Initial Priority Development Pipeline

Phase I Trial of CycloSam®
is Actively Recruiting

A dose-finding study of CycloSam® (153Sm-DOTMP) to treat solid tumor(s) in the bone or Metastatic to the bone

(Metastatic Prostate, Breast, and Lung, Osteosarcoma, Ewing’s Sarcoma, and other solid tumor(s) to the bone all eligible)


Metastatic Bone Cancers

Metastatic bone cancer occurs when cancer cells break away from the original tumor and spread to the bones, where they begin to multiply. Once cancer has spread to the bones it can rarely be cured, but often it can still be treated to slow its growth, relieve pain and help prevent complications. 

Bones are one of the most common sites of metastases for many types of solid cancers.  Nearly all types of cancer can spread (metastasize) to the bones, but prostate and breast cancer are responsible for the majority of the skeletal metastases (up to 70%). Bone metastases are a major cause for morbidity, characterized by severe pain, impaired mobility, pathologic fractures, spinal cord compression, bone marrow aplasia and hypercalcemia.

QSAM has initiated Phase 1 clinical trials for CycloSam® as a treatment for cancer that has metastasized to the bone from the lung, breast, prostate and other areas, and is currently enrolling. 

Based on prior studies, QSAM anticipates that its multi-dose treatment regimen made possible by the lower impurity profile of CycloSam® may result in disease-modifying effects. 

Pediatric Osteosarcoma/Ewing's Sarcoma

Pediatric Osteosarcoma and Ewing’s sarcoma are the most common bone malignancy in children. Osteosarcoma, the more common of the two types, usually presents in bones around the knee while Ewing’s sarcoma may affect bones of the pelvis, thigh, upper arm, or ribs.  Treatment options involve surgery, including amputation, multi-agent chemotherapy and radiation therapy.  Side effects of these treatments include development of secondary cancers, , heart and kidney damage, loss of hearing, chemo brain, memory impairment, learning problems, scarring of lungs and the liver, dental problems, loss of fertility, mobility issue – never being able to run or jump again. 

Cancer in children is generally rare, making it difficult for doctors to plan treatments unless they know what has been most effective in other children. That is why more than 60% of children with cancer are treated as part of a clinical trial when one is available.

QSAM is deeply committed to developing a viable solution for this vulnerable patient population.

In August 2021, the FDA granted Orphan Drug Designation for the use of CycloSam® to treat osteosarcoma and in January 2022, CycloSam was granted Rare Pediatric Disease Designation. Although patients with osteosarcoma or Ewing’s sarcoma are eligible to participate in our initial Phase 1 trials, we anticipate filing an amended protocol to our current commercial IND application this year to commence clinical trials specifically for these primary, pediatric bone cancers.

Bone Marrow Ablation

Certain cancers, immune system diseases, blood diseases, and sickle cell disease require bone marrow ablation/transplantation (BMA/T). The standard protocol for BMA/T consists of high dose chemotherapy and/or Total Body Irradiation (TBI). These treatment regimens are physically devastating to patients, have significant associated mortality and morbidity, and disease recurrence remains a problem.

CycloSam represents a valuable alternate approach by delivering targeted radiotherapy to the marrow using the bone-seeking agent, DOTMP, labelled with the medium-energy beta emitter, Samarium 153, with the aim of delivering a potentially ablative radiation dose to marrow while minimizing non-hematological toxicity.   CycloSam’s short 46 hour half-life and low impurity profile provide unique advantages for clinical utility in this indication.  

CycloSam® was recently studied for the first time in humans under a Single Patient Investigational New Drug (IND) for Emergency Use at a major medical institution.

Investigator concluded that high-dose CycloSam® can be administered safely to ablate bone marrow with no apparent renal toxicity and no unexpected adverse events attributable to the drug. Skeletal targeting with sparing of other tissues was observed after the high dose.


A single high dose (32 mCi/kg) of CycloSam® administered for bone marrow ablation prior to stem cell transplant on terminally ill, 25-year-old male with Osteosarcoma and Myelodysplastic Syndrome


CycloSam® targeted bone; preferential uptake in tumors
CycloSam® delivered to target
Dose to marrow
Dose proportionate radiation
Cleared major organs within hours
Normal kidney function