Randomized phase III trial of trabectedin versus doxorubicin-based chemotherapy as first-line therapy in translocation-related sarcomas (TRS) Sant P. Chawla, Andrew Hendifar, Michael Leahy, Antoine Italiano, Shreyaskumar Patel, Peter Hohenberger, Armando Santoro, Arthur P. Staddon, Nicolas Penel, Sophie Piperno-Neumann, Pilar Lardelli, Antonio Nieto, Carmen Kahatt, Jean-Yves Blay As the audience knows, trabectedin is a marine derived alkaloid that has demonstrated efficacy in soft tissue sarcoma. This study was conducted to fulfill a specific obligation from the EMA: to identify predictors of response to trabectedin. High response rate of trabectedin in myxoid liposarcomas is well-documented. A trial was performed in order to verify if this higher activity extrapolated to other translocation related sarcomas as compared to doxorubicin containing regimens.

Study Design An adaptive design in chemonaïve patients with advanced TRS, stratified by performance status and subtype, then randomized to receive: Trabectedin: 1.5 mg/m2 in 24h iv infusion q3wk Doxorubicin based chemotherapy (DXCT): single agent 75 mg/m2 q3wk, or 60 mg/m2 combined with ifosfamide 6-9 g/m2 q3wk MRCL (n= 40) Other TRS (n= 40) RANDOMIZATION (1:1) Eligible patients PS= 0 PS= 1-2 An adaptive design was used as shown 80 chemonaïve patients were planned to be enrolled with at least 50% patients with myxoid liposarcoma. Eligible patients were stratified by ECOG performance status and histological subtype (myxoid liposarcoma versus other histologies) and randomized 1:1 to receive trabectedin or doxorubicin based chemotherapy

Study Objectives Primary: Progression free survival (PFS) of trabectedin vs DXCT Secondary: PFS at 6 months Response rate (RR) Overall survival Safety PFS/RR analyzed by investigator assessment for all randomized patients PFS/RR analyzed by independent review only for confirmed TRS patients Primary efficacy endpoint was progression-free survival. After randomization, translocation was confirmed by FISH. Secondary endpoints included progression-free survival at 6 months, response rates, overall survival and safety. Response rates were analyzed for all randomized patients by investigator assessment and only TRS confirmed patients by independent review

Results: Baseline Characteristics Trabectedin (n=61) DXCT (n=60) Age (yr) Median (range) 47 (19-78) 49 (19-78) Sex Male / female 36 (59%) / 25 (41%) 38 (63%) / 22 (37%) ECOG PS 28 (46%) 29 (48%) 1 32 (52%) 30 (50%) 2 1 (2%) Sarcoma type by Investigator MRCL 28 (47%) Other 33 (54%) 32 (53%) Sarcoma type by central pathology 23 (38%) 17 (28%) 20 (33%) Not confirmed* 10 (16%) A total of 121 patients were randomized , 61 to trabectedin arm and 60 to doxorubicin-based chemotherapy. Baseline characteristics were well balanced as shown Pathological review did not confirm TRS diagnosis and/or translocation in 33 of 121 randomized patients. Therefore, TRS confirmed population consisted of 88 patients: 40 (33%) with MRCL and 48 (40%) with other TRS. * Wrong diagnosis 4 (7%) and 9 (15%) patients of the trabectedin and DXCT arms, no evidence of translocation in 3 (5%) and 2 (3%) patients, and lack of available material for central review in 3 (5%) and 12 (20%) patients

Histology According Central Diagnosis (TRS Confirmed Patients N=88) Trabectedin (n=51) DXCT (n=37) N % MYXOID LIPOSARCOMA 23 45.1 17 45.9 SYNOVIAL SARCOMA 15 29.4 9 24.3 ALVEOLAR SOFT PART SARCOMA 2 3.9 5.4 CLEAR CELL SARCOMA 3 5.9 4 10.8 DESMOPLASTIC SMALL ROUND CELL 1 2.0 2.7 EXTRASKELETAL MYXOID CHONDROSARCOMA 5 9.8 LOW GRADE ENDOMETRIAL STROMAL SARCOMA LOW GRADE FIBROMYXOID SARCOMA . As described earlier, almost 50% of patients in either arm had myxoid liposarcoma Other histological sybtypes mainly included synovial sarcoma, alveolar soft part sarcoma, clear cell sarcoma and extraskeletal myxoid chondrosarcoma. Ewings and Rhabdomyosarcoma were excluded due to high response rates seen with standard chemotherapy.

Results: Baseline Characteristics Trabectedin (n=61) DXCT (n=60) Disease Extension Locally advanced 18 (30%) 13 (22%) Metastatic 43 (70%) 47 (78%) Prior surgery (radical/palliative) 33 (54%) 38 (63%) Prior radiotherapy 24 (39%) 21 (35%) Number of sites involved at baseline, Median (range) 2 (1-8) 2 (1-5) Months from first diagnosis to randomization, Median (range) 10 (1-187) 8 (0-310) Patients with advanced or metastatic disease as well as patients receiving prior surgery and radiotherapy were also balanced as shown.

Patient Exposure Trabectedin (n=61) DXCT (n=57) Number of cycles 441 264 Number of cycles per patient Median (range) 5 (1-31) 6 (1-8) Doxorubicin single agent (n=36) plus ifosfamide (n=21) 4 (1-8) Time on treatment (weeks) 19.3 (2.4-101.7) 19.2 (4.1-25.6) 14.3 (4.3-26.3) Median number of cycles was similar in both treatment arms but trabectedin could be administered indefinitely due to its lack of cumulative toxicities.

Censoring A high percentage of patients were censored in both arms Main reasons for censoring: Surgical removal of lesions 24% in trabectedin arm and 16% in the DXCT arm Administration of a new anticancer therapy (chemotherapy or radiotherapy) before progression of the disease 18% in trabectedin arm and 24% in DXCT arm Importantly, 35-40% patients in either arm ended up receiving the drug in the other arm Patients in trabectedin arm also received DXCT Patients in DXCT arm also received trabectedin A high percentage of patients were censored in both treatment arms rendering the analyses underpowered. Censoring rate was balanced between both arms. Main censoring reason was surgical lesion removal before disease progression Other frequent censoring reason was administration of other anticancer therapy or radiotherapy before disease progression Importantly, 35-40% patients in either arm received the opposite drug. Patients in the trabectedin arm received doxorubicin based chemotherapy and vice-versa.

Results: Response Rate Investigator Assessment All randomized patients Trabectedin (n=61) DXCT (n=60) Best objective response (RECIST) PR 5 (8%) 15 (25%) 0.0150 SD 40 (66%) 33 (55%) DCR 45 (74%) 48 (80%) PD 11 (18%) 8 (13%) NE 4 (7%) For all randomized patients, partial responses by RECIST were significantly higher in the doxorubicin based chemotherapy arm. But overall disease control rate was similar; 75% in both arms.

Results: Response Rate Independent Review  TRS confirmed patients Trabectedin (n=51) DXCT (n=37) p-value Best objective response (RECIST) PR 3 (6%) 10 (27%) 0.0123 SD 39 (77%) 22 (60%) DCR 42 (82%) 32 (87%) PD 6 (12%) 1 (3%) NE 4 (11%) Histology of PR patients 2 MRCL 1 Synovial 5 MRCL 4 Synovial 1 Desmoplastic Round cell For TRS confirmed patients, partial response rates were significantly higher for the doxorubicin based chemotherapy arm. However, disease control rate was again similar; 85% in both arms. Response rates in the TRS confirmed patients were similar to the rates for all randomized patients. In the Trabectedin arm, out of 3 patients who had partial response, 2 were Myxoid round cell liposarcomas and 1 was synovial sarcoma In the doxorubicin based chemotherapy arm, out of 10 patients who had PR, 5 were again myxoid round cell LPS, 4 were synovial sarcomas and 1 was a desmoplastic round cell sarcoma

Results: PFS by Investigators Median: 16.1 months (95% CI, 5.5-21.9) Hazard ratio: 0.85, p=0.5551. Log rank p=0.5533 Median: 8.8 months (95% CI, 5.5-12.7) For all randomized patients, median PFS was 16 months in trabectedin arm versus 9 months in doxorubicin based chemotherapy arm, but given the high rate of censoring, was not statistically significant.

Results: PFS by Independent Review Hazard ratio: 0.86; p=0.6992. Stratified log-rank p=0.9573 Median: 18.8 months (95% CI, 5.7-not reached) Median: 8.3 months (95% CI, 7.1-25.0) For TRS confirmed patients, median PFS was 19 months in trabectedin arm versus 8 months in doxorubicin based chemotherapy arm, but again, given the high censoring, was not statistically significant.

Results: Overall Survival Median: 27.3 months (95% CI, 21.3-39.6) Median: 38.9 months (95% CI, 24.2-nr) Hazard ratio: 0.77, p=0.3672. Log rank p=0.3659 For all randomized patients, median overall survival was 39 months in trabectedin arm vs 27 months in doxorubicin- based chemotherapy arm, but was not statistically significant due to the high rate of censoring Survival curves separated in favor of trabectedin after 20 months.

OS in Myxoid Liposarcoma In subset analysis, which may not be kosher for the statistical aficionados in the audience, overall survival appears longer in patients with myxoid liposarcoma, but may not be valid due to the high censoring. Median: 95% CI (-) Median: 33.1 95% CI (21.2-39.6) Hazard ratio: 0.25, p=0.0453. Log rank p=0.0314

Results: Hematologic and Other Laboratory Toxicity Trabectedin DXCT Grade1-2 (%) Grade 3-4 (%) Laboratory disorders Neutropenia 25.0% 55.0% 10.7% 75% Febrile neutropenia - 1.6% 12.3% Thrombocytopenia 26.2% 16.4% 37.5% 14.3% ALT increase 40.0% 53.3% 37.0% 1.9% AST increase 51.7% 33.3% ALKP increase 56.7% 5.0% 38.9% Bilirubin increase 20.0% 1.7% 13.0% CPK increase 34.5% 8.6% 8.2% 4.1% Incidence of grade 3/4 neutropenia was higher in doxorubicin arm The most common severe laboratory abnormality associated with trabectedin was transient transaminases elevation

Results: Non-Hematologic Toxicity Trabectedin DXCT Grade1-2 (%) Grade 3-4 (%) Treatment related AEs Fatigue 59.0% 6.5% 61.4% 1.8% Nausea 68.9% 1.6% 64.9% - Vomiting 42.6% 26.3% Mucositis 4.9% 8.8% Alopecia 43.9% As expected, severe fatigue was seen more frequently in trabectedin arm while febrile neutropenia and mucositis were more commonly observed in doxorubicin-based chemotherapy arm.

Summary The study was underpowered to detect any statistical significant differences in the two arms due to high rate of censoring in both arms Overall, no statistically significant differences in PFS/OS were observed Median PFS was 19 mo. in trabectedin arm vs. 8 mo. in DXCT arm Median OS was 39 mo. in trabectedin arm vs. 27 mo. in DXCT arm Safety profiles for trabectedin and DXCT were consistent with previous studies Ability to administer trabectedin over prolonged periods without cumulative toxicity may allow for longer disease control Trabectedin should be further explored in a definitive randomized study in myxoid liposarcoma patients High rate of censoring in both arms rendered the study underpowered to detect any statistically significant differences. No statistical significant differences were observed in PFS or OS. As expected, safety profiles for both arms was consistent with previous studies The ability to administer multiple cycles of trabectedin without significant cumulative toxicity may allow for longer disease control Trabectedin deserves further exploration in a definitive randomized study in myxoid liposarcoma patients

Back-up slides

All randomized patients Censoring Reasons Efficacy population Trabectedin (n=51) DXCT (n=37) Surgery 12 (24%) 6 (16%) Chemotherapy 6 (12%) 7 (19%) Radiotherapy 3 (6%) 2 (5%) Last tumor assessmenta 5 (14%) Otherb 2 (4%) 4 (11%) Total 35 (69%) 24 (65%) All randomized patients Trabectedin (n=61) DXCT(n=60) 11 (18%) 12 (20%) 5 (8%) 4 (7%) 3 (5%) 6 (10%) 9 (15%) 32 (52%) 34 (57%) a Patients on follow-up for disease assessment or with event/subsequent therapy out of study window or without PD at last tumor assessment available in database at cut-off date. b Censored at randomization (e.g.: untreated) or withdrawn due to related/unrelated adverse event or refusal before treatment onset/disease progression or new treatment out of study window. Censoring rates were similar in both arms for both the primary efficacy population and the all randomized population. Surgical removal of the lesions was the most common reason for censure, and was similar in trabectedin and in Doxo-based chemotherapy arms.

Subsequent Chemotherapy Agents in Censored Patients Trabectedin (n=35) DXCT (n=24) N % CEDIRANIB . 1 4.2 CYCLOPHOSPHAMIDE 2 5.7 8.3 DACARBAZINE DOCETAXEL 3 8.6 DOXORUBICIN 10 28.6 12.5 DOXORUBICIN HYDROCHLORIDE EPIRUBICIN 2.9 ETOPOSIDE GEMCITABINE 5 14.3 IFOSFAMIDE 6 17.1 8 33.3 PAZOPANIB SORAFENIB SORAFENIB TOSILATE SUNITINIB TRABECTEDIN 4 11.4 9 37.5 VINORELBINE VORINOSTAT Chemotherapy agents given to patients with no disease progression, in both treatment arms. Patients were therefore censored for PFS.

Responders’ Histology Patient Treatment arm Central Diagnosis 103013 Trabectedin Synovial sarcoma 182003 Myxoid liposarcoma 21021 103008 DXCT 14034 Desmoplastic small round cell sarcoma 184025 191006 221011 33014 44016 71020 71026 72011 Histological subtype of sarcoma in patients who responded by RECIST (Independent Review).

Discontinuations and Dose Reductions Trabectedin (n=61) DXCT (n=57) n % N Deaths associated with treatment- related AEs 1 1.6 1.8 Discontinuations associated with treatment-related AEs 10 16.4 6 10.5 Delays associated with treatment- related AEs 32 52.5 8 14.0 Dose reductions associated with treatment-related AEs 24 39.4 Administration delays and dose reductions occurred more frequently in the trabectedin arm, partially due to the prolonged treatment duration. Transaminase increase was the main reason for dose reduction. Neutropenia was the most common cause of administration delay. Neutropenia was controlled in trabectedin arm mainly with dose delay, while G-CSF was more frequently administered in Doxo arm (61.4% of patients) than in trabectedin arm (49.2%). Administration delays and dose reductions occurred more frequently in the trabectedin arm, partially due to the prolonged treatment duration. Transaminase increase was the main reason for dose reduction Neutropenia was the most common cause of administration delay.

Results: Safety in DXCT DXCT+Ifosfamide (n=21) DXCT (n=36) Grade1-2 (%) Grade 3 (%) Grade 4 (%) Grade 4(%) Treatment related AEs Fatigue 57.1% - 63.9% 2.8% Nausea 52.4% 72.2% Vomiting 19.0% 30.6% Mucositis 9.5% 4.8% 36.1% 11.1% Alopecia 38.1% 47.2% Febrile neutropenia 14.3% 5.6% Laboratory disorders Neutropenia 23.8% 42.9% 2.9% 34.3% Thrombocytopenia 45.7% 5.7% ALT increase 31.6% 5.3% 40.0% AST increase 26.3% Alkaline phosphatase increase 52.6% 31.4% Bilirubin increase 10.5% CPK increase 5.9% 12.5% 3.1% Most frequent adverse events and laboratory abnormalities in patients from arm B (doxo-based chemotherapy), split by treatment type: doxorubicin alone or in combination with ifosfamide.