Approximately 60 pediatric patients will be treated with DAY101, an oral pan-RAF inhibitor,
      for a planned period of 26 cycles will be treated with DAY101 for a planned period of 26
      cycles (approximately 24 months).

      DAY101 will be administered at the recommended Phase 2 dose (RP2D) of 420 mg/m2 (not to
      exceed 600 mg) orally once weekly (QW) for each 28-day treatment cycle.

      Treatment cycles will repeat every 28 days in the absence of disease progression or
      unacceptable toxicity. Patients will undergo radiographic evaluation of their disease at the
      end of every third cycle. Patients will continue on DAY101 until radiographic evidence of
      disease progression by RANO criteria as determined by treating investigator, unacceptable
      toxicity, patient withdrawal of consent, or death.

      Patients who have radiographic evidence of disease progression may be allowed to continue
      DAY101 if, in the opinion of the investigator and approval by the Sponsor, the patient is
      deriving clinical benefit from continuing study treatment. Disease assessments for patients
      being treated beyond progression should continue as per regular schedule.

      DAY101 is an oral pan-RAF inhibitor administered as an oral tablet at 420 mg/m2 (not to
      exceed 600 mg).