TiNT: This phase II trial is evaluating the effectiveness of a targeted therapy (trametinib) in children, teenagers and young adults with neurofibromatosis type 1 (NF1) associated Plexiform Neurofibromas and Optic Pathway GliomasA phase II study of trametinib in paediatric, adolescent and young adult patients with neurofibromatosis type 1 associated plexiform neurofibromas or progressive optic pathway gliomas

Inclusion

NF1-PN and NF1-OPG Cohorts:
1. Age of patient: Patient must be between 3 months and 25 years at time of enrolment
2. Diagnosis of NF1: Patient must meet NIH criteria for NF1 or has a documented germline genetic lesion in NF1 gene predicted to be deleterious
3. PN (clinically or pathologically diagnosed) with actual or impending functional or major cosmetic deficit and surgery not deemed appropriate
or
OPG (radiologically or pathologically diagnosed) which has progressed after at least 1 line of previous chemotherapy.
4. Measurable disease:
For OPG cohort: Must have measurable target lesion/s. Measurable lesions are defined as bidimensional lesions with clearly defined margins by MRI, with two perpendicular diameters of at least 10 mm, visible on two or more axial slices. For participants with smaller lesion/s who exhibit visual loss, this inclusion criteria may be waived following discussion with the study chairs.
or
For PN cohort: Must have measurable target lesion/s amenable to volumetric MRI analysis. At least 1 target lesion must be seen on at least 3 consecutive MRI slices, and have reasonably well-defined contours in all dimensions. Minimum tumour size for measurable disease is 3 cm3. If volumetric MRI analysis not available at site, 2D analysis is permissible. Target Lesion Size must be >= 30mm in longest diameter. Most lesions >=30mm in longest diameter will have a volume greater than 3 cm3. For participants with smaller lesion/s who have significant symptoms, this inclusion criteria may be waived following discussion with the study chairs.
5. Lansky/Karnofsky performance score greater than or equal to 50 (Use Karnofsky for patients greater than 16 years of age and Lansky for patients less than or equal to 16 years of age. Patients who are unable to walk because of paralysis, but who are up in a wheelchair, will be considered ambulatory for the purpose of assessing the performance score)
6. Life expectancy greater than 3 months
7. Haematologic function defined as:
i. Haemoglobin greater than or equal to 80 g/L
ii. Absolute Neutrophil Count greater than or equal to 1000/µL
iii. Platelet count greater than or equal to 100,000/µL
8. Adequate renal function defined as Serum creatinine normal as per institutional parameters for age and sex
9. Adequate liver function defined as:
i. Total bilirubin less than or equal to 1.5 x upper limit of normal for age
ii. AST and ALT less than or equal to 2.5 x upper limit of normal for age
10. Adequate cardiac function defined as:
i. Fractional shortening (FS) greater than or equal to 27% by echocardiogram or Ejection fraction = 53% by echocardiogram
ii. Corrected QT interval less than 460ms
11. Negative pregnancy test for women of child bearing potential (WOCBP)
12. For those of reproductive potential:
i. Agreement to use effective contraception (methods that result in less than 1% pregnancy rates) for the duration of study and 16 weeks after stopping study treatment AND
ii. Agreement not to breastfeed for the duration of study and 4 weeks after stopping study treatment
13. Provide a signed and dated informed consent form or has a legally acceptable representative capable of understanding the informed consent document and providing consent on the participant’s behalf.

Neurocognitive/Behavioural/QoL Substudy Control Group:
1. Age of patient: Patient must be between 3 months and 25 years at time of enrolment
2. Diagnosis of NF1: Patient must meet NIH criteria for NF1 or has a documented germline genetic lesion in NF1 gene predicted to be deleterious
3. Provide a signed and dated informed consent form or has a legally acceptable representative capable of understanding the informed consent document and providing consent on the participant’s behalf.