Early discontinuation of PD-1 blockade upon achieving a complete or partial response in patients with advanced melanoma: the multicentre prospective Safe Stop trial

Background

The introduction of programmed cell death protein 1 (PD-1) blockers (i.e. nivolumab and pembrolizumab) has significantly improved the prognosis of patients with advanced melanoma. However, the long treatment duration (i.e. two years or longer) has a high impact on patients and healthcare systems in terms of (severe) toxicity, health-related quality of life (HRQoL), resource use, and healthcare costs. While durable tumour responses have been observed and PD-1 blockade is discontinued on an individual basis, no consensus has been reached on the optimal treatment duration. The objective of the Safe Stop trial is to evaluate whether early discontinuation of first-line PD-1 blockade is safe in patients with advanced and metastatic melanoma who achieve a radiological response.

Methods

The Safe Stop trial is a nationwide, multicentre, prospective, single-arm, interventional study in the Netherlands. A total of 200 patients with advanced and metastatic cutaneous melanoma and a confirmed complete response (CR) or partial response (PR) according to response evaluation criteria in solid tumours (RECIST) v1.1 will be included to early discontinue first-line monotherapy with nivolumab or pembrolizumab. The primary objective is the rate of ongoing responses at 24 months after discontinuation of PD-1 blockade. Secondary objectives include best overall and duration of response, need and outcome of rechallenge with PD-1 blockade, and changes in (serious) adverse events and HRQoL. The impact of treatment discontinuation on healthcare resource use, productivity losses, and hours of informal care will also be assessed. Results will be compared to those from patients with CR or PR who completed 24 months of treatment with PD-1 blockade and had an ongoing response at treatment discontinuation. It is hypothesised that it is safe to early stop first-line nivolumab or pembrolizumab at confirmed tumour response while improving HRQoL and reducing costs.

Discussion

From a patient, healthcare, and economic perspective, shorter treatment duration is preferred and overtreatment should be prevented. If early discontinuation of first-line PD-1 blockade appears to be safe, early discontinuation of PD-1 blockade may be implemented as the standard of care in a selected group of patients.

Trial registration

The Safe Stop trial has been registered in the Netherlands Trial Register (NTR), Trial NL7293 (old NTR ID: 7502), https://www.trialregister.nl/trial/7293. Date of registration September 30, 2018.

Characterization of male breast cancer: results of the EORTC 10085/TBCRC/BIG/NABCG International Male Breast Cancer Program

Background

Male breast cancer (BC) is rare, managed by extrapolation from female BC. The International Male BC Program aims to better characterize and manage this disease. We report the results of part I, a retrospective joint analysis of cases diagnosed during a 20-year period.

Methods

Patients with follow-up and tumor samples, treated between 1990 and 2010, in 93 centers/9 countries. Samples were centrally analyzed in three laboratories (the United Kingdom, the Netherlands and the United States).

Results

Of 1822 patients enrolled, 1483 were analyzed; 63.5% were diagnosed between 2001 and 2010, 57 (5.1%) had metastatic disease (M1). Median age at diagnosis: 68.4 years. Of 1054 M0 cases, 56.2% were node-negative (N0) and 48.5% had T1 tumors; 4% had breast conserving surgery (BCS), 18% sentinel lymph-node biopsy; half received adjuvant radiotherapy; 29.8% (neo)adjuvant chemotherapy and 76.8% adjuvant endocrine therapy (ET), mostly tamoxifen (88.4%). Per central pathology, for M0 tumors: 84.8% ductal invasive carcinomas, 51.5% grade 2; 99.3% estrogen receptor (ER)-positive; 81.9% progesterone receptor (PR)-positive; 96.9% androgen receptor (AR)-positive [ER, PR or AR Allred score ≥3]; 61.1% Ki67 expression low (<14% positive cells); using immunohistochemistry (IHC) surrogates, 41.9% were Luminal-A-like, 48.6% Luminal-B-like/HER-2-negative, 8.7% HER-2-positive, 0.3% triple negative. Median follow-up: 8.2 years (0.0-23.8) for all, 7.2 years (0.0-23.2), for M0, 2.6 years (0.0-12.7) for M1 patients. A significant improvement over time was observed in age-corrected BC mortality. BC-specific-mortality was higher for men younger than 50 years. Better overall (OS) and recurrence-free survival (RFS) were observed for highly ER+ (P = 0.001), highly PR+ (P = 0.002), highly AR+ disease (P = 0.019). There was no association between OS/RFS and HER-2 status, Ki67, IHC subtypes nor grade.

Conclusions

Male BC is usually ER, PR and AR-positive, Luminal B-like/HER2-negative. Of note, 56% patients had T1 tumors but only 4% had BCS. ER was highly positive in >90% of cases but only 77% received adjuvant ET. ER, PR and AR were associated with OS and RFS, whereas grade, Ki67 and IHC surrogates were not. Significant improvement in survival over time was observed.

European Organisation for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group Experience with Advanced/Metastatic Epithelioid Sarcoma Patients Treated in Prospective Trials: Clinical Profile and Response to Systemic Therapy

AIMS

Epithelioid sarcoma is a soft tissue sarcoma associated with a high rate of local recurrence after wide resection and high incidence of distant metastasis. Little is known about the clinical course and response to systemic treatments in epithelioid sarcoma patients. We carried out a retrospective analysis of clinical data from epithelioid sarcoma patients to provide a reference for the design of future epithelioid sarcoma-specific studies.

PATIENTS AND METHODS

Data from patients with epithelioid sarcoma entered in prospective multi-sarcoma phase II/III trials were pooled: EORTC trial 62012 (doxorubicin versus doxorubicin/ifosfamide), 62043 (pazopanib), 62072 (pazopanib versus placebo) and 62091 (doxorubicin versus trabectedin). Patients had either a local or a centrally confirmed diagnosis of epithelioid sarcoma, had inoperable/metastatic disease at study entry and were eligible for the according trial. Response was assessed according to RECIST 1.1. Progression-free survival (PFS) and overall survival were calculated from date of entry.

RESULTS

Among 976 patients with advanced sarcomas, 27 epithelioid sarcoma patients (2.8%) were eligible for the analysis (17 men, median age at diagnosis 50 years, range 19-72). Eighteen (66.7%) received chemotherapy as first-line treatment (five doxorubicin, eight doxorubicin/ifosfamide, two pazopanib, three trabectedin) and nine (33.3%) received pazopanib as second line or later. The primary tumour was located in the lower extremity (n = 8; 29.6%), upper extremity (n = 5; 18.5%), retro/intra-abdominal (n = 4; 14.8%) and in other locations (n = 10; 37.0%). At entry, metastases were mainly found in lung (n = 17; 63%), lymph nodes (n = 9; 33.3%), bone (n = 8; 29.6%) and soft tissue (n = 7; 25.9%). The best response for first-line patients was four partial responses (22.2%), 10 stable disease (55.6%) and four progressive disease (22.2%). In subsequent lines, pazopanib achieved one partial response (11.1%), four stable disease (44.4%) and four progressive disease (44.4%). All patients but one progressed on treatment. The median PFS and overall survival were 3.8 (95% confidence interval 2.2-4.8) and 10.8 months (95% confidence interval 8.1-21.3), respectively. Five patients were still alive at the time of the according trial analysis.

CONCLUSION

With all limitations of such a rare disease and small data set, objective response and survival outcomes are similar in epithelioid sarcoma to non-selected sarcoma populations. The clinical testing of novel systemic treatments for epithelioid sarcoma remains an unmet medical need and a high priority.

Investigating the heterogeneity of alkylating agents' efficacy and toxicity between sexes: A systematic review and meta-analysis of randomized trials comparing cyclophosphamide and ifosfamide (MAIAGE study)

BACKGROUND

A marginal interaction between sex and the type of alkylating agent was observed for event-free survival in the Euro-EWING99-R1 randomized controlled trial (RCT) comparing cyclophosphamide and ifosfamide in Ewing sarcoma. To further evaluate this interaction, we performed an individual patient data meta-analysis of RCTs assessing cyclophosphamide versus ifosfamide in any type of cancer.

METHODS

A literature search produced two more eligible RCTs (EICESS92 and IRS-IV). The endpoints were progression-free survival (PFS, main endpoint) and overall survival (OS). The hazard ratios (HRs) of the treatment-by-sex interaction and their 95% confidence interval (95% CI) were assessed using stratified multivariable Cox models. Heterogeneity of the interaction across age categories and trials was explored. We also assessed this interaction for severe acute toxicity using logistic models.

RESULTS

The meta-analysis comprised 1,528 pediatric and young adult sarcoma patients from three RCTs: Euro-EWING99-R1 (n = 856), EICESS92 (n = 155), and IRS-IV (n = 517). There were 224 PFS events in Euro-EWING99-R1 and 200 in the validation set (EICESS92 + IRS-IV), and 171 and 154 deaths in each dataset, respectively. The estimated treatment-by-sex interaction for PFS in Euro-EWING99-R1 (HR = 1.73, 95% CI = 1.00-3.00) was not replicated in the validation set (HR = 0.97, 95% CI = 0.55-1.72), without heterogeneity across trials (P = 0.62). In the pooled analysis, the treatment-by-sex interaction was not significant (HR = 1.31, 95% CI = 0.89-1.95, P = 0.17), without heterogeneity across age categories (P = 0.88) and trials (P = 0.36). Similar results were observed for OS. No significant treatment-by-sex interaction was observed for leucopenia/neutropenia (P = 0.45), infection (P = 0.64), or renal toxicity (P = 0.20).

CONCLUSION

Our meta-analysis did not confirm the hypothesis of a treatment-by-sex interaction on efficacy or toxicity outcomes.

Pazopanib in advanced vascular sarcomas: an EORTC Soft Tissue and Bone Sarcoma Group (STBSG) retrospective analysis

BACKGROUND

Pazopanib is a multitargeted tyrosine kinase inhibitor approved for the treatment of patients with selective subtypes of advanced soft tissue sarcoma (STS) who have previously received standard chemotherapy including anthracyclines. Data on the efficacy in vascular sarcomas are limited. The main objective of this study was to investigate the activity of pazopanib in vascular sarcomas.

PATIENTS AND METHODS

A retrospective study of patients with advanced vascular sarcomas, including angiosarcoma (AS), epithelioid hemangioendothelioma (HE) and intimal sarcoma (IS) treated with pazopanib in real life practice at EORTC centers as well as patients treated within the EORTC phase II and III clinical trials (62043/62072) was performed. Patient and tumor characteristics were collected. Response was assessed according to RECIST 1.1. and survival analysis was performed.

RESULTS

Fifty-two patients were identified, 40 (76.9%), 10 (19.2%) and two (3.8%) with AS, HE and IS, respectively. The response rate was eight (20%), two (20%) and two (100%) in the AS, HE and IS subtypes, respectively. There was no significant difference in response rate between cutaneous and non-cutaneous AS and similarly between radiation-associated and non-radiation-associated AS. Median progression-free survival (PFS) and median overall survival (OS; from commencing pazopanib) were three months (95% CI 2.1-4.4) and 9.9 months (95% CI 6.5-11.3) in AS, respectively.

CONCLUSION

The activity of pazopanib in AS is comparable to its reported activity in other STS subtypes. In this study, the activity of pazopanib was similar in cutaneous/non-cutaneous and in radiation/non-radiation-associated AS. In addition, pazopanib showed promising activity in HE and IS, worthy of further evaluation.

Outcome of uterine sarcoma patients treated with pazopanib: A retrospective analysis based on two European Organisation for Research and Treatment of Cancer (EORTC) Soft Tissue and Bone Sarcoma Group (STBSG) clinical trials 62043 and 62072

BACKGROUND

Uterine sarcomas are a group of mesenchymal tumours comprising several histologies. They have a high recurrence rate following surgery, modest outcome to systemic therapy, and poor overall survival. Pazopanib is a multi-targeted tyrosine kinase inhibitor approved for non-adipocytic advanced soft tissue sarcomas (STS). Here we investigated whether response to pazopanib in patients with uterine sarcomas differs from that of patients with non-uterine sarcomas.

PATIENTS AND METHODS

Uterine sarcoma patients were retrieved from all soft tissue sarcoma patients treated with pazopanib in EORTC Phase II (n=10) and Phase III (PALETTE) (n=34) studies. Patient and tumour characteristics, response, progression free and overall survival data were compared.

RESULTS

Forty-four patients with uterine sarcoma were treated with pazopanib. The majority of patients had uterine leiomyosarcoma (LMS) (n=39, 88.6%) with high grade tumours (n=37, 84.1%) compared to 54.8% (n=164) in the non-uterine population. The median age was 55years (range 33-79) and median follow up was 2.3years. Uterine patients were heavily pre-treated, 61.3% having ≥2 lines of chemotherapy prior to pazopanib compared to 40.8% in the non-uterine population. Five patients (11%), all LMS, had a partial response (95% CI 3.8-24.6). Median progression free survival (PFS) 3.0months (95% CI 2.5-4.7) in uterine versus 4.5 (95% CI 3.7-5.1) in non-uterine STS. Median overall survival (OS) was 17.5months (95% CI 11.1-19.6), longer than the non-uterine population, 11.1months (95% CI 10.2-12.0) (p=0.352).

CONCLUSIONS

Despite heavy pre-treatment, pazopanib shows signs of activity in patients with uterine sarcoma with the similar outcomes to patients with non-uterine STS.

Hypertension (HTN) as a potential biomarker of efficacy in pazopanib-treated patients with advanced non-adipocytic soft tissue sarcoma. A retrospective study based on European Organisation for Research and Treatment of Cancer (EORTC) 62043 and 62072 trials

BACKGROUND

Reliable biomarkers of pazopanib's efficacy in soft tissue sarcoma (STS) are lacking. Hypertension (HTN) is an on-target effect of vascular endothelial growth factor (VEGF)-receptor inhibitors such as pazopanib. We evaluated the association of pazopanib-induced HTN with antitumour efficacy in patients with metastatic non-adipocytic STS.

METHODS

Associations between pazopanib-induced-HTN and antitumour efficacy were retrospectively assessed across 2 prospective studies (European Organisation for Research and Treatment of Cancer (EORTC) study 62043 and 62072) in metastatic STS patients who received pazopanib 800 mg daily. Only patients with baseline blood pressure (BP)<150/90 mmHg, were included. BP was measured monthly. HTN was reported according to National Cancer Institute-Common Toxicity Criteria Adverse Events (NCI-CTC AE) grading (v3.0), and as absolute differences compared to baseline. The effect of HTN developing in patients without baseline anti-hypertensive medication was assessed on progression-free (PFS) and overall survival (OS) using a landmark analysis stratified by study; univariately using the Kaplan-Meier method and a log-rank test, and in a multivariate Cox regression model after adjustment for important prognostic factors.

RESULTS

Of the 337 patients eligible for this analysis, 21.7% received anti-hypertensive medication at baseline and had a similar PFS and OS compared to those who did not. In patients without baseline anti-hypertensive medication, 38.6% developed HTN. As the majority of patients developing HTN did so within 5 weeks after initiation of pazopanib (68.6%), this time point was used as landmark. Univariately, there was no effect on PFS or OS from occurrence of HTN within 5 weeks of treatment expressed either in NCI-CTC AE criteria or as maximal differences from baseline in systolic and diastolic BP. Also in multivariate analysis, after adjusting for important prognostic factors, the occurrence of HTN expressed in the different parameters was not associated with PFS and OS.

CONCLUSIONS

In this retrospective analysis, pazopanib-induced HTN did not correlate with outcome in pazopanib-treated STS patients. The occurrence of HTN cannot serve as biomarker in this setting.

A phase IIb multicentre study comparing the efficacy of trabectedin to doxorubicin in patients with advanced or metastatic untreated soft tissue sarcoma: the TRUSTS trial

PURPOSE

To evaluate whether trabectedin as first-line chemotherapy for advanced/metastatic soft tissue sarcoma prolongs progression-free survival (PFS), compared to doxorubicin and, in the phase IIb part here, to select the most appropriate trabectedin treatment schedule (3-hour or 24-hour infusion) in terms of safety, convenience and efficacy.

PATIENTS AND METHODS

In this randomised multicentre prospective dose-selection phase IIb superiority trial, 133 patients were randomised between doxorubicin (n=43), trabectedin (3-hour infusion, T3h) (n=47) and trabectedin (24-hour infusion, T24h) (n=43). PFS was defined as time from random assignment until objective progression by response evaluation criteria in solid tumours (RECIST 1.1), a global deterioration of the health status requiring discontinuation of the treatment, or death from any cause.

RESULTS

The study was terminated due to lack of superiority in both trabectedin treatment arms as compared to the doxorubicin control arm. Median PFS was 2.8months in the T3h arm, 3.1months in the T24h arm and 5.5months in the doxorubicin arm. No significant improvements in PFS were observed in the trabectedin arms as compared to the doxorubicin arm (T24h versus doxorubicin: hazard ratio (HR) 1.13, 95% confidence interval (CI) 0.67-1.90, P=.675; T3h versus doxorubicin: HR 1.50, 95% CI 0.91-2.48, P=.944). Only one toxic death occurred in the T3h arm, but treatment had to be stopped due to toxicity in 7 (15.2%) (T3h), 8 (19.5%) (T24h) and 1 (2.5%) doxorubicin patients.

CONCLUSION

Doxorubicin continues to be the standard treatment in eligible patients with advanced/metastatic soft-tissue sarcoma (STS). Trabectedin 1.5mg/m(2)/24-hour infusion is the overall proven approach to delivering this agent in the second-line setting for patients with advanced or metastatic STS.

First-line anthracycline-based chemotherapy for angiosarcoma and other soft tissue sarcoma subtypes: pooled analysis of eleven European Organisation for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group trials

BACKGROUND

Angiosarcoma is a rare subtype of soft tissue sarcoma (STS). Doxorubicinis the standard first-line chemotherapy for advanced STS. It is not known whether angiosarcoma response to anthracycline-based chemotherapy is different to other STS subtypes.

METHODS

Pooled data were analysed from 11 prospective randomised and non-randomized European Organisation for Research and Treatment of Cancer (EORTC) clinical trials of first-line anthracycline-based chemotherapy for advanced STS. Baseline patient characteristics, chemotherapy response, progression free survival (PFS) and overall survival (OS) of angiosarcoma patients were compared with other STS patients. Analysis was performed to identify factors prognostic for angiosarcoma response to chemotherapy, PFS and OS.

RESULTS

With a median follow-up of 4.2 years, data from 108 locally advanced and metastatic angiosarcoma patients and 2557 patients with other STS histologies were analysed. 25% of angiosarcoma patients had a complete or partial response to chemotherapy compared to 21% for other STS histotypes. The median PFS was 4.9 months and OS 9.9 months, which were not significantly different from other STS histotypes. In univariate analysis, bone metastases were an adverse prognostic factor for OS (hazard ratio (HR) 1.66, 95% confidence interval (CI) 1.03–2.67; p = 0.036). Tumour grade was as an adverse prognostic factor for PFS (HR 1.72, 95% CI 1.01–2.92; p = 0.044) and OS (HR 2.03; 95% CI 1.16–3.56; p = 0.011). Compared to single agent anthracyclines, doxorubicin + ifosfamide was associated with improved PFS (HR 0.53, 95% CI 0.33–0.86; p = 0.010) and OS (HR 0.53, 95% CI 0.32–0.90; p = 0.018).

CONCLUSIONS

Angiosarcoma response and survival following first-line anthracycline-based chemotherapy was similar to other STS histotypes. Our analysis provides a useful measure of angiosarcoma response to chemotherapy for comparison with future clinical trials.

Guidelines for time-to-event end point definitions in sarcomas and gastrointestinal stromal tumors (GIST) trials: results of the DATECAN initiative (Definition for the Assessment of Time-to-event Endpoints in CANcer trials)†

BACKGROUND

The use of potential surrogate end points for overall survival, such as disease-free survival (DFS) or time-to-treatment failure (TTF) is increasingly common in randomized controlled trials (RCTs) in cancer. However, the definition of time-to-event (TTE) end points is rarely precise and lacks uniformity across trials. End point definition can impact trial results by affecting estimation of treatment effect and statistical power. The DATECAN initiative (Definition for the Assessment of Time-to-event End points in CANcer trials) aims to provide recommendations for definitions of TTE end points. We report guidelines for RCT in sarcomas and gastrointestinal stromal tumors (GIST).

METHODS

We first carried out a literature review to identify TTE end points (primary or secondary) reported in publications of RCT. An international multidisciplinary panel of experts proposed recommendations for the definitions of these end points. Recommendations were developed through a validated consensus method formalizing the degree of agreement among experts.

RESULTS

Recommended guidelines for the definition of TTE end points commonly used in RCT for sarcomas and GIST are provided for adjuvant and metastatic settings, including DFS, TTF, time to progression and others.

CONCLUSION

Use of standardized definitions should facilitate comparison of trials' results, and improve the quality of trial design and reporting. These guidelines could be of particular interest to research scientists involved in the design, conduct, reporting or assessment of RCT such as investigators, statisticians, reviewers, editors or regulatory authorities.

Identification of SNPs associated with response of breast cancer patients to neoadjuvant chemotherapy in the EORTC-10994 randomized phase III trial

Using cell line panels we identified associations between single-nucleotide polymorphisms (SNPs) and chemosensitivity. To validate these findings in clinics, we genotyped a subset of patients included in a neoadjuvant breast cancer trial to explore the relationship between genotypes and clinical outcome according to treatment received and p53 status. We genotyped 384 selected SNPs in the germline DNA extracted from formalin-fixed paraffin-embedded non-invaded lymph nodes of 243 patients. The polymorphisms of five selected genes were first studied, and then all 384 SNPs were considered. Correction for multiple testing was applied. CYP1B1 polymorphism was significantly associated with pathological complete response (pCR) in patients who had received DNA-damaging agents. MDM2, MDM4 and TP53BP1 polymorphisms were significantly associated with pCR in patients harboring a p53-positive tumor. In the complete SNP panel, there was a significant association between overall survival (OS) and a SNP of ADH1C, R272Q (P=0.0023). By multivariate analysis, only ADH1C genotype and p53 status were significantly associated with OS.

Pathological complete response after neoadjuvant chemotherapy is an independent predictive factor irrespective of simplified breast cancer intrinsic subtypes: a landmark and two-step approach analyses from the EORTC 10994/BIG 1-00 phase III trial

BACKGROUND

Pathological complete response (pCR) following chemotherapy is strongly associated with both breast cancer subtype and long-term survival. Within a phase III neoadjuvant chemotherapy trial, we sought to determine whether the prognostic implications of pCR, TP53 status and treatment arm (taxane versus non-taxane) differed between intrinsic subtypes.

PATIENTS AND METHODS

Patients were randomized to receive either six cycles of anthracycline-based chemotherapy or three cycles of docetaxel then three cycles of eprirubicin/docetaxel (T-ET). pCR was defined as no evidence of residual invasive cancer (or very few scattered tumour cells) in primary tumour and lymph nodes. We used a simplified intrinsic subtypes classification, as suggested by the 2011 St Gallen consensus. Interactions between pCR, TP53 status, treatment arm and intrinsic subtype on event-free survival (EFS), distant metastasis-free survival (DMFS) and overall survival (OS) were studied using a landmark and a two-step approach multivariate analyses.

RESULTS

Sufficient data for pCR analyses were available in 1212 (65%) of 1856 patients randomized. pCR occurred in 222 of 1212 (18%) patients: 37 of 496 (7.5%) luminal A, 22 of 147 (15%) luminal B/HER2 negative, 51 of 230 (22%) luminal B/HER2 positive, 43 of 118 (36%) HER2 positive/non-luminal, 69 of 221(31%) triple negative (TN). The prognostic effect of pCR on EFS did not differ between subtypes and was an independent predictor for better EFS [hazard ratio (HR) = 0.40, P < 0.001 in favour of pCR], DMFS (HR = 0.32, P < 0.001) and OS (HR = 0.32, P < 0.001). Chemotherapy arm was an independent predictor only for EFS (HR = 0.73, P = 0.004 in favour of T-ET). The interaction between TP53, intrinsic subtypes and survival outcomes only approached statistical significance for EFS (P = 0.1).

CONCLUSIONS

pCR is an independent predictor of favourable clinical outcomes in all molecular subtypes in a two-step multivariate analysis.

CLINICALTRIALSGOV

EORTC 10994/BIG 1-00 Trial registration number NCT00017095.

Long-term responders and survivors on pazopanib for advanced soft tissue sarcomas: subanalysis of two European Organisation for Research and Treatment of Cancer (EORTC) clinical trials 62043 and 62072

BACKGROUND

Pazopanib recently received approval for the treatment of certain soft tissue sarcoma (STS) subtypes. We conducted a retrospective analysis on pooled data from two EORTC trials on pazopanib in STS in order to characterize long-term responders and survivors.

PATIENTS AND METHODS

Selected patients were treated with pazopanib in phase II (n = 118) and phase III study (PALETTE) (n = 226). Combined median progression-free survival (PFS) was 4.4 months; the median overall survival (OS) was 11.7 months. Thirty-six percent of patients had a PFS ≥ 6 months and were defined as long-term responders; 34% of patients survived ≥18 months, defined as long-term survivors. Patient characteristics were studied for their association with long-term outcomes.

RESULTS

The median follow-up was 2.3 years. Patient characteristics were compared among four subgroups based on short-/long-term PFS and OS, respectively. Seventy-six patients (22.1%) were both long-term responders and long-term survivors. The analysis confirmed the importance of known prognostic factors in metastatic STS patients treated with systemic treatment, such as performance status and tumor grading, and additionally hemoglobin at baseline as new prognostic factor. We identified 12 patients (3.5%) remaining on pazopanib for more than 2 years: nine aged younger than 50 years, nine females, four with smooth muscle tumors and nine with low or intermediate grade tumors at initial diagnosis. The median time on pazopanib in these patients was 2.4 years with the longest duration of 3.7 years.

CONCLUSIONS

Thirty-six percent and 34% of all STS patients who received pazopanib in these studies had a long PFS and/or OS, respectively. For more than 2 years, 3.5% of patients remained progression free under pazopanib. Good performance status, low/intermediate grade of the primary tumor and a normal hemoglobin level at baseline were advantageous for long-term outcome. NCT00297258 (phase II) and NCT00753688 (phase III, PALETTE).