Sequential treatment with ipilimumab and BRAF inhibitors in patients with metastatic melanoma: Data from the Italian cohort of ipilimumab expanded access programme (EAP)

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Background: Ipilimumab and vemurafenib have recently been approved as single agents for the treatment of unresectable or metastatic melanoma. Currently, limited data exist on the sequential treatment with these agents in patients (pts) with the BRAF mutation; here we evaluate the efficacy outcomes of pts enrolled in the EAP in Italy who sequentially received a BRAF-inhibitor and ipilimumab, or vice versa. Methods: Ipilimumab was available upon physician request for pts aged ≥16 years with unresectable stage III/stage IV melanoma who had either failed systemic therapy or were intolerant to ≥1 systemic treatment and for whom no other therapeutic option was available. Ipilimumab 3 mg/kg was administered intravenously every 3 weeks for 4 doses. Tumour assessments were conducted at baseline and after completion of induction therapy using immune-related response criteria. Patients were considered for this analysis if they tested positive for the BRAF mutation and had received a BRAF-inhibitor before or after ipilimumab treatment. Results: In total, 855 Italian pts participated in the EAP from June 2010 to January 2012 across 55 centres. Out of 173 BRAF positive pts, 93 (53.7%) were treated sequentially with both treatments: 48 pts received a BRAF inhibitor upon disease progression with ipilimumab and 45 pts received ipilimumab upon disease progression with a BRAF inhibitor. As of December 2012, median overall survival was 14.5 months (11.1-17.9) and 9.7 months (4.6-14.9) for the two groups, respectively (p=0.01). Among the 45 BRAF inhibitors pretreated pts, 18 (40%) had rapid disease progression (median overall survival: 5.8 months) and were unable to complete all four induction doses of ipilimumab, while the remaining 27 (60%) pts had slower disease progression (median overall survival: 19.3 months) and were able to complete the therapy with ipilimumab. Conclusions: These preliminary results suggest that, in BRAF-mutated pts, to start the sequential treatment with ipilimumab can provide a better survival than the reverse sequence. These findings deserve confirmation in a prospective study.

Combination therapy with ipilimumab and electrochemotherapy: Preliminary efficacy results and correlation with immunologic parameters

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Background: Ipilimumab is the first agent approved for the treatment of advanced melanoma that showed a survival benefit in randomized phase 3 trials. Despite the survival benefit, due to its mechanism of action it is associated with a slow onset and low rate of responses and, in many cases, responses occur after other therapies, like chemotherapy, targeted therapy and radiotherapy. Electrochemotherapy (ECT) has been shown to be effective and well tolerated for local control of metastatic melanoma with superficial lesions. The current challenge is to improve ipilimumab efficacy by combination/sequence with other therapies. We performed a pilot study of combination with ipilimumab and ECT in order to verify the possible increase of response rate. Furthermore, due to the lack of predictive markers, we evaluated the possible predictive role of circulating T-regulatory cells (T-Reg) variations in peripheral blood mononuclear cells (PBMC) of treated patients. Methods: We collected data from 10 patients (pts) with advanced melanoma (6 stage IIIc and 4 stage IV M1c) treated with ipilimumab at 3 mg/kg every 3 weeks for 4 cycles (day 1) and ECT with bleomycine at 15 mg/m2 (day 2) on superficial lesions. Blood draws were collected on day 0, 1 and 2, then on day 15 and 30 from ECT, at each cycle of ipilimumab and at every tumor evaluation (every 12 weeks). PBMC were thawed and labeled with anti-CD4-Pe-Cy-5, CD25-Pe and anti-FoxP3-AlexaFlour488 for T-Reg. Results: 10/10 (100%) pts showed local objective responses (4 CR and 6 PR). 7/10 (70%) pts showed local response (6 PR and 1 CR) after the second ipilimumab dose and 3/10 showed response (3 CR) at week 12. Two pts with PR (28%) out of the group of 7 showed response on distant lesions at week 24 (abscopal effect). All pts are still alive with a median follow up of 11 months (range 6-18). We found in all pts a decrease of T-Reg of 0.10% (range 0.50-2.6%) per cycle and no variation of CD4+ and CD25+ lymphocytes. Conclusions: Our preliminary results show that a combination approach with ipilimumab and ECT may increase responses to ipilimumab. T-Reg decrease in PBMC could be associated with response to treatment. Further studies about this combination are warranted.

Italian cohort of ipilimumab expanded access programme (EAP): Efficacy, safety, and correlation with mutation status in metastatic melanoma patients

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Background: Ipilimumab was the first agent approved for the treatment of unresectable or metastatic melanoma to show a survival benefit in randomised phase III trials. Efficacy and safety of ipilimumab treatment outside of clinical trials and the correlation with BRAF and NRAS mutation status were evaluated. Methods: Ipilimumab was available upon physician request for patients (pts) aged ≥16 years with unresectable stage III/stage IV melanoma who had either failed systemic therapy or were intolerant to ≥1 systemic treatment and for whom no other therapeutic option was available. Ipilimumab 3 mg/kg was administered intravenously every 3 weeks for 4 doses. Tumour assessments were conducted at baseline and after completion of induction therapy using immune-related response criteria. BRAF and NRAS mutation status was retrospectively collected for all available pts. Patients were monitored for adverse events, including immune-related AEs, using Common Terminology Criteria for Adverse Events v.3.0. Results: In total, 855 Italian pts participated in the EAP from June 2010 to January 2012 across 55 centres. With a median follow-up of 6.5 months (range 0.5-30), the disease control rate among 833 pts evaluable for response was 34.3%: 28 pts (3.4%) with complete response, 83 (10.0%) with partial response and 175 (20.9%) with stable disease. As of December 2012, median progression-free survival and overall survival were 3.3 months and 7.2 months respectively, with 1-year survival rate of 36%. The Table shows mutation status for available patients. Disease control rates were comparable among pts with BRAF positive tumors and BRAF wild-type (37.5% vs 39.5%) and among pts with NRAS positive tumors and NRAS wild-type (57.1% vs 49.3%). Survival curves were also comparable between groups. 399 pts (46.7%) had a AEs of any grade, with 286 (33.5%) considered IrAEs. IrAEs were reversible with protocol specific guidelines. Conclusions: Based on EAP data, ipilimumab is an effective and safe treatment for pretreated pts with metastatic melanoma regardless BRAF and NRAS mutation status. [Table: see text]

Abstract 2672: Early evaluation of response to Vemurafenib treatment with FDG PET/CT in patients with metastatic melanoma

Targeted therapy against the V600 mutated form of BRAF is a proven effective therapy for melanoma. Reduction of FDG accumulation on PET/CT studies occurs very rapidly in responding patients. This exploratory study aims to correlate early changes in FDG uptake patterns with treatment outcome in patients undergoing Vemurafenib treatment. Patients treated at our institution were evaluated with PET-CT at baseline and at day 7, 14 and 28 from the start of therapy. Maximal Standardized Uptake Value (SUVmax) and Total Lesion Glycolysis (TLG, mean SUV x lesion volume) were recorded and compared for single lesions in the 4 studies. Patients were then monitored for clinical, laboratory and imaging signs of progression and results correlated to the early PET/CT findings. Fifteen patients have been studied. A total of 87 lesions are available for comparative evaluation. A greater than 30% reduction in SUVmax compared to baseline was seen in 69 lesions at day 7, 76 at day 14 and 75 at day 28. Nineteen lesions showed a greater than 20% increase in FDG uptake between day 14 and 28. Similar results were found when comparing TLG values. Quantitative and visual analysis of PET/CT studies identified 5 patients showing signs of metabolic progression between day 14 and 28 likely indicating early signs of treatment resistance. Three of these patients showed signs of disease progression by other means within 4 months from the beginning of treatment while 2 are still in treatment with 3 months follow-up. Of the 10 patients not showing metabolic signs of progression at day 28, four have progressed between 2 and 9 months from the beginning of treatment, while the remaining 6 are still in treatment and progression free with 2 to 12 months of follow-up. In conclusion, our preliminary results suggest that PET/CT may be a powerful surrogate marker of treatment response to vemurafenib. Sequential monitoring of targeted therapy with PET/CT may be useful in early identification of treatment resistance, aid in tailoring alternative strategies and deserves further investigation.

Citation Format: Luigi Aloj, Corradina Caracò, Francesca Di Gennaro, Antonio M. Grimaldi, Ester Simeone, Marcello Curvietto, Corrado Caracò, Nicola Mozzillo, Valter Torri, Paolo A. Ascierto, Secondo Lastoria. Early evaluation of response to Vemurafenib treatment with FDG PET/CT in patients with metastatic melanoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2672. doi:10.1158/1538-7445.AM2013-2672

Do BRAF inhibitors select for populations with different disease progression kinetics?

Ipilimumab, an anti-CTLA-4 monoclonal antibody, has been shown to improve overall survival in patients with metastatic melanoma. Preliminary data suggest that patients who fail BRAF inhibitor treatment experience a very rapid progression of disease. Such selectivity for more rapid disease progression may mean these patients do not receive the same benefit from subsequent treatment with ipilimumab as patients without prior BRAF inhibitor treatment. The current challenge is focused on how to identify and approach the two populations of fast and slow progressors and recent hypothesis suggest that treatment choice could be guided by baseline risk factors. However, no data have yet defined which the best sequence is and more research is needed to identify predictors of response in patients with metastatic melanoma to help guide whether a BRAF inhibitor or ipilimumab should be used first in sequential therapy.

Phase III randomized study of fotemustine and dacarbazine versus dacarbazine with or without interferon-α in advanced malignant melanoma

BACKGROUND

The effect of the addition of fotemustine and/or interferon (IFN) to standard therapy with dacarbazine alone in patients with advanced malignant melanoma was investigated in a multicenter, randomized 2x2 factorial design trial.

METHODS

A total of 260 patients were randomly assigned to one of four treatment groups: (A) fotemustine and dacarbazine repeated on 3-week cycle; (B) same treatment as (A) plus IFN-α2b three times per week; (C) dacarbazine alone repeated on 3-week cycle; (D) same treatment as (C) plus IFN-α2b three times per week. Two comparisons were planned to assess the efficacy of fotemustine (groups A+B vs. C+D) and IFN-α2b (groups A+C vs. B+D).

RESULTS

Addition of fotemustine did not significantly improve overall survival (OS) (p=0.28) or progression-free survival (PFS) (p=0.55); Hazard ratio (HR) for OS was 0.93 (95% CI 0.71-1.21). Similarly, addition of IFN-α2b did not improve OS (p=0.68) or PFS (p=0.65); HR for OS was 0.92 (95% CI 0.70-1.20). Overall response rate was not improved by the addition of either fotemustine (p=0.87) or IFN-α2b (p=0.57). The combination of all three drugs resulted in the highest occurrence of adverse events.

CONCLUSIONS

No significant improvement in outcomes were observed with the addition of either fotemustine or IFN-α2b to dacarbazine.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01359956.

Update on PEG-interferon α-2b as adjuvant therapy in melanoma

Based on the results of European Organization for Research and Treatment of Cancer (EORTC) 18991 trial, the US Food and Drug Administration (FDA) approved PEG-interferon α-2b (PEG-IFN) (Sylatron) as adjuvant therapy for high-risk melanoma. The EORTC 18991 trial was an open-label study of resectable stage III melanoma with 1,256 patients who were randomized to observation-alone or to treatment with PEG-IFN for up to 5 years. The median recurrence-free survival of the treatment groups was significantly longer, while overall survival, a secondary endpoint, was not significantly different between the two groups. This review, after a short summary of interferon α-2b trials, critically analyzes the EORTC18991 trial, as well as the subgroup results and future perspectives for this stage of disease.

Ipilimumab and fotemustine in patients with advanced melanoma (NIBIT-M1): an open-label, single-arm phase 2 trial

BACKGROUND

Ipilimumab improves survival of patients with metastatic melanoma, many of whom develop brain metastases. Chemotherapy-induced release of tumour antigens might amplify ipilimumab's antitumour activity. We aimed to investigate the efficacy and safety of ipilimumab plus fotemustine in patients with metastatic melanoma with or without asymptomatic brain metastases.

METHODS

In our open-label, single-arm phase 2 trial, we enrolled patients 18 years or older with measurable, locally advanced, unresectable stage III or stage IV melanoma between July 6, 2010, and April 14, 2011. Eligible patients had a life expectancy of 16 weeks or more and an Eastern Cooperative Oncology Group performance status of 1 or less, and could have received a maximum of one previous line of chemotherapy. Participants received induction treatment of 10 mg/kg intravenous ipilimumab every 3 weeks to a total of four doses, and 100 mg/m(2) intravenous fotemustine weekly for 3 weeks and then every 3 weeks from week 9 to week 24. Patients with a confirmed clinical response were eligible for maintenance treatment from week 24, with ipilimumab every 12 weeks and fotemustine every 3 weeks. The primary endpoint was the proportion of patients with immune-related disease control as established with immune-related response criteria. Analyses were done per protocol. This trial is registered with EudraCT, number 2010-019356-50, and with ClinicalTrials.gov, number NCT01654692.

FINDINGS

86 patients were eligible for treatment, of whom 20 had asymptomatic brain metastases at baseline. 40 patients in the study population achieved disease control (46·5%, 95% CI 35·7-57·6), as did ten with brain metastases (50·0%, 27·2-72·8). 47 patients (55%) had grade 3 or 4 treatment-related adverse events, of which the most common was myelotoxicity (thrombocytopenia in 21 [24%] patients and neutropenia in 16 [19%]). The most common grade 3 or 4 immune-related adverse events were hepatic: 21 patients (24%) had grade 3 or 4 increases in concentrations of alanine aminotransferase or aspartate aminotransferase.

INTERPRETATION

The combination of ipilimumab plus fotemustine has clinical activity in patients with metastatic melanoma, including those with brain metastases.

FUNDING

Bristol-Myers Squibb.

[Severe intermittent claudication: PGE1 treatment. A 40-week registry, efficacy and costs]

AIM

Intermittent claudication (IC) in peripheral vascular disease is characterized by lower limb pain appearing on effort. Treatment with PGE1 has been successfully used to manage IC patients. This registry has evaluated safety and costs of PGE1 in the management of IC.

METHODS

In this study a long-term treatment protocol (LTP), a short-term protocol (STP) and an outpatient (OP), "on-demand" treatment have been compared. A treadmill effort test has been used to evaluate walking distance. The follow up for these three protocols was 40 weeks. PGE1 treatment was associated to a risk reduction plan and to an exercise program.

RESULTS

The final analysis has included 252 LTP patients, 223 STP patients and 284 OP patients (total 659 valid cases). A group of 171 comparable patients not treated with PGE1 was used for a parallel comparison. Cardiovascular mortality and morbidity has been evaluated in 731 PGE1 patients completing 24 months of follow up. All protocols have been well tolerated. No side effects were observed. The lower cost has been observed for OP patients. In the long term, mortality and morbidity were lower in patients treated with PGE1 in comparison with patients not treated with PGE1.

CONCLUSION

Considering costs and results (increase in walking distance) and improvement in Karnofsky scale the STP plan appears to be better than LTP for IC patients. The OP, "on-demand" treatment offers further improvements. This last treatment plan is simpler; the plan allows better timing for exercise. The treatment can be used even in non-specialized centers.

The role of BRAF V600 mutation in melanoma

BRAF is a serine/threonine protein kinase activating the MAP kinase/ERK-signaling pathway. About 50 % of melanomas harbors activating BRAF mutations (over 90 % V600E). BRAFV600E has been implicated in different mechanisms underlying melanomagenesis, most of which due to the deregulated activation of the downstream MEK/ERK effectors. The first selective inhibitor of mutant BRAF, vemurafenib, after highly encouraging results of the phase I and II trial, was compared to dacarbazine in a phase III trial in treatment-naïve patients (BRIM-3). The study results showed a relative reduction of 63 % in risk of death and 74 % in risk of tumor progression. Considering all trials so far completed, median overall survival reached approximately 16 months for vemurafenib compared to less than 10 months for dacarbazine treatment. Vemurafenib has been extensively tested on melanoma patients expressing the BRAFV600E mutated form; it has been demonstrated to be also effective in inhibiting melanomas carrying the V600K mutation. In 2011, both FDA and EMA therefore approved vemurafenib for metastatic melanoma carrying BRAFV600 mutations. Some findings suggest that continuation of vemurafenib treatment is potentially beneficial after local therapy in a subset of patients with disease progression (PD). Among who continued vemurafenib >30 days after local therapy of PD lesion(s), a median overall survival was not reached, with a median follow-up of 15.5 months from initiation of BRAF inhibitor therapy. For patients who did not continue treatment, median overall survival from the time of disease progression was 1.4 months. A clinical phase I/II trial is evaluating the safety, tolerability and efficacy of vemurafenib in combination with the CTLA-4 inhibitor mAb ipilimumab. In the BRIM-7 trial vemurafenib is tested in association with GDC-0973, a potent and highly selective inhibitor of MEK1/2. Preliminary data seem to indicate that an additional inhibitor of mutated BRAF, GSK2118436, might be also active on a wider range of BRAF mutations (V600E-K-D-R); actually, treatment with such a compound is under evaluation in a phase III study among stage III-IV melanoma patients positive for BRAF mutations. Overall, BRAF inhibitors were well tolerated; common adverse events are arthralgia, rash, fatigue, alopecia, keratoacanthoma or cutaneous squamous-cell carcinoma, photosensitivity, nausea, and diarrhea, with some variants between different inhibitors.

Sequencing of BRAF inhibitors and ipilimumab in patients with metastatic melanoma: a possible algorithm for clinical use

BACKGROUND

Ipilimumab and vemurafenib have both been shown to improve survival in phase III trials of patients with metastatic melanoma. Although vemurafenib is associated with a rapid onset of activity, responses are often of limited duration. Conversely, responses to ipilimumab take time to develop, but can be durable. Currently, limited data exist on the sequencing of these agents in patients with the BRAFV600 mutation. The aim of this analysis was to identify factors that could potentially be used to optimise the order in which ipilimumab and BRAF inhibitors are administered in this patient population.

METHODS

This was a retrospective, single-institution, analysis of patients treated with vemurafenib 960 mg or dabrafenib 150 mg twice-daily and ipilimumab 3 mg/kg every 3 weeks for 4 doses as part of a clinical trial or expanded access program. Eligible patients tested positive for the BRAFV600 mutation and had sequentially received treatment with vemurafenib or dabrafenib followed by ipilimumab, or vice versa.

RESULTS

In total, 34 BRAF-mutation positive patients were eligible, comprising six patients who received ipilimumab followed by a BRAF inhibitor, and 28 patients treated with a BRAF inhibitor who subsequently received ipilimumab. Of these 28 patients, 12 (43%) had rapid disease progression resulting in death and were unable to complete ipilimumab treatment as per protocol. These patients were classified as having rapid disease progression. Median overall survival for rapid progressors was 5.7 months (95% CI: 5.0-6.3), compared with 18.6 months (95% CI: 3.2-41.3; p < 0.0001) for those patients who were able to complete ipilimumab treatment. Baseline factors associated with rapid progression were elevated lactate dehydrogenase, a performance status of 1 and the presence of brain metastases. Patients were more likely to have rapid disease progression if they had at least two of these risk factors at baseline.

CONCLUSIONS

Our analysis suggests it may be possible to identify those patients at high risk of rapid disease progression upon relapse with a BRAF inhibitor who might not have time to subsequently complete ipilimumab treatment. We hypothesise that these BRAF-mutation positive patients may benefit from being treated with ipilimumab first.

Immunological and biological changes during ipilimumab (Ipi) treatment and their correlation with clinical response and survival

8573

Background: Ipilimumab (Ipi) is approved in the US as first and second line therapy in patients with metastatic melanoma (MM) and in MM patients with previous therapy in the EU, based on an overall survival benefit shown in a phase III study (Hodi, NEJM 2010). To date, no clinical parameter has been found to be predictive for response to treatment and only few immunologic changes have been identified as potential candidates. Methods: From June 2010 to November 2011 we treated in the Expanded Access Program with Ipi at 3 mg/kg, 95 pre-treated metastatic melanoma patients. The median age was 58 yrs (range 17-84); 10 pts (10,5%) were stage IIIc inoperable, 2 pts (2,1%) stage M1a, 4 pts (4,2%) stage M1b, and 79 pts (83,2%) stage M1c. 30/95 pts had brain metastases and 1/95 spinal cord metastases. All 95 patients were evaluable for response (DCR = CR+PR+SD according the irRC), overall survival, safety, including changes in LDH, CRP (C-reactive protein) and lymphocyte populations (CD4+,CD4CD25+,FOXP3/T-Reg cells). PBMC and sera were collected at week 0, 4, 7, 10 and 12. Results: We found a statistical significant decrease of LDH, CRP and FOXP3/T-Reg cells (p<0.0001; χ2 and Mann-Whitney), and an increase of lymphocyte count (p<.0001) in the responders group. These differences were also correlated to survival (log-rank test). No differences were observed for CD4+ and CD4+CD25+ between responders and non-responders (p=0.39;p=0.83; Mann-Whitney). An ORR of 22.1% (1CR+20PR; 95% CI 13.8-30.4) and a DCR at week 24 of 37.9% (36/95; 28.1-47.6, 95% CI) were observed. Median overall survival was estimated of 7.8 months (95%CI:5.0-10.6), with a p value not evaluable at the moment of the analysis due to insufficient follow-up because of long-term survival. Adverse events were registered in 40% (38/95) of patients and the most frequent were of grade 1 and 2 (pruritus 57.9%; rash 5.3%; thyroditis 5.3%). Conclusions: The decrease of LDH, CRP and T-Reg cells during Ipi treatment suggest these parameters should be further explored as potential predictive markers for response and survival. Given the potential clinical utility of these findings, these data warrants further prospective validation in a randomized trial.

Phase II multicenter trial of ipilimumab combined with fotemustine in patients with metastatic melanoma: The Italian Network for Tumor Biotherapy (NIBIT)-M1 trial

8513

Background: Ipilimumab (ipi), an antibody against cytotoxic T-lymphocyte-associated antigen-4, improves survival in patients (pts) with metastatic melanoma (MM); however, objective tumor responses are limited. NIBIT-M1 aims to investigate the efficacy and safety of ipi plus fotemustine (FTM), a cytotoxic alkylating drug, in pts with MM. Methods: Eligible pts, with or without brain metastases, received induction therapy with ipi 10 mg/kg every 3 weeks (Q3W) for four doses and FTM 100 mg/m2 weekly for 3 weeks. Ipi and FTM maintenance therapy was provided Q12W from Week 24 and Q3W from Week 9, respectively. The primary objective was the immune-related (ir) disease control rate (irDCR: pts with complete response [CR], partial response [PR] or stable disease [SD] as determined using the ir response criteria). Secondary objectives included ir objective response rate (ORR), duration of response (DOR) and progression-free survival (PFS); overall survival (OS), and safety. Tumor assessments were performed Q8W from Week 12 to Week 36 and Q12W thereafter. Results: Among 86 pts with unresectable stage III (n=3) or stage IV (n=83) MM treated at 7 NIBIT centers, 42 were previously untreated, 44 had progressed following first-line treatment and 20 had asymptomatic brain metastases. As of December 2011, the irDCR was 46.5% (40/86; 95% CI, 35.7–57.6%); the irORR was 29.1% (95% CI, 19.8–39.8%; 5 CRs and 20 PRs) and with a median 8.3 months follow-up, median irPFS was 5.3 months (95% CI, 3.5–7.1). The 1-year OS rate was 51.8% (95% CI, 37.5–66.1%); median OS was not yet reached. Among all pts, 58.1% and 87% completed ipi or FTM induction, respectively. The most common grade 3/4 drug-related adverse events (AEs) (reported in 54.6% pts overall) were myelotoxicity (43.5%), increased ALT/AST (14.1/10.6%), gastrointestinal (4.7%) and skin-related (2.3%). AEs were generally manageable and reversible per protocol guidance. Conclusions: The study reached its primary objective with 46.5% of pts achieving disease control. The combination of ipi plus FTM is safe; the irDCR, 1-year OS rate and median irPFS warrant its further investigation in MM pts.

An imaging study of vemurafenib in patients with BRAFV600-mutated metastatic melanoma

e19034

Background: Targeted therapy against the mutated form of BRAF V600 is a proven effective therapy for melanoma. Objective of this exploratory study was to describe the change over time of PET-scan results and verify the association of PET-scan examination with the objective response (OR) (defined by RECIST criteria) in melanoma pts treated with vemurafenib. These preliminary results reported here regards the description of changes over time of PET-scan. Methods: Patients treated with vemurafenib at our institution were considered eligible. Patients were evaluated with PET-scan at baseline and at day 7, 15 and 30 from the start of therapy. Maximal Standardized Uptake Value (SUVmax) and Total Lesion Glycolysis (mean SUV x lesion volume) were recorded and compared for single lesions in the 4 exams. Differences between each PET-scan performed during therapy and baseline were calculated and coded as yes/no response basing on predefined criteria. Association of PET responses and achievement of OR were estimated by means of logistic regression models. Odds ratio and C statistics were used to define strength of association and discriminant capability. C statistics obtained with PET/CT at different timepoints were compared. Results: As of January 2012, 7 out of 20 required pts have been enrolled. A total of 48 lesions were available for evaluation. A reduction in lesion SUVmax and TLG values compared to baseline was evident in all the post-therapy studies (reduction in SUV max at day 7 – 51 ± 28 %, day 14 – 67 ± 24 % and day 30 –69 ± 29 %, reduction in TLG at day 7 – 41 ± 83 %, day 14 – 69 ± 35 % and day 30 – 68 ± 37 %). A comparison of the day 15 and day 30 studies showed essentially stable uptake values (SUV max variation -3 ± 41 %, TLG 5 ± 56 %). However, 14/23 lesions in 3 patients showed increased SUV max and TLG values between the day 15 and day 30 studies likely indicating early signs of treatment resistance. Conclusions: Our preliminary results suggest that PET/CT may be an early surrogate marker of treatment response to vemurafenib. Sequential monitoring of targeted therapy with PET/CT may be useful in identification of treatment resistance, aid in tailoring alternative strategies and deserves further investigation.

The NIBIT-M1 trial: Activity of ipilimumab plus fotemustine in patients with melanoma and brain metastases

8529

Background: Patients (pts) with metastatic melanoma (MM) often develop treatment-resistant brain metastases (mets). Treatment includes fotemustine (FTM), which crosses the blood-brain barrier. Ipilimumab (ipi) has shown activity in pts with MM and asymptomatic brain mets (Heller et al. ASCO 2011; abs 8581). In the phase II NIBIT-M1 trial, MM pts with asymptomatic brain mets were eligible for treatment with ipi plus FTM. Here, data from this pt subset are reported. Methods: Eligible pts received induction therapy with ipi 10 mg/kg every 3 wks (Q3W) x4 and FTM 100 mg/m2 weekly for 3 wks, followed by ipi Q12W from Week (W) 24 and FTM Q3W from W9. The primary objective was the immune-related (ir) disease control rate (irDCR: complete/partial response [CR/PR] or stable disease [SD] using the ir response criteria). Secondary objectives included ir objective response rate (ORR) and progression-free survival (PFS); overall survival (OS), and safety. Tumor assessments were performed Q8W from W12 to W36 and Q12W thereafter. Results: Among 86 enrolled pts, 20 had brain mets. Of these, 7 had prior whole brain radiotherapy (n=4) or radiosurgery (n=3). As of December 2011, the irDCR was 50% (10/20; 95% CI, 27.2–72.8%) with an irORR of 40% (95% CI, 19.1–63.9%: 2 CRs and 6 PRs). Pts with irDC also had stability/reduction (n=5) or disappearance (n=5) of brain mets. Among pts with progressive disease, all but one had progression in the brain. With median follow-up of 8.3 months (range: 0.4–16.9), median irPFS was 4.6 months (95% CI, 0.7–12.3). The 1-year OS rate was 52.9% (95% CI, 26.6–79.2); median OS was not reached. Induction with ipi and FTM was completed by 55% and 85% pts, respectively. Grade 3/4 drug-related adverse events (AEs) occurred in 60% pts; most commonly myelotoxicity (50%), increased ALT/AST (5%) and gastrointestinal (5%). AEs were generally manageable and reversible per protocol guidance. CNS AEs of any grade (i.e., haemorrhage, headache and seizure) occurred in 25% pts (grade 3/4 in 2 pts) and were attributed to disease progression. Conclusions: The combination of ipi plus FTM is active and safe in pts with MM and brain mets, regardless of prior treatment, and will be further explored in the phase III NIBIT-M2 trial.

Neoplastic leptomeningitis presenting in a melanoma patient treated with dabrafenib (a V600EBRAF inhibitor): a case report

INTRODUCTION

Leptomeningeal metastases are occurring at higher frequency in cancer patients. The prognosis of leptomeningeal metastases is poor and standard treatment, which includes radiotherapy and chemotherapy, is mostly ineffective. Melanoma represents one of the tumors with the highest incidence of leptomeningeal metastases. For such a disease, the BRAF inhibitors have recently been demonstrated to be effective on melanoma brain metastases harboring the V600EBRAF mutation.

CASE PRESENTATION

We report a case of a 39-year-old Italian woman with advanced melanoma with brain, lung and peritoneum metastases harboring the V600EBRAF mutation. In August 2010 she was enrolled into the BRIM3 trial and after the randomization process she received dacarbazine. After two cycles, there was evidence of disease progression in her peritoneum and lung. For this reason, she was enrolled into another clinical trial with the GSK2118436 BRAF inhibitor, dabrafenib, as a second line of therapy. She had a partial response that was maintained until 13 weeks of treatment. In January 2011 she developed symptoms typical for brain metastases and received a diagnosis of leptomeningeal involvement of melanoma cells after an examination of her cerebral spinal fluid; magnetic resonance imaging was negative for meningitis or brain metastases. Analysis of her cerebral spinal fluid sample confirmed that the melanoma cells still carried the V600EBRAF mutation. After a few days, our patient went into a coma and died.

CONCLUSION

Starting with a clinical case, we discuss the pathogenesis of leptomeningeal metastases and whether the leptomeninges may represent a sanctuary where melanoma cells may generate resistance and/or BRAF inhibitors cannot reach an adequate concentration for significant activity. We assess whether treatment with BRAF inhibitors in melanoma patients should be interrupted as soon as disease progression appears or continued beyond progression, through the administration of additional compounds.

Immunomodulating antibodies in the treatment of metastatic melanoma: the experience with anti-CTLA-4, anti-CD137, and anti-PD1

Clinical activity of anti-CTLA-4 (cytotoxic T-lymphocyte antigen-4) monoclonal antibodies (mAb) has changed the approaches for the treatment of cancer in terms of patterns of response, duration of response, and adverse event profiles. In fact, antibodies that block the interaction of CTLA-4 with its ligands B7.1 and B7.2 can enhance immune responses, including anti-tumor immunity. Two recent studies using ipilimumab (an anti-CTLA-4 mAb) demonstrated improvements in overall survival in the treatment of advanced melanoma. These studies utilized two different schedules of treatment in different patient categories (first and second line of treatment). However, the results were quite similar despite the different dosage used and the combination with dacarbazine in the first line treatment. Ongoing clinical studies will establish the efficacy of ipilimumab as monotherapy or in combination with other drugs for the treatment of metastatic melanoma and a variety of other cancers. Other antibodies, such as CD137 agonists and PD-1 antagonists, are currently in various stages of pre-clinical and clinical development. Agonist antibodies directed against CD137 (4-1BB) on the surface of antigen-primed T-lymphocytes increase tumor immunity that is curative against some transplantable murine tumors. Programmed death-1 (PD1) is a surface molecule delivering inhibitory signals important to maintain T-cell functional silence against their cognate antigens. Interference with PD1 or its ligand PD-L1 (B7-H1) increases anti-tumor immunity. As a result, human mAbs anti-PD1 and anti-PD-L1 are under clinical development. This paper reviews recent studies in the treatment of advanced melanoma with these types of monoclonal antibodies. Ipilimumab can be considered a cornerstone of a new era in melanoma treatment. However, the aim is to optimize the therapy with anti-CTLA-4 antibodies to define the best schedule for next combination regimens (other immunomodulatory antibodies, BRAF/MEK inhibitors, vaccines, etc.) that represent the natural evolution of future melanoma therapy.

Clinical experiences with anti-CD137 and anti-PD1 therapeutic antibodies

Monoclonal antibodies (mAbs) provide a pharmacological platform to block or activate the function of surface receptors. The immune system has evolved receptor-ligand pairs that repress or empower the cellular immune response, which, if tampered with, unleash more potent cellular immunity against tumor antigens. Agonist antibodies directed against CD137 (4-1BB) on the surface of antigen-primed T lymphocytes increase tumor immunity that is curative against some transplantable murine tumors. A fully human IgG4 anti-CD137 antibody is under development with signs of clinical activity and cases of severe liver toxicity that seem to be on-target and dose-dependent effects. Programmed death-1 (PD1) is a surface molecule delivering inhibitory signals important to maintain T-cell functional silence against their cognate antigens. Interference with PD1 or its ligand PD-L1 (B7-H1) increases antitumor immunity. As a result anti-PD1 and anti-PD-L1 human mAbs are under clinical development. Phase I trials with anti-PD1 mAb have yielded encouraging results with durable objective responses and a reasonable safety profile. As new class of drugs in cancer therapy, immunostimulatory mAbs have resulted in redefinition of tumor response criteria and rethinking of the rationale for combining these among each other and with other strategies.

Regulatory T cell frequency in patients with melanoma with different disease stage and course, and modulating effects of high-dose interferon-alpha 2b treatment

BACKGROUND

High-dose interferon-alpha 2b (IFN-alpha 2b) is the only approved systemic therapy in the United States for the adjuvant treatment of melanoma. The study objective was to explore the immunomodulatory mechanism of action for IFN-alpha 2b by measuring serum regulatory T cell (Treg), serum transforming growth factor-beta (TGF-beta), interleukin (IL)-10, and autoantibody levels in patients with melanoma treated with the induction phase of the high-dose IFN-alpha 2b regimen.

METHODS

Patients with melanoma received IFN-alpha 2b administered intravenously (20 MU/m2 each day from day 1 to day 5 for 4 consecutive weeks). Serum Treg levels were measured as whole lymphocytes in CD4+ cells using flow cytometry while TGF-beta, IL-10, and autoantibody levels were measured using enzyme-linked immunosorbent assays.

RESULTS

Twenty-two patients with melanoma received IFN-alpha 2b treatment and were evaluated for Treg levels. Before treatment, Treg levels were significantly higher in patients with melanoma when compared with data from 20 healthy subjects (P = 0.001; Mann-Whitney test). Although a trend for reduction of Treg levels following IFN-α 2b treatment was observed (average decrease 0.29% per week), statistical significance was not achieved. Subgroup analyses indicated higher baseline Treg levels for stage III versus IV disease (P = 0.082), early recurrence versus no recurrence (P = 0.017), deceased versus surviving patients (P = 0.021), and preoperative neoadjuvant versus postoperative adjuvant treatment groups (not significant). No significant effects were observed on the levels of TGF-beta, IL-10, and autoantibodies in patients with melanoma treated with IFN-alpha 2b.

CONCLUSIONS

Patients with melanoma in this study showed increased basal levels of Treg that may be relevant to their disease and its progression. Treg levels shifted in patients with melanoma treated with IFN-alpha 2b, although no firm conclusions regarding the role of Tregs as a marker of treatment response or outcome can be made at present.