Adjuvant bevacizumab as treatment for melanoma patients at high risk of recurrence: Final results for the AVAST-M trial

9501

Background: Bevacizumab (Bev) is a recombinant humanised monoclonal antibody to vascular endothelial growth factor (VEGF) shown to improve survival in several advanced solid tumours. As VEGF is a relevant target in melanoma, AVAST-M aimed to evaluate the role of Bev in melanoma patients at high risk of recurrence. Methods: AVAST-M (ISRCTN81261306) is a randomised phase III trial evaluating single agent Bev (7.5mg/kg IV 3 weekly for 1 year) as adjuvant therapy after resection of AJCC stage IIB, IIC and III cutaneous melanoma compared to standard observation (Obs). 1320 patients were needed to detect 8% differences in 5 year overall survival (OS) rate from 40% to 48%; 85% power, 5% alpha level. Primary endpoint was OS; secondary endpoints included disease free interval (DFI), distant-metastasis free interval (DMFI). BRAF and NRASmutation status were obtained in 682 patients in a translational sub-study. Results: From July 2007 to March 2012, 1343 patients were recruited (671 to Bev; 672 to Obs). 56% were male, median age was 56 years (range 18-88 years), 14% were stage IIIA and 59% were stage IIIB/C. With 6 years median follow-up, 505 (38%) patients had died (251 [37%] on Bev; 254 [38%] on Obs); 699 (52%) patients had recurred (335 [50%] on Bev, 369 [55%] on Obs). OS at 5 years was 64% on Bev versus 63% on Obs (Hazard ratio [HR] 0.99; 95% confidence interval [CI] 0.84-1.18, p=0.96). At 5 years, 51% were disease free on Bev versus 45% on Obs (HR 0.85; 95% CI 0.74-0.99, p=0.04) and 59% were distant metastasis free on Bev versus 54% on Obs (HR 0.91; 95% CI 0.77-1.07, p=0.24). A BRAF V600 mutation was found in 44% of tumours assessed; 20% were NRAS mutant. BRAF mutant patients treated with Bev tended to have better DFI (HR=0.79 95% CI 0.58-1.08, p=0.14) and OS (HR=0.79; 95% CI 0.55-1.13, p=0.20); this was not evident for BRAF WT. NRAS mutant patients tended to have worse DFI (HR=1.39; 95% CI 1.03-1.88; p=0.03) and OS (HR=1.18; 95% CI 0.85-1.62, p=0.20) than NRASWT patients. Conclusions: This large, multi-centre trial of melanoma patients at high risk of recurrence has shown that adjuvant Bev improves DFI, but this does not translate into an overall survival benefit. Funding:Cancer Research UK; drug supplied by Roche Products Ltd. Clinical trial information: ISRCTN81261306.

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.

Uveal Melanoma UK National Guidelines

The United Kingdom (UK) uveal melanoma guideline development group used an evidence based systematic approach (Scottish Intercollegiate Guidelines Network (SIGN)) to make recommendations in key areas of uncertainty in the field including: the use and effectiveness of new technologies for prognostication, the appropriate pathway for the surveillance of patients following treatment for primary uveal melanoma, the use and effectiveness of new technologies in the treatment of hepatic recurrence and the use of systemic treatments. The guidelines were sent for international peer review and have been accredited by NICE. A summary of key recommendations is presented. The full documents are available on the Melanoma Focus website.

Ribosome recycling induces optimal translation rate at low ribosomal availability

During eukaryotic cellular protein synthesis, ribosomal translation is made more efficient through interaction between the two ends of the messenger RNA (mRNA). Ribosomes reaching the 3′ end of the mRNA can thus recycle and begin translation again on the same mRNA, the so-called ‘closed-loop’ model. Using a driven diffusion lattice model of translation, we study the effects of ribosome recycling on the dynamics of ribosome flow and density on the mRNA. We show that ribosome recycling induces a substantial increase in ribosome current. Furthermore, for sufficiently large values of the recycling rate, the lattice does not transition directly from low to high ribosome density, as seen in lattice models without recycling. Instead, a maximal current phase becomes accessible for much lower values of the initiation rate, and multiple phase transitions occur over a wide region of the phase plane. Crucially, we show that in the presence of ribosome recycling, mRNAs can exhibit a peak in protein production at low values of the initiation rate, beyond which translation rate decreases. This has important implications for translation of certain mRNAs, suggesting that there is an optimal concentration of ribosomes at which protein synthesis is maximal, and beyond which translational efficiency is impaired.

The Liverpool uveal melanoma liver metastases pathway: outcome following liver resection

AIM

To determine the outcome of patients that underwent liver resection for metastases from uveal melanoma.

METHODS

Over a 9-year period, patients referred with uveal melanoma metastases were included. Following treatment of primary uveal melanoma, high-risk patients were offered to be enrolled into a 6-monthly non-contrast liver magnetic resonance imaging (MRI) surveillance. Following detection of liver metastases, patients were staged with a contrast-enhanced (Primovist(®)) liver MRI, computer tomography (CT) of the thorax and staging laparoscopy.

RESULTS

155 patients were referred with uveal melanoma liver metastases, of which 17 (11.0%) patients had liver resection and one patient was treated with percutaneous radio-frequency ablation. The majority of patients undergoing liver resection were treated with multiple metastectomies (n = 8) and three patients had major liver resections. The overall median survival for patients treated with surgery/ablation was 27 (14-90) months, and this was significantly better compared to patients treated palliatively [median = 8(1-30) months, P < 0.001]. Following surgery, 11 patients had recurrent disease [median = 13(6-36) months]. Patients who had undergone a major liver resection had a significantly poorer disease-free survival (P = 0.037).

CONCLUSIONS

Patients who can undergo surgical resection for metastatic uveal melanoma have a more favorable survival compared to those who do not.

Adjuvant bevacizumab in patients with melanoma at high risk of recurrence (AVAST-M): preplanned interim results from a multicentre, open-label, randomised controlled phase 3 study

BACKGROUND

Bevacizumab, a monoclonal antibody that targets VEGF, has shown restricted activity in patients with advanced melanoma. We aimed to assess the role of bevacizumab as adjuvant treatment for patients with resected melanoma at high risk of recurrence. We report results from the preplanned interim analysis.

METHODS

We did a multicentre, open-label, randomised controlled phase 3 trial at 48 centres in the UK between July 18, 2007, and March 29, 2012. Patients aged 16 years or older with American Joint Committee on Cancer stage (AJCC) stage IIB, IIC, and III cutaneous melanoma were randomly allocated (1:1), via a central, computer-based minimisation procedure, to receive intravenous bevacizumab 7.5 mg/kg, every 3 weeks for 1 year, or to observation. Randomisation was stratified by Breslow thickness of the primary tumour, N stage according to AJCC staging criteria, ulceration of the primary tumour, and patient sex. The primary endpoint was overall survival; secondary endpoints included disease-free interval, distant-metastases interval and quality of life. Analysis was by intention-to-treat. This trial is registered as an International Standardised Randomised Controlled Trial, number ISRCTN81261306.

FINDINGS

1343 patients were randomised to either the bevacizumab group (n=671) or the observation group (n=672). Median follow-up was 25 months (IQR 16-37) in the bevacizumab group and 25 months (17-37) in the observation group. At the time of interim analysis, 286 (21%) of 1343 enrolled patients had died: 140 (21%) of 671 patients in the bevacizumab group, and 146 (22%) of 672 patients in the observation group. 134 (96%) of patients in the bevacizumab group died because of melanoma versus 139 (95%) in the observation group. We noted no significant difference in overall survival between treatment groups (hazard ratio [HR] 0.97, 95% CI 0.78-1.22; p=0.76); this finding persisted after adjustment for stratification variables (HR 1.03; 95% CI 0.81-1.29; p=0.83). Median duration of treatment with bevacizumab was 51 weeks (IQR 21-52) and dose intensity was 86% (41-96), showing good tolerability. 180 grade 3 or 4 adverse events were recorded in 101 (15%) of 671 patients in the bevacizumab group, and 36 (5%) of 672 patients in the observation group. Bevacizumab resulted in a higher incidence of grade 3 hypertension than did observation (41 [6%] vs one [<1%]). There was an improvement in disease-free interval for patients in the bevacizumab group compared with those in the observation group (HR 0.83, 95% CI 0.70-0.98, p=0.03), but no significant difference between groups for distant-metastasis-free interval (HR 0.88, 95% CI 0.73-1.06, p=0.18). No significant differences were noted between treatment groups in the standardised area under the curve for any of the quality-of-life scales over 36 months. Three adverse drug reactions were regarded as both serious and unexpected: one patient had optic neuritis after the first bevacizumab infusion, a second patient had persistent erectile dysfunction, and a third patient died of a haemopericardium after receiving two bevacizumab infusions and was later identified to have had significant predisposing cardiovascular risk factors.

INTERPRETATION

Bevacizumab has promising tolerability. Longer follow-up is needed to identify an effect on the primary endpoint of overall survival at 5 years.

Hepatic intra-arterial versus intravenous fotemustine in patients with liver metastases from uveal melanoma (EORTC 18021): a multicentric randomized trial

BACKGROUND

In uveal melanoma (UM) with metastatic disease limited to the liver, the effect of an intrahepatic treatment on survival is unknown. We investigated prospectively the efficacy and toxicity of hepatic intra-arterial (HIA) versus systemic (IV) fotemustine in patients with liver metastases from UM.

PATIENTS AND METHODS

Patients were randomly assigned to receive either IV or HIA fotemustine at 100 mg/m(2) on days 1, 8, 15 (and 22 in HIA arm only) as induction, and after a 5-week rest period every 3 weeks as maintenance. Primary end point was overall survival (OS). Response rate (RR), progression-free survival (PFS) and safety were secondary end points.

RESULTS

Accrual was stopped after randomization of 171 patients based on the results of a futility OS analysis. A total of 155 patients died and 16 were still alive [median follow-up 1.6 years (range 0.25-6 years)]. HIA did not improve OS (median 14.6 months) when compared with the IV arm (median 13.8 months), hazard ratio (HR) 1.09; 95% confidence interval (CI) 0.79-1.50, log-rank P = 0.59. However, there was a significant benefit on PFS for HIA compared with IV with a median of 4.5 versus 3.5 months, respectively (HR 0.62; 95% CI 0.45-0.84, log-rank P = 0.002). The 1-year PFS rate was 24% in the HIA arm versus 8% in the IV arm. An improved RR was seen in the HIA (10.5%) compared with IV treatment (2.4%). In the IV arm, the most frequent grade ≥3 toxicity was thrombocytopenia (42.1%) and neutropenia (62.6%), compared with 21.2% and 28.7% in the HIA arm. The main grade ≥3 toxicity related to HIA was catheter complications (12%) and liver toxicity (4.5%) apart from two toxic deaths.

CONCLUSION

HIA treatment with fotemustine did not translate into an improved OS compared with IV treatment, despite better RR and PFS. Intrahepatic treatment should still be considered as experimental.

EUDRACT NUMBER AND CLINICALTRIALSGOV IDENTIFIER

2004-002245-12 and NCT00110123.

Phase II pilot study of intravenous high-dose interferon with or without maintenance treatment in melanoma at high risk of recurrence

PURPOSE

High-dose interferon alfa-2b (HDI) has emerged as a potentially effective adjuvant therapy in patients with resected melanoma at high risk of recurrence. Evidence suggests it may be the early, very-high-dose part of the regimen that is critical. This pilot study sought to provide an early indication of whether the same effects can be achieved with the intravenous component of HDI alone and inform the feasibility and design of a phase III trial.

PATIENTS AND METHODS

Patients with stage 2B, 2C, 3B, and 3C melanoma were randomly assigned to receive interferon alfa-2b (IFN-α-2b) 20 MIU/m(2) intravenously (IV) daily 5 days per week for 4 weeks (arm A) versus the same regimen followed by IFN-α-2b 10 MIU/m(2) administered subcutaneously three times per week for 48 weeks (arm B) and observed for relapse-free survival (RFS) and overall survival.

RESULTS

Between 2003 and 2009, 194 patients were enrolled (arm A, 96; arm B, 98). After median follow-up of 39.5 months, RFS was 22.7 months (95% CI, 14.1 to 38.1 months) in arm A versus 33.3 months (95% CI, 18.2 to not reached) in arm B (P = .28). The proportions of patients free of relapse at 2 years were 50% and 54.1% (P = .569; hazard ratio, 0.89), respectively. Overall survival favored arm B (median, 41.5 months v not reached; P = .05).

CONCLUSION

Clinical outcomes were better in patients who had the longer regimen. Our results do not support either the use of a month of IV HDI alone in place of the year-long regimen or the initiation of a larger trial on this question.

The impact of a new acute oncology service in acute hospitals: experience from the Clatterbridge Cancer Centre and Merseyside and Cheshire Cancer Network

The 2008 National Confidential Enquiry into Patient Outcomes and Death highlighted an urgent need to improve the quality, safety and efficiency of care for cancer patients following emergency presentation to acute general hospitals. A network-wide acute oncology service (AOS) was therefore commissioned and implemented on the basis of recommendations from the National Chemotherapy Advisory Group (NCAG). Through a continuous programme of raising awareness regarding both the role of the AOS and the necessity of early patient referral to acute oncology teams, we have been able to establish an AOS across all acute trusts in our cancer network. The network-wide AOS has improved communication across clinical teams, enabled rapid review of over 3,000 patients by oncology staff, reduced hospital stay, increased understanding of oncology emergencies and their treatment, and enhanced pathways for rapid diagnosis and appropriate referrals for patients presenting with malignancy of undefined origin (MUO). These achievements have been made by developing a network protocol book for managing common oncology emergencies, by introducing local pathways for managing MUO and by collaborating with palliative care teams to introduce local acute oncology (AO) multi-disciplinary team (MDT) meetings.

Adjuvant bevacizumab as treatment for melanoma patients at high risk of recurrence: Preplanned interim results for the AVAST-M trial

LBA9000

Background: Bevacizumab (Bev) is a recombinant humanized monoclonal antibody to vascular endothelial growth factor (VEGF) shown to improve survival in several advanced solid tumors. Multiple adjuvant trials are underway, but trials that have reported in colon and triple-negative breast cancer did not meet their primary end points. Since VEGF is a relevant target in melanoma, AVAST-M aimed to evaluate the role of Bev in patients (pts) with resected melanoma at high risk of recurrence. Methods: AVAST-M is a randomized phase III trial evaluating single agent Bev (7.5mg/kg IV 3 weekly for 1 year) as adjuvant therapy following resection of AJCC stage IIB, IIC, and III cutaneous melanoma compared to standard observation (Obs). 1,320 pts were required to detect 8% differences in 5-year overall survival (OS) rate from 40% to 48%; 85% power, 5% alpha level. Primary endpoint is OS; secondary endpoints are disease free interval (DFI), distant-metastasis free interval (DMFI), safety, and quality of life (QoL). An associated translational study is ongoing. Results of the first pre-planned interim analysis (agreed by the IDSMC) are reported here. Results: Between July 2007 and March 2012, 1,343 pts were recruited. 56% were male; median age 56 years (range 18-88 years), 16% were stage IIB, 11% IIC, 15% IIIA, 36% IIIB, 20% IIIC, and 2% unknown stage. Ulceration status of the primary melanoma was: 38% present, 45% absent, 17% unknown. At the time of the interim analysis, 286 (21%) patients had died. Median follow-up for survival was 25 months. Median duration of Bev treatment in 671 treated pts was 51 weeks (dose intensity 86%). Main outcomes are shown in the table. Grade 3/4 adverse events were experienced in 101 (15%) Bev pts and 36 (5%) Obs pts. Conclusions: Interim analysis of this large, multicenter trial of melanoma patients at high risk of recurrence has shown that adjuvant Bev monotherapy is well tolerated and improved DFI. Longer follow-up is required to determine an impact on the primary endpoint of 5-year OS. Clinical trial information: 81261306. [Table: see text]

AVAST-M: Adjuvant bevacizumab as treatment for melanoma patients at high risk of recurrence

LBA9000

The full, final text of this abstract will be available at abstract.asco.org at 7:30 AM (EDT) on Saturday, June, 1, 2013, and in the Annual Meeting Proceedings online supplement to the June 20, 2013, issue of Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Saturday edition of ASCO Daily News.

A randomized phase II study of sunitinib versus dacarbazine in the treatment of patients with metastatic uveal melanoma

TPS8605

Background: Metastatic uveal melanoma represents an orphan disease area with a median survival of less than 6 months. There is currently no effective systemic therapy for metastatic uveal melanoma and few clinical trials have been conducted. In the absence of phase III data, many patients in the UK continue to receive single agent dacarbazine or best supportive care outside of the context of clinical trials. Uveal melanoma is characterized by activation of the MAP kinase pathway via functionally activating mutations in Gnaq/11. Evidence also suggests that dysfunctional c-Kit signalling and angiogenesis may both play a role in disease progression and a small single-arm phase II trial recently reported preliminary activity using the multi-targeted receptor tyrosine kinase inhibitor, sunitinib (Tijani et al, ASCO 2010). Methods: The SUAVE trial aims to evaluate the Progression Free Survival (PFS) of good performance status patients treated with sunitinib or dacarbazine. Secondary objectives include: Overall Survival (OS), Overall Response Rate (ORR), safety, crossover PFS and response and biomarker analyses. SUAVE is a CR-UK-funded, open-label, randomised, phase II trial that will include 124 patients. Patients will be stratified according to their Helsinki Prognostic Index (ALP, largest diameter of largest metastasis, ECOG). Inclusion Criteria: good performance status patients with confirmed unresectable metastatic uveal melanoma, with at least one target lesion measurable by RECIST 1.1. Patients must not have received previous systemic therapy. At confirmed progression, good performance status patients may crossover to the other study treatment. The trial opened in Oct 2010 and as of 23 January 2012, had randomized 49 patients with at least 1 recruited from each of the 12 recruiting sites. There will be a total of 13 sites. Completion of the recruitment phase is expected within 36 months. Prospective tissue and blood sample collection for translational biomarker analyses is also ongoing. The SUAVE trial represents one of the largest randomised trials in this rare disease area (Clinical trial registry number: 2008-008794-55).

Randomized phase III trial of intravenous (IV) versus hepatic intra-arterial (HIA) fotemustine in patients with liver metastases from uveal melanoma: Final results of the EORTC 18021 study

8532

Background: HIA fotemustine has shown promising results in Phase II studies that led to the EORTC randomized phase III trial (18021) in unpretreated patients (pts) with liver metastases from uveal melanoma. Methods: The treatment consisted in an induction cycle of either HIA (fotemustine 100 mg/m² over 4 hours, day 1, 8, 15, 22) vs IV control arm (fotemustine 100 mg/m² over 1 hour, day 1, 8, 15). After a 5-week break, maintenance cycles were given every 3 weeks. Randomization was stratified by PS (0 vs 1), LDH (normal vs abnormal) and center. Main endpoint was overall survival (OS). Required accrual per protocol was set to 262 pts, with final analysis planned after 220 deaths (hazard ratio (HR) =0.67, power=85%, 1-sided α=2.5%). Due to poor accrual an interim analysis was done after 134 deaths, in order to test futility (power=79%). Results: Between Feb-2005- Feb-2011, 171 pts were randomized (HIA: 86, IV: 85). Characteristics: PS 1: 20%, abnormal LDH: 42%, male: 50%, median age: 59 y.; balanced between arms. In the HIA arm 20 (23%) pts never started treatment mainly due to catheter problems and 2 pts in the IV arm. In those who started the treatment, leucopenia grade 3-4 was 18% and thrombopenia grade 3-4: 21% in the HIA arm compared to 32% and 42% in the IV arm. Non-hematological grade 3-4 toxicities were minimal (GI toxicity, catheter complications). In May 2011, as the OS HR=1.097 was > critical value 0.87, the IDMC recommended stopping accrual for futility. The final results from Jan-2012 are presented in the table below. Treatment comparison adjusted by PS and LDH provided similar results. Conclusions: Even if HIA fotemustine administration could not start in 23% of pts, it led to a higher ORR and longer PFS compared to IV administration. HIA did not translate into an improvement in OS. [Table: see text]

High-risk uveal melanoma: A prospective study evaluating the role of magnetic resonance imaging of the liver

8564

Background: Almost 50% of uveal melanomas are fatal. Metastatic death occurs almost exclusively with tumours showing chromosome 3 loss and 8q gain. Metastases, which almost always involve the liver, are resectable in some patients. They are rarely detectable when the patient presents with the primary ocular tumour. Screening is therefore necessary, but there is no consensus as to who should be screened, how often, and for how long. Methods: Uveal melanoma patients with ECOG performance status 0-2 were eligible if their risk of metastatic death at 5 years exceeded 50%. Survival probability was estimated by multivariate analysis of tumour stage, histological grade and genetic tumour type. Patients underwent screening 6monthly, clinical examination, non-contrast liver MRI and liver function tests for at least five years. Results: Between Jan 2000 and November 2010, 279 high-risk patients were referred for screening. Of these, 188 (84 male, 104 female) accepted screening and underwent as least 1 MRI. The median age was 63 years (IQR 16.5). Median basal tumour diameter was 16.5mm (IQR 5.25). Chromosome 3 loss was detected in 175 tumours. Median follow up time was 28.8 months (IQR 29.1). Median relapse-free survival was 33 months (95% CI 28-38) with a 35% relapse-free survival at 5 years. After a median of 18 months (IQR 20), screening detected metastases in 90/188 (48%), 83 of whom were asymptomatic. 12 patients underwent R0 liver resection, which increased the median survival from 10 (95% CI 8.1 - 11.9) to 24 (95% CI 20.2- 27.8) months. The screening programme stimulated a UK NCRI portfolio of clinical trials in which 23 of these patients were subsequently treated. Conclusions: Six-monthly liver MRI detects metastases from uveal melanoma at an early stage, thereby enhancing opportunities for surgical metastatectomy, clinical trial participation and prolonging life.

A Cancer Research UK two-stage multicenter phase II study of imatinib in the treatment of patients with c-kit positive metastatic uveal melanoma (ITEM)

8523

Background: The median overall survival (OS) for metastatic uveal melanoma is less than 6 months with a median progression free survival(PFS) of 3 months. No systemic or regional therapy has shown a survival advantage over best supportive care. Despite pre-clinical evidence suggesting anti-tumour activity for the KIT tyrosine kinase inhibitor imatinib, there are several negative phase II trials in unselected patients. Our primary aim was to test the efficacy of imatinib in patients with prospectively-tested c-kit immunopositive metastatic uveal melanoma. Secondary aims included assessment of toxicity and patient recruitment. Methods: A phase II UK multicentre single-arm, two-stage Gehan design recruited 25 evaluable patients receiving imatinib 400mg OD until progression/unacceptable toxicity. Primary efficacy outcome was PFS at 3 months. Secondary outcomes were OS, overall PFS, disease response (RECIST) and toxicity. Prospective sample collection for putative biomarkers was included. Results: After 16.6 months 37 patients were screened, with 25 were registered and included in final efficacy analyses. The sample included PS 0-1 patients with a median age of 63 yrs and a median 9.3 months from diagnosis of metastatic disease. 82% had high LDH levels (>460IU/L), 65% had no previous treatment for metastatic disease and 8% did not have liver involvement by metastasis. Preliminary final results indicate the estimated proportion of patients progression free at 3 months is 0.24 (95% CI, 0.09 to 0.45). Median PFS and OS were 12.0 weeks (95% CI,11.6 to 14.3) and 29.6 weeks (95% CI, 19.3 to 61.0) respectively. Two patients had confirmed PR with response duration of 93 and 112 weeks, respectively, despite the absence of mutations in exons 11, 13, and 17 of the c-KIT gene. Conclusions: The trial successfully recruited to target in this rare disease area failing to convincingly show improved PFS in a selected cohort of c-kit immunopositive patients. Both patients with PR experienced long periods of disease control. Response was not dependent upon the presence of activating mutations in KIT. Further translational studies are ongoing to determine putative biomarkers of response.