Food-effect study of weekly administration of (bi-)daily Oral Docetaxel (ModraDoc006) in combination with ritonavir

1. Histological or cytological proof of cancer;2. Patients for whom no standard therapy of proven benefit exists ;3. Patients who might benefit from treatment with docetaxel, e.g. advanced breast, gastric, esophagus, bladder, ovarian cancer and non-small cell lung cancer, head and neck cancers, prostate cancer and carcinoma of unknown primary site. ;4. Age 18 years or older;5. Able and willing to give written informed consent;6. Able and willing to undergo blood sampling for pharmacokinetics;7. Life expectancy more than 3 months;8. Minimal acceptable safety laboratory values;8.1. Hb >= 6.0 mmol/l;8.2. ANC >= 1.5 x 109 /L;8.3. Platelet count >= 100 x 109 /L;8.4. Serum bilirubin >= 1.5 x ULN, ALAT and ASAT >= 2.5 x ULN (or >= 5 x ULN in case of presence of liver metastases);8.5. Serum creatinine < 1.5 x ULN or creatinine clearance >= 50 ml/min (by Cockcroft-Gault formula).;9. WHO performance status of >= 1 ;10. No radio- or chemotherapy within the last 4 weeks prior to first dose of study medication (palliative radiation on limited field for pain reduction is allowed);11. Able and willing to swallow oral medication.

1. Patients with known alcoholism, drug addiction and/or psychotic disorders in the medical history that are not suitable for adequate follow up;2. Women who are pregnant or breast-feeding. ;3. Men and women, who do not agree to use two reliable contraceptive methods throughout the study (adequate contraceptive methods are: use of oral, injected or implanted hormonal methods of contraception, placement of an intrauterine device (IUD) or intrauterine system (IUS), barrier methods of contraception: condom, diaphragm with spermicide, male sterilization, true abstinence). ;4. Concomitant use of MDR and CYP3A modulating drugs such as Ca¬¬+-entry blockers (verapamil, dihydropyridines), cyclosporine, quinidine, quinine, tamoxifen, megestrol and grapefruit juice, concomitant use of HIV medications; other protease inhibitors, (non) nucleoside analogs, St. Johns wort or macrolide antibiotics like erythromycin and clarithromycin. ;5. Uncontrolled infectious disease or known HIV-1 or HIV-2 infection;6. Unresolved (>grade 1) toxicities of previous chemotherapy, excluding alopecia;7. Bowel obstructions or motility disorders or previous surgery that may influence the absorption of drugs;8. Neurologic disease that may render a patient at increased risk for peripheral or central neurotoxicity;9. Pre-existing neuropathy greater than CTC grade 1;10. Patients with suspected or known brain metastases, unless they have been adequately treated and are asymptomatic without use of corticosteroids (for at least 1 month) ;11. Evidence of any other disease, neurological or metabolic dysfunction, physical examination finding or laboratory finding giving reasonable suspicion of a disease or condition that contraindicates the use of an investigational drug or puts the patient at high risk for treatment-related complications.