Inclusion Criteria:

          1. Histological proof of advanced melanoma with BRAF V600 mutation;

          2. Progression of disease, according to RECIST 1.1, while on treatment with BRAFi, such
             as vemurafenib or dabrafenib; or a combination of BRAF - and MEK inhibitors, such as
             trametinib and dabrafenib;

          3. Previous documented response (partial or complete) for at least 4 weeks to treatment
             with BRAFi and/or BRAFi+MEKi;

          4. Start with vorinostat treatment within a maximum period of 1 week after
             discontinuation of BRAFi and/or BRAFi+MEKi.

             The BRAFi and/or BRAFi+MEKi can be continued after progression to provide sufficient
             time to perform baseline assessments;

          5. Age ≥ 18 years;

          6. Able and willing to give written informed consent;

          7. WHO performance status of 0, 1 or 2;

          8. Able and willing to undergo blood sampling for PK and PD analysis;

          9. Life expectancy ≥ 3 months allowing adequate follow up of toxicity evaluation and
             antitumor activity;

         10. Evaluable disease according to RECIST 1.1;

         11. Minimal acceptable safety laboratory values

               -  ANC of ≥ 1.5 x 109 /L

               -  Platelet count of ≥ 100 x 109 /L

               -  Hemoglobin ≥ 6.0 mmol/L

               -  Hepatic function as defined by serum bilirubin ≤ 1.5 x ULN, ALAT and ASAT ≤ 2.5 x
                  ULN, or in case of liver metastases ALAT and ASAT ≤ 5 x ULN

               -  Renal function as defined by serum creatinine ≤ 1.5 x ULN or creatinine clearance
                  ≥ 50 ml/min (by Cockcroft-Gault formula, or MDRD).

         12. Negative pregnancy test (urine/serum) within 72 hours before receiving the first dose
             of study medication for female patients with childbearing potential;

         13. Able and willing to undergo fresh histological tumor sampling prior to start, upon
             treatment and upon progression of vorinostat.

        Exclusion Criteria:

          1. Any treatment with investigational drugs, except BRAFi and MEKi, within 28 days prior
             to receiving the first dose of investigational treatment; or 21 days for standard
             chemotherapy and immunotherapy;

          2. Patients who have had previous treatment with vorinostat or other HDAC inhibitors;

          3. Leptomeningeal disease;

          4. Symptomatic brain metastasis. Patients previously treated or untreated for the
             condition and/or who are asymptomatic in the absence of corticosteroid therapy are
             allowed to enroll. Patients are not permitted to receive enzyme inducing
             anti-epileptic drugs or corticosteroids;

          5. Clinical progression of melanoma in the first week of discontinuation of BRAFi or
             BRAFi/MEKi;

          6. Woman who are pregnant or breast feeding;

          7. Unreliable contraceptive methods. Both men and women enrolled in this trial must agree
             to use a reliable contraceptive method from screening until 30 days after the last
             dose of study medication (adequate contraceptive methods are: oral or injected or
             implanted hormonal methods of contraception, condom, sterilization, other barrier
             contraceptive measures preferably in combination with condoms, true abstinence);

          8. Radiotherapy within the last 4 weeks prior to receiving the first dose of
             investigational treatment; except 1x8 Gray for pain palliation;

          9. Uncontrolled infectious disease or known Human Immunodeficiency Virus HIV-1 or HIV-2
             type patients;

         10. Patients with a known history of hepatitis B or C;

         11. Recent myocardial infarction (< 6 months before receiving the first dose of study
             medication) or unstable angina;