Osteosarcoma Collaborative, Inc.

06/02/2026

OS Therapies Achieves Statistically Significant 2.5-Year Overall Survival in Phase 2b Trial of OST-HER2 in Fully Resected Pulmonary Metastatic Osteosarcoma

75% 2.5-year overall survival for OST-HER2 vs. 47% pooled historical control (p = 0.003), with no new patient deaths reported since the 2-year…...

05/13/2026

This brings hope for new European and US osteosarcoma treatment options!! I remember when the Osteosarcoma Information facebook group was up in arms that the vaccine was not being used in a human trial after a successful canine trial! Thankful for all the perseverance and hard work being done at OS Therapies!!!

OS Therapies recently hosted a biomarker-focused conference call reviewing updates across its OST-HER2 clinical and regulatory program.

The call featured strategic advisors Dr. Craig Eagle and Dr. Bob Langer, and pediatric oncology key opinion leaders Dr. Brian Ladle of Johns Hopkins and Dr. Peter Anderson of Cleveland Clinic. Discussion included:

• Biomarker and immune response findings from the Phase 2b study
• Clinical development updates in osteosarcoma
• Ongoing regulatory engagement across the U.S., Europe, U.K. and Australia
• Considerations related to confirmatory study planning and future regulatory submissions

ICYMI, view the presentation here: https://bit.ly/42O0lM1

04/29/2026

Thanks goes out to Dr Kaplan for dedicating her career to osteosarcoma research. Short read ….full of hope

When a tumor grows, its microenvironment views cancer cells not as foreign, but as injured tissue that needs to heal. This means that, unfortunately, the same healing process that repairs our normal tissue enables tumors to grow.

“A lot of cancer patients think their immune system failed them — that it did not recognize the cancer and was not able to get rid of it,” says Rosandra N. Kaplan, MD, a pediatric oncologist. “But the same features that repair us also help our tumors grow and spread.”

Dr. Kaplan and other researchers are working to illuminate key elements of cancer metastasis in order to create more effective osteosarcoma therapies.

Read more about Dr. Kaplan’s research here: osinst.org/blog/tumor-microenvironment

04/28/2026

Reminder: OS Therapies will host its OST-HER2 pharmacodynamic response biomarker conference call later this week.

Date: April 30, 2026
Time: 8:30 a.m. ET

The discussion will focus on the data supporting the OST-HER2 Immune Signature and its potential role in regulatory submissions across the U.S., Europe, and the U.K.

Register: https://bit.ly/4vYvGsC

04/09/2026

Excited to see OS Therapies continue to drive forward towards FDA approval!

OS Therapies has completed submission of Phase 2b clinical and biomarker data for OST-HER2 to the FDA in preparation for its upcoming Pre-BLA Meeting later this quarter.

This submission follows prior FDA alignment, confirming pre-specified immune biomarkers as suitable surrogate endpoints alongside the clinical outcomes data from the Phase 2b study.

Read the full details here: https://bit.ly/4v2gbQ6

02/04/2026

The Michaela Naylon Give Kids A Chance Act has officially become law. 💛.

Thank you to EVERYONE who had a part in this!!!

This bill reauthorizes the FDA’s Priority Review Voucher (PRV) program, fast-tracking profitable drugs in exchange for developing treatments for rare pediatric diseases — expanding children’s access to cutting-edge treatments. The Mikaela Naylon Give Kids A Chance Act also authorizes the FDA to direct companies to study combinations of cancer drugs and therapies in pediatric trials.

Many Osteosarcoma patients are sized more like an adult than a child — yet they were and still are denied access to proven treatments because they were labeled “pediatric,” while the drugs were labeled “adult.”
In osteosarcoma, therapies that worked in animals sometimes never make it to human trials because the disease is rare — and companies likely do not see the value.

This law changes everything. For kids still fighting — and for families who don’t even know yet. 💛

12/02/2025

On this Giving Tuesday, we’re grateful for every donor who stands with us. Every dollar—100%—goes straight to research chosen by a scientific board and is powered to a meaty grant through collaboration across leading and grassroots osteosarcoma nonprofits.

Your support moves science. Your support gives hope. 💛

Please consider supporting the Osteosarcoma Collaborative

Donate Donate by clicking on the donate button below or on one of our kid’s pages. Both donation options go directly to our organization to help fund osteosarcoma research. Donate Meet Our Kids

10/17/2025

After a successful Osteosarcoma Phase 2b trial, OS Therapies Granted Final Type C Meeting by U.S. FDA and pre-MAA Meeting by U.K. MHRA for OST-HER2 in the Prevention or Delay of Recurrent, Fully Resected, Pulmonary Metastatic Osteosarcoma!!!

The United States FDA has granted OS Therapies (NYSE: OSTX) a second Type C Meeting, following its successful End of Phase 2 Meeting. The primary purpose of the meeting is to gain alignment on the clinical efficacy data endpoints to support a BLA under the Accelerated Approval Program for OST-HER2 following a successful Phase 2b clinical trial in the prevention or delay of recurrent, fully resected, pulmonary metastatic osteosarcoma (the "Metastatic Osteosarcoma Program").

The meeting is scheduled for December 11, 2025, which allows for sufficient time for the company to receive biomarker data from the Phase 2b trial to correlate immune activation with clinical outcomes.

Read the press release: https://t.co/hZOFjReLdQ

09/11/2025

ICYMI this week: OS Therapies provided stakeholders with a detailed update regarding the Company's OST-HER2 recurrent, fully resected, pulmonary metastatic osteosarcoma program following a highly productive End of Phase 2 Meeting with the US Food & Drug Administration.

We remain on track to begin rolling submission of a Biologics Licensing Application request to FDA for the Metastatic Osteosarcoma Program in September 2025.

https://bit.ly/4mIZiVW