Inclusion criteria

        Patients must meet all of the inclusion criteria in order to be eligible to participate in
        the study.

        Cohort 1:

          1. Relapsed and/or refractory stage IVA, IVB SS who have received at least two prior
             systemic therapies;

          2. Prior treatment with mogamulizumab;

          3. Patients should have blood stage B2 at screening based on central evaluation by flow
             cytometry;

          4. Feasibility of obtaining at least one skin biopsy at screening;

             Cohorts 2 and 3:

          5. Relapsed and/or refractory stage IB, IIA, IIB, III, IV MF;

          6. KIR3DL2 expression (Cohort 2) or non-expression (Cohort 3) in at least one skin lesion
             based on central evaluation by IHC;

          7. Patients should have received at least two prior systemic therapies;

          8. Feasibility of obtaining at least one skin biopsy at screening;

             Additional inclusion criteria applicable to all cohorts:

          9. Male or Female, at least 18 years of age;

         10. ECOG performance status ≤2;

         11. The patient must have a minimum wash-out period of 3 weeks between the last dose of
             prior systemic therapy and the first dose of IPH4102;

         12. Patients should have recovered from all non-hematological adverse events related to
             prior therapy to ≤ grade 1 except for alopecia;

         13. Adequate baseline laboratory data:

             Hematology:

               -  Hemoglobin >9 g/dL,

               -  Absolute neutrophil count (ANC) ≥1,500/µL,

               -  Platelets ≥100,000/µL,

             Biochemistry:

               -  Bilirubin ≤1.5 X upper limit of normal (ULN) or ≤3 X ULN for patients with
                  Gilbert's disease,

               -  Serum creatinine ≤1.5 X ULN,

               -  Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≤2.5 X ULN;

         14. Women of childbearing potential (WOCBP): Premenopausal females who had at least one
             menstrual cycle in the past 12 months and capable to become pregnant. They must have a
             negative serum beta-HCG pregnancy test result within seven days from start of
             treatment;

         15. Women of childbearing potential and all men (and their female partners of childbearing
             potential) who are sexually active must agree to use adequate method of contraception
             at study entry, during treatment and for at least 9 months (270 days) following the
             last dose of study drug;

         16. Signed informed consent form prior to any protocol-specific procedures.

        Exclusion Criteria:

        Patients meeting any of the following exclusion criteria will not be eligible to
        participate in the study:

          1. Patients with evidence of large cell transformation (LCT) based on central histologic
             evaluation at screening;

          2. Receipt of live vaccines within 4 weeks prior to treatment;

          3. Central nervous system (CNS) lymphoma involvement;

          4. Prior administration of IPH4102;

          5. Concurrent enrollment in another clinical trial, unless it is an observational (non -
             interventional) clinical study or the follow-up period of an interventional study;

          6. Autologous stem cell transplantation less than 3 months prior to enrollment;

          7. Prior allogenic transplantation;

          8. Patients who have undergone major surgery ≤ 4 weeks prior to study entry;

          9. Patients with known NCI CTCAE grade 3 or higher active systemic or cutaneous viral,
             bacterial, or fungal infection;

         10. Patients who have active Hepatitis B or C virus infection;

         11. Known or tested positive for human immunodeficiency virus (HIV);

         12. Patients with a history of other malignancies during the past five years apart from
             the disease subject of this study. The following are exempt from the five-year limit:
             non-melanoma skin cancer, lymphomatoid papulosis, resected thyroid cancer,
             biopsy-proven cervical intraepithelial neoplasia, Ductal carcinoma in situ (DCIS) or
             cervical carcinoma in situ;

         13. Pregnant or breastfeeding women;

         14. Patients with congestive heart failure, Class III or IV, by New York Heart Association
             (NYHA) criteria;

         15. Patients with autoimmune disease on systemic immunosuppressive treatment;

         16. Patients with any serious underlying medical condition that would impair their ability
             to receive or tolerate the planned treatment and/or comply with study protocol;

         17. Patients with dementia or altered mental status that would preclude understanding and
             rendering of informed consent document.