Clinical and Demographic Characteristics of Adult p Atients With NEurofibromatosis in RUSsia

Inclusion Criteria: 1. Age ≥ 18 years at the time of inclusion. 2. Signed and dated written informed consent in accordance with ICH-GCP and local law prior to inclusion in the study. 3. NF1 diagnosed (according to the international consensus criteria for evaluating NF1 \[18\]), see Appendix A. 4. Confirmed PN by clinical assessment, USI, MRI, biopsy; one method is sufficient (histologic confirmation of PN is not necessary in the presence of radiographic findings). 5. Existing of PN-associated symptoms. 6. Adult patients (≥18 years) with newly diagnosed PN or established PN naïve to MEK-inhibitor therapy verified by medical records/histories (e.g., prior prescriptions, hospitalization data). Exclusion Criteria: 1. The participation in any clinical study currently (patients participating in other non-interventional studies may be included); 2. Patients with the evidence of a malignant glioma, malignant peripheral nerve sheath tumor, or other cancer, requiring treatment with chemotherapy or radiation therapy. 3. In the opinion of the investigator the patient is not able to return for follow-up visits or obtain required follow-up studies. 4. Individuals who are pregnant or breast feeding or who become pregnant while enrolled on this trial, if they are unable to undergo radiographic evaluations or MRI scans requested for research purposes, or other studies which might negatively impact on the pregnancy. 5. Prior receipt of any MEK-inhibitor for PN therapy within 4 months before screening or initiation of therapy prior to age 18 verified by medical records/histories (e.g., prior prescriptions, hospitalization data). 6. Patients who modify their index pathogenetic therapy regimen during the study (for example, pathogenetic antitumor therapy of PN; switching to a different therapy), as determined by the investigator at any protocol-specified visit during the a study, will be excluded from the primary efficacy analysis population from the point of modification onward and will not continue study participation.