Supplementary appendix

Transcription

1 Supplementary appendix This appendix formed part of the original submission and has been peer reviewed. We post it as supplied by the authors. Supplement to: Tap WD, Jones RL, Van Tine BA, et al. Olaratumab and doxorubicin versus doxorubicin alone for treatment of soft-tissue sarcoma: an open-label phase 1b and randomised phase 2 trial. Lancet 2016; published online June 9. org/ /s (16)

2 Supplementary Appendix Olaratumab and doxorubicin versus doxorubicin alone for treatment of soft-tissue sarcoma: an open-label phase 1b and randomised phase 2 trial William D. Tap, Robin L. Jones, Brian A. Van Tine, Bartosz Chmielowski, Anthony D. Elias, Douglas Adkins, Mark Agulnik, Matthew Cooney, Michael B. Livingston, Gregory Pennock, Meera R. Hameed, Gaurav D. Shah, Amy Qin, Ashwin Shahir, Damien M. Cronier, Robert Ilaria Jr, Ilaria Conti, Jan Cosaert, Gary K. Schwartz Table of Contents Investigative Sites.Page 2 Supplementary Online Methods...Page 2 Supplementary Figures (N=4).. Page 9 Supplementary Tables (N=17)..Page 16 1

3 Investigative Sites Accelerated Community Oncology Research Network, Memphis, Tennessee Arizona Cancer Center, Tucson, Arizona Cancer Therapy and Research Center, San Antonio, Texas Carolinas Hematology Oncology Associates, Charlotte, North Carolina Emory Clinic, Atlanta, Georgia Mayo Clinic, Rochester, Minnesota MD Anderson Cancer Center Orlando, Orlando, Florida Memorial Sloan Kettering Cancer Center, New York, New York Northwestern University, Chicago, Illinois Seattle Cancer Care Alliance, Seattle, Washington UCLA Medical Center, Los Angeles, California University Hospitals Case Medical Center, Cleveland, Ohio University of Colorado Health Sciences Center, Aurora, Colorado University of Florida School of Medicine, Gainesville, Florida University of Wisconsin-Madison Hospital and Health Clinic, Madison, Wisconsin Washington University in Saint Louis, Saint Louis, Missouri Supplementary Online Methods Objectives 2

4 The primary objective of the Phase 1b portion of this study was to evaluate the safety profile of olaratumab when administered in combination with doxorubicin to patients with advanced Soft Tissue Sarcoma (STS) not amenable to treatment with surgery or radiotherapy. The secondary objectives of the Phase 1b portion of the study were to evaluate the pharmacokinetics (PK) and immunogenicity of olaratumab in combination with doxorubicin. The primary objective of the Phase 2 portion of this study was to compare progression free survival (PFS) in patients with advanced STS not amenable to treatment with surgery or radiotherapy when treated with olaratumab in combination with doxorubicin versus doxorubicin alone. The secondary objectives of the Phase 2 portion of the study were to evaluate and compare the 3-month PFS (PFS-3m) rate, objective response rate (ORR), change in tumor size from baseline to best overall response, and overall survival (OS) of olaratumab in combination with doxorubicin versus doxorubicin alone; to evaluate the PK and immunogenicity of olaratumab in combination with doxorubicin; and to evaluate the association between tumor platelet derived growth factor receptor alpha (PDGFRα) expression and clinical outcomes, including the primary and secondary objectives. Planned Enrollment For the Phase 1b portion of the study, patients were enrolled until 10 patients had been treated for at least 2 cycles. The Phase 2 portion of the study planned to randomize approximately 130 patients (65 in each study arm) at approximately 18 to 25 study sites in the US. Inclusion and Exclusion Criteria Male and female patients 18 years with histologically- or cytologically-confirmed, locally advanced or metastatic STS (excluding Kaposis Sarcoma) with documented disease progression, not amenable to treatment with surgery or radiotherapy were enrolled and treated at the study sites. Patients were required to have measurable disease according to the Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1), an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2, a life expectancy 3 months, adequate hematologic, hepatic, renal, and coagulation function (as defined by an absolute neutrophil count [ANC] 1500 µl, hemoglobin 9.0 g/dl, and a platelet count of 100,000/µL, a total bilirubin 1.5 mg/dl, and aspartate transaminase [AST] and alanine transaminase [ALT] 3.0 the upper limit of normal [ULN], a serum creatinine 1.5 the institutional ULN [if creatinine is above the ULN, the patient s creatinine clearance was required to be 45 ml/min], an international normalized ratio [INR] 1.5 and a partial thromboplastin time [PTT] 5 seconds above the ULN if not receiving anticoagulation therapy). Patients on full-dose anticoagulation must have been on a stable dose of oral anticoagulant or low molecular weight heparin, have a therapeutic INR (if applicable), no active bleeding (defined as within 14 days prior to first dose of study medication), and no pathological condition that carries a high risk of bleeding (e.g., tumor involving major vessels or known varices). The patient was required to have available tumor tissue from either the primary or metastatic tumor for determination of PDGFRα expression by immunohistochemistry (IHC). Prior treatment with systemic cytotoxic agents was allowed but not necessary and there was no limit to the number of prior treatment regimens. Patients were required to have a prestudy echocardiogram (ECHO) or multigated acquisition (MUGA) scan with an actual left ventricular ejection fraction (LVEF) 50%, within 21 days prior to first dose of study medication. Women of childbearing potential and sexually active males must have agreed to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Prior treatment with doxorubicin, daunorubicin, idarubicin, and/or other anthracyclines and anthracenediones and previous therapy with any agent that targets the PDGF or PDGFR was not allowed. Study Procedures After providing written informed consent, patients underwent screening for eligibility to participate within the study. 3

5 For the Phase 1b portion of the study, patients received 15 mg/kg of olaratumab on Days 1 and 8 of each 21-day treatment cycle, administered intravenously. On Day 1, doxorubicin 75 mg/m 2 was administered one hour after the completion of the olaratumab infusion. The actual (not planned) administration of each doxorubicin infusion defined Day 1 of each 21-day treatment cycle. The combination treatment could continue for up to 8 cycles at the investigator s discretion. For patients continuing treatment with olaratumab and doxorubicin from Cycles 5 through 8, dexrazoxane could be administered (at the investigator s discretion), prior to doxorubicin on Day 1 of each 21-day cycle at a 1:10 ratio of doxorubicin to dexrazoxane (e.g. 750 mg/m 2 ). Patients were assessed for tumor response every 6 weeks via RECIST v1.1. Patients without disease progression could continue to receive treatment until the development of unacceptable toxicity, noncompliance, withdrawal of consent by the patient, or investigator decision. If doxorubicin was discontinued (e.g., doxorubicin had been administered for 8 cycles or discontinued for reasons of toxicity), patients could continue on olaratumab monotherapy in the absence of disease progression or other withdrawal criteria. For patients who discontinued olaratumab during the first 8 cycles of treatment, doxorubicin could be continued (for up to 8 cycles), provided no withdrawal criteria were met. Once 10 patients received study treatment for 2 cycles, the Phase 1b portion of the study was closed to enrollment. A Safety Review Committee (SRC) reviewed the patient safety data and confirmed the safety of the combination before starting the Phase 2 portion of the study. Enrollment for the Phase 2 portion of the study could then begin, provided the drug was well tolerated and no major safety concerns arose. Enrolled patients in the Phase 2 portion of the study who met all eligibility criteria were randomized 1:1 to one of two treatment groups. As described in the supplementary statistical section, a dynamic randomization algorithm was used. To determine tumor type and PDGFRα expression in the Phase 2 patients, a tumor sample from either a biopsy or previously archived tumor tissue sample was obtained. Patients on the combination arm received olaratumab and doxorubicin at the same dose and schedule as outlined in the Phase Ib portion of the study. The combination treatment (olaratumab and doxorubicin) could continue for up to 8 cycles. In the absence of disease progression or other withdrawal criteria, patients in group 1 who completed 8 cycles of therapy could receive subsequent olaratumab monotherapy (15mg/kg), administered on Days 1 and 8 of each 21-day cycle until documented disease progression. Furthermore, if doxorubicin was discontinued (e.g., for reasons of toxicity) and in the absence of withdrawal criteria, patients could continue to receive olaratumab monotherapy. For patients who discontinued olaratumab during the first 8 cycles of treatment, doxorubicin could be continued (for up to 8 cycles), provided no withdrawal criteria were met. Patients on the doxorubicin only arm received doxorubicin 75mg/m2 on Day 1 of each cycle, for up to 8 cycles. The actual (not planned) administration of each doxorubicin infusion defined Day 1 of each 21-day treatment cycle. Treatment with doxorubicin could continue for up to 8 cycles. Dexrazoxane could also be administered in both groups during cycles 5 through 8 as outlined in the Phase Ib portion of the study at the investigator s discretion, on Day 1 of each cycle. Patients on the doxorubicin only arm, who discontinued study therapy because of therapy-related toxicity or completion of doxorubicin treatment and experienced stable disease (or better), could stay on study schedule with assessments until progressive disease was documented. At the time of documented disease progression, patients could receive olaratumab monotherapy at the same dosing regimen and duration as those patients from the combination arm, who continued on olaratumab monotherapy post combination therapy. Treatment could continue until disease progression, development of unacceptable toxicity, noncompliance or withdrawal of consent by the patient, or investigator decision. Dose Modification In general, discontinuation of 1 study agent (olaratumab or doxorubicin) did not necessitate discontinuation of the other for patients in the Phase 1b portion or on the olaratumab+doxorubicin arm of the Phase 2 portion of the study. In the event of alteration or discontinuation of olaratumab therapy because of an olaratumab-related toxicity, doxorubicin did not need to be altered, and the planned doxorubicin schedule was maintained. Similarly, olaratumab therapy was not 4

6 to be altered or discontinued for doxorubicin-related toxicity. Alteration or discontinuation of doxorubicin always necessitated a corresponding change to dexrazoxane in order to maintain a dosage ratio of 10:1 (dexrazoxane:doxorubicin). All dose reductions were permanent. Olaratumab Discontinuation If a patient enrolled in the Phase 1b portion or in the combination arm of the Phase 2 portion of the study was permanently withdrawn from olaratumab therapy because of a toxicity clearly attributed to olaratumab, the patient could continue to receive doxorubicin for a maximum of 8 cycles as long as all other study criteria were met. Pharmacokinetics Blood samples for PK assessment were collected from all patients who received olaratumab including those patients on the doxorubicin-only arm treated with olaratumab monotherapy after documented disease progression. More intensive PK sampling was performed in all patients of the Phase 1b portion and in a subset of patients in the Phase 2 portion. In addition, blood samples were also collected for immunogenicity analyses and in the event of an olaratumab infusion reaction. If antibodies against olaratumab were detected or in the setting of an, this sample also was used to assess circulating levels of olaratumab (PK assay). PDGFRα Expression Tumor tissue sample sufficient to establish PDGFRα expression were required for all patients in both Phase 1b and Phase 2. For Phase 1b patients, biopsy was performed on either the primary or metastatic tumor within 21 days prior to enrollment. To determine PDGFRα expression in the Phase 2 patients, a tumor sample from either a biopsy (similar to that performed for Phase 1b patients) or previously archived tumor tissue sample was sufficient. Biopsies were performed within 21 days prior to randomization; archived tissue sample was also permitted if obtained within this timeframe. PDGFRα expression (positive or negative) was assessed by Clinical Laboratory Improvement Amendments-approved immunohistochemistry before enrollment (Phase 1b) or randomization (Phase 2). These assessments were done at Memorial Sloan Kettering Cancer Center using Santa Cruz Biotechnology rabbit polyclonal antibody (Sc-338). A staining result of 2 or greater signified a PDGFRα-positive status. A second, retrospective, exploratory analysis was also performed by using the Cell Signaling Technology rabbit monoclonal antibody (clone D13C6) (Exploratory Assay). PDGFRα protein expression (pretreatment) by Assay 2 immunohistochemistry was assessed at Lilly Clinical Diagnostics Laboratory in tumor cells, and was provided as a dichotomous variable with positive and negative expression, where positive corresponds to weak intensity membranous staining comprising greater than 30% of the tumor and/or moderate to strong intensity membranous staining comprising greater than 5% of the tumor, and negative corresponds to staining that does not meet these requirements. Staining from both analyses was compared with outcomes. Test Product Olaratumab was supplied in sterile, preservative-free solution for intravenous infusion in single-use vials containing 500 mg/50 ml of olaratumab (10 mg/ml). Criteria for Evaluation and Statistical Methods Efficacy Evaluation The primary efficacy variable in the Phase 2 portion of this study was PFS, defined as the time from randomization until the first radiographic documentation of objective disease progression defined by RECIST,v1.1 or death from any cause. A patient who died without a reported prior progression of disease was considered to have progressed on the day of his or her death. Secondary efficacy endpoints included ORR and OS. 5

7 Pharmacokinetic Analyses Pharmacokinetic parameters for olaratumab were determined using non-compartmental methods using Phoenix 64,WinNonlin Version 6.3. Exposure-response Analyses The exposure-response analyses were performed using data obtained from all 133 patients of the intent-to-treat (ITT) population. Matched case-control (MCC) analyses (Yang et al. 2013) were performed comparing overall survival and PFS in subgroups of the Investigational Arm (defined by quartiles of olaratumab serum exposure) to that in a matching subgroup of the Control Arm. Quartiles of olaratumab serum exposure were based on 1) the trough olaratumab serum concentration at the end of cycle 1 (C min1 ) and 2) the average olaratumab serum concentration throughout the duration of treatment (C avg ). Owing to the relative sparsity of the PK data available in the study, individual C min1 and C avg estimates for each patient were obtained by means of population PK modeling (data not shown). Each matched subgroup of the Control Arm was selected by matching patients propensity scores over 7 potential prognostic covariates for overall survival. These covariates, listed below, were selected based on having sufficient prognostic impact on OS and/or PFS, as measured by step wise multivariate Cox models of the randomized OS and PFS data: ECOG PS 0 vs 1 vs 2; Leiomyosarcoma versus Liposarcoma versus other, number of prior systemic therapies in the adjuvant or metastatic setting (0 versus >0), baseline weight (as a continuous variable), sex (M versus F), baseline albumin ( 38 versus <38), baseline white blood cells ( 10 versus >10). Safety Evaluation and Parameters Treatment-emergent adverse events (TEAEs) were summarized by the Medical Dictionary for Regulatory Activities (MedDRA, version 7.1) System Organ Class (SOC) and Preferred Term (PT). If more than one AE was recorded for a patient within any SOC or PT term, the patient was counted once for the most severe grade and the closest relationship to treatment. TEAEs were also summarized based on consolidated terms to minimize the excess granularity of the MedDRA PTs. For example, neutrophil count decreased and neutropenia were summarized as one consolidated TEAE to allow meaningful interpretation of the data. Summaries included AEs that were serious, with grades 3, leading to discontinuation of any study drug, and with outcomes of death. Deaths and their causes that occurred after the administration of the first dose and within 30 days of the last dose of study therapy were summarized. AEs of special interest were determined by the clinical team. Statistics The sample size for Phase 1b was not based on statistical consideration. Patients were enrolled into the Phase 2 portion of the study once the safety of the drug in the Phase 1b portion of the study was confirmed. The sample size of 130 patients for the Phase 2 portion of the study was based on the assumption of a 12-month accrual period, a follow-up of at least 3 months after the last patient was enrolled, and a 1:1 randomization to treatment and control arms, respectively. This sample size allowed for the detection of an improvement in PFS-3m from 25% in group 2 (doxorubicin alone) to 40% (hazard ratio=0.67) for group 1 (olaratumab in combination with doxorubicin), with a one-sided log-rank test at the 0.1 significance level and a power of 80%. The primary analysis in the phase 2 portion was originally planned to be done when at least 110 PFS events were observed. However, when protocol-defined censoring rules resulted in a higher than expected censoring rate that precluded attainment of the required number of PFS events, the statistical analysis plan and protocol were amended to define a data cutoff date of August 15, 2014 for the final primary analysis, by which time a projected 100 PFS events would have been observed. After the validation of the reporting database was completed, the actual number of PFS events attained by the data cutoff date of 15 August 2014 was

8 An interim efficacy analysis of PFS for Phase 2 was planned after at least 80 PFS events were observed, assigning a two-sided nominal alpha of After review of the interim PFS (and interim OS) results by the Assessment Committee, the study continued. With a Bonferroni correction, the final analysis of PFS was therefore adjusted to be performed using a two-sided alpha level of This PFS interim analysis was prespecified as nonbinding. The final analysis for OS was prospectively planned to occur at the later date of 2 years after the last patient started study treatment, or when approximately 91 events had occurred in the randomized and treated study population. Given the change in planned efficacy analyses to focus on the full ITT population, the final OS database was locked with 91 ITT OS events based on a 16 May 2015 data cutoff date. For the Phase 2 portion of the study, a dynamic randomization algorithm was employed using four pre-defined risk factors: 1) PDGFRα expression (positive versus negative) of tumor tissue sample submitted at baseline, 2) number of previous lines of treatment (0 versus 1 line of therapy), 3) histological tumor type (leiomyosarcoma versus synovial sarcoma versus other tumor type), and 4) ECOG performance status (0 to 1 versus 2). Dynamic randomization, with a probability factor of 0.8, was used to minimize the imbalance for each risk factor, as well as for the overall treatment group. The primary efficacy analysis for the Phase 2 portion of the study included all randomized and treated patients (ITT population), regardless of compliance with the treatment regimen and protocol. Safety analyses were performed on the safety population which was defined as all patients who received any dose of study medication, regardless of their eligibility for the study. Patients were analyzed by the treatment they actually received, regardless of the treatment arm to which they were randomized. The Kaplan-Meier method was used to estimate the median PFS time, together with a 95% confidence interval (CI). Of interest, the 3-month PFS was estimated. Comparison between arms was performed using the log-rank test and the hazard ratios were estimated by a Cox proportional hazards regression model. The stratified analysis was performed only when there were sufficient numbers of patients in each stratum. As there was a limited number of patients with either a performance status of 2 or a PDGFRα negative tumor sample, the actual stratified analyses used only 2 randomization balancing variables: number of lines of prior therapy and histologic subtype. Few patients entered the trial with synovial sarcoma; therefore, the histologic variable was defined as leiomyosarcoma versus non-leiomyosarcoma for analysis stratification purposes. Overall survival was defined as the time from the date of randomization to the date of death from any cause. If the patient was alive at the end of the follow-up period or was lost to follow-up, OS was censored on the last date the patient was known to be alive. Overall survival was evaluated by the Kaplan-Meier method and a 95% CI was provided for the median OS. The hazard ratio and 95% confidence limit for OS was estimated from the Cox regression model, stratified by the 2 randomization balancing variables, number of lines of prior therapy, and histologic subtype. As a sensitivity analysis, patients in group 2 were censored at the date they received olaratumab monotherapy. The ORR was equal to the proportion of patients achieving a best overall response of partial or complete responses, according to RECIST v1.1 from the start of the treatment until disease progression/recurrence. Patients who did not have a tumor response assessment for any reason were considered nonresponders and were included in the denominator when calculating the response rate. The number of patients who achieved a response were divided by the total of randomized patients to yield the proportion responding. The ORR in each treatment group was compared using Fisher s exact test. Exact confidence bounds (95% CI) were determined. 7

9 For patients in the doxorubicin only arm who received olaratumab monotherapy at the time of documented disease progression, the best overall response was assessed separately for prior to and after the start of olaratumab therapy. The duration of response for responders only was measured from the time of documented partial/complete response (whichever was first recorded) until the first date of documented Progressive Disease, or death, or start of new anticancer treatment. The efficacy analyses were performed in the population of patients who underwent randomization (i.e., ITT population). The safety analyses were performed in the population of patients who received at least one dose of study treatment (i.e., safety population). Complete Response: The disappearance of all target lesions. Any pathological target or non-target lymph nodes must have a reduction in the short axis to <10 mm. Partial Response: At least a 30% decrease in the sum of the diameters of target lesions (including the short axes of any target lymph nodes), taking as reference the baseline sum diameters. Progressive Disease: At least a 20% increase in the sum diameters of target lesions (including the short axes of any target lymph nodes), taking as reference the smallest sum longest diameter recorded since the treatment started, including the baseline sum, and an absolute increase in the sum diameter of at least 5 mm. The appearance of one or more new lesion(s) also qualifies as progressive disease. Stable Disease: Neither sufficient shrinkage to qualify for partial response nor sufficient increase to qualify as progressive disease, taking as reference the smallest sum diameter since the treatment started. In-evaluable or Non-evaluable: A target lesion present at baseline which is subsequently not measured or which is unable to be evaluated, leading to an inability to determine the status of that particular tumor for the time point in question. When no measurement at all is made at a particular time point, the case is considered non-evaluable at that time point. If only a subset of lesion measurements are made at a time point, the case is usually considered non-evaluable at that time point, unless a convincing argument can be made otherwise. This category also includes scans that are not performed at the time point to evaluate the target lesion(s). The reason(s) explaining the absence of the evaluation or non-evaluable nature of the lesion(s) should be specified at the time of the assessment (e.g., early death due to malignant disease; early death due to toxicity; tumor assessments not repeated or incomplete; other [specify]). Supplementary Online Results: Secondary Endpoints According to the investigator assessment, the 3-month PFS rate was higher in the combination group: 69.0% (95% CI: 55.7, 78.9) versus 59.9% (95% CI: 45.9, 71.4) in the doxorubicin-only group. 8

10 The mean maximum change in tumor size was 10.3% in the combination group and 8.2% in the doxorubicin-only group. There was no statistical difference in the change in tumor size between the 2 treatment arms. Supplementary Figures Supplementary Figure Legends Figure S1. Enrollment and outcomes for Phase 1. Figure S2. Figure S3. Figure S4. Kaplan-Meier curve for progression-free survival of a blinded independent, retrospective review of radiologic assessments for olaratumab plus doxorubicin versus doxorubicin alone in the intention-to-treat population. Matched case-control analysis of overall survival by olaratumab quartiles. Matched case-control analysis of progression-free survival by olaratumab quartiles. 9

11 Figure S1. Enrollment and outcomes in Phase 1. Phase 1b 15 patients were enrolled 15 patients received olaratumab + doxorubicin 15 discontinued from study treatment: 0 had adverse events 1 died within 30 days of last dose of study treatment 12 progressive disease 2 withdrew consent Data cut-off date: 16 May

12 Figure S2. Kaplan-Meier curve for progression-free survival of a blinded independent, retrospective review of radiologic assessments for olaratumab plus doxorubicin versus doxorubicin alone in the intention-to-treat population. Progression-free Survival 1.0 Olaratumab + Doxorubicin doxorubicin 0.9 Patients/Events 66/37 67/ Median, months (95% CI) 8.2 (5.5, 9.8) 4.4 (3.1, 7.4) HR (95% CI) 0.67 (0.40, 1.12) Stratified p-value Olaratumab + doxorubicin Doxorubicin Number at Risk Time (months) Olaratumab + doxorubicin Control Arm

13 Figure S3a. Matched case-control analysis of overall survival by olaratumab C min1 quartiles. Abbreviations: C min1 = trough serum level at the end of the first cycle of treatment; Dox = doxorubicin treatment group; HR = hazard ratio; Ola + Dox = olaratumab plus doxorubicin treatment group; OS = overall survival; Q = quartile. 12

14 Figure S3b. Matched case-control analysis of overall survival by olaratumab C avg quartiles Abbreviations: C avg = average concentration over patient s entire treatment; Dox = doxorubicin treatment group; HR = hazard ratio; Ola + Dox = olaratumab plus doxorubicin treatment group; OS = overall survival; Q = quartile. 13

15 Figure S4a. Matched case-control analysis of progression-free survival by olaratumab C min1 quartiles. Abbreviations: C min1 = trough serum level at the end of the first cycle of treatment; Dox = doxorubicin treatment group; HR = hazard ratio; Ola + Dox = olaratumab plus doxorubicin treatment group; PFS = progression-free survival; Q = quartile. 14

16 Figure S4b. Matched case-control analysis of progression-free survival by olaratumab C avg quartiles. Abbreviations: C avg = average concentration over patient s entire treatment; Dox = doxorubicin treatment group; HR = hazard ratio; Ola + Dox = olaratumab plus doxorubicin treatment group; PFS = progression-free survival; Q = quartile. 15

17 Supplementary Tables Supplementary Table S1. Disease at Baseline by Histologic Subtype (Phase 2) (see also Table 2 of main article) Histological type no. (%) Olaratumab + Doxorubicin (N=66) Doxorubicin (N=67) Angiosarcoma a 4 (6.1) 3 (4.5) Fibrosarcoma 1 (1.5) 0 Leiomyosarcoma 24 ( 36.4) 27 (40.3) Liposarcoma 8 ( 12.1) 15 ( 22.4) Neurofibrosarcoma 1 (1.5) 0 Pleomorphic undifferentiated sarcoma 10 (15.2) 14 ( 20.9) Synovial sarcoma 1 (1.5) 2 (3.0) Other b Alveolar soft part sarcoma 1 (1.5) 0 Chondrosarcoma bone 0 2 (3.0) Clear cell sarcoma 1 (1.5) 0 Endometrial stromal sarcoma 1 (1.5) 0 Epithelioid sarcoma 2 (3.0) 0 Extraskeletal chondrosarcoma 0 1 (1.5) Extraskeletal myxoid chondrosarcoma 1 (1.5) 0 Fibromyxoid sarcoma 1 (1.5) 1 (1.5) Fibrosarcomatous transformation in a recurrent dermatofibrosarcoma 1 (1.5) 0 Hemangiopericytoma 1 (1.5) 1 (1.5) Malignant glomus tumor 1 (1.5) 0 Malignant peripheral nerve sheath tumor 1 (1.5) 0 Malignant solitary fibrous tumor 1 (1.5) 0 Myxofibrosarcoma 1 (1.5) 0 Myxoid chondrosarcoma 1 (1.5) 0 Myxoid sarcoma 0 1 (1.5) Soft tissue undifferentiated round cell carcoma negative for EWS 1 (1.5) 0 Undifferentiated neoplasm 1 (1.5) 0 Undifferentiated uterine sarcoma 1 (1.5) 0 16

18 Abbreviation: EWS = Ewing s sarcoma. a The following 8 subtypes were prespecified in the original study case report form: angiosarcoma, fibrosarcoma, leiomyosarcoma, liposarcoma, neurofibrosarcoma, malignant fibrous histiocytoma (MFH), synovial sarcoma, and other. MFH was subsequently included into the undifferentiated pleomorphic sarcoma category to align with the most recent WHO soft tissue sarcoma classification. b Other subtypes were entered into the case report form as free text fields; therefore, some histologies were consolidated. For example, epithelioid and epithelioid sarcoma were merged, and chondrosarcoma bone and chondrosarcoma primary bone were merged. 17

19 Supplementary Table S2. Progression-Free Survival (Investigator Review), Phase 2, ITT Population Olaratumab + Doxorubicin N = 66 Doxorubicin N = 67 Number of Events, n (%) 55 (83.3) 48 (71.6) Number Censored, n (%) 11 (16.7) 19 (28.4) No Baseline Tumor Assessments 1 (1.5) 2 (3.0) No Post-Baseline Tumor Assessments 2 (3.0) 2 (3.0) Death or Progression After Two or More Missed Visits 1 (1.5) 3 (4.5) Start of New Anticancer Therapy 5 (7.6) 5 (7.5) No Documented Progression 2 (3.0) 6 (9.0) Withdrew Consent 0 1 (1.5) Median a (months) % CI a (4.1, 8.3) (2.8, 5.4) Q25 - Q75 a months PFS Rate a (%) % CI a (55.7, 78.9) (45.9, 71.4) 6 months PFS Rate a (%) % CI a (40.6, 65.4) (18.9, 44.1) Stratified Log-rank p-value b,d Stratified Hazard Ratio c,d % CI c (0.442, 1.021) Unstratified Log-rank p-value b,d Hazard Ratio c,d % CI c (0.494,1.079) 18

20 Abbreviations: CI = confidence interval; ITT = intent-to-treat; N = number of randomized patients; n = number of patients in category; PFS = progression-free survival; Q = quartile. Data cut-off date: 15 August a Estimated by the Kaplan-Meier method. b Derived from a two sided test. c Hazard ratio is expressed as olaratumab + doxorubicin/doxorubicin and estimated from Cox model. d Between olaratumab + doxorubicin arm and doxorubicin arm. 19

21 Supplementary Table S3. Response to Treatment (Phase 2) Investigator and Independent Assessments Characteristic Investigator Assessment Independent Assessment Olaratumab + Doxorubicin (N=66) Doxorubicin (N=67) Olaratumab + Doxorubicin (N=66) Doxorubicin (N=67) Best overall response no. (%) Complete response 2 (3.0) 1 (1.5) 3 (4.5) 1 (1.5) Partial response 10 (15.2) 7 (10.4) 9 (13.6) 4 (6.0) Stable disease 39 (59.1) 34 (50.7) 37 (56.1) 36 (53.7) Progressive disease 11 (16.7) 15 (22.4) 11 (16.7) 15 (22.4) Not evaluable 4 (6.1) 10 (14.9) 6 (9.1) 11 (16.4) Disease control a No. of patients (%) 51 (77.3) 42 (62.7) 49 (74.2) 41 (61.2) 95% CI 65.3, , , , 72.9 Objective response b No. of patients (%) 12 (18.2) 8 (11.9) 12 (18.2) 5 (7.5) 95% CI 9.8, , , , 16.6 P value (Fisher s exact test) Duration of response mo. Median % CI 2.7, ,

22 Supplementary Table S4. Post-Treatment Anticancer Therapies Received (Phase 2) Post-treatment regimen no. pt (%) Olaratumab + Doxorubicin (N=66) Doxorubicin a (N=67) Regimens Doxorubicin 1 (1.5) 6 (9.0) Gemcitabine/Docetaxel 14 (21.2) 8 (11.9) Other a 40 (60.6) 43 (64.2) Single Agents Gemcitabine 15 (22.7) 11 (16.4) Pazopanib 15 (22.7) 10 (14.9) Docetaxel 14 (21.2) 8 (11.9) Dacarbazine 12 (18.2) 8 (11.9) Trabectedin 11(16.7) 3 (4.5) Investigational Drug 8 (12.1) 2 (3.0) Ifosfamide 8 (12.1) 8 (11.9) Eribulin 3 (4.5) 2 (3.0) a In the doxorubicin group, patients who were on olaratumab monotherapy were counted as receiving additional post-treatment anticancer therapy under Other regimen. 21

23 Supplementary Table S5. Ad hoc Sensitivity Analysis of Overall Survival Overall Survival Stratified HR (95% CI) b,c p Value a,c Primary Analysis (0.301, 0.710) Censoring at the date of starting any new anticancer treatment (0.193, 0.933) Censoring at the date of starting selected post-study anticancer therapies pazopanib, eribulin, gemcitabine + docetaxel, doxorubicin, and trabectedin (0.192,0.647) HR = hazard ratio a. Derived from a two sided test. b. Hazard ratio is expressed as olaratumab + doxorubicin/doxorubicin and estimated from Cox model. c. Between olaratumab + doxorubicin arm and doxorubicin arm. 22

24 Supplementary Table S6. Post hoc sensitivity analysis of overall survival Olaratumab + Doxorubicin N = 66 Doxorubicin N = 67 Excluding patients discontinuing study treatment within 8 cycles due to AE or symptomatic PD Patients OS Events Median, months Unstratified OS HR 0.55 Unstratified log rank p-value Excluding patients completing <4 cycles doxorubicin Patients OS Events Median, months Unstratified OS HR 0.47 Unstratified log rank p-value Abbreviations: AE = adverse event; HR = hazard ratio; ITT = intent-to-treat; N = number of randomized patients; OS = overall survival; PD = progressive disease. Note on supplementary Table S6: Sensitivity analyses were performed post hoc to consider the impact of the number of cycles of therapy on overall survival. Per study protocol, patients were to be treated with doxorubicin either in combination with olaratumab or as a single agent up to 8 cycles or until progressive disease, whichever came first. 23

25 Supplementary Table S7. Peak and trough olaratumab serum levels in patients receiving 15 mg/kg olaratumab either in combination with 75 mg/m 2 doxorubicin or as a monotherapy Cycle/Day N Olaratumab 15 mg/kg + Doxorubicin 75 mg/m 2 C max b C min (µg/ml) N (µg/ml) Geometric Mean (CV%) a N Olaratumab 15 mg/kg Monotherapy C max (µg/ml) 1/ (23.3) (47.9) (24.8) - NC 1/ (30.5) (40.4) - NC - NC 2/ (26.5) NC N C min b (µg/ml) 2/8 - NC (51.7) - NC (46.5) 3/ (31.6) (27.7) (38.8) - NC 3/ (21.8) (39.6) - NC - NC 4/ (26.2) - NC - NC - NC 4/8 - NC - NC (31.8) 5/1 - NC - NC (26.9) - NC 5/8 - NC (32.7) - NC - NC 6/ (29.0) - NC - NC - NC 6/8 - NC 2 239; NC (44.3) Abbreviations: C max = observed maximum serum concentration, C min = minimum observed serum concentration; CV = coefficient of variation; NC = not calculated. a Individual values are reported when n <3. b C min is the concentration of olaratumab in the sample taken just prior to the following dose. 24

26 Supplementary Table S8. Olaratumab pharmacokinetic parameters during cycle 1 and cycle 3 in patients who received 15 mg/kg olaratumab in combination with 75 mg/m 2 doxorubicin Geometric Mean (CV%) Parameter Cycle 1, Day 8 (N=7) Cycle 3, Day 8 (N=4) C max (µg/ml) 305 (12.4) 296 (19.9) t max (h) a 2.00 ( ) 2.04 ( ) C min (µg/ml) 44.7 (47.0) 84.3 (47.2) t last (h) 350 ( ) 321 ( ) AUC (0-168) (µg h/ml) (29.0) (35.0) C av (µg/ml) 117 (29.0) 141 (35.0) CL (ml/h) 32.7 (33.0) 23.8 (25.8) t ½ (day) b 6.70 ( ) 14.4; 6.67 c V ss (L) 7.03 (33.7) 9.46; 6.56 c Abbreviations: AUC (0-168) = area under the concentration versus time curve during the second dosing interval of the cycle; C av = average drug concentration during the dosing interval; CL = systemic clearance; C max = observed maximum observed serum concentration; C min = the observed serum concentration at t last ; CV = coefficient of variation; t ½ = apparent terminal elimination half-life; t last = last time point where the concentration is above the limit of quantitation; t max = time of observed maximum serum concentration; V ss = volume of distribution. a Median (range) and is referenced to the start of infusion. b Geometric mean (range). c Individual values are given when N <3. 25

27 Supplementary Table S9. Matched-Case Control Analysis of Overall Survival by C min1 and C avg Quartiles Olaratumab Exposure Quartiles (µg/ml) Number of patients/number of events Olara + Doxo Doxo Hazard Ratio (95% CI) p-value (Wald s) Quartiles based on C min1 Q1 ( < 62.8) 15/13 15/ (0.617, 2.976) Q2 ( < 86.9) 16/10 16/ (0.231, 1.206) Q3 ( < 105.6) 15/5 15/ (0.126, 1.182) Q4 ( ) 16/9 16/ (0.330, 2.001) Quartiles based on C avg Q1 (56 < 134.4) 15/13 15/ (0.474, 2.215) Q2 ( < 175.2) 16/9 16/ (0.158, 0.851) Q3 ( < 249.9) 15/7 15/ (0.251, 2.046) Q4 ( ) 16/8 16/ (0.226, 1.397) Abbreviations: C avg = average concentration over patient s entire treatment; CI = confidence interval; C min1 = trough serum level at the end of the first cycle of treatment; Doxo = doxorubicin; Olara = olaratumab; Q = quartile. 26

28 Supplementary Table S10. Matched-Case Control Analysis of Progression-Free Survival by C min1 and C avg Quartiles Olaratumab Exposure Quartiles (µg/ml) Number of patients/number of events Olara + Doxo Doxo Hazard Ratio (95% CI) p-value (Wald s) Quartiles based on C min1 Q1 ( < 62.8) 15/13 15/ (0.801, 4.087) Q2 ( < 86.9) 16/14 16/ (0.654, 3.510) Q3 (( < 105.6) 15/13 15/ (0.192, 1.033) Q4 (( ) 16/14 16/ (0.386, 1.899) Quartiles based on C avg Q1 (56 < 134.4) 15/13 15/ (0.846, 3.951) Q2 ( < 175.2) 16/15 16/ (0.514, 2.642) Q3 (( < 249.9) 15/12 15/ (0.408, 2.490) Q4 (( ) 16/14 16/ (0.211, 1.005) Abbreviations: C avg = average concentration over patient s entire treatment; CI = confidence interval; C min1 = trough serum level at the end of the first cycle of treatment; Doxo = doxorubicin; Olara = olaratumab; Q = quartile. 27

29 Supplementary Table S11. Exposure to Doxorubicin in the Phase 2 Portion of the Study, Safety Population Duration of Doxorubicin Treatment (weeks) Olaratumab + doxorubicin N = 64 Doxorubicin N = 65 Median duration (range; Q1 Q3) 21.3 ( ; ) 12.3 ( ; ) Number of Infusions, n Median (range; Q1 Q3) 7.0 ( ; ) 4.0 ( ; ) Cumulative Dose Level (mg/m 2 ) Median (range; Q1 Q3) ( ; ) ( ; ) Dose Intensity (mg/m 2 /week) Median (range; Q1 Q3) 24.8 ( ; ) 24.7 ( ; ) Relative Dose Intensity (%) Median (range; Q1 Q3) 99.1 ( ; ) 99.0 ( ; ) Abbreviations: N = number of treated patients; n = number of patients in category. Data cut-off date: 16 May

30 Supplementary Table S12. Exposure to Olaratumab in the Phase 2 Portion of the Study, Safety Population Duration of Olaratumab Treatment (weeks) Olaratumab + doxorubicin N = 64 Olaratumab, median duration (range; Q1 Q3) 26.1 ( ; ) Number of Infusions, n Olaratumab, median (range; Q1 Q3) 16.5 ( ; ) Olaratumab monotherapy postcombination, median (n = 34) (range; Q1 Q3) 9 ( ; ) Doxorubicin N = 30 Olaratumab monotherapy (postprogression) (n = 30), median (range; Q1 Q3) 4.0 ( ; ) Abbreviations: N = number of treated patients; n = number of patients in category. Data cut-off date: 16 May

31 Supplementary Table S13. Adverse Events (Phase 1b) a Olaratumab + Doxorubicin (N=15) Event A11 Grades Grade 3 Grade 4 Any adverse event no. of patients (%) b 15 (100.0) 9 ( 60.0) 3 (20.0) Anemia c 11 (73.3) 5 (33.3) 0 Fatigue d 10 (66.7) 1 (6.7) 0 Nausea 8 (53.3) 2 (13.3) 0 Leukopenia e 7 (46.7%) 3 (20.0%) 0 Vomiting 6 (40.0) 2 (13.3) 0 Neutropenia f 5 (33.3%) 3 (20.0%) 1 (6.7%) Abdominal pain g 4 (26.7) 3 (20.0) 0 Back pain 3 (20.0) 2 (13.3) 0 Febrile neutropenia h 2 (13.3) 2 (13.3) 0 Treatment-related adverse event no. of patients (%) 14 (93.3) 8 (53.3) 1 (6.7) Adverse event leading to discontinuation of treatment no. of patients (%) 0 Serious adverse event no. of patients (%) Any event 7 (46.7) 6 (40.0) 1 (6.7) Treatment-related event 3 (20.0) i 3 (20.0) i 0 a Adverse events and clinical laboratory toxicity were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0. b The adverse events listed here were reported in at least 15% of patients in the Phase 1b group, except as noted in footnote h. Included are individual preferred terms from the Medical Dictionary for Regulatory Activities [MedDRA] and certain consolidated terms combining clinically synonymous MedDRA preferred terms. c Consolidated term comprising the following preferred terms: anemia, hemoglobin decreased. d Consolidated term comprising the following preferred terms: fatigue, asthenia. e Consolidated term comprising the following preferred terms: leukopenia, white blood cell count decreased. f Consolidated term comprising the following preferred terms: neutropenia, neutrophil count decreased. 30

32 g Consolidated term comprising the following preferred terms: abdominal pain upper, abdominal pain, abdominal pain lower. h These events are included here because they were associated with Grade 3 events and considered clinically important. i Two patients with febrile neutropenia, 1 patient with nausea, and 1 patient with vomiting 31

33 Supplementary Table S14. Hospitalisations Hospitalizations Olaratumab + Doxorubicin N=64 Doxorubicin N=65 Patients Hospitalized n (%) 25 (39.1) 24 (36.9) Total Number of Hospitalizations Number of Hospitalization per Patient N Median (range) 1.0 (1-3) 1.0 (1-3) Length of Hospital Stays N Median (range) 5.0 (2-15) 4.0 (1-40) Abbreviations: N = number of treated patients; n = number of patients in category. 32

34 Supplementary Table S15. Summary of Anti-olaratumab Antibodies, All Patients Olaratumab + Doxorubicin Phase 1b N = 15 Phase 2 N = Olaratumab Control Arm: Olaratumab Monotherapy After Doxorubicin N = 30 Overall number of evaluable patients a Baseline ADA positive 2 (18.2) 8 (13.8) 1 (6.3) Baseline ADA negative 8 (72.7) 45 (77.6) 13 (81.3) Baseline ADA missing 1 (9.1) 5 (8.6) 2 (12.5) Post-baseline ADA negative b 10 (90.9) 53 (91.4) 15 (93.8) Post-baseline ADA inconclusive b 0 1 (1.7) 0 Post-baseline ADA positive b 1 (9.1) 4 (6.9) 1 (6.3) TE positive ADA c 1 (9.1) 3 (5.2) 1 (6.3) Transient d 0 1 (33.3) 0 Persistent e 1 (100.0) 2 (66.7) 1 (100.0) Positive neutralizing ADA f 1 (100.0) 3 (100.0) 1 (100.0) Negative neutralizing ADA Inconclusive neutralizing ADA g Abbreviations: ADA = anti-drug antibodies; N = number of treated patients. Data cut-off date: 16 May Note: Percentages for the baseline, overall post-baseline and TE positive ADA summaries are calculated using the number of evaluable patients as the denominator. All other percentages are calculated using the number of TE positive patients as the denominator. a Evaluable: 1) Patient with an evaluable baseline sample and at least 1 evaluable post-baseline sample (that is, sample after administration of study drug); 2) patient with no evaluable baseline sample whose evaluable post-baseline samples are all ADA negative.

35 b Post-baseline ADA-negative: a patient without an ADA-positive sample at any post-baseline time; ADA-inconclusive: An ADA non-positive patient who cannot irrefutably be classified as post-baseline ADA negative (for example, those for whom drug levels may interfere with the immunogenicity assay). For patients with no ADA positive samples at any post-baseline time, if either the last test value is inconclusive or 2 or more sequential tests are inconclusive, the patient will be considered ADA inconclusive. (If the actual olaratumab concentration exceeds 500 ug/ml, then the negative ADA result is considered as Inconclusive.) c TE-ADA positive: 1) a patient with a 4-fold (2 dilutions) increase over a positive baseline antibody titer; or 2) for a negative baseline titer, a patient with an increase from the baseline to a level of 1:20. d Treatment-Emergent Persistent Positive ADA Patients: TE-ADA positive results detected at >=2 sample times where the first and last TE-ADA positive samples are separated by >=12 weeks or if: 1) the last sample obtained while on study treatment or in the follow-up period is TE-ADA positive but with no further opportunity to assess persistence or; 2) the last sample obtained while on study treatment is TE-ADA positive and the first sample within the followup period is also positive. e Treatment-Emergent Transient Positive ADA Patients: TE-ADA positive result(s) detected that do not satisfy the conditions required of TE persistent positive ADA patients. This would include patients that are TE-ADA positive at >=1 sampling time points where the time between the first and last positive sample is <12 weeks and the last obtained sample while on study treatment or in the follow-up period is ADA-negative or if the last obtained sample during the treatment period is TE-ADA positive and does not persist into the follow-up period. f Positive neutralizing ADA Sample: ADA positive samples will undergo further testing to detect neutralizing antibodies. This lab test will have a unique lab test code with result Detected or Not detected. Samples where neutralizing antibodies are detected meet the definition of positive neutralizing ADA. Only patients with TE positive ADA are included in neutralizing ADA summaries. 34

36 g Neutralizing ADA Inconclusive Sample: Every neutralizing ADA result will either be Detected or Not Detected in the database. To identify inconclusive results, olaratumab drug concentrations at the same time of the immunogenicity sample (or within 3 weeks before or after the immunogenicity sample collection) will need to be compared to the assay tolerance levels as defined below. 35

37 Supplementary Table S16. Use of Granulocyte-Colony Stimulating Factor G-CSF use Phase 1b Olaratumab + doxorubicin Phase 2 Doxorubicin Phase 2 Crossover from doxorubicin to olaratumab Phase 1b (n = 15) (n = 64) (n = 65) (n = 30) Patients with Any Use of G-CSF 6 (40.0) 35 (54.7) 24 (36.9) 0 Filgrastim 1 (6.7) 10 (15.6) 5 (7.7) 0 Pegfilgrastim 5 (33.3) 31 (48.4) 22 (33.8) 0 Abbreviation: G-CSF = granulocyte-colony stimulating factor. Number of patients (%) shown. Note: Olaratumab + doxorubicin had a higher rate of G-CSF use than doxorubicin alone (55% for Olaratumab + doxorubicin v. 37% doxorubicin alone). The lack of difference in febrile neutropenia between the study arms suggests that patients were appropriately treated with supportive care for grade 3-4 neutropenia in this study. 36

38 Supplementary Table S17. Study-drug Related Adverse Events of Grades 3 and Higher in Patients Who Received the Optional Olaratumab Monotherapy After Receiving Doxorubicin. Adverse events n = 30 Related to olaratumab Related to any study drug Any grade Grade 3 Grade 4 Any grade Grade 3 Grade 4 Nausea 3 (10.0) (13.3) 0 0 Chills 2 (6.7) (10.0) 0 0 Infusion-related reaction 2 (6.7) 0 1 (3.3) 2 (6.7) 0 1 (3.3) Dizziness 2 (6.7) (6.7) 0 0 Edema peripheral 2 (6.7) (6.7) 0 0 Fatigue 2 (6.7) (6.7) 0 0 Neuropathy peripheral 2 (6.7) (6.7) 0 0 Anemia 1 (3.3) (10.0) 0 0 Cardiac arrest 1 (3.3) 0 1 (3.3) 1 (3.3) 0 1 (3.3) Abdominal distention 1 (3.3) (3.3) 0 0 Abdominal pain 1 (3.3) (3.3) 0 0 Arthralgia 1 (3.3) (3.3) 0 0 Blister 1 (3.3) (3.3) 0 0 Blood alkaline phosphatase increase 1 (3.3) (3.3) 0 0 Dermatitis acniform 1 (3.3) (3.3) 0 0 Diarrhea 1 (3.3) (3.3) 0 0 Dry mouth 1 (3.3) (3.3) 0 0 Flatulence 1 (3.3) (3.3) 0 0 Gastroesophageal reflux disease 1 (3.3) (3.3) 0 0 Hypersensitivity 1 (3.3) (3.3) 0 0 Hypoesthesia 1 (3.3) (3.3) 0 0 Influenza-like illness 1 (3.3) (3.3) 0 0 Myalgia 1 (3.3) (3.3)

39 Onychoclasis 1 (3.3) (3.3) 0 0 Pain in extremity 1 (3.3) (3.3) 0 0 Productive cough 1 (3.3) (3.3) 0 0 Pyrexia 1 (3.3) (3.3) 0 0 Rash 1 (3.3) (3.3) 0 0 Rash pruritic 1 (3.3) (3.3) 0 0 Vertigo 1 (3.3) (3.3) 0 0 Vomiting 1 (3.3) (3.3) 0 0 Weight decrease (6.7) 0 0 Alopecia (3.3) 0 0 Constipation (3.3) 0 0 Decreased appetite (3.3) 0 0 Hot flush (3.3) 0 0 Hypoalbuminemia (3.3) 0 0 Stomatitis (3.3)