Study to Evaluate the Effect of Bosentan on the Pharmacokinetics of Lurbinectedin in Patients With Advanced Solid Tumors

All patients will receive a maximum of three cycles: two consecutive cycles of lurbinectedin, one cycle with and one cycle without bosentan co-administration (in different order depending on the study Sequence 1 or Sequence 2 of treatment), followed by a third cycle with lurbinectedin alone (this last optional for patients with clinical benefit). Lurbinectedin will be administered as a 1-hour intravenous (i.v.) infusion every three weeks (q3wk) via a central or peripheral vein. The dose of lurbinectedin will be 3.2 mg/m² for all patients when administered with and without bosentan. If toxicity occurs, the appropriate intra-patient dose level (DL) reductions will be implemented in the subsequent cycle.

Patients will be randomized in a 1:1 ratio to Sequence 1 (TR: Test-Reference; lurbinectedin + bosentan in Cycle 1) or Sequence 2 (RT: reference-Test; lurbinectedin + bosentan in Cycle 2).

Patients will receive lurbinectedin until disease progression, unacceptable toxicity, consent withdrawal or while it is considered to be in their best interest.

Treatment with lurbinectedin outside this study could be continued under a Compassionate Use Agreement after the completion of the optional third study cycle.