Phase I Dose Escalation Trial of Efavirenz in Solid Tumours or Non-Hodgkin Lymphoma in Therapeutic Failure.

This is a Phase I dose escalation strategy according to the method described by CRML O'Quigley and Shen \[O'Quigley et al. Biometrics 1996\] and commonly used in phase I trials in oncology. Six levels of doses are initially defined: 600 mg, 1200 mg, 1800 mg, 2200 mg, 2600 mg, 3000 mg. The maximum potential dose-limiting toxicities allowed is 25%. Dose limiting toxicities will be defined as follows: * Any drug-related toxicity with grade ≥ 3 according to NCI-CTCAE v4.0 (except alopecia, nausea and vomiting, regardless of grade), * Any drug-related toxicity, regardless of grade, who led a treatment delay\> 14 days, * Score ≥ 19 HAD during treatment.