CD163-positive tumor-associated macrophages and CD8-positive cytotoxic lymphocytes are powerful diagnostic markers for the therapeutic stratification of osteosarcoma patients: An immunohistochemical analysis of the biopsies fromthe French OS2006 phase 3 trial

The French phase 3 trial (OS 2006) testing zoledronic acid, an osteoclast inhibitor, with chemotherapy and surgery did not improve the outcome of patients with osteosarcoma (OS). To understand this unexpected result, the presence of infiltrating immune cells was investigated in 124 pre-therapeutic biopsies of patients enrolled in the trial. The percentage of CD68/CD163 tumor-infiltrating macrophages (TAMs), CD8⁺ lymphocytes, osteoclasts, and the PD1/PDL-1 checkpoint were assessed by immunohistochemistry. M1/M2 macrophage polarization was characterized by pSTAT1/CMAF staining. The expression of these biomarkers was correlated with clinical outcome. No statistical correlations were found with response to chemotherapy. High CD163 levels (>50% of cells per core; 43.8% of patients) were associated with CMAF nuclear expression and significantly correlated with better overall survival (p = 0.0025) and longer metastasis progression-free survival (MPFS, p = 0.0315) independently of metastatic status (p = 0.002). Only a trend was observed for patients with high CD68-positive cells (p = 0.0582). CD8⁺ staining was positive in >50% of cases with a median staining of 1%. Lower CD8⁺ levels were associated with metastatic disease at diagnosis and the presence of CD8-positive cells significantly correlated with improved overall survival in zoledronate-treated patients (p = 0.0415). PD1/PDL-1 staining was negative in >80% of cases and was not correlated with outcome. Finally, CD163-positive TAMs and CD8 positive cells are crucial prognostic biomarkers in OS, whereas PD1/PDL-1 checkpoint plays a minor role. For the first time, we described a correlation between CD8 positive cells and survival in zoledronate-treated patients. The immunohistochemical analysis of the microenvironment in biopsies may represent a novel tool for therapeutic stratification.

Surgical versus non-surgical approach in primary desmoid-type fibromatosis patients: A nationwide prospective cohort from the French Sarcoma Group

PURPOSE

The outcome of desmoid-type fibromatosis (DTF) is unpredictable. Currently, a wait-and-see approach tends to replace large en bloc resection as the first therapeutic approach. Nevertheless, there are no validated factors to guide the treatment choice.

METHOD

We conducted a prospective study of 771 confirmed cases of DTF. We analysed event-free survival (EFS) based on the occurrence of relapse after surgery, progressive disease during the wait-and-see approach, or change in therapeutic strategy. Identification of prognostic factors was performed using classical methods (log-rank test and Cox model).

RESULTS

Overall, the 2-year EFS was 56%; this value did not differ between patients undergoing an operation and those managed by the wait-and-see approach (53% versus 58%, p = 0.415). In univariate analysis, two prognostic factors significantly influenced the outcome: the nature of diagnostic sampling (p = 0.466) and primary location (p = 0.0001). The 2-year EFS was only 32% after open biopsy. The 2-year EFS was 66% for favourable locations (abdominal wall, intra-abdominal, breast, digestive viscera and lower limb) and 41% for unfavourable locations. Among patients with favourable locations, the 2-year EFS was similar in patients treated by both surgery (70%) and the wait-and-see approach (63%; p = 0.413). Among patients with unfavourable locations, the 2-year EFS was significantly enhanced in patients initially managed with the wait-and-see approach (52%) compared with those who underwent initial surgery (25%; p = 0.001).

CONCLUSION

The location of DTF is a major prognostic factor for EFS. If these findings are confirmed by independent analysis, personalised management of DTF must consider this easily obtained parameter.

Prognosis of desmoid tumors (DT): A prospective nationwide survey of 771 patients (pts)

11047

Background: Prognostic factors and optimal management of DT are not yet established. Methods: We analyzed the outcome of 771 consecutive DT pts treated between 01/2010 and 12/2016 in France. We have calculated event-free survival (EFS) defined as local relapse after surgery, progressive disease during non surgical approach or change in treatment strategy (e.g. from wait and see to systemic treatment or local treatment). Results: The sex ratio M/F was 219/552, the median age was 39 (2-90), and the median size 57 mm (4-700). 596 DT are found CTNNB1-mutated (71%). The 1st treatment was wait and see (369, 48%), surgery (343, 44%), systemic treatment (25, 3%), or radiotherapy (3, 0%). The median follow-up was 32 mo. 230 events occurred (including 1 death). The median EFS was 27 mo. After initial wait and see, pts required systemic treatment in 61 cases (15%), radiotherapy (4; 1%), cryotherapy (3; 1%), surgery (2; 0%) and radiofrequency (1, 0%). After initial surgery, DT pts required wait and see for relapse in 88 cases (25%), systemic treatment in 17 cases (5%), radiotherapy (6; 2%), cryotherapy (2; 0%) and surgery (1, 0%). Univariate analysis identified 3 factors associated with EFS: favorable locations (median not reached (NR) vs. 21 mo; p = 0.0001), nature of sampling (core needle biopsy: 31 mo; resection 26 mo and open biopsy 15 mo, p = 0.046) and superficial DT (NR vs. 28 mo, p = 0.00001). Favorable locations included: abdominal wall (236 pts), intra-abdominal (78 pts), breast (27 pts) and digestive viscera (42 pts). Chest wall (209 pts), head and neck (28 pts), lower limb (90 pts), upper limb (25 pts) and pelvis (18 pts) were all associated with poor EFS. Multivariate analysis identified only 1 prognostic factor for EFS: favorable location HR = 0.52 [0.39-0.69]. Compared to surgery, wait and see as 1st treatment was associated with better EFS in unfavorable DT locations (HR = 0.74 [0.74-0.56]; p = 0.001) but not associated with EFS in favorable locations (HR = 0.89 [0.69-1.13]; p = 0.420). Conclusions: Since primary location of DT is the major determinant of DT outcome, stratified approach according to location has to be prospectively assessed. Correlative biology analyses are warranted to better understand these findings.

Undifferentiated endometrial sarcomas (UES): Results of a French sarcoma group (FSG) retrospective series of 52 patients (pts)

e17109

Background: UES are rare tumors of very poor prognosis. Although large surgical resection is the cornerstone of curative intent treatment, the optimal post-operative strategy remains unclear. Methods: We conducted a retrospective analysis of UES pts over the last 8 years in 10 FSG centers, from Netsarc and RRePs databases. Results: Fifty-two pts with primary UES treated from 2008 to 2016 were included. The median age was 59 years (range, 42-82), and median ECOG was 0 (range, 0-3): 33 were localized (FIGO I-III) and 19 metastatic at diagnosis. Metrorrhagia, abdominal pain, and pelvic mass bleeding were the most common symptoms. Surgical procedures were radical hysterectomy and bilateral adnexectomy for 23/33 (70%) of localized and 11/19 (58%) of metastatic UES. Metastases were identified post operatively for 9/19 pts. In the localized group, 19 pts (58%) received radiotherapy, 10 (30%) complementary brachytherapy and 9 (27%) adjuvant chemotherapy. In the metastatic group, 16/19 (84%) received chemotherapy (polyCT, n=11). With a median follow-up of 28 months (0.3-112),24/52 pts are alive, 18/33 (58%) localized pts relapsed with 6 local relapses and 11 metastases. The 3- and 5-year Overall Survival (OS) rates were 40.7% and 29.1% respectively, for the whole group. In the localized group; median OS and Relapse-Free Survival (RFS) were 32.7 (23.3-42.1) and 22.9 months (2.3-43.7). In univariate analysis; early FIGO stage (p <0.0001), complete resection (R0-R1 vs R2; p=0.015) and adjuvant radiotherapy (p=0.001) were associated with a better OS; complete resection (p=0.021) and adjuvant radiotherapy (p=0.026) were associated with a better RFS. In the metastatic group, median OS was 16.4 months (12.0-20.7). In univariate analysis, no significant prognostic factor was retrieved neither on OS nor on RFS. Conclusions: Treatment of primary UES is radical hysterectomy and bilateral adnexectomy. Adjuvant radiotherapy appears beneficial for RFS. Due to the rarity and complexity of UES, referring patients to expert sarcoma centers is highly recommended.

Expression and prognostic significance of PDGF ligands (A, B, C, and D) and PDGFR (A, B, and L) in soft-tissue sarcomas and GIST

11067

Background: Sarcomas are a variety of rare connective tissue cancers. Doxorubicin and olaratumab (Ab against PDGFRA) improved survival in a recent Phase 1/2 study. Besides PDGFRA mutated gastrointestinal stroma tumor (GIST) and dermatofibrosarcoma protuberans, the role of PDGFR and the according ligands in the biology of sarcoma remain unclear. Methods: The expression levels of PDGF (A,B,C,D) and PDGFRs (A,B,L) were studied in a series of 255 sarcoma pts in localized phase using the Agilent 014850 platform. Data are available online (http://atg-sarc.sarcomabcb.org). Histologies were GIST (n = 60), myxoid liposarcoma (MLPS, n = 50), synovial sarcoma (SyS, n = 58), and sarcoma with complex genomics (SCG, n = 87). Expression levels were analyzed and tested for prognostic values for metastasis free survival (MFS) in uni- and multivariate analysis using SPSS 19.0. Results: Expression levels (ELs) of PDGFs and PDGFRs varied across histotypes: PDGFA levels were highest in SyS and lowest in MLPS (p < 0.0001). PDGFB and C levels were lower in GIST (p < 0.0001), while PDGFD ELs were similar across histological subtypes. PDGFRA ELs were highest in MLPS, while PDGFRB & L ELs were lowest in GIST and SyS (p < 0.0001 all). Complex patterns of correlation of expression between ligands and receptors were observed in each individual subtypes. PDGFA ELs above median were associated with a marginally higher risk of metastasis . Conversely, PDGFD ELs above median was associated with a reduced risk of metastasis in the whole cohort (p = 0.02). The ELs of the 3 receptors were not correlated to MFS. In multivariate analysis using Cox model on the non-GIST sarcoma cohort (histology, grade, depth, with size, PDGFA, PDGFD as continuous variables): histology, size, grade and PDGFA ELs were independent adverse prognostic factors (PF), while PDGFD ELs was a favorable PF for MFS. In the GIST cohort, testing AFIP score, PDGFA & D ELs as continuous variable, PDGFD ELs was also an independent favorable PF for MFS, in addition to AFIP score. Conclusions: The expression of PDGFs and the according receptors varies across sarcoma histological subtypes. PDGFA and D expression levels correlate independently to the risk of metastatic relapse.

A randomized multicenter phase 3 trial of adjuvant fotemustine versus surveillance in high risk uveal melanoma (UM) patients (FOTEADJ)

9502

Background: Up to 30% of UM patients will develop metastases, with a median survival of 12 months in the metastating setting. Prognostic factors combine clinical features of the primary tumor (diameter, thickness, retinal detachment, extra-scleral extension) and genetic factors (monosomy 3, 8 q gain and class 1 /2 gene expression profiling).The genomic analysis is feasible by fine needle aspiration biopsies before radiotherapy for small UM or on enucleated eyes. Methods: Multicenter randomized phase 3 trial with adjuvant fotemustine, 6 cycles, 100 mg/m2 versus surveillance for 3 years (liver tests/3 months, liver MRI or CT/6 months, whole body CT/12 months) in patients with high risk of recurrence, defined by clinical criteria (diameter > 15 mm with extra scleral extension and/or retinal detachment or diameter > 18 mm) or genomic high risk signature by array-CGH (monosomy 3 or deletion of 3p associated with gain of chromosome 8). The primary objective was 5-year Metastasis Free Survival (MFS). With an expected increase of 5-year MFS from 50 to 70%, 302 patients and 99 events were required to achieve an 95%-power with a 5% type I error rate. Secondary objectives were overall survival (OS), safety (NCI-CTC v3), quality of life (QLQ-C30). Interim analyses were planned for safety and after 50 events, disclosed to an independent safety monitoring board. Results: The trial was stopped for futility after 244 patients had been recruited between June 2009 and January 2016. No unexpected toxicity was found in the chemotherapy group. The study was amended to go on with intensive surveillance in new high risk patients. Ninety-one metastases and 43 deaths were reported, with no treatment-related death. With a median follow-up of 3 years, the 3-year MFS is 60.3% in the chemo group and 60.7% in the surveillance group (HR 0.97 [0.64-1.47]). The 3-year OS is 79.4% [73.2-85.7], with no difference between the 2 groups of patients. Conclusions: FOTEADJ is the first adjuvant randomized phase 3 trial based on genomic analysis in high risk UM patients. Despite negative results, it shows the feasibility of multicenter adjuvant studies in this rare cancer and provides genomic data in small tumors for future trials. Clinical trial information: NCT02843386.

Weekly paclitaxel (WP) +/- bevacizumab (B) in angiosarcoma (AS) patients (pts): Analysis of prognostic/predictive factors from a randomized phase 2 trial

11024

Background: WP is an active regimen for treatment of AS pts (Ray-Coquard JCO 2015). We report here the correlative analysis conducted during a phase 2 trial assessing WP +/- B. Methods: Circulating pro/anti-angiogenic factors (FGF, PlGF, SCF, Selectin, thrombospondin, VEGF, VEGF-C) were collected at D1 and D8. Prognostic value for PFS was assessed using Cox model (biomarkers as continuous variables). We attempt to identify subgroups of pts benefiting from adding B using interaction tests (predictive factors). Results: Among the 51 pts enrolled in this trial, 45 were analyzable: 20 in Arm A (WP without B) and 25 in Arm B (with B). Median PFS was 5.5 and 6.1 months, respectively (p = 0.84). Samples were collected in 45 pts at D1 and 42 pts at D1 and 8. Baseline biomarkers were similar in both arms (excluding Selectin, significantly lower in arm A: median of 25 vs. 35 ng/mL, p = 0.03). In arm A, there was no significant difference between values at D1 and D8. In arm B, there were a significant decrease in VEGF (from a median of 0.49 to 0.08 ng/mL; p < 0.01) and selectin (from a median of 35.3 to 31.7 ng/mL; p < 0.01), and a significant increase in PlGF (from a median of 16.1 to 30.0 pg/mL; p < 0.01). In univariate analysis, factors associated with PFS were: de novo vs. radiation-induced AS (HR = 2.39 (p < 0.01), visceral vs. superficial AS (HR = 2.04; p < 0.03), VEGF-C at D1 (HR = 0.77; p < 0.03), FGF at D8 (HR = 1.17; p < 0.01), difference in FGF D8-D1 (HR = 1.24; p < 0.01), and PlGF value at D1 (HR = 1.02; p < 0.05). In multivariate analysis, factors associated with PFS were: de novo AS (HR = 2.39; p = 0.03), VEGF-C at D1 (HR = 0.73; p < 0.02) and FGF difference between D8 and D1 (HR = 1.16; p < 0.02). None of these factors were associated with benefit of adding B. Conclusions: Baseline VEGF-C levels and change in FGF were independent prognostic factors in pts with or without B. Addition of B significantly decreased the level of circulating VEGF and selectin and increased the level of circulating PlGF in AS patients. We did not identify subgroup of pts benefiting from adding of B to WP. Clinical trial information: NCT01303497.

Combination of pembrolizumab and metronomic cyclophosphamide in patients with advanced sarcomas and GIST: A French Sarcoma Group phase II trial

11053

Background: There is a good rationale for immunotherapy in sarcoma. We report results of the first open-label multicentre phase 2 study assessing the anti-PD-1 antibody pembrolizumab in combination with metronomic cyclophosphamide (CP) in patients (pts) with advanced soft tissue sarcomas (STS) and gastro-intestinal stromal tumor (GIST). Methods: This trial included 4 cohorts of pts with advanced STS: leiomyosarcoma (LMS), undifferentiated pleomorphic sarcoma (UPS), other sarcomas (Others), and GIST. All pts received CP 50 mg BID one week on, one week off, and pembrolizumab 200mg IV q21 days. The primary endpoint encompassed non-progression and objective response at 6 months per RECIST evaluation criteria v1.1 for LMS, UPS, and Others, and 6-month non-progression for GIST. Correlative studies of immune biomarkers were planned on pt’s tumor and plasma samples. Results: Between June 2015 and July 2016, 57 pts were included, and 50 were assessable for efficacy. Three pts experienced tumor shrinkage resulting in a partial response (PR) in one of them. The 6-month non-progression rate was 0%, 0%, 14.3% (95%CI 1.8-42.8), and 11.1% (95%CI 2.8-48.3) in LMS, UPS, Others, and GIST respectively. The most frequent adverse events were grade 1 or 2 fatigue, diarrhea, anemia. The only pt who experienced PR was the only one with a PD-L1-positive staining in more than 10% of immune cells on archived tumor sample. A strong macrophage infiltration was observed in tumor samples, and these macrophages largely expressed the inhibitory enzyme Indoleamine-2,3-dioxygenase-1 (IDO1). Moreover, a significant increase of the kynurenine/tryptophane ratio was observed in pts plasma samples during study treatment (p =0.0007). Conclusions: PD-1 inhibition has limited activity in advanced STS and GIST. This primary resistance may be explained by the low percent of PD-L1 positivity in these tumors, and an immune-suppressive tumor microenvironment resulting from macrophage infiltration and IDO1 pathway activation. Further strategies assessing drugs such as CSF1-R inhibitors and/or IDO inhibitors combined with anti-PD-1/PD-L1 in selected sarcoma subtypes are warranted. Clinical trial information: NCT02406781.

Post-cross-over activity of regorafenib (RE) in soft tissue sarcoma: Analysis from the REGOSARC trial

11052

Background: Based on the placebo (PBO) controlled phase 2 trial (Mir, Lancet Oncol 2016), RE has shown to be an active drug in patients (pts) with leiomyosarcoma (LMS), synovial sarcoma (SS) and other non-adipocytic sarcoma (OTH), but not in liposarcoma. Pts initially allocated to PBO were allowed to cross-over to RE after progression. We here report the activity of RE after cross-over. Methods: From July 2013 to Dec 2014, 138 pts were enrolled in the non-adipocytic sarcoma cohorts (LMS, SS & OTH). After update in Dec 2016, median follow-up was 32 mo (vs 17 mo in the initial publication). Benefit of RE vs PBO in terms of progression-free survival (PFS) and overall survival (OS) from randomization was estimated by hazard ratio (HR) in Cox models. In the PBO arm, intra-patient benefit of RE after cross-over was evaluated by the growth modulation index (GMI), where PFS1=PFS with PBO before cross-over, and PFS2=PFS with RE after cross-over. The impact of timing of RE allocation (delayed after cross-over, vs early at study entry) was evaluated by comparing PFS after cross-over in PBO arm to PFS after randomization in RE arm. Results: As detailed in the table, major PFS benefit of RE vs PBO allocated by randomization was confirmed with long follow-up (HR=0.50 [95%CI 0.35-0.71] p<.0001). However, this translates into a smaller and non-significant OS benefit (HR=0.78 [0.54-1.12] p=.18). This finding may partially be explained by the fact that 55 of the 68 pts who progressed in the PBO arm (81%) could receive RE after progression and benefit from RE: 56% of them had a GMI greater than 1.3. Delayed start of RE was associated with a non-significantly shorter PFS compared to earlier treatment (HR=1.21, [0.84-1.73] p=.30). Conclusions: Efficacy of RE vs PBO is confirmed with longer follow-up in non-adipocytic sarcoma. PFS of pts receiving RE after cross-over is not significantly shorter than that of pts initially randomized to receive RE. Clinical trial information: NCT01900743. [Table: see text]

First-line Bevacizumab and Paclitaxel for HER2-negative Metastatic Breast Cancer: A French Retrospective Observational Study

AIM

To assess outcomes in patients treated with first-line bevacizumab-containing therapy for human epidermal growth factor receptor (HER)2-negative metastatic breast cancer (mBC) at a single centre with a homogenous standard-of-care.

PATIENTS AND METHODS

Information on patient and disease characteristics, efficacy, and safety was extracted from computer-based records of all patients receiving first-line bevacizumab-paclitaxel at the Curie Institute, Paris, France, between 2008 and 2011.

RESULTS

Median progression-free survival in the 116 treated patients was 13.2 months; median overall survival was 38.4 months. Corresponding values were 9.0 and 18.8 months, respectively, in patients with triple-negative mBC, and 19.4 and 58.8 months, respectively, in patients receiving maintenance endocrine therapy. No new safety signals were seen.

CONCLUSION

Outcomes in patients treated with bevacizumab-paclitaxel at our center were consistent with efficacy in prospective clinical trials, with notable activity in poor-prognosis disease. Maintenance endocrine or oral therapy with bevacizumab after paclitaxel discontinuation was associated with long-term disease control.

Protein Tyrosine Phosphatase 4A3 (PTP4A3) Promotes Human Uveal Melanoma Aggressiveness Through Membrane Accumulation of Matrix Metalloproteinase 14 (MMP14)

PURPOSE

To study PTP4A3 phosphatase and MMP14 metalloprotease synergy in uveal melanoma aggressiveness.

METHODS

Cell membrane localization of matrix metalloprotease 14 (MMP14) in uveal melanoma cells expressing protein tyrosine phosphatase A3 (PTP4A3) was assessed by flow cytometry or immunohistochemistry. The vesicular trafficking of MMP14 in the presence of PTP4A3 was evaluated in OCM-1 cells expressing either the wild-type or mutated phosphatase. Finally, MMP14 localization at the cell membrane of OCM-1 cells was impaired using RNA interference, and the PTP4A3-related migration in vitro and invasiveness in vivo of the treated cells were evaluated.

RESULTS

We found that the membrane-anchored MMP14 is enriched at the cell surface of OCM-1 cells, patient-derived xenograft cells, and human primary uveal melanoma tumors expressing PTP4A3. Moreover, we show that PTP4A3 and MMP14 colocalize and that the vesicular trafficking of MMP14 is faster in the presence of active PTP4A3. Finally, we demonstrate that inhibition of MMP14 expression in uveal melanoma cells expressing PTP4A3 impairs their migration in vitro and invasiveness in vivo.

CONCLUSIONS

Our observations indicate that PTP4A3 increases cell membrane accumulation of MMP14 as a result of increased cellular trafficking of the metalloprotease. We also show that downregulation of MMP14 expression reduced PTP4A3-induced cell migration and invasiveness. Taken together, our findings suggest that PTP4A3-related subcellular localization of MMP14 is an important event in metastasis induction.

Validation of a Prognostic Staging for Metastatic Uveal Melanoma: A Collaborative Study of the European Ophthalmic Oncology Group

PURPOSE

To validate a staging system for metastatic uveal melanoma that will facilitate planning, reporting, and interpreting the results of clinical trials.

DESIGN

Reliability and validity study.

METHODS

The performance index, the largest diameter of the largest metastasis and alkaline phosphatase level at the time of diagnosis of metastases, and overall survival of 249 patients from 7 ocular oncology centers who died of dissemination were analyzed. Predicted median survival time calculated according to the Helsinki University Hospital Working Formulation was used to assign patients to stages IVa, IVb, and IVc, which correspond to predicted survival times of ≥12, <12-6, and <6 months, respectively. The predictions were compared against observed survival.

RESULTS

The 3 variables used to assign stage were independent predictors of survival in the validation dataset. Of the 249 patients, 110 (44%), 109 (44%), and 30 (12%) were classified to Working Formulation stages IVa, IVb, and IVc, respectively. Corresponding median observed survival times were 18.6, 10.7, and 4.6 months and worsened by increasing stage (P < .001). Of 201 patients managed without surgical resection of metastases, 83 (41%), 89 (44%), and 29 (15%) were classified to stages IVa, IVb, and IVc, respectively, and their median observed survival times were 17.2, 10.0, and 4.6 months (P < .001). Survival of 47 patients who underwent resection did not differ by working formulation stage (P = .69).

CONCLUSIONS

This multicenter study confirms that the Working Formulation is a reliable and valid, repeatable system for dividing metastatic uveal melanoma into distinct prognostic subgroups, especially for stage-specific reporting of survival in prospective clinical trials.

Abstract 3027: Dual inhibition of PKC and p53-MDM2 or PKC and mTORC1 are novel efficient therapeutic approaches for uveal melanoma

Uveal melanoma (UM), although rare in incidence, is the most common cancer of the eye in adults. Many UM patients develop metastases for which no curative treatment has been identified and therefore novel therapeutic approaches are urgently needed. UM is characterized by mutations in the genes GNAQ and GNA11 which activate the PKC pathway. This has led to the use of PKC inhibitors as a rational targeting strategy to treat UM tumors. Encouraging clinical activity has been noted in UM patients treated with PKC inhibitors. However, it is likely that curative treatment regimens will require a combination of targeted therapeutic agents. Employing a large panel of UM patient-derived xenograft models, several PKC inhibitor-based combination studies were performed using the PKC inhibitor AEB071 (Sotrastaurin). When combined with AEB071, the targeted agents CGM097 (p53-MDM2 inhibitor), RAD001 (Everolimus, mTORC1 inhibitor) and MEK162 (Binimetinib, a MEK inhibitor) demonstrated greater activity in the UM patient-derived xenograft models than their activity as single agents. Importantly, tumor regressions were observed in several UM models with AEB071 + RAD001 and AEB071 + CGM097 co-treatments. Follow-up in vitro studies in UM cell lines using AEB071 combined with either CGM097 or RAD001 provided a more detailed mechanistic understanding of their combination activity and confirmed their ability to induce cell death. Together, these preclinical studies reveal that combining PKC and p53-MDM2 inhibitors or PKC and mTORC1 inhibitors may provide significant clinical benefit for patients with UM.

Citation Format: Guillaume Carita, Estelle Frisch Dit Leitz, Ahmed Dahmani, Chloe Raymondie, Nathalie Cassoux, Sophie Piperno-Neumann, Fariba Némati, Ensar Halilovic, Sebastien Jeay, Andrew Wylie, Caroline Emery, Sergio Roman-Roman, Marie Schoumacher, Didier Decaudin. Dual inhibition of PKC and p53-MDM2 or PKC and mTORC1 are novel efficient therapeutic approaches for uveal melanoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3027.