A Phase 1/2 interventional study of BMS-986504 in Malignant Peripheral Nerve Sheath Tumors and MPNST, sponsored by Ankit Mangla, MD. Recruiting at 1 site in United States. Open to participants aged 12 Years and older. Per ClinicalTrials.gov, last updated 2026-08-11.
Sponsored by Ankit Mangla, MD · Phase 1/2, Interventional, and Treatment
People who have a cancer called MPNST, or Malignant Peripheral Nerve Sheath Tumor, may be eligible for this study. The purpose of this study is to see if a new medicine called BMS-986504 may work better than other available medicines for people with MPNST. Methylthioadenosine Phosphorylase (MTAP) loss is a gene mutation that some people have. MTAP loss seems to increase the chance that BMS-986504 can kill MPNST cancer cells. People who are missing MTAP from their tumor may be able to enroll in this study. Treating MPNST based on MTAP loss is considered experimental and is not approved by the US Food and Drug Administration (FDA) for determining whether BMS-98650 will be active against cancer. The purpose of this study is to evaluate the safety and effectiveness of BMS-986504 in participants with MPNST.
Malignant Peripheral Nerve Sheath Tumors (MPNSTs) are fast-growing, aggressive cancers that develop in soft tissues. They are the main cause of serious illness and death in people with neurofibromatosis type 1 (NF1), a condition that increases the risk of cancer. MPNSTs are rare, affecting about 1 in 100,000 people. In the United States, about 800 to 1,000 new cases are diagnosed each year. The 5-year survival rate is about 50%. However, this drops to about 20% when the cancer has spread or cannot be removed with surgery. Chemotherapy is often less effective, especially when the tumor cannot be removed by surgery, with response rates under 20%. There is a strong need to develop new and more targeted therapies for this type of cancer.
When some benign (non-cancerous) nerve tumors, called neurofibromas, turn into MPNST, it is often caused by the loss of a group of genes called CDKN2A on chromosome 9. These genes normally help prevent tumors from forming. When a part of chromosome 9 called 9p21 is deleted, it can also cause the loss of a nearby gene called MTAP. MTAP is missing in about 25-50% of people with MPNST. MTAP plays an important role in the methionine salvage pathway and serves a critical role in methylation reactions. When MTAP is lost, cells have problems with purine metabolism and become more dependent on another pathway, the arginine methylation pathways. This pathway is important for processes like DNA repair and control of the cell cycle. An enzyme called protein arginine methyltransferase 5 (PRMT5) helps carry out arginine methylation by adding small chemical groups (methyl groups) to proteins. When both copies of the MTAP gene are lost (called homozygous deletion), cells rely even more on PRMT5 to survive. At the same time, a substance called methylthioadenosine builds up and partly blocks PRMT5 activity. Because of this, completely blocking PRMT5 can cause MTAP-deficient cancer cells to die, a concept known as "synthetic lethality." For people with MPNST who have homozygous MTAP deletion confirmed by next-generation sequencing (NGS), drugs that block PRMT5 may help shrink tumors. A drug called BMS-986504 is a first-in-class PRMT5 inhibitor designed to specifically target MTAP-deficient tumor cells by binding to the PRMT5-MTA complex.
BMS-986504 was recently studied in a Phase 1 trial and showed evidence of anti-tumor activity. People with tumors that could not be removed with surgery with a homozygous MTAP deletion and whose disease had gotten worse since their last treatment were given varying doses of BMS-986504. Three of the 6 people enrolled had disease progression. The remaining 3 participants had partial responses, meaning that there was a >30% improvement from their baseline per RECIST v1.1 criteria. Each of these 3 participants had different doses of the study drug, which suggests a dose-independent response.
Since the current treatments for MPNST that cannot be removed through surgery are poor, it is important to identify new treatment strategies that may improve how long someone lives with this type of cancer and their health outcomes. This study aims to assess the safety and efficacy of BMS-986504 in people with MPNST that cannot be removed with surgery and with homozygous MTAP deletion.
Pathohistological verification of MPNST.
Normal marrow function and recovery of blood cell counts from any myelosuppressive chemotherapy prior to entering study:
Adequate organ function, including:
Liver function:
Renal function:
Performance status at time of screening:
Exclusion Criteria:
Participants will receive BMS-986504 on Days 1-28 of each cycle. Treatment will continue until disease progression, unacceptable toxicity, or withdrawal of consent.
Drug: BMS-986504
Participants will receive 600 milligrams (mg) of BMS-986504 taken orally (by mouth) on Days 1-28 of each 28-day cycle. Treatment will continue until disease progression, unacceptable toxicity, or withdrawal of consent (up to 2 years). Participants who experience dose-limiting toxicity can be transitioned to 400 mg daily, then 200 mg daily of BMS-986504, or taken off the clinical trial. Nine participants will be enrolled in stage 1. If ≥ 1 participant demonstrates a complete or partial response in stage 1, the trial will proceed to stage 2, where an additional eight participants will be enrolled. If there are no responses or significant safety concerns arise, the trial will be halted.
Objective response rate (ORR)
ORR is defined as the proportion of participants with a confirmed complete response (CR) or partial response (PR) per Response Evaluation Criteria in Solid Tumors (RECIST) guideline (version 1.1). CR is defined as disappearance of all target lesions. PR is defined as at least a 30% decrease in the sum of diameters of target lesions.
Time frame: Up to 2 years
Progression free survival (PFS)
Progression-Free Survival (PFS) is defined as the duration of time from start of treatment to time of progression or death, whichever occurs first.
Time frame: Up to 2 years
Overall survival (OS)
OS is defined as the time from treatment initiation to death from any cause.
Time frame: Up to 2 years
Incidence of adverse events (AEs)
AEs will be defined and graded per the National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0 (CTCAE v5.0).
Time frame: 30 days post-treatment discontinuation (up to 2 years)
Rate of treatment discontinuation
Proportion of participants discontinuing treatment due to toxicity will be calculated.
Time frame: Up to 2 years
Plan to share: No
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