Study of Ruxolitinib in the Treatment of Cachexia in Patients With Tumor-Associated Chronic Wasting Diseases.

Inclusion Criteria:

* Definition of cachexia (see Section 11.1) fulfilled
* Age ≥ 18 years
* Confirmed tumor of any site
* Life expectancy of ≥3 months
* Subject must be willing to receive transfusion of blood products
* Patient must give written informed consent
* Females of childbearing potential (FCBP) must undergo pregnancy testing (serum) and pregnancy result must be negative.\*
* Reliable contraception should be maintained throughout the study and for 28 days after study treatment discontinuation
* Unless practicing complete abstinence from heterosexual intercourse, sexually active FCBP must agree to use adequate contraceptive methods
* Males (including those who have had a vasectomy) must use barrier contraception (condoms) when engaging in sexual activity with FCBP. Males must agree not to donate semen or sperm

Exclusion Criteria:

* Pregnant or breast feeding females
* Lack of written informed consent
* No consent for registration, storage and processing of the individual disease-characteristics and course as well as information of the family physician about study participation.
* No consent for "Translational Research" and "Biobanking" (see separate documents "Aufbewahrung und Weiterverwendung von biologischem Material und von Daten für die biomedizinische Forschung" und "Biobankreglement" for the RUXexia Trial).
* Thrombocytopenia \< 50 x 10e9/l
* Peroral intake not possible, in particular by stenosis of the esophagus
* New started treatment of the tumor (first 3 months of a new treatment). Patients with a new treatment of the cancer disease should delay screening/enrollment until 3 months after start of this treatment.
* Presence of any medical/psychiatric condition or laboratory abnormalities which may limit full compliance with the study, increase the risk associated with study participation or study drug administration, or may interfere with the interpretation of study results and, in the judgment of the Investigator, would make the patient inappropriate for entry into this study
* Patients with a Myeloproliferative Neoplasm
* Patients receiving any "Prohibited Medications" (see protocol) within 7 days prior to the first dose of study drug
* Patients with clinically significant bacterial, fungal, parasitic or viral infection which require therapy. Patients with acute bacterial infections requiring antibiotic use should delay screening/enrollment until the course of antibiotic therapy has been completed.