Peptide vaccine targeting the DNAJB1-PRKACA fusion in fibrolamellar liver cancer and related tumors

Inclusion Criteria:

* Ability to understand and willingness to sign a written informed consent document.
* Histologically confirmed Fibrolamellar hepatocellular carcinoma (FL-HCC) or other malignant disease in an adjuvant setting, defined as:

  * Presence of DNAJB1-PRKACA fusion transcript, assessed by RNA-based NGS or RT-PCR
  * Achievement of complete remission (CR) according to RECIST1.1 by any of the following therapeutic measures:
* surgical procedures,
* radiotherapy,
* local therapeutic measures (e.g. TACE, SIRT, etc.)
* systemic treatment (e.g. chemotherapy)
* Age ≥ 12 years. Note: Subjects aged ≥ 12 years but \< 18 are eligible to enroll now because 6 adult patients have been enrolled in the study.
* Patients \<18 years must have a body weight ≥ 40 kg
* Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2.
* Adequate laboratory values for

  * Absolute Lymphocyte Count \> 500 /µl
  * Platelets \> 50.000 /µl
  * Creatinine clearance GFR \> 30 ml/min
  * Alanine aminotransferase (ALT) and aminotransferase (AST) ≤ 5 times upper limit range
  * Bilirubin ≤ 3 mg/dl
* Negative serological hepatitis B test or negative PCR in case of positive serological test without evidence of an active infection, negative testing of hepatitis C RNA, negative HIV test within 6 weeks prior to study inclusion.
* Female patients of child bearing potential (FCBP) and male patients with partners of child bearing potential who are sexually active must agree to the use of two effective forms (at least one highly effective method) of contraception. This should be started from the signing of the informed consent and be continued until 3 months (both female and male patients) after last dose of the vaccination
* For FCBP two negative pregnancy tests (sensitivity of at least 25 mIU/mL) prior to first application of the study drug (vaccination at visit V1), one at screening and the other one at visit V1 prior (\< 24h) to first vaccination.
* Postmenopausal or evidence of non-child-bearing status.
* Be willing to minimize blood and body fluid exposure after vaccination until end of study

  * Refrain from sperm or ovary egg donation
  * Refrain from blood donation

Exclusion Criteria:

* Pregnant or breastfeeding.
* Unwilling or unable to follow the study schedule for any reason.
* Concurrent or previous treatment within 14 days in another interventional clinical trial with an investigational anti-cancer treatment.
* Concurrent treatment with any of the following therapeutic measures:

  * surgical procedures,
  * radiotherapy,
  * local therapeutic measures (e.g. TACE, SIRT, etc.)
  * systemic treatment (e.g. chemotherapy)
* Concurrent or previous treatment within 6 months with an anti-cancer vaccine treatment.
* Any live vaccine therapy used for prevention of infectious diseases within 28 days of study treatment
* Known sensitivity to or history of allergic reactions to investigational drug.
* Active autoimmune disease that has required systemic treatment in the past 2 years, or a documented history of clinically severe autoimmune disease, or a syndrome that requires systemic steroids (\> 10 mg per day) or immunosuppressive agents (Please note, patients after liver transplantation requiring immunosupressants are allowed).
* Uncontrolled intercurrent illness including, but not limited to, uncontrolled infection, symptomatic congestive heart failure, unstable angina, cardiac arrhythmia, metastatic cancer, or psychiatric illness/social situations that would limit compliance with study requirements.