Therapies, commented, “We are excited to meet with the FDA – and commence market access discussions - the goal of receiving Accelerated Approval for a Biologics License Application of OST-HER2 in the prevention or delay of recurrence lung metastatic osteosarcoma by year-end 2025. We believe that we have identified the comparator data necessary to address the comments from FDA regarding our prior BTD request. We expect this data will also be able to support our application for Accelerated Approval. Our clinical and regulatory teams are diligently preparing for the meeting and the subsequent BLA submission that is targeted to begin after the public release of additional clinical trial data at MIB Factor in June.” See the full news release at https://lnkd.in/e6Jtianp. As a reminder, we are holding an analyst day today in New York at the New York Stock Exchange. For more information, please see https://lnkd.in/evVj6szi. Learn more about OS Therapies’ work at https://lnkd.in/eetih6v7 and for investor-related questions, please visit OS Therapies’ Investor Relations page or email irpr@ostherapies.com.

We will be holding an Analyst Day at the New York Stock Exchange on April 7, 2025, at 10:00 AM ET. Hosting the event at the iconic NYSE reflects our growing presence and continued momentum as we prepare to share important updates with investors and industry leaders. The event will spotlight our OST-HER2 program for recurrent, fully resected lung metastatic osteosarcoma, which we're positioning for Accelerated Approval in late 2025. Attendees will also hear about advancements in the OST-HER2 canine osteosarcoma program, new initiatives targeting HER2+ breast cancer and other solid tumors, and updates on the tunable ADC (tADC) platform, part of the company’s broader innovation strategy. The pipeline of assets recently acquired from Ayala Pharmaceuticals will also be featured. See the full news release at https://lnkd.in/e9f9yVjy For additional information about the event, please see https://lnkd.in/evVj6szi We recently gained new research coverage from Lake Street Capital Markets, highlighting growing interest in the company’s strategic progress. The initiation report by Chad Messer, Ph.D., outlines the company’s investment thesis, Listeria Platform, management profile, valuation, and near-term milestones. Learn more about our work at https://lnkd.in/eetih6v7 and for investor-related questions, please visit OS Therapies’ Investor Relations page or email irpr@ostherapies.com.

We are proud to announce important progress in advancing our regulatory strategy for OST-HER2, a novel immunotherapy candidate for osteosarcoma. We have initiated regulatory correspondence with the FDA and UK MHRA and is preparing to engage with the European Medicines Agency (EMA) in the coming months. We're focused on achieving accelerated approval for OST-HER2, aiming to address a significant unmet need in treating this rare pediatric cancer. Highlights from the announcement include: • Initiation of regulatory correspondence with the FDA and MHRA in Q1 2025. • Plans to initiate EMA regulatory interactions in Q2 2025. • Introduction of new canine elite responder biomarkers to enhance the human biomarker strategy for OST-HER2, based on data from the company’s canine osteosarcoma program. • The company’s strategic focus is on obtaining accelerated approval for OST-HER2, with the aim of making a meaningful impact on treating rare pediatric cancers. CEO Paul Romness commented, “We are making rapid progress in putting together an appropriate data package to achieve accelerated approval for OST-HER2 given the feedback we’ve received to date from the FDA. We know one of the US government’s stated priorities is to treat deadly childhood cancers, and we believe that OST-HER2 for osteosarcoma aligns well with that mission.” See the full news release here: https://lnkd.in/eTTMue9e We also note that Analyst Jason Kolbert from D. Boral Capital recently gave OS Therapies a “Buy” rating with a 12-month price target of $20.00, which we share for informational purposes without endorsing the report or its conclusions. Learn more about OS Therapies’ work at https://lnkd.in/eetih6v7 and for investor-related questions, please visit OS Therapies’ Investor Relations page or email irpr@ostherapies.com. #OSTherapies #Immunotherapy #Osteosarcoma

We are proud to announce that we have scheduled a Scientific Advice Meeting (SAM) with the United Kingdom’s (UK) Medicines and Healthcare products Regulatory Agency (MHRA) in Q3 2025 to discuss the Innovative Licensing and Access Pathway (ILAP) for our OST-HER2 immunotherapy candidate. The planned meeting has been scheduled to position the company to bring OST-HER2 to the UK market in 2025. CEO Paul Romness commented on the meeting, “Today’s announcement marks the beginning of the regulatory process required to bring our OST-HER2 immunotherapy to market globally. As we prepare for regulatory interactions in the UK, US, Europe and other regulatory bodies worldwide, we are now focused on aligning our regulatory strategy to getting our product to patients as quickly as possible.” The UK is a reference country for multiple national drug approval agencies worldwide. For this reason, approval in the UK will make us eligible to receive approval in more than a dozen other countries, including Canada, Germany, France, Italy, and Australia. OST-HER2 has received Fast Track and Orphan Drug Designations from the European Medicines Agency. See the full news release here: https://lnkd.in/emDyD6eX Learn more about our work at https://lnkd.in/eetih6v7 and for investor-related questions, please visit OS Therapies’ Investor Relations page or email irpr@ostherapies.com.

OS Therapies held a live investor webinar and Q&A session yesterday, February 27, 2025, at 4:15 p.m. ET. The event, presented by RedChip Companies, featured CEO Paul Romness and Chief Business Officer Gerald Commissiong to discuss the company’s latest developments and plans. You can watch it on demand here: https://lnkd.in/eGZ3RaY6 It included discussions on OS Therapies’ key programs, including OST-HER2 and its drug development pipeline. See the press release here: https://lnkd.in/eqq_eBke Led by CEO Paul Romness and a highly experienced executive team, including Christopher Acevedo (CFO), Robert Petit (Chief Medical and Scientific Officer), John Doll (Chief of Staff), and Gerald Commissiong (Chief Business Officer), OS Therapies is focused on driving its pipeline forward to deliver potentially transformative treatments for osteosarcoma and other hard-to-treat cancers. For investor-related questions, please visit OS Therapies’ Investor Relations page or email irpr@ostherapies.com. #OSTherapies #Immunotherapy #CancerResearch

Today we issued a press release announcing that we have formed a new subsidiary, OS Drug Conjugates (OSDC), to advance our tunable ADC (tADC) and tunable drug conjugates (tDC) platforms. We are also exploring strategic options to create value through potential joint ventures that could be spun into standalone public companies, with stock dividends distributed to shareholders if successful. Highlights from the announcement include: · OSDC will focus on the company’s proprietary silicon-based, pH-sensitive SiLinkers™, designed to selectively release therapeutic agents within tumor environments. · We are discussing joint ventures with clinical-stage ADC companies in the U.S., China, and other markets. · The global antibody-drug conjugates market is projected to grow from $10.8 billion in 2023 to $47.0 billion by 2029, reflecting a 28.4% CAGR.OST-HER2, Our lead immunotherapy for lung metastatic osteosarcoma, has received Fast Track, Orphan Drug, and Rare Pediatric Disease designations. Following positive Phase 2b trial results, the company plans to submit a Biologics Licensing Application (BLA) to the FDA in 2025. OST-HER2 has also shown preclinical efficacy in breast cancer models and is conditionally approved in the U.S. for canine osteosarcoma. See the full announcement at https://lnkd.in/g8hi-B3e. Led by CEO Paul Romness and a highly experienced executive team, including Christopher Acevedo (CFO), Robert Petit (Chief Medical and Scientific Officer), John Doll (Chief of Staff), and Gerald Commissiong (Chief Business Officer), OS Therapies (NYSE-A: $OSTX) is focused on driving its pipeline forward to deliver potentially transformative treatments for osteosarcoma and other hard-to-treat cancers. Learn more about OS Therapies’ work at https://ostherapies.com. For investor-related questions, please visit OS Therapies’ Investor Relations page or email irpr@ostherapies.com. #OSTherapies #Immunotherapy #CancerResearch