for people ages 2 years and up (full criteria)
at UC Davis UC Irvine UCLA
study started
estimated completion
Principal Investigator
by Phioanh (Leia) Nghiemphu (ucla)Daniela Bota, MD (uci)Reuben Antony, MD (ucdavis)



This study evaluates mirdametinib (PD-0325901) in the treatment of symptomatic inoperable neurofibromatosis type-1 (NF1)-associated plexiform neurofibromas (PNs). All participants will receive mirdametinib (PD-0325901).

Official Title

A Phase 2b Trial of the MEK 1/2 Inhibitor (MEKi) PD-0325901 in Adult and Pediatric Patients With Neurofibromatosis Type 1 (NF1)-Associated Inoperable Plexiform Neurofibromas (PNs) That Are Causing Significant Morbidity


Neurofibromas are benign peripheral nerve sheath tumors, which are classified as plexiform neurofibromas (PNs) if they extend longitudinally along a nerve and involve multiple fascicles. PNs are a major cause of morbidity and disfigurement in individuals with NF1, and as the tumor growth progresses, can cause a multitude of clinical deficits including pain and impaired physical function. PNs have the potential to undergo malignant transformation to Malignant Peripheral Nerve Sheet Tumors (MPNST). Mirdametinib (PD-0325901) is an orally delivered, highly selective small-molecule inhibitor of the dual specificity kinases, MEK1 and MEK2 (MAPK/ERK Kinase) which prevents the phosphorylation and subsequent activation of mitogen-activated protein kinase (MAPK). Previous studies of mirdametinib (PD-0325901) demonstrated PN shrinkage and sustained inhibition of pERK. Reduced tumor volume indicated that cell proliferation or cell death may be altered in PNs with administration of mirdametinib (PD-0325901).


Plexiform Neurofibroma Neurofibromatosis Type 1 (NF1) Neurofibromatoses Neurofibromatosis 1 PD-0325901 MEK Inhibitor Neurofibroma Mirdametinib Neurofibroma, Plexiform Mirdametinib (PD-0325901) oral capsule or dispersible tablet Mirdametinib (PD-0325901)


You can join if…

Open to people ages 2 years and up

  • Participant has documented NF1 mutation or a diagnosis of neurofibromatosis type 1 (NF1) using National Institute of Health (NIH) Consensus Conference criteria inclusive of the presence of a plexiform neurofibroma (PN).
  • Participant has a PN that is causing significant morbidity.
  • Participant has a PN that cannot be completely surgically removed.
  • Participant has a target tumor that is amenable to volumetric MRI analysis.
  • Participant is willing to undergo a tumor biopsy pre and post treatment if ≥ 18 years of age.
  • Participant has adequate organ and bone marrow function.

You CAN'T join if...

  • Participant has abnormal liver function or history of liver disease.
  • Participant has lymphoma, leukemia or any malignancy within the past 5 years (except for resected basal/squamous skin carcinomas without metastases within 3 years).
  • Participant has breast cancer within 10 years.
  • Participant has active optic glioma or other low-grade glioma requiring treatment.
  • Participant has abnormal QT interval corrected or other heart disease within 6 months.
  • Participant has a history of retinal pathology, risk factors for retinal vein occlusion or has a history of glaucoma.
  • Participant has known malabsorption syndrome or gastrointestinal conditions that would impair absorption of mirdametinib (PD-0325901).
  • Participant has received NF1 PN-targeted therapy within 45 days.
  • Participant previously received or is currently receiving therapy with mirdametinib (PD-0325901) or any other MEK1/2 inhibitor.
  • Participant has received radiation therapy within 6 months or has received radiation to the orbit at any time.
  • Participant is unable to undergo or tolerate MRI.
  • Participant has active bacterial, fungal or viral infection.
  • Participant has experienced other severe acute or chronic medical or psychiatric conditions within 1 year.


  • UCLA Oncology Center accepting new patients
    Los Angeles California 90095 United States
  • University of California - Irvine Health accepting new patients
    Orange California 92868-3201 United States
  • University of California - Davis Comprehensive Cancer Center accepting new patients
    Sacramento California 95817 United States
  • Children's Hospital Los Angeles accepting new patients
    Los Angeles California 90027 United States
  • Children's Hospital of Orange County accepting new patients
    Orange California 92868 United States

Lead Scientists at UC Cancer


accepting new patients
Start Date
Completion Date
SpringWorks Therapeutics, Inc.
Study-specific website
Phase 2
Study Type
Last Updated