Assessing the Efficacy of Repeat, Monthly Treatments of Alexandrite Laser for NF1-associated Cutaneous Neurofibromas (cNFs)

Assessing the Efficacy of Repeat, Monthly Treatments of Alexandrite Laser for NF1 Associated Cutaneous Neurofibromas (cNFs)

The goal of this clinical trial is to evaluate the tolerability and effectiveness of multiple treatments of Alexandrite (755 nm) Laser in those with Neurofibromatosis Type 1 (NF1) Cutaneous Neurofibromas (cNFs). The main questions it aims to answer are:

Will performing up to 6 months of treatment sessions with alexandrite laser will result in tolerable local skin reactions and reduction in both individual cNF size by >50% as well as improved cNF appearance in the treated field? If there is a comparison group: Researchers will compare laser treatment with cooling to both laser treatment without cooling and an untreated control see if laser treatments are effective and if cooling makes treatment more tolerable.

Participants will:

• Receive up to 6 monthly laser treatments.
• Complete surveys asking about pain during and after treatments.
• Complete surveys asking about satisfaction with the treatments.
• Undergo 2D photography and 3D imaging of treatment areas.
• Optionally, receive biopsies of up to 6 treated lesions to investigate characteristics of tumors that respond well to treatment as well as non-respondent tumors.

Study Overview

• Status: Suspended
• Conditions: Neurofibromatosis 1 (NF1); Neurofibromatosis Type I
• Intervention / Treatment: Device: GentleMax Pro (with skin cooling); Device: GentleMax Pro (without skin cooling)

• Study Type: Interventional
• Enrollment (Estimated): 10
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Wellman Center for Photomedicine, Massachusetts General Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Participant is an adult ≥18 years of age.
• Participant has a diagnosis of NF1 based on germline genetic testing or by meeting ≥ 2 the following criteria:
• Family history of NF1
• Six or more light brown ("cafe-au-lait") spots on the skin
• Presence of two or more neurofibromas of any type, or one or more plexiform neurofibromas
• Freckling under the arms or in the groin area
• Two or more pigmented, benign bumps on the eye's iris (Lisch nodules)
• A distinctive bony lesion: dysplasia (abnormal growth) of the sphenoid bone behind the eye, or dysplasia of long bones, often in the lower leg
• Tumor on the optic nerve that may interfere with vision
• Participant is seeking treatment for cNF.
• Participants must have ≥ 12 paired cNF (6 to be treated without DCD, 6 to be treated with DCD) that are visible and measure at least 2 mm in size in the target treatment area. The target treatment area must be amenable to both laser treatments and surveillance with digital and 3D photography. Preferred locations are trunk (back or chest), arms and legs.
• Participant is able and willing to comply with all visit, treatment, and evaluation schedules and requirements.
• Participant is able to understand and provide written informed consent.
• Participant has no concurrent injury or wound in the target area.

Exclusion Criteria:

• Participant cannot give informed consent or adhere to study schedule.
• Participant is Fitzpatrick skin type V-VI.
• Participant is actively tanning during the course of the study.
• For female participants: participant is pregnant.
• Participant has any condition which, in the Investigator's opinion, would make it unsafe (for the participant or study personnel) to treat the participant as part of this research study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Treated cutaneous neurofibromas (cNFs); Participants will receive treatment with laser at a wavelength of 755 nm to the cutaneous Neurofibromas lesion.	Device: GentleMax Pro (with skin cooling); Treatment will be performed with the GentleMax Pro laser (755 nm wavelength), which targets hemoglobin. A negative pressure hand piece provides temporary, mild suction (~1/2 atm) before laser exposure. A pulse fluence of 60-100 J/cm2 (single or double pulse) will be used with 8 mm diameter exposure spot size, and 3 ms pulse duration. The laser system includes a dynamic cryogen spray cooling device (DCD) for epidermal protection. A spurt of cryogen cools the epidermis just before arrival of the treatment laser pulse.; Other Names: Alexandrite Laser; 755 nm Laser; Dynamic Cryogen Spray Cooling Device; DCD; Device: GentleMax Pro (without skin cooling); Treatment will be performed with the GentleMax Pro laser (755 nm wavelength), which targets hemoglobin. A negative pressure hand piece provides temporary, mild suction (~1/2 atm) before laser exposure. A pulse fluence of 60-100 J/cm2 (single or double pulse) will be used with 8 mm diameter exposure spot size, and 3 ms pulse duration.; Other Names: Alexandrite Laser; 755 nm Laser
No Intervention: Control cutaneous neurofibromas (cNFs); A complementary region of cNFs of similar characteristics to the treatment area in the same body region will be selected to serve as an untreated control group.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Treatment-Emergent Adverse Events (Safety and Tolerability)	Treatment will be considered tolerable if <40% of participants treated have a >Grade 2 CTCAE v5 adverse event (AE).	Anytime from initiation of treatment through study completion, an average of 8 months.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient Global Assessment of cNF Improvement (Likert Scale)	Patient rates degree of change of treated cNFs on a scale from -3 (very much worse) to 3 (very large improvement).	Baseline, Day 90, and 30 days after final treatment (up to Day 240).
Clinician Global Assessment of cNF Improvement (Likert Scale)	Clinician rates degree of change of treated cNFs on a scale from -3 (very much worse) to 3 (very large improvement).	Baseline, Day 90, and 30 days after final treatment (up to Day 240).
VAS Pain Scale	Participants will be asked to rate their pain using a visual analog scale (0 to 10) at each treatment visit and 1 week after each treatment.	Baseline, every 30 days (up to Day 240).
Patient Satisfaction	Satisfaction with each treatment modality is rated from 1 (very unsatisfied) to 5 (very satisfied).	Baseline, Day 90, and 30 days after final treatment (up to Day 240).
Rate of Healing	Measured clinically via photography completed by a member of the study team at baseline, and all in-person visits.	Baseline, every 30 days (up to Day 240).
cNF Appearance (Height)	Clinically completed 3D Cherry Imaging. Change from baseline in height of cNFs.	Baseline, Day 90, and 30 days after final treatment (up to Day 240).
cNF Appearance (Volume)	Clinically completed 3D Cherry Imaging. Change from baseline in volume of cNFs.	Baseline, Day 90, and 30 days after final treatment (up to Day 240).

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Biologic Effect/Histology	A subset of 2-6 cNFs from the treatment region will be assessed after the final treatment session.	3 months after final treatment session.

Collaborators and Investigators

• Sponsor: Massachusetts General Hospital
• Collaborators: Johns Hopkins University
• Investigators: Principal Investigator: Richard R. Anderson, MD, Massachusetts General Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): January 1, 2027
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: March 31, 2025
• First Submitted That Met QC Criteria: April 10, 2025
• First Posted (Actual): April 18, 2025

Study Record Updates

• Last Update Posted (Actual): June 4, 2026
• Last Update Submitted That Met QC Criteria: June 2, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: NF1; Neurofibromatosis; Cutaneous Neurofibroma; cNF; GentleMax Pro
• Additional Relevant MeSH Terms: Nervous System Diseases; Neoplasms; Neuromuscular Diseases; Genetic Diseases, Inborn; Peripheral Nervous System Diseases; Neoplasms by Histologic Type; Neurodegenerative Diseases; Neoplasms, Nerve Tissue; Heredodegenerative Disorders, Nervous System; Nerve Sheath Neoplasms; Neoplastic Syndromes, Hereditary; Neurocutaneous Syndromes; Neurofibroma; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Neurofibromatoses; Neurofibromatosis 1; Equipment and Supplies; Optical Devices; Radiation Equipment and Supplies; Lasers; Lasers, Solid-State
• Other Study ID Numbers: 2025P000283

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes