REGOMAIN: A randomized, placebo-controlled, double-blinded, multicenter, comparative phase II study of the efficacy of regorafenib as maintenance treatment in patients (pts) with high-grade bone sarcomas (HGBS) at diagnosis or relapse and without complete remission after standard treatment

TPS11585

Background: Primary metastatic osteosarcoma (OS) patients are treated with a curative intent following the same principles of non-metastatic OS, while the treatment of recurrent OS is primarily surgical in the case of isolated lung metastases. When complete removal of all metastases cannot be achieved, the prognosis remains poor, with a median Progression-Free Survival (PFS) between 3 to 8 months, and therefore there is a clinical need to reduce the risk of progression after the initial treatment sequence. The REGOBONE study reported a significant PFS benefit of regorafenib (REG) compared to placebo (in osteosarcomas: median PFS: 16.4 versus 4.1 weeks) and a manageable safety profile in patients with histologically confirmed HGBS (i.e., osteosarcoma or other bone sarcomas with the exception of Ewing sarcomas, chondrosarcoma and chordoma). Methods: This multicenter trial is ongoing to study the efficacy and safety of maintenance REG in pts > = 16 years old with HGBS, without complete remission but with no progressive disease after standard treatment, either at diagnosis or at relapse. Sixty pts will be randomly allocated in a 1:1 ratio to receive either oral REG at a daily dose of 120mg or its matching placebo, continuously for a maximum of 12 months. Randomization is stratified according to the setting of the disease: initial diagnosis versus relapse. The primary objective is to compare the efficacy (PFS) between the 2 arms. The expected 4-month PFS rates are 30% in the control arm and 60% in the REGO arm (HR = 0.42). Fifty-two events will provide 87% power to show significant improvement in PFS, using a 2-sided log-rank test at a 5% level. Secondary endpoints include Overall Response Rate (ORR), Disease Control Rate (DCR), Time to Treatment Failure (TTF), Overall Survival (OS), Quality of Life (QoL), and safety profile. Radiological endpoints will be evaluated using the RECIST 1.1 with tumor assessments every 2 months (first 6 months) and then every 3 months. Translational objectives will identify predictive biomarkers for efficacy of REG as maintenance therapy. Pts of the control arm who experience disease progression may switch to receive open label REG. As of Feb 1st, 2022, 3 patients have been randomized. 14 sites of the French Sarcoma Group will participate. An amendment is being implemented to lower the age limit (12 years old) and to expand tumor types to other HGBS (Ewing sarcomas, chondrosarcomas, Undifferentiated Pleomorphic Sarcomas, Leiomyosarcomas and angiosarcomas). Clinical trial information: NCT04698785.

Activity of regorafenib in patients with non-adipocytic soft tissue sarcoma (NASTS): Evaluation of heterogeneity of treatment effect on the updated analysis of pooled cohorts

11555

Background: Results of the double-blind randomized phase 2 trial (NCT01900743), showed that regorafenib (REG) is an active treatment in patients (pts) previously treated with chemotherapy for an NASTS (cohorts B-leiomyosarcoma, C-synovial sarcoma, D-other sarcoma, Mir 2016), and in pts previously treated with pazopanib (PAZ) (cohort E, Penel 2019). We now present an updated analysis of progression-free survival (PFS) in all NASTS pts to assess the heterogeneity of treatment effect according to histological subtype and prior exposure to PAZ. Methods: Pts received REG 160 mg/d, 21/28 d, or placebo (PB). Pts receiving PB were offered optional cross over in case of centrally confirmed disease progression. The primary endpoint was PFS, according to RECIST-1.1, based on full blinded central review of imaging (including a re-review for cohorts B, C and D, because first analysis was based on a partial central review in these cohorts). Overall survival (OS) was a secondary endpoint. We performed a pooled analysis of cohorts B, C, D and E, on the intent-to-treat dataset, including a multivariate analysis with interaction terms to assess the heterogeneity of treatment effect according to covariates. Results: From 06/2013 to 10/2017, 175 pts were randomized (87 REG vs 88 PB; 56, 27, 55, 37 pts in cohorts B, C, D and E, respectively). The median age was 59 yrs (range, 20-81). There were 101 women (58%). Histological subtype was leiomyosarcoma in 80 pts (LMS; 41 REG vs 39 PB; 56 in cohort B and 24 in cohort E), synovial sarcoma in 28 (SS; 13 REG vs 15 PB; 27 in cohort C and 1 in cohort E), and other sarcoma in 67 (33 REG vs 34 PB; 55 in cohort D and 12 in cohort E). The median number of prior lines of systemic treatment was 2 (range, 1-6). Overall, 43 pts had received prior PAZ (21 REG vs 22 PB). Out of 88 pts assigned to PB, 69 switched to REG after progression (79%). We confirmed a significant PFS-benefit associated with REG in multivariate analysis of the pooled study population, with a HR = 0.48 (95%CI, 0.35–0.66, p < 0.001); median PFS = 2.1 vs 1.0 months, respectively. This benefit appears significant in each histological subtype. However, we observed a borderline interaction between histological subtype and treatment effect (p = 0.09): PFS benefit appears larger in pts with SS (HR = 0.21, 0.10-0.48, p < 0.001) and other sarcoma (HR = 0.49, 0.30-0.81, p = 0.006) than in LMS (HR = 0.59, 0.37-0.93, p = 0.022). PFS benefit appears rather homogeneous across strata of pts with vs without prior exposure to PAZ (interaction test, p = 0.26). Overall, in this study, regorafenib does not show any statistically significant OS-benefit (HR = 0.77, 0.57–1.05, p = 0.10), likely due to the fact that 79% of PB pts crossed over to REG at progression. Conclusions: The present study confirms the clinical PFS benefit associated with regorafenib in all NASTS pts, regardless of prior treatment with pazopanib. Clinical trial information: NCT01900743.

Pembrolizumab in soft-tissue sarcomas with tertiary lymphoid structures: a phase 2 PEMBROSARC trial cohort

Immune checkpoint inhibitors (ICIs) show limited clinical activity in patients with advanced soft-tissue sarcomas (STSs). Retrospective analysis suggests that intratumoral tertiary lymphoid structures (TLSs) are associated with improved outcome in these patients. PEMBROSARC is a multicohort phase 2 study of pembrolizumab combined with low-dose cyclophosphamide in patients with advanced STS (NCT02406781). The primary endpoint was the 6-month non-progression rate (NPR). Secondary endpoints included objective response rate (ORR), progression-free survival (PFS), overall survival (OS) and safety. The 6-month NPR and ORRs for cohorts in this trial enrolling all comers were previously reported; here, we report the results of a cohort enrolling patients selected based on the presence of TLSs (n = 30). The 6-month NPR was 40% (95% confidence interval (CI), 22.7-59.4), so the primary endpoint was met. The ORR was 30% (95% CI, 14.7-49.4). In comparison, the 6-month NPR and ORR were 4.9% (95% CI, 0.6-16.5) and 2.4% (95% CI, 0.1-12.9), respectively, in the all-comer cohorts. The most frequent toxicities were grade 1 or 2 fatigue, nausea, dysthyroidism, diarrhea and anemia. Exploratory analyses revealed that the abundance of intratumoral plasma cells (PCs) was significantly associated with improved outcome. These results suggest that TLS presence in advanced STS is a potential predictive biomarker to improve patients' selection for pembrolizumab treatment.

No Geographical Inequalities in Survival for Sarcoma Patients in France: A Reference Networks' Outcome?

The national reference network NETSARC+ provides remote access to specialized diagnosis and the Multidisciplinary Tumour Board (MTB) to improve the management and survival of sarcoma patients in France. The IGéAS research program aims to assess the potential of this innovative organization to address geographical inequalities in cancer management. Using the IGéAS cohort built from the nationwide NETSARC+ database, the individual, clinical, and geographical determinants of the 3-year overall survival of sarcoma patients in France were analyzed. The survival analysis was focused on patients diagnosed in 2013 (n = 2281) to ensure sufficient hindsight to collect patient follow-up. Our study included patients with bone (16.8%), soft-tissue (69%), and visceral (14.2%) sarcomas, with a median age of 61.8 years. The overall survival was not associated with geographical variables after adjustment for individual and clinical factors. The lower survival in precarious population districts [HR 1.23, 95% CI 1.02 to 1.48] in comparison to wealthy metropolitan areas (HR = 1) found in univariable analysis was due to the worst clinical presentation at diagnosis of patients. The place of residence had no impact on sarcoma patients' survival, in the context of the national organization driven by the reference network. Following previous findings, this suggests the ability of this organization to go through geographical barriers usually impeding the optimal management of cancer patients.

Lack of prognostic value of CTNNB1 mutation profile in desmoid-type fibromatosis

PURPOSE

This prospective nationwide cohort study aimed to investigate desmoid-type fibromatosis (DF) outcomes, focusing on the prognostic value of CTNNB1 mutations.

EXPERIMENTAL DESIGN

ALTITUDES (NCT02867033) was a nationwide prospective cohort study of DF diagnosed between January 2016 and December 2020. At diagnosis, CTNNB1 molecular alterations were identified using next-generation sequencing or Sanger sequencing. The primary endpoint was event-free survival (EFS) (progression, relapse, or death). We enrolled 628 patients managed by active surveillance (AS), surgical resection (SR), or systemic treatment as front-line therapy.

RESULTS

Overall, 516 (82.2%) patients (368 females [71.3%], median age 40.3 years [range, 1-89]) were eligible for analysis. In 435 (84.3%) cases, there was one CTNNB1 molecular alteration: p.T41A, p.S45F, or p.S45P. The front-line management was AS in 352 (68.2%), SR in 120 (23.3%), and systemic treatments in 44 (8.5%) patients. CTNNB1 mutation distribution was similar across the three therapeutic groups. The median follow-up period was 24.7 (range, 0.4-59.7) months. The estimated 3-year EFS rate was 66.2% (95%CI, 60.5%-71.2%). DF harboring p.S45F was significantly associated with male sex (p=0.03), non-abdominal wall sites (p=0.05), pain (p=0.007), and large tumor size (p=0.025). CTNNB1 p.S45F mutation was not significantly associated with EFS, either in univariate (hazard ratio [HR]=1.06; 95% confidence interval [CI], 0.65-1.73; p=0.81), or in multivariate analysis (HR=0.91; 95% CI, 0.55-1.49; p=0.71).

CONCLUSIONS

We found that CTNNB1 mutation profile was associated with unfavorable prognostic factors but was not a prognostic factor for EFS.

Patterns of care and outcomes of 417 patients with METAstatic SYNovial sarcoma (METASYN): real-life data from the French Sarcoma Group (FSG)

Background

Synovial sarcoma (SS) occurs in both adult and pediatric patients. The primary aim of this study is to describe the outcomes, prognostic factors, and treatment of patients with metastatic SS within a nationwide cohort.

Patients and methods

All pediatric and adult patients with metastatic SS are registered in the French Sarcoma Group database. Data were collected from the national database https://conticabase.sarcomabcb.org/ up to March 2020. Descriptive and comparative analyses were conducted using SAS 9.4 and Stata Special Edition 16.1 software.

Results

Between January 1981 and December 2019, 417 patients with metastatic SS from 17 French sarcoma centers were included, including 64 (15.3%) under the age of 26 years. Median age was 42.5 years (range 9-87 years). The metastases were synchronous (cohort 1) or metachronous (cohort 2) in 18.9% (N = 79) and 81.1% (N = 338) patients, respectively. Median overall survival (OS) from the date of metastasis was 22.3 months (95% confidence interval 19.7-24.1 months). First-line chemotherapy without ifosfamide and/or doxorubicin was unfavorable for progression-free survival and OS (P < 0.001). Concerning cohort 1, young age, surgery of the primary tumor, and single metastatic site were independent favorable prognostic factors for OS. In cohort 2, surgery within an expert French Sarcoma Group center, absence of chemotherapy in the perioperative setting, the lungs as a single metastatic site, time to first metastasis >12 months, local therapy, and ifosfamide in the first metastatic line were independent favorable prognostic factors.

Conclusions

The outcome of patients with metastatic SS is influenced by local treatment, management in reference centers, and cytotoxic treatments given in the perioperative and metastatic setting.

•

METASYN is the largest retrospective study on metastatic adult and pediatric SS.

•

This study confirms that surgery remains the mainstay for improving OS in reference centers.

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METASYN emphasizes the importance of focal treatment of metastases for OS.

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This study offers real-life results in a metastatic setting and is a useful support for developing new strategies.

Randomized phase II study to assess the efficacy and tolerability of sunitinib by dose administration regimen in anti-angiogenic naïve patients with metastatic renal cell carcinoma (mRCC): Final analysis of SURF study

344

Background: SUN is approved in mRCC setting at the dose of 50mg daily for 4 weeks followed by 2 weeks rest (4/2 schedule). The 4/2 schedule often requires dose modifications for toxicity. Current recommendation is to reduce the dose to 37.5mg per day. Alternative schedules (2 weeks of treatment followed by one-week rest (2/1 schedule) have shown promising results. SURF trial evaluated prospectively schedule 2/1 when toxicity occurs. Methods: SURF [NCT02689167] is a prospective, non-comparative randomized study. Patients (pts) with mRCC (clear cell) were included at SUN initiation. When a dose adjustment of SUN was required, patients were randomized between 4/2 schedule at 37.5mg daily and experimental 2/1 schedule at 50mg daily. Primary objective was to assess duration of SUN treatment among the 73 first evaluable pts. Overall 226 pts were enrolled with 133 randomized. All other analyses are shown for the 133 randomized patients. Results: Pts were 75.2% males, with a median age 63.7 years for 94% with a Karnofsky ≥ 80%. Of them, 54.9% had partial/total nephrectomy. IMDC risk score was favourable (45.1%), intermediate (46.6%) or poor (8.3%). Pts characteristics were well balanced between 2 arms. Metastatic sites were lungs (60.5%), bones (16.3%), lymph nodes (15.5%). At 6 months, 48 patients (65.8%) of the 2/1 schedule were still on treatment (above predefined threshold for positivity). Other data are listed on the table. No new safety signal was identified. Permanent SUN discontinuation due to toxicity was 22.2% in control arm vs 12.3% in experimental arm. Conclusions: SURF is the largest prospective randomised trial evaluating two different SUN schedules modifications in mRCC in case of toxicity. This positive trial confirms the role of adapting SUN to a 2/1 schedule rather than reducing SUN dose to the classical 4/2 schedule. Clinical trial information: NCT02689167. [Table: see text]

Patient Preference Between Cabazitaxel and Docetaxel for First-line Chemotherapy in Metastatic Castration-resistant Prostate Cancer: The CABADOC Trial

BACKGROUND

The taxanes docetaxel and cabazitaxel prolong overall survival for men with metastatic castration-resistant prostate cancer (mCRPC), with cabazitaxel approved in the postdocetaxel setting only. Recent data suggest they have similar efficacy but a different safety profile in the first-line mCRPC setting.

OBJECTIVE

To assess patient preference between docetaxel and cabazitaxel among men who received one or more doses of each taxane and did not experience progression after the first taxane.

DESIGN, SETTING, AND PARTICIPANTS

Chemotherapy-naïve patients with mCRPC were randomized 1:1 to receive docetaxel (75 mg/m² every 3 wk × 4 cycles) followed by cabazitaxel (25 mg/m² every 3 wk × 4 cycles) or the reverse sequence. Randomization was stratified by prior abiraterone or enzalutamide use.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was patient preference, assessed via a dedicated questionnaire after the second taxane. Secondary endpoints included reasons for patient preference, prostate-specific antigen response, radiological progression-free survival, and overall survival. This clinical trial is registered at ClinicalTrials.gov as NCT02044354.

RESULTS AND LIMITATIONS

Of 195 men randomized, 152 met the prespecified modified intent-to-treat criteria for analysis. Overall, 66 patients (43%) preferred cabazitaxel, 40 (27%) preferred docetaxel, and 46 (30%) had no preference (p = 0.004, adjusted for treatment period effect). More patients preferred treatment period 1 (43%, 95% confidence interval [CI] 36-52%) versus period 2 (27%, 95% CI 20-34%). Patient preference for cabazitaxel was mainly related to less fatigue (72%), better quality of life (64%), and other adverse events (hair loss, pain, nail disorders, edema). Adverse events were consistent with the known safety profile of each drug.

CONCLUSIONS

A significantly higher proportion of chemotherapy-naïve men with mCRPC who received both taxanes preferred cabazitaxel over docetaxel. Less fatigue and better quality of life were the two main reasons driving patient choice.

PATIENT SUMMARY

Men with metastatic castration-resistant prostate cancer preferred cabazitaxel over docetaxel for chemotherapy, mainly because of less fatigue and better quality of life.

Rare bone sarcomas: A retrospective analysis of 145 adult patients from the French Sarcoma Group

The benefit of chemotherapy (CT) in rare bone sarcomas is not documented in prospective studies. Our retrospective study from the French sarcoma network for bone tumors ResOs was performed in adult patients (pts) from 1976 to 2014, with histologically verified diagnosis of leiomyosarcomas (LMS), undifferentiated pleomorphic sarcoma (UPS) or radiation-associated sarcomas of bone. The median follow-up was 4.7 years (95% CI: 3.7-6.5). Clinical features, treatment modalities and outcomes were recorded and analyzed from 145 pts (median age 53 years [range 20-87]). Site of disease was extremities (66%) or axial skeleton (34%), 111 (77%) presented with localized and potentially resectable disease. The most common histological subtypes were UPS (58%) and LMS (33%); 58% were high-grade tumors. Surgery was performed in 127 pts. In the 111 localized pts, 28 pts (25%) underwent upfront surgery or exclusive radiotherapy (RT; >50 Gy) without CT, whereas 83 pts (75%) received either neoadjuvant (n = 26) or adjuvant CT (n = 13) or both (n = 44). Neoadjuvant and adjuvant CT was mostly doxorubicin-based (95%/86%) and cisplatin-based (67%/63%). R0 resection was achieved in 59 pts, and a good histological response in 15 patients (25%). Adjuvant RT was performed in 24 (22%) pts. For the whole cohort (n = 145), the 5-year overall survival (OS) rate was 53% [42; 62]. In univariate analysis, age ≤ 60 was associated with a longer disease-free survival (DFS) (P = .0436). Neoadjuvant and adjuvant CT tended to be associated with better DFS (P = .056) with no significant impact on OS in this retrospective series.

Treatment of 120 adult osteosarcoma patients with metachronous and synchronous metastases: A retrospective series of the French Sarcoma Group

Treatment options for metastatic osteosarcomas are scarce. Following failure of standard first line therapy, patients who relapse present a challenging treatment dilemma, and have a poor prognosis. Surgical removal of all metastases is essential. A retrospective analysis of patients with metastatic osteosarcomas was conducted in 15 French Sarcoma Group centers. From January 2009 to December 2018, we identified 120 adult patients; 36 with synchronous and 84 with metachronous metastases with 74 males and 46 females. Mean age was 30 years (18-53). Metastatic sites were lung, bone and other in 91, 11 and 24 patients, respectively. Mean time to first metachronous metastases was 22 months (4-97). All patients except 13 (10.8%) with metachronous metastases received a first line systemic treatment for relapse, and 39 patients (32.5%) were included in a clinical trial. Eighty-one patients (67.5%) had local treatment of distant metastases. Median progression free survival (PFS) and overall survival (OS) were 5.5 (95% CI 4.6-6.4) and 20.5 months (95% CI 13.2-27.7) respectively for the overall group. In multivariate analysis, more than five metastases, time to first metastases <24 months, were statistically significant negative prognostic factors for OS and PFS (P = .002, ≤.001 and P = .006, ≤.001, respectively). Surgery of metastases was associated with better prognosis on OS and PFS (P = .001 and .037, respectively). The presence of bone metastases was a negative prognostic factor on OS but not on PFS (P = .021). In reference sarcoma centers, relapsed osteosarcoma patients with more than one metastasis commonly receive more than one line of systemic therapy, and are included in clinical trial if available.

Determinants of the access to remote specialised services provided by national sarcoma reference centres

Background

Spatial inequalities in cancer management have been evidenced by studies reporting lower quality of care or/and lower survival for patients living in remote or socially deprived areas. NETSARC+ is a national reference network implemented to improve the outcome of sarcoma patients in France since 2010, providing remote access to specialized diagnosis and Multidisciplinary Tumour Board (MTB). The IGéAS research program aims to assess the potential of this innovative organization, with remote management of cancers including rare tumours, to go through geographical barriers usually impeding the optimal management of cancer patients.

Methods

Using the nationwide NETSARC+ databases, the individual, clinical and geographical determinants of the access to sarcoma-specialized diagnosis and MTB were analysed. The IGéAS cohort (n = 20,590) includes all patients living in France with first sarcoma diagnosis between 2011 and 2014. Early access was defined as specialised review performed before 30 days of sampling and as first sarcoma MTB discussion performed before the first surgery.

Results

Some clinical populations are at highest risk of initial management without access to sarcoma specialized services, such as patients with non-GIST visceral sarcoma for diagnosis [OR 1.96, 95% CI 1.78 to 2.15] and MTB discussion [OR 3.56, 95% CI 3.16 to 4.01]. Social deprivation of the municipality is not associated with early access on NETSARC+ remote services. The quintile of patients furthest away from reference centres have lower chances of early access to specialized diagnosis [OR 1.18, 95% CI 1.06 to 1.31] and MTB discussion [OR 1.24, 95% CI 1.10 to 1.40] but this influence of the distance is slight in comparison with clinical factors and previous studies on the access to cancer-specialized facilities.

Conclusions

In the context of national organization driven by reference network, distance to reference centres slightly alters the early access to sarcoma specialized services and social deprivation has no impact on it. The reference networks’ organization, designed to improve the access to specialized services and the quality of cancer management, can be considered as an interesting device to reduce social and spatial inequalities in cancer management. The potential of this organization must be confirmed by further studies, including survival analysis.

High clinical activity of pembrolizumab in chordoma, alveolar soft part sarcoma (ASPS) and other rare sarcoma histotypes: The French AcSé pembrolizumab study from Unicancer

11520

Background: AcSé Pembrolizumab is a Phase 2, non-randomized parallel arms, open-label, multicentric study from Unicancer investigating the efficacy and safety of pembrolizumab monotherapy in different cohorts of patients with rare cancers (NCT03012620). Here we report the results of pembrolizumab in the rare sarcoma cohort. Methods: Selected histotypes were all rare sarcomas patients (pts) (incidence < 0.2/100,000/year). Main inclusion criteria were age > 18, ECOG PS≤1 and advanced or metastatic disease resistant to standard treatment. Patients received pembrolizumab 200 mg IV as a 30-minute infusion on Day 1 of every 21-day cycle for a maximum of 2 years. The primary endpoint was the confirmed objective response rate according to RECIST v1.1 at 12 weeks. Secondary endpoints included clinical benefit rate, duration of response, progression-free survival (PFS), overall survival (OS), and safety. Five groups of pts were distinguished, namely chordoma, alveolar soft-part sarcoma (ASPS), desmoplastic small round cell tumor (DSRCT), smarca4 deficient malignant rhabdoid tumor (SMRT), and other histotypes. Results: 98 patients including 34 with chordoma, 14 ASPS, 11 SMRT, 8 DSCRT and 31 with other histotypes, were included from July 2017 to December 2020. The median number of cycles was 5 (range, 1 to 35) with 78 (79.6%) patients who discontinued the trial after a median of 4 cycles. There were 6 (7.3%) partial response (PR) at 12 weeks. The best response was CR in 1 patient (1%), PR in 14 patients (14.3%), and stable disease (SD) in 33 (33.7%). Median duration of response was 8.2 months [IQR, 4.1 to 9.0]. The occurrence of best response depended on the histotype, with 3 (8.8%) responses in chordoma, 7 (50%) in ASPS, 3 (27%) in SMRT, 1 (12.5%) in DSCRT and 1 (3.2%) in other histotypes (p = 0.0011). At the data cut off, median PFS was 2.75 months, and median OS was 19.7 months on the overall population. Outcomes differed according to the histotype group, with the 12 months PFS rates at 31.2% (chordoma), 35.7% (ASPS), 18.2% (SMRT), 0% (DSCRT) and 3.3% (other), respectively (p < 0.0001), and median PFS at 6.6 (chordoma), 7.5 (ASPS), 1.1 (SMRT), 2.1 (DSCRT) and 2.1 months (other), while 1-year OS rates were 76.6% (chordoma), 85.7% (ASPS), 36.4% (SMRT), 17.5% (DSCRT) and 42.9% (other) with median OS only reached for SMRT (2.4 months), DSRCT (10 months), and the other histotype group (7.1 months) (p = 0.004). The side effect profile of pembrolizumab was similar to other tumor type. Conclusions: Pembrolizumab is safe and well tolerate in this pop od STS pts, AcSé study reports high levels response rate and prolonged activity in selected subtypes of rare sarcomas. Clinical trial information: NCT03012620.

PD1 inhibition in soft-tissue sarcomas with tertiary lymphoid structures: A multicenter phase II trial

11507

Background: PD1 inhibition has shown limited activity in all comers clinical trials including patients with advanced soft-tissue sarcomas (STS). In the PEMBROSARC study, objective response rate, progression-free (PFS) and overall survival (OS) were respectively 2.1%, 1.4 and 7.1 months respectively (Toulmonde et al. Jama Oncol 2017). We have recently shown that the presence of tertiary lymphoid structures (TLS) may represent a biomarker to select patients who are more likely to benefit from immunotherapy (PetitPrez et al., Nature 2020). We report here the first clinical trial investigating the efficacy of PD1 inhibition in TLS-positive STS. Methods: PEMBROSARC is an open-label multicenter phase II study of pembrolizumab in combination with low-dose cyclophosphamide in pts with STS selected based on the presence of TLS. TLS status has been assessed centrally has previously described (PetitPrez et al., Nature 2020). Eligible patients received pembrolizumab 200mg IV q21 days and cyclophosphamide 50 mg BID 1week on, 1 week off. All patients had confirmed progressive disease at inclusion based on central review of two imaging performed at less than 6 months interval. The primary efficacy endpoint was 6-month non-progression (as per RECIST evaluation criteria v1.1). Based on the following hypotheses: 15% 6-month non-progression rate (H0), 40% acceptable 6-month non-progression rate (H1), 5% type I error rate, 90% power, a total of 29 assessable patients were necessary and 8 patients or more had to be progression-free at 6 months to reach the first endpoint. Results: 240 patients were screened for TLS status between September 2018 and January 2020 in 7 centers of the French Sarcoma Group. Among them, 48 were found to be TLS+ as per central review and 35 were included in the study. The three most frequent histological subtypes were: well-differentiated/dedifferentiated liposarcoma (n = 13); UPS (n = 6), and leiomyosarcoma (n = 4). 30 patients were eligible for efficacy. Of those, as per central imaging review, 13 patients (43.3%) had tumor shrinkage resulting in partial response in 8 patients (26.7%) and stable disease in 5 cases (16.7%). 10 patients had progressive disease. Twelve patients were progression-free at 6 months (40.0% 95%CI = [22.7 – 59.4]).Median PFS and OS were 4.1 months (95%CI, 1.4-9.6) and 14.5 months (95%CI, 8.5- 18.3 months), respectively. Conclusions: With an objective response and a 6-month non-progression rates of 26.7% and 40% respectively versus 2.1% and 4.2% in all comers, the PEMBROSARC study confirms that selection based on TLS status is an efficient approach to tailor immunotherapy in STS patients. Clinical trial information: NCT02406781.

ODENZA: A French prospective, randomized, open-label, multicenter, cross-over phase II trial of preference between darolutamide and enzalutamide in men with asymptomatic or mildly symptomatic metastatic castrate-resistant prostate cancer (CRPC)

5046

Background: Darolutamide (Daro) and enzamutamide (Enza) are both next generation androgen receptor inhibitors with demonstrated activity in men with CRPC. Although both agents are associated with survival improvement, their toxicity profiles are different. To help decipher whether this may impact on patient preference, we designed the ODENZA trial. Methods: ODENZA is a prospective, randomized, open-label, multicenter, cross-over, phase II trial of preference between Daro and Enza in men with asymptomatic or mildly symptomatic metastatic CRPC. Patients were randomized 1/1 to receive Daro 1200 mg/d for 12 weeks followed by Enza 160 mg/d for 12 weeks (Daro-Enza arm) or the reverse sequence (Enza-Daro arm). In both arms, the second treatment was given in absence of evidence of cancer progression at week 12. The primary endpoint was patient preference between the two drugs, as assessed by a questionnaire at week 24. The Prescott's test was used to determine treatment preference in patients fullfilling pre planned criteria (exposure to both treatments, no progression at week 12, and completion of the preference questionnaire). A p-value greater than 0.05 indicates that there is no difference in preference between treatments. Stratification factors were performance status and prior taxane for mCSPC. After week 24, patients went on to an extension period during which they received the chosen treatment until progression or toxicity. The main secondary objectives included reasons for preference, response at week 12, cognitive assessment, and toxicity. Results: Overall 249 pts were randomized, median age 72y (68; 79), ECOG PS 0 (56%), prior taxanes (22%). Two hundred pts fulfilled the pre-planned criteria for evaluation of the preference primary endpoint : 97 (48.5% [41.3;55.7]), 80 (40.0% [33.0;47.0]), and 23 (11.5% [6.8;16.2]) chose Daro, Enza, and had no preference, respectively (unilateral p-value of 0.92). After preference assessment, 186 patients entered the extension period: 103 (55.4%) and 83 (44.6%) received Daro and Enza respectively. The most common factors influencing patient preference all numerically favored Daro over Enza, without significant differences were: less fatigue (44% vs 29%), ease of taking the medication (37% vs 31%), better quality of life (36% vs 28%), ability to be more active (26% vs 15%), ability to concentrate (22% vs 15%) and less falls (6% vs 3%). A PSA50 response was achieved in 76.2% and 83.9% at week 12 with Daro and Enza respectively (p = 0.13). Fatigue was the most frequently reported all grade adverse event at week 12, in 21% and 36% with Daro and Enza, respectively. Conclusions: More patients with early mCRPC preferred Daro over Enza, although the difference did not reach significance, with fatigue as the key influencing factor. Clinical trial information: NCT03314324.

REGOSTA: A randomized, placebo-controlled, double-blinded, multicenter study evaluating the efficacy and safety of regorafenib (REGO) as maintenance therapy after first-line treatment in patients (pts) with osteosarcoma (OS) and non-osteosarcomas (non-OS) of bone (non-Ewing, non-chondrosarcomas and non-chordomas)

TPS11576

Background: Pts with OS and non-OS of bone are treated with a multimodal sequence therapy of neoadjuvant chemotherapy (CT), surgery and adjuvant CT, followed by a close surveillance until recurrence. At recurrence, the prognosis remains poor with objective response rates of 3-29%, and a median Progression-Free Survival (PFS) of less than 4 months in OS. There is a clinical need to reduce the risk of recurrence after the initial treatment sequence. The REGOBONE study reported a significant clinical benefit of regorafenib compared to placebo in patients with relapsed OS (median PFS: 16.4 versus 4.1 weeks). Methods: This multicenter trial is ongoing to study the efficacy and safety of maintenance REGO in pts > = 16 years, with complete remission after initial treatment sequence of their bone sarcoma. 168 pts will be randomly allocated in a 1:1 ratio to receive either oral REGO or its matching placebo (control arm) at a daily dose of 120mg, continuously and for a maximum of 12 months. Randomization will be stratified according to the following risk factors: metastases (mets) at diagnosis and/or poor response to neoadjuvant CT versus no mets at diagnosis and good response to neoadjuvant CT. The primary objective is to compare the efficacy (Relapse-Free Survival) between the 2 arms. The expected 3-year RFS rates are 55% in the control arm and 74.6% in the REGO arm (HR = 0.5). 66 events will provide 80% power to show significant improvement in RFS, using a 2-sided log-rank test at a 5% level. Secondary endpoints include Time to Treatment Failure, Overall Survival, Quality of Life, safety profile, and compliance to treatment. Radiological endpoints will be evaluated using the RECIST 1.1. Translational objectives will be to identify predictive biomarkers for efficacy of REGO as maintenance therapy using liquid biopsies. As of Feb 1st, 2021, 3 patients have been randomized. 15 sites of the French Sarcoma Group will participate. Clinical trial information: NCT04055220.

Impact of surgical margins on survival in cutaneous sarcomas: A nationwide study of French Sarcoma Group (FSG) from NETSARC Database

e23537

Background: R0 surgery in reference centers is the cornerstone for sarcomas treatment with better local control and survival and is mandatory for ESMO-EURACAN and NCCN guidelines. The medical community is out on this issue for cutaneous sarcomas, if they have to follow suit. This retrospective descriptive study focused on margin status and local relapse-free survival (LRFS) and overall survival (OS) of patients (pts) with cutaneous sarcomas. Methods: Between 01/01/10 and 30/12/17, surgery was performed on 2044 pts with cutaneous sarcomas from 20 centers. Data were collected from the NETSARC national network database ( http://netsarc.sarcomabcb.org ). Diagnosis of cutaneous sarcoma was reviewed and histologically confirmed by a local expert pathologist of RRePS (“Network for expert pathology diagnosis in sarcoma”). Dermatofibrosarcoma, Kaposi sarcoma and rare subtypes (< 20 cases in the database) were excluded. Univariate analyses were conducted using log rank test or Cox test. Multivariate analyses were conducted using Cox test. Age and tumor size were analyzed as continuous values. Two-sided significant p level was set at < 0.05. Results: Mean age was 66 years. Primary tumor was localized in lower limb, trunk wall, head and neck and upper limb for 30%, 26%, 26% and 18% pts respectively. Main subtypes were leiomyosarcoma, undifferentiated sarcoma, and myxofibrosarcoma for 29%, 29%, and 14% pts respectively. Angiosarcoma was the subtype of 9% of the patients (n = 193). Mean size was 45 mm. FNCLCC grade was 1, 2, and 3 for 14%, 29.5%, and 24% tumors respectively. Before surgery, imaging and biopsy were performed for 21% and 51% pts respectively. Surgery was carried out in a NETSARC center for 26% of the pts. Margin status after initial surgery was R0, R1, and R2 for 35% (n = 724), 34% (n = 696), and 12% pts (n = 246) respectively. Re-excision was performed for 34% (703/2044 pts), leading to a subsequent R0 margin for 74% of them (523/703 pts, equivalent to 26% of the overall population). Local relapse occurred for 21% of pts after a median time of 10 months. Metastatic relapse occurred for 13% of pts after a median time of 11 months. One hundred and ninety-three pts (9%) died. Median follow-up was 12 months. In multivariate analyses, statistically significant favorable prognostic factors for LRFS were: young age, small tumor size and non-angiosarcoma subtype. Significant prognostic factors associated with longer OS were: young age, small tumor size, non-angiosarcoma subtype, FNCLCC grade (1 vs 2 and 1 vs 3) and initial R0 surgery. Conclusions: Cutaneous sarcomas share same favorable clinical prognostic factors than non-cutaneous sarcomas. Quality of surgery remains the mainstay for OS.

A randomized phase III trial comparing trabectedin to best supportive care in patients with pre-treated soft tissue sarcoma: T-SAR, a French Sarcoma Group trial

BACKGROUND

The French Sarcoma Group assessed the efficacy, safety, and quality of life (QoL) of trabectedin versus best supportive care (BSC) in patients with advanced soft tissue sarcoma (STS).

PATIENTS AND METHODS

This randomized, multicenter, open-label, phase III study included adults with STS who progressed after 1-3 prior treatment lines. Patients were randomized (1 : 1) to receive trabectedin 1.5 mg/m² every 3 weeks or BSC, stratified into L-STS (liposarcoma/leiomyosarcoma) and non-L-STS groups (other histotypes). Patients from the BSC arm were allowed to cross over to trabectedin at progression. The primary efficacy endpoint was progression-free survival (PFS) confirmed by blinded central review and analyzed in the intention-to-treat population.

RESULTS

Between 26 January 2015 and 5 November 2015, 103 heavily pre-treated patients (60.2% with L-STS) from 16 French centers were allocated to receive trabectedin (n = 52) or BSC (n = 51). Median PFS was 3.1 months [95% confidence interval (CI) 1.8-5.9 months] in the trabectedin arm versus 1.5 months (0.9-2.6 months) in the BSC arm (hazard ratio = 0.39, 95% CI 0.24-0.64, P < 0.001) with benefits observed across almost all analyzed subgroups, but particularly in patients with L-STS (5.1 versus 1.4 months, P = 0.0001). Seven patients (13.7%) in the trabectedin arm (all with L-STS) achieved a partial response, while no objective responses were observed in the BSC arm (P = 0.004). The most common grade 3/4 adverse events were neutropenia (44.2% of patients), leukopenia (34.6%), and transaminase increase (32.7%). Health-related 30-item core European Organization for the Research and Treatment of Cancer Quality-of-Life Questionnaire evidenced no statistical differences between the arms for any domain and at any time point. After progression, 91.8% of patients crossed over from BSC to trabectedin.

CONCLUSION

Trabectedin demonstrates superior disease control to BSC without impairing QoL in patients with recurrent STS of multiple histologies, with greater impact in patients with L-STS.

Successive Osteosarcoma Relapses after the First Line O2006/Sarcome-09 Trial: What Can We Learn for Further Phase-II Trials?

Simple Summary

Osteosarcoma is the most common primary malignant bone tumour in adolescents and young adults. The survival of osteosarcoma patients has not improved for four decades. The purpose was to describe first and subsequent relapses in patients from the OS2006/Sarcome-09 trial, to help future trial design. Among the 434 patients with a confirmed osteosarcoma who achieved CR1 during first line treatment, 157 patients experienced at least one relapse. The 3-year progression-free and overall survival rates were 21% and 37%, respectively. Only a quarter of the patients were included in clinical trials at first recurrence. We want to promote randomised phase-II trials in osteosarcoma relapses, with broad inclusion criteria at study entry in terms of age and disease status, and PFS as primary endpoint. Surgery/local treatment of all residual lesions should be allowed when feasible. Single-arm trial design could be used for subsequent relapses.

Abstract

The purpose was to describe first and subsequent relapses in patients from the OS2006/Sarcome-09 trial, to help future trial design. We prospectively collected and analysed relapse data of all French patients included in the OS2006/Sarcome-09 trial, who had achieved a first complete remission. 157 patients experienced a first relapse. The median interval from diagnosis to relapse was 1.7 year (range 0.5–7.6). The first relapse was metastatic in 83% of patients, and disease was not measurable according to RECIST 1.1 criteria in 23%. Treatment consisted in systemic therapy (74%) and surgical resection (68%). A quarter of the patients were accrued in a phase-II clinical trial. A second complete remission was obtained for 79 patients. Most of them had undergone surgery (76/79). The 3-year progression-free and overall survival rates were 21% and 37%, respectively. In patients who achieved CR2, the 3y-PFS and OS rates were 39% and 62% respectively. Individual correlation between subsequent PFS durations was poor. For osteosarcoma relapses, we recommend randomised phase-II trials, open to patients from all age categories (children, adolescents, adults), not limited to patients with measurable disease (but stratified according to disease status), with PFS as primary endpoint, response rate and surgical CR as secondary endpoints.

Exploratory gene-by-gene analysis of olaparib in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC): PROfound

126

Background: The Phase 3 PROfound trial (NCT02987543) met its primary endpoint and key secondary endpoints, including improved overall survival (OS) for olaparib in men with mCRPC with alterations in BRCA1, BRCA2, or ATM (Cohort A). We report gene-by-gene analysis of olaparib antitumor activity among the 15 prespecified homologous recombination repair (HRR) genes. Methods: Pts were randomized to olaparib (300 mg bid; n=256) or physician’s choice of enzalutamide or abiraterone (control; n=131). Exploratory analyses in pts with alterations in BRCA1 and/or BRCA2 (BRCA, regardless of co-occurring alterations with other HRR genes) or in single genes were conducted. Results: Evidence of olaparib antitumor activity was observed in subgroups with >10 pts (table). Data for pts with alterations in only BRCA1, BRCA2, PPP2R2A, RAD51B, RAD54L, PALB2, BRIP1, CHEK1, BARD1, and RAD51D will be reported (no FANCL or RAD51C enrolled). Conclusions: Small subgroups limit interpretation for some genes. Olaparib antitumor activity is greatest in pts with BRCA alterations, with a spectrum of clinical sensitivity to olaparib as defined by rPFS and OS across the broader population with alterations in other HRR genes. Clinical trial information: NCT02987543. [Table: see text]

Management of sarcomas in children, adolescents and adults: Interactions in two different age groups under the umbrellas of GSF-GETO and SFCE, with the support of the NETSARC+ network

Sarcomas are a rare heterogeneous group of malignant neoplasms that can arise in almost any anatomic site and any age. Close collaboration among adult and pediatric cancer specialists in the management of these tumors is of foremost importance. In this review, we present the current multidisciplinary organization in care of patients with sarcoma in France and we review the main advances made in the last decades in systemic and radiotherapy treatment in the main sarcoma types diagnosed in children, adolescents and young adults (AYA), thanks to the international collaboration.

Pharmacogenetic Study of Trabectedin-Induced Severe Hepatotoxicity in Patients with Advanced Soft Tissue Sarcoma

Hepatotoxicity is an important concern for nearly 40% of the patients treated with trabectedin for advanced soft tissue sarcoma (ASTS). The mechanisms underlying these liver damages have not yet been elucidated but they have been suggested to be related to the production of reactive metabolites. The aim of this pharmacogenetic study was to identify genetic variants of pharmacokinetic genes such as CYP450 and ABC drug transporters that could impair the trabectedin metabolism in hepatocytes. Sixty-three patients with ASTS from the TSAR clinical trial (NCT02672527) were genotyped by next-generation sequencing for 11 genes, and genotype-toxicity association analyses were performed with R package SNPassoc. Among the results, ABCC2 c.1249A allele (rs2273697) and ABCG2 intron variant c.-15994T (rs7699188) were associated with an increased risk of severe cytolysis, whereas ABCC2 c.3563A allele had a protective effect, as well as ABCB1 variants rs2032582 and rs1128503 (p-value < 0.05). Furthermore, CYP3A5*1 rs776746 (c.6986A > G) increased the risk of severe overall hepatotoxicity (p = 0.012, odds ratio (OR) = 5.75), suggesting the implication of metabolites in the hepatotoxicity. However, these results did not remain significant after multiple analysis correction. These findings need to be validated on larger cohorts of patients, with mechanistic studies potentially being able to validate the functional consequences of these variants.