On October 23, 2015, the U. S. Food and Drug Administration approved trabectedin (Yondelis Injection, Janssen) for the treatment of patients with unresectable or metastatic liposarcoma or leiomyosarcoma who have received a prior anthracycline-containing regimen.
The approval of trabectedin is based on improvement in progression-free survival (PFS) in a multicenter, randomized, open‑label, active‑controlled trial.
Patients were randomized (2:1) to receive trabectedin 1.5 mg/m2 administered as an intravenous infusion over 24 hours once every 3 weeks (n=345) or dacarbazine 1000 mg/m2 administered as an intravenous infusion over 20 to 120 minutes once every 3 weeks (n=173). Randomization was stratified by soft tissue sarcoma subtype (leiomyosarcoma vs. liposarcoma), ECOG performance status, and number of prior chemotherapy regimens. The efficacy outcome measures were investigator‑assessed PFS per Response Evaluation Criteria in Solid Tumors (RECIST v1.1), overall survival, confirmed objective response rate, and response duration. Patients randomized to the dacarbazine arm were not offered trabectedin at the time of disease progression.
The median age was 56 years (range: 17 to 81); 30% were male; 76% White, 12% Black, and 4% Asian; 73% leiomyosarcoma and 27% liposarcoma; 49% had an ECOG PS of 0; and 89% received 2 or more prior chemotherapy regimens. The most common drugs administered as prior therapy were doxorubicin (90%), gemcitabine (81%), docetaxel (74%), and ifosfamide (59%). Approximately 10% of patients had received pazopanib.
The study demonstrated a statistically significant improvement in PFS (HR= 0.55; 95% CI: 0.44, 0.70; p<0.001). The median PFS (investigator-determined) was 4.2 and 1.5 months in the trabectedin and dacarbazine arms, respectively. There was no difference in overall survival between treatment arms (HR of 0.93; 95% CI: 0.75, 1.15; p=0.49]; the median overall survival was 13.7 and 13.1 months on the trabectedin and the dacarbazine arms, respectively. The confirmed objective response rates were 7% and 6% on the trabectedin and dacarbazine arms, respectively.
The most serious risks of trabectedin are neutropenic sepsis, rhabdomyolysis, cardiomyopathy, hepatotoxicity, anaphylaxis, and extravasation leading to tissue necrosis. Among the 378 patients who received at least one dose of trabectedin in the randomized trial, the most common (greater than or equal to 20% of patients) adverse reactions were nausea, fatigue, vomiting, constipation, decreased appetite, diarrhea, peripheral edema, dyspnea, and headache. The most common treatment-emergent, grade 3 or 4 laboratory abnormalities (greater than or equal to 5% of patients) were neutropenia, increased ALT, thrombocytopenia, anemia, increased AST, and increased creatine phosphokinase.
The recommended dose and schedule for trabectedin is 1.5 mg/m2 as a 24-hour intravenous infusion through a central venous line every 3 weeks in patients with normal bilirubin and with AST and ALT less than or equal to 2.5 times the upper limit of normal. Premedicate with dexamethasone 20 mg intravenously 30 minutes prior to each dose of trabectedin. There is no recommended dose of trabectedin for patients with serum bilirubin levels above the institutional upper limit of normal.
Full prescribing information is available at: http://www.accessdata.fda.gov/drugsatfda_docs/label/2015/207953s000lbl.pdf.
Healthcare professionals should report all serious adverse events suspected to be associated with the use of any medicine and device to FDA’s MedWatch Reporting System by completing a form online at http://www.fda.gov/medwatch/report.htm, by faxing (1-800-FDA-0178) or mailing the postage-paid address form provided online, or by telephone (1-800-FDA-1088).