Neoadjuvant Chemotherapy in High-Grade Myxoid Liposarcoma: Results of the Expanded Cohort of a Randomized Trial From Italian (ISG), Spanish (GEIS), French (FSG), and Polish Sarcoma Groups (PSG)

PURPOSE

A randomized trial was conducted to compare neoadjuvant standard (S) anthracycline + ifosfamide (AI) regimen with histology-tailored (HT) regimen in selected localized high-risk soft tissue sarcoma (STS). The results of the trial demonstrated the superiority of S in all STS histologies except for high-grade myxoid liposarcoma (HG-MLPS) where S and HT appeared to be equivalent. To further evaluate the noninferiority of HT compared with S, the HG-MLPS cohort was expanded.

PATIENTS AND METHODS

Patients had localized high-grade (cellular component >5%; size ≥5 cm; deeply seated) MLPS of extremities or trunk wall. The primary end point was disease-free survival (DFS). The secondary end point was overall survival (OS). The trial used a noninferiority Bayesian design, wherein HT would be considered not inferior to S if the posterior probability of the true hazard ratio (HR) being >1.25 was <5%.

RESULTS

From May 2011 to June 2020, 101 patients with HG-MLPS were randomly assigned, 45 to the HT arm and 56 to the S arm. The median follow-up was 66 months (IQR, 37-89). Median size was 107 mm (IQR, 84-143), 106 mm (IQR, 75-135) in the HT arm and 108 mm (IQR, 86-150) in the S arm. At 60 months, the DFS and OS probabilities were 0.86 and 0.73 (HR, 0.60 [95% CI, 0.24 to 1.46]; log-rank P = .26 for DFS) and 0.88 and 0.90 (HR, 1.20 [95% CI, 0.37 to 3.93]; log-rank P = .77 for OS) in the HT and S arms, respectively. The posterior probability of HR being >1.25 for DFS met the Bayesian monitoring cutoff of <5% (4.93%). This result confirmed the noninferiority of trabectedin to AI suggested in the original study cohort.

CONCLUSION

Trabectedin may be an alternative to standard AI in HG-MLPS of the extremities or trunk when neoadjuvant treatment is a consideration.

CINSARC in high-risk soft tissue sarcoma patients treated with neoadjuvant chemotherapy: Results from the ISG-STS 1001 study

BACKGROUND

The Complexity INdex in SARComas (CINSARC) is a transcriptional signature derived from the expression of 67 genes involved in mitosis control and chromosome integrity. This study aims to assess CINSARC value of in an independent series of high-risk patients with localized soft tissue sarcoma (STS) treated with preoperative chemotherapy within a prospective, randomized, phase III study (ISG-STS 1001).

PATIENTS AND METHODS

Patients with available pre-treatment samples, treated with 3 cycles of either standard (ST) preoperative or histotype-tailored (HT) chemotherapy, were scored according to CINSARC (low-risk, C1; high-risk, C2). The 10-year overall survival probability (pr-OS) according to SARCULATOR was calculated, and patients were classified accordingly (low-risk, Sarc-LR, 10-year pr-OS>60%; high-risk, Sarc-HR, 10-year pr-OS<60%). Survival functions were estimated using the Kaplan-Meier method and compared using log-rank test.

RESULTS

Eighty-six patients were included, 30 C1 and 56 C2, 49 Sarc-LR and 37 Sarc-HR. A low level of agreement between CINSARC and SARCULATOR was observed (Cohen's Kappa = 0.174). The 5-year relapse-free survival in C1 and C2 were 0.57 and 0.55 (p = 0.481); 5-year metastases-free survival 0.63 and 0.64 (p = 0.740); 5-year OS 0.80 and 0.72 (p = 0.460). The 5-year OS in C1 treated with ST and HT chemotherapy was 0.84 and 0.76 (p = 0.251) respectively; in C2 treated it was 0.72 and 0.70 (p = 0.349). The 5-year OS in Sarc-LR treated with S and HT chemotherapy was 0.80 and 0.82 (p = 0.502) respectively; in Sarc-HR it was 0.70 and 0.61 (p = 0.233).

CONCLUSIONS

Our results, although constrained by the small size of the series, suggest that CINSARC has weak prognostic power in high-risk, localized STS treated with neoadjuvant chemotherapy.

Pexidartinib Long-Term Hepatic Safety Profile in Patients with Tenosynovial Giant Cell Tumors

Background

Pexidartinib is approved in the U.S. for tenosynovial giant cell tumors (TGCTs). Herein, we assessed the hepatic safety profile of pexidartinib across patients with TGCTs receiving pexidartinib.

Materials, and Methods

Hepatic adverse reactions (ARs) were assessed by type and magnitude of liver test abnormalities, classified as (a) isolated aminotransferase elevations (alanine [ALT] or aspartate [AST], without significant alkaline phosphatase [ALP] or bilirubin elevations), or (b) mixed or cholestatic hepatotoxicity (increase in ALP with or without ALT/AST and bilirubin elevations, based on adjudication). Median follow‐up from initial pexidartinib treatment was 39 months (range, 32–82) in 140 patients with TGCTs across clinical studies NCT01004861, NCT02371369, NCT02734433, and NCT03291288.

Results

In total, 95% of patients with TGCTs (133/140) treated with pexidartinib (median duration of exposure, 19 months [range, 1–76]), experienced a hepatic AR. A total of 128 patients (91%) had reversible, low‐grade dose‐dependent isolated AST/ALT elevations without significant ALP elevations. Five patients (4%) experienced serious mixed or cholestatic injury. No case met Hy's law criteria. Onset of hepatic ARs was predominantly in the first 2 months. All five serious hepatic AR cases recovered 1–7 months following pexidartinib discontinuation. Five patients from the non‐TGCT population (N = 658) experienced serious hepatic ARs, two irreversible cases.

Conclusion

This pooled analysis provides information to help form the basis for the treating physician's risk assessment for patients with TCGTs, a locally aggressive but typically nonmetastatic tumor. In particular, long‐term treatment with pexidartinib has a predictable effect on hepatic aminotransferases and unpredictable risk of serious cholestatic or mixed liver injury.

Implications for Practice

This is the first long‐term pooled analysis to report on the long‐term hepatic safety of pexidartinib in patients with tenosynovial giant cell tumors associated with severe morbidity or functional limitations and not amenable to improvement with surgery. These findings extend beyond what has been previously published, describing the observed instances of hepatic toxicity following pexidartinib treatment across the clinical development program. This information is highly relevant for medical oncologists and orthopedic oncologists and provides guidance for its proper use for appropriate patients within the Pexidartinib Risk Evaluation and Mitigation Safety program.

Pexidartinib is approved in the U.S. for treatment of tenosynovial giant cell tumors (TGCT). This article assesses the hepatic safety profile of pexidartinib in TGCT cases and describes risk mitigation procedures designed to identify any instances of serious liver injury as early as possible to better inform prescribers and patients about this drug.

Neoadjuvant Chemotherapy in High-Risk Soft Tissue Sarcomas: Final Results of a Randomized Trial From Italian (ISG), Spanish (GEIS), French (FSG), and Polish (PSG) Sarcoma Groups

PURPOSE

To determine whether the administration of histology-tailored neoadjuvant chemotherapy (HT) was superior to the administration of standard anthracycline plus ifosfamide neoadjuvant chemotherapy (A+I) in high-risk soft tissue sarcoma (STS) of an extremity or the trunk wall.

PATIENTS AND METHODS

This was a randomized, open-label, phase III trial. Patients had localized high-risk STS (grade 3; size, ≥ 5 cm) of an extremity or trunk wall, belonging to one of the following five histologic subtypes: high-grade myxoid liposarcoma (HG-MLPS); leiomyosarcoma (LMS), synovial sarcoma (SS), malignant peripheral nerve sheath tumor (MPNST), and undifferentiated pleomorphic sarcoma (UPS). Patients were randomly assigned in a 1:1 ratio to receive three cycles of A+I or HT. The HT regimens were as follows: trabectedin in HG-MLPS; gemcitabine plus dacarbazine in LMS; high-dose prolonged-infusion ifosfamide in SS; etoposide plus ifosfamide in MPNST; and gemcitabine plus docetaxel in UPS. Primary and secondary end points were disease-free survival (DFS) and overall survival (OS), estimated using the Kaplan-Meier method and compared using Cox models adjusted for treatment and stratification factors. The study is registered at ClinicalTrials.gov (identifier NCT01710176).

RESULTS

Between May 2011 and May 2016, 287 patients (UPS: n = 97 [33.8%]; HG-MLPS: n = 65 [22.6%]; SS: n = 70 [24.4%]; MPNST: n = 27 [9.4%]; and LMS: n = 28 [9.8%]) were randomly assigned to either A+I or HT. At the final analysis, with a median follow-up of 52 months, the projected DFS and OS probabilities were 0.55 and 0.47 (log-rank P = .323) and 0.76 and 0.66 (log-rank P = .018) at 60 months in the A+I arm and HT arm, respectively. No treatment-related deaths were observed.

CONCLUSION

In a population of patients with localized high-risk STS, HT was not associated with a better DFS or OS, suggesting that A+I should remain the regimen to choose whenever neoadjuvant chemotherapy is used in patients with high-risk STS.

Abstract CT009: A Phase Ib study assessing biomarker modulation in soft tissue sarcoma patients treated with olaratumab followed by olaratumab plus doxorubicin

Background: Olaratumab (olara), an IgG1 monoclonal antibody, blocks platelet-derived growth factor receptor (PDGFR) α activation. In a randomized Phase 2 study, olara plus doxorubicin (dox) improved overall survival in advanced soft tissue sarcoma (STS) patients (pts). The aim of this study (JGDM, NCT02783599) was to further evaluate potential biomarkers and the mechanism of action of olara in pts with STS.

Methods: Pts with potentially resectable STS received olara monotherapy for one cycle followed by up to 6 cycles of olara plus dox (75 mg/m2 on Day 1). Olara was administered at 20 mg/kg (Cycles 1 and 2) and 15 mg/kg (Cycles 3-7) on Days 1 and 8 of a 21-day cycle. Co-primary objectives were enumeration of circulating tumor cells (CTCs) and PDGFR biomarker expression in tumor tissue pre- and post-olara monotherapy. PDGFR protein expression was analyzed by a validated immunohistochemistry (IHC) assay; Epic Sciences performed CTC enumeration. Secondary objectives included antitumor activity, safety, and pharmacokinetics (PK).

Results: Of the 51 pts enrolled, 35 were evaluable for CTC enumeration and 43 were evaluable for PDGFR expression. Median number of CTCs detected before and after olara monotherapy were 1.0/mL (range: 0.1-9.2) and 0.1/mL (range: 0.1-18.7), respectively, in the analysis population. The proportion of pts with a decrease in CTC counts post-olara monotherapy in Cycle 1 was higher in pts with disease control (58%; 11 of 19 pts) compared with pts with no disease control (31%; 5 of 16 pts) after Cycle 2 (p=0.22). In the 43 pts evaluable for tumor tissue PDGFR analysis, IHC staining at baseline was positive in 31 (72.1%) pts for PDGFRα and 36 (83.7%) pts for PDGFRβ. Post-olara monotherapy samples showed similar rates of qualitative IHC expression for PDGFRα (n=30, 69.8%) and PDGFRβ (n=33, 76.7%). Qualitative IHC expression for either marker did not appear to correlate with clinical outcome in the analysis population. Clinically, overall response rate (CR+PR) was 11.8% (n=6), 27% of pts (n=14) had a decrease in size of target lesions, and 35.3% of pts (n=18) underwent tumor resection following systemic treatment. The safety and PK profiles of olara in combination with dox were consistent with previous reports.

Conclusions: CTC enumeration in STS pts is feasible and disease control after Cycle 2 was associated with a statistically non-significant decrease in CTC following olara monotherapy in Cycle 1. Qualitative detection of PDGFRα in pre-treatment samples showed no association with clinical outcome and similar rates of qualitative detection in post-treatment samples. Further quantitative exploration of tissue biopsy results and correlations with exploratory findings in CTCs is ongoing.

Citation Format: Javier Martin-Broto, Antonio Lopez Pousa, Andrew Brohl, Brian A. Van Tine, Benjamin Powers, Silvia Stacchiotti, Jean-Yves Blay, James S. Hu, Gerard J. Oakley, Hong Wang, Anna Szpurka, Donna E. Levy, Gary Mo, Matteo Ceccarelli, Robin Jones. A Phase Ib study assessing biomarker modulation in soft tissue sarcoma patients treated with olaratumab followed by olaratumab plus doxorubicin [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT009.

Neoadjuvant chemotherapy in high-risk soft tissue sarcomas: Final results of a randomized clinical trial from the Italian Sarcoma Group, the Spanish Sarcoma Group (GEIS), the French Sarcoma Group (FSG), and the Polish Sarcoma Group (PSG)

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Background: A ISG randomized trial on 5 cycles of adjuvant epirubicin+ifosfamide (EI) versus no chemotherapy suggested an OS benefit in localized high-risk STS (JCO 2001;19:1238). A subsequent trial showed no difference between 3 vs 5 cycles of the same neoadjuvant regimen (JCO 2012;30:850). The aim of this trial was to compare 3 cycles of EI versus a histology-tailored (HT) neoadjuvant regimen in selected localized high-risk STS. Methods: This is a multicenter European randomized trial comparing EI versus a HT regimen: gemcitabine+docetaxel in undifferentiated pleomorphic sarcoma (UPS); trabectedin in high-grade myxoid liposarcoma; high-dose prolonged-infusion ifosfamide in synovial sarcoma (SS); etoposide+ifosfamide in malignant peripheral nerve sheath tumors (MPNST); gemcitabine+dacarbazine in leiomyosarcoma (LMS). Patients had localized high-risk (grade = 3; size ≥5 cm) STS of extremities or trunk wall. Primary end-point was Disease Free Survival (DFS). The final analysis was planned after the observation of 130 events. This allows an 80% power to detect a significant difference at the 5% 2-sided level, if the true HR is 0.6 in favor of EI, as shown by the interim analysis (Lancet Oncol 2017;18:812-822). Results: From May 2011 to May 2016, 287 patients were randomized (97 = UPS; 65 = myxoid liposarcoma; 70 = SS; 27 = MPNST; 28 = LMS). The median follow-up was 51.75 months for the alive patients (IQ 28.03) The DFS and OS probability at 60 months were 0.48 and 0.55 (HR:1.232; 95%CI: 0.875-1.733; log rank p=0.323) and 0.66 and 0.76 (HR:1.766; 95%CI:1.101-2.831; log rank p=0.018), in the HT and EI arm, respectively. Conclusions: The final analysis shows a non-statistically significant DFS difference in favor of EI over HT chemotherapy with a larger and statistically significant OS difference. The outcome of patients on EI overlapped previous ISG trials. EI should remain the regimen of choice when neoadjuvant chemotherapy is used in high-risk localized STS. However this trial cannot be used as a formal proof of efficacy of (neo)adjuvant chemotherapy per se. EUDRACT 2010 – 023484 – 17. Funding source: Eurosarc FP7 278472. Clinical trial information: NCT01710176.

Dovitinib in patients with gastrointestinal stromal tumour refractory and/or intolerant to imatinib

Background:

This multicentre phase II trial (DOVIGIST) evaluated the antitumour activity of dovitinib as second-line treatment of patients with gastrointestinal stromal tumour (GIST) refractory to imatinib or who do not tolerate imatinib.

Methods:

Patients received oral dovitinib 500 mg day⁻¹, 5 days on/2 days off, until GIST progression or unacceptable toxicity, with an objective to evaluate efficacy, assessed as the disease control rate (DCR) at 12 weeks. Tumour assessment and response to dovitinib therapy were evaluated by Response Evaluation Criteria In Solid Tumours (RECIST v1.1) and the Choi criteria. Secondary objectives included assessment of progression-free survival (PFS), safety and tolerability, and DCR at the end of treatment.

Results:

Thirty-eight of the 39 patients enrolled had histologically confirmed GIST. The DCR at 12 weeks was 52.6% (90% confidence interval (CI), 38.2–66.7%) meeting the preset efficacy criterion for the primary end point. The objective response rate (complete response+partial response) was 2.6% (1 of 38; 90% CI, 0.1–11.9%), and 5.3% (n=2; 90% CI, 0.9–15.7%) at the end of the study. The median PFS was 4.6 months (90% CI, 2.8–7.4 months). Dose interruption was required in 26 patients (66.7%), of which 18 (69.2%) were due to adverse events. The most frequently observed grade 3 adverse events included hypertension (n=7), fatigue (n=5), vomiting (n=4), hypertriglyceridaemia (n=4), and γ-glutamyltransferase increase (n=4).

Conclusions:

Dovitinib is an active treatment for patients with GIST who are intolerant to imatinib or whose GIST progresses on imatinib.

Ten-Year Progression-Free and Overall Survival in Patients With Unresectable or Metastatic GI Stromal Tumors: Long-Term Analysis of the European Organisation for Research and Treatment of Cancer, Italian Sarcoma Group, and Australasian Gastrointestinal Trials Group Intergroup Phase III Randomized Trial on Imatinib at Two Dose Levels

Purpose

To report on the long-term results of a randomized trial comparing a standard dose (400 mg/d) versus a higher dose (800 mg/d) of imatinib in patients with metastatic or locally advanced GI stromal tumors (GISTs).

Patients and Methods

Eligible patients with advanced CD117-positive GIST from 56 institutions in 13 countries were randomly assigned to receive either imatinib 400 mg or 800 mg daily. Patients on the 400-mg arm were allowed to cross over to 800 mg upon progression.

Results

Between February 2001 and February 2002, 946 patients were accrued. Median age was 60 years (range, 18 to 91 years). Median follow-up time was 10.9 years. Median progression-free survival times were 1.7 and 2.0 years in the 400- and 800-mg arms, respectively (hazard ratio, 0.91; P = .18), and median overall survival time was 3.9 years in both treatment arms. The estimated 10-year progression-free survival rates were 9.5% and 9.2% for the 400- and 800-mg arms, respectively, and the estimated 10-year overall survival rates were 19.4% and 21.5%, respectively. At multivariable analysis, age (< 60 years), performance status (0 v ≥ 1), size of the largest lesion (smaller), and KIT mutation (exon 11) were significant prognostic factors for the probability of surviving beyond 10 years.

Conclusion

This trial was carried out on a worldwide intergroup basis, at the beginning of the learning curve of the use of imatinib, in a large population of patients with advanced GIST. With a long follow-up, 6% of patients are long-term progression free and 13% are survivors. Among clinical prognostic factors, only performance status, KIT mutation, and size of largest lesion predicted long-term outcome, likely pointing to a lower burden of disease. Genomic and/or immune profiling could help understand long-term survivorship. Addressing secondary resistance remains a therapeutic challenge.

Histotype-tailored neoadjuvant chemotherapy versus standard chemotherapy in patients with high-risk soft-tissue sarcomas (ISG-STS 1001): an international, open-label, randomised, controlled, phase 3, multicentre trial

BACKGROUND

Previous trials from our group suggested an overall survival benefit with five cycles of adjuvant full-dose epirubicin plus ifosfamide in localised high-risk soft-tissue sarcoma of the extremities or trunk wall, and no difference in overall survival benefit between three cycles versus five cycles of the same neoadjuvant regimen. We aimed to show the superiority of the neoadjuvant administration of histotype-tailored regimen to standard chemotherapy.

METHODS

For this international, open-label, randomised, controlled, phase 3, multicentre trial, patients were enrolled from 32 hospitals in Italy, Spain, France, and Poland. Eligible patients were aged 18 years or older with localised, high-risk (high malignancy grade, 5 cm or longer in diameter, and deeply located according to the investing fascia), soft-tissue sarcoma of the extremities or trunk wall and belonging to one of five histological subtypes: high-grade myxoid liposarcoma, leiomyosarcoma, synovial sarcoma, malignant peripheral nerve sheath tumour, and undifferentiated pleomorphic sarcoma. Patients were randomly assigned (1:1) to receive three cycles of full-dose standard chemotherapy (epirubicin 60 mg/m² per day [short infusion, days 1 and 2] plus ifosfamide 3 g/m² per day [days 1, 2, and 3], repeated every 21 days) or histotype-tailored chemotherapy: for high-grade myxoid liposarcoma, trabectedin 1·3 mg/m² via 24-h continuous infusion, repeated every 21 days; for leiomyosarcoma, gemcitabine 1800 mg/m² on day 1 intravenously over 180 min plus dacarbazine 500 mg/m² on day 1 intravenously over 20 min, repeated every 14 days; for synovial sarcoma, high-dose ifosfamide 14 g/m², given over 14 days via an external infusion pump, every 28 days; for malignant peripheral nerve sheath tumour, intravenous etoposide 150 mg/m² per day (days 1, 2, and 3) plus intravenous ifosfamide 3 g/m² per day (days 1, 2, and 3), repeated every 21 days; and for undifferentiated pleomorphic sarcoma, gemcitabine 900 mg/m² on days 1 and 8 intravenously over 90 min plus docetaxel 75 mg/m² on day 8 intravenously over 1 h, repeated every 21 days. Randomisation was stratified by administration of preoperative radiotherapy and by country of enrolment. Computer-generated random lists were prepared by use of permuted balanced blocks of size 4 and 6 in random sequence. An internet-based randomisation system ensured concealment of the treatment assignment until the patient had been registered into the system. No masking of treatment assignments was done. The primary endpoint was disease-free survival. The primary and safety analyses were planned in the intention-to-treat population. We did yearly futility analyses on an intention-to-treat basis. The study was registered with ClinicalTrials.gov, number NCT01710176, and with the European Union Drug Regulating Authorities Clinical Trials, number EUDRACT 2010-023484-17, and is closed to patient entry.

FINDINGS

Between May 19, 2011, and May 13, 2016, 287 patients were randomly assigned to a group (145 to standard chemotherapy and 142 to histotype-tailored chemotherapy), all of whom, except one patient assigned to standard chemotherapy, were included in the efficacy analysis (97 [34%] with undifferentiated pleomorphic sarcoma; 64 [22%] with high-grade myxoid liposarcoma; 70 [24%] with synovial sarcoma; 27 [9%] with malignant peripheral nerve sheath tumour; and 28 [10%] with leiomyosarcoma). At the third futility analysis, with a median follow-up of 12·3 months (IQR 2·75-28·20), the projected disease-free survival at 46 months was 62% (95% CI 48-77) in the standard chemotherapy group and 38% (22-55) in the histotype-tailored chemotherapy group (stratified log-rank p=0·004; hazard ratio 2·00, 95% CI 1·22-3·26; p=0·006). The most common grade 3 or higher adverse events in the standard chemotherapy group (n=125) were neutropenia (107 [86%]), anaemia (24 [19%]), and thrombocytopenia (21 [17%]); the most common grade 3 or higher adverse event in the histotype-tailored chemotherapy group (n=114) was neutropenia (30 [26%]). No treatment-related deaths were reported in both groups. In agreement with the Independent Data Monitoring Committee, the study was closed to patient entry after the third futility analysis.

INTERPRETATION

In a population of patients with high-risk soft-tissue sarcoma, we did not show any benefit of a neoadjuvant histotype-tailored chemotherapy regimen over the standard chemotherapy regimen. The benefit seen with the standard chemotherapy regimen suggests that this benefit might be the added value of neoadjuvant chemotherapy itself in patients with high-risk soft-tissue sarcoma.

FUNDING

European Union grant (Eurosarc FP7 278472).

Adjuvant therapy in primary GIST: state-of-the-art

BACKGROUND

The management of primary gastrointestinal stromal tumours (GISTs) has evolved with the introduction of adjuvant therapy. Recently reported results of the SSG XVIII/AIO trial by the Scandinavian Sarcoma Group (SSG) and the German Working Group on Medical Oncology (AIO) represent a significant change in the evidence for adjuvant therapy duration. The objectives of this European Expert Panel meeting were to describe the optimal management and best practice for the systemic adjuvant treatment of patients with primary GISTs.

MATERIALS AND METHODS

A panel of medical oncology experts from European sarcoma research groups were invited to a 1-day workshop. Several questions and discussion points were selected by the organising committee prior to the conference. The experts reviewed the current literature of all clinical trials available on adjuvant therapy for primary GISTs, considered the quality evidence and formulated recommendations for each discussion point.

RESULTS

Clinical issues were identified and provisional clinical opinions were formulated for adjuvant treatment patient selection, imatinib dose, duration and patient recall, mutational analysis and follow-up of primary GIST patients. Adjuvant imatinib 400 mg/day for 3 years duration is a standard treatment in all patients with significant risk of recurrence following resection of primary GISTs. Patient selection for adjuvant therapy should be based on any of the three commonly used patient risk stratification schemes. R1 surgery (versus R0) alone is not an indication for adjuvant imatinib in low-risk GIST. Recall and imatinib restart could be proposed in patients who discontinued 1-year adjuvant imatinib within the previous 3 months and may be considered on a case-by-case basis in patients who discontinued within the previous year. Mutational analysis is recommended in all cases of GISTs using centralised laboratories with good quality control. Treatment is not recommended in an imatinib-insensitive D842V-mutated GIST. During adjuvant treatment, patients are recommended to be clinically assessed at 1- to 3-month intervals. Upon discontinuation, computed tomography scan (CT) scans are recommended every 3 to 4 months for 2 years when the risk of relapse is highest, followed by every 6 months until year 5 and annually until year 10 after treatment discontinuation.

CONCLUSIONS

Key points in systemic adjuvant treatment and clinical management of primary GISTs as well as open questions were identified during this European Expert Panel meeting on GIST management.

Complete longitudinal analyses of the randomized, placebo-controlled, phase III trial of sunitinib in patients with gastrointestinal stromal tumor following imatinib failure

PURPOSE

To analyze final long-term survival and clinical outcomes from the randomized phase III study of sunitinib in gastrointestinal stromal tumor patients after imatinib failure; to assess correlative angiogenesis biomarkers with patient outcomes.

EXPERIMENTAL DESIGN

Blinded sunitinib or placebo was given daily on a 4-week-on/2-week-off treatment schedule. Placebo-assigned patients could cross over to sunitinib at disease progression/study unblinding. Overall survival (OS) was analyzed using conventional statistical methods and the rank-preserving structural failure time (RPSFT) method to explore cross-over impact. Circulating levels of angiogenesis biomarkers were analyzed.

RESULTS

In total, 243 patients were randomized to receive sunitinib and 118 to placebo, 103 of whom crossed over to open-label sunitinib. Conventional statistical analysis showed that OS converged in the sunitinib and placebo arms (median 72.7 vs. 64.9 weeks; HR, 0.876; P = 0.306) as expected, given the cross-over design. RPSFT analysis estimated median OS for placebo of 39.0 weeks (HR, 0.505, 95% CI, 0.262-1.134; P = 0.306). No new safety concerns emerged with extended sunitinib treatment. No consistent associations were found between the pharmacodynamics of angiogenesis-related plasma proteins during sunitinib treatment and clinical outcome.

CONCLUSIONS

The cross-over design provided evidence of sunitinib clinical benefit based on prolonged time to tumor progression during the double-blind phase of this trial. As expected, following cross-over, there was no statistical difference in OS. RPSFT analysis modeled the absence of cross-over, estimating a substantial sunitinib OS benefit relative to placebo. Long-term sunitinib treatment was tolerated without new adverse events.

Pegfilgrastim primary prophylaxis vs. current practice neutropenia management in elderly breast cancer patients receiving chemotherapy

We investigated the incidences of febrile neutropenia (FN) and related complications in elderly (> or =65 years) breast cancer patients receiving chemotherapy supported by pegfilgrastim primary prophylaxis (PP; n=150) or current practice (CP) neutropenia management (n=104) in a subanalysis of NeuCuP (Neulasta) vs. current practice neutropenia management). Studies involving regimens with moderately high to high (> or =15%) FN risk were identified by literature review, and individual patient data were integrated for analysis. FN incidence was 6% (95% CI: 2, 10%) in the PP group and 24% (95% CI: 16, 32%) in the CP group. In cycle 1, incidences were 3 and 15%, respectively. FN-related hospitalisation incidence was 5% (PP group) and 15% (CP group), while dose reductions (>/=15%) occurred in 15 and 29% of patients. Pegfilgrastim provided effective PP in elderly patients, a population who may be vulnerable to chemotherapy-related FN and for whom current practice may not provide adequate protection.