389 Phase II of CD40 agonistic antibody sotigalimab (APX005M) in combination with nivolumab in subjects with metastatic melanoma with confirmed disease progression on anti-PD-1 therapy

Background

A significant number of melanoma patients treated with anti-PD-1 alone or in combination with anti-CTLA-4 have transient or no response to treatment. Sotigalimab is a CD40 agonist antibody with unique epitope specificity and Fc receptor binding profile for optimal therapeutic application. Preclinical studies suggest that sotigalimab can be combined with PD-1 blockade to trigger effective anti-tumor immunity. We conducted a multi-center, open label, Phase Ib-parallel arm phase II trial (NCT03123783) to evaluate the combination of sotigalimab with nivolumab in subjects with anti-PD-1/PD-L1 refractory metastatic melanoma.

Methods

The study objective was to evaluate the efficacy and safety of sotigalimab in combination with nivolumab in anti-PD-1/PD-L1 refractory advanced melanoma patients. Subjects received sotigalimab (0.3mg/kg) combined with nivolumab (360mg) every 3 weeks. Thirty-eight subjects with unresectable or metastatic melanoma who had confirmed progressive disease during treatment with anti-PD-1 therapy (documented by 2 consecutive tumor assessments) were enrolled (evaluable for safety) and 33 subjects were evaluable for efficacy.

Results

Six subjects had PR (including one unconfirmed PR) for an ORR of 18%. The mDOR was 18.7 months. Two subjects with PR received treatment for >2 years. Three of the six responding subjects remain off all therapy for ≥26 months, and one patient required stereotactic radiosurgery to a single brain lesion ten months after stopping therapy and has not required additional local or systemic therapy since. Three additional subjects had prolonged SD (12.6, 7.6, 6.2 months). The DCR was 48% and 33% of subjects experienced reduction in target lesions. Efficacy was observed in patients regardless of their tumor PD-L1 expression. The overall safety profile of the combination is consistent with the profiles of individual agents. The majority of AEs observed were of mild to moderate intensity (CTCAE Grade ≤2). The most commonly observed AEs were: pyrexia, chills, nausea, fatigue, pruritus, transaminitis, headache, asthenia, myalgia, rash, vomiting and arthralgia. There were no Grade 4 or 5 AEs related to study drugs. There were no treatment discontinuations due to AEs.

Conclusions

The combination of sotigalimab and nivolumab demonstrated treatment benefit (tumor response or prolonged disease control) in anti-PD-1/PD-L1 refractory melanoma patients with an overall favorable safety and tolerability profile. Notably, a subset of patients remain in response off treatment for ≥26 months. These results warrant further study of this combination in advanced, refractory melanoma.

Acknowledgements

We extend our gratitude to the patients and their families who made this trial possible and the clinical study teams involved in this trial. We thank BMS for providing the nivolumab for this study.

Trial Registration

NCT03123783

Ethics Approval

This study was approved by the Institutional Review Boards at Yale University (#20170300), University of Nebraska Medical Center (#543-18-CB) and The Hospital Regional de Málaga (#19.03.1341E1-GHM).

Novel phosphatidylserine-binding molecule enhances antitumor T-cell responses by targeting immunosuppressive exosomes in human tumor microenvironments

Background

The human tumor microenvironment (TME) is a complex and dynamic milieu of diverse acellular and cellular components, creating an immunosuppressive environment, which contributes to tumor progression. We have previously shown that phosphatidylserine (PS) expressed on the surface of exosomes isolated from human TMEs is causally linked to T-cell immunosuppression, representing a potential immunotherapeutic target. In this study, we investigated the effect of ExoBlock, a novel PS-binding molecule, on T-cell responses in the TME.

Methods

We designed and synthesized a new compound, (ZnDPA)₆-DP-15K, a multivalent PS binder named ExoBlock. The PS-binding avidity of ExoBlock was tested using an in vitro competition assay. The ability of this molecule to reverse exosome-mediated immunosuppression in vitro was tested using human T-cell activation assays. The in vivo therapeutic efficacy of ExoBlock was then tested in two different human tumor xenograft models, the melanoma-based xenomimetic (X-)mouse model, and the ovarian tumor-based omental tumor xenograft (OTX) model.

Results

ExoBlock was able to bind PS with high avidity and was found to consistently and significantly block the immunosuppressive activity of human ovarian tumor and melanoma-associated exosomes in vitro. ExoBlock was also able to significantly enhance T cell-mediated tumor suppression in vivo in both the X-mouse and the OTX model. In the X-mouse model, ExoBlock suppressed tumor recurrence in a T cell-dependent manner. In the OTX model, ExoBlock treatment resulted in an increase in the number as well as function of CD4 and CD8 T cells in the TME, which was associated with a reduction in tumor burden and metastasis, as well as in the number of circulating PS+ exosomes in tumor-bearing mice.

Conclusion

Our results establish that targeting exosomal PS in TMEs with ExoBlock represents a promising strategy to enhance antitumor T-cell responses.

Selumetinib in Combination With Dacarbazine in Patients With Metastatic Uveal Melanoma: A Phase III, Multicenter, Randomized Trial (SUMIT)

Purpose Uveal melanoma is the most common primary intraocular malignancy in adults with no effective systemic treatment option in the metastatic setting. Selumetinib (AZD6244, ARRY-142886) is an oral, potent, and selective MEK1/2 inhibitor with a short half-life, which demonstrated single-agent activity in patients with metastatic uveal melanoma in a randomized phase II trial. Methods The Selumetinib (AZD6244: ARRY-142886) (Hyd-Sulfate) in Metastatic Uveal Melanoma (SUMIT) study was a phase III, double-blind trial ( ClinicalTrial.gov identifier: NCT01974752) in which patients with metastatic uveal melanoma and no prior systemic therapy were randomly assigned (3:1) to selumetinib (75 mg twice daily) plus dacarbazine (1,000 mg/m2 intravenously on day 1 of every 21-day cycle) or placebo plus dacarbazine. The primary end point was progression-free survival (PFS) by blinded independent central radiologic review. Secondary end points included overall survival and objective response rate. Results A total of 129 patients were randomly assigned to receive selumetinib plus dacarbazine (n = 97) or placebo plus dacarbazine (n = 32). In the selumetinib plus dacarbazine group, 82 patients (85%) experienced a PFS event, compared with 24 (75%) in the placebo plus dacarbazine group (median, 2.8 v 1.8 months); the hazard ratio for PFS was 0.78 (95% CI, 0.48 to 1.27; two-sided P = .32). The objective response rate was 3% with selumetinib plus dacarbazine and 0% with placebo plus dacarbazine (two-sided P = .36). At 37% maturity (n = 48 deaths), analysis of overall survival gave a hazard ratio of 0.75 (95% CI, 0.39 to 1.46; two-sided P = .40). The most frequently reported adverse events (selumetinib plus dacarbazine v placebo plus dacarbazine) were nausea (62% v 19%), rash (57% v 6%), fatigue (44% v 47%), diarrhea (44% v 22%), and peripheral edema (43% v 6%). Conclusion In patients with metastatic uveal melanoma, the combination of selumetinib plus dacarbazine had a tolerable safety profile but did not significantly improve PFS compared with placebo plus dacarbazine.

Overall Survival in Patients With Advanced Melanoma Who Received Nivolumab Versus Investigator's Choice Chemotherapy in CheckMate 037: A Randomized, Controlled, Open-Label Phase III Trial

Purpose Until recently, limited options existed for patients with advanced melanoma who experienced disease progression while receiving treatment with ipilimumab. Here, we report the coprimary overall survival (OS) end point of CheckMate 037, which has previously shown that nivolumab resulted in more patients achieving an objective response compared with chemotherapy regimens in ipilimumab-refractory patients with advanced melanoma. Patients and Methods Patients were stratified by programmed death-ligand 1 expression, BRAF status, and best prior cytotoxic T-lymphocyte antigen-4 therapy response, then randomly assigned 2:1 to nivolumab 3 mg/kg intravenously every 2 weeks or investigator's choice chemotherapy (ICC; dacarbazine 1,000 mg/m² every 3 weeks or carboplatin area under the curve 6 plus paclitaxel 175 mg/m² every 3 weeks). Patients were treated until they experienced progression or unacceptable toxicity, with follow-up of approximately 2 years. Results Two hundred seventy-two patients were randomly assigned to nivolumab (99% treated) and 133 to ICC (77% treated). More nivolumab-treated patients had brain metastases (20% v 14%) and increased lactate dehydrogenase levels (52% v 38%) at baseline; 41% of patients treated with ICC versus 11% of patients treated with nivolumab received anti-programmed death 1 agents after randomly assigned therapy. Median OS was 16 months for nivolumab versus 14 months for ICC (hazard ratio, 0.95; 95.54% CI, 0.73 to 1.24); median progression-free survival was 3.1 months versus 3.7 months, respectively (hazard ratio, 1.0; 95.1% CI, 0.78 to 1.436). Overall response rate (27% v 10%) and median duration of response (32 months v 13 months) were notably higher for nivolumab versus ICC. Fewer grade 3 and 4 treatment-related adverse events were observed in patients on nivolumab (14% v 34%). Conclusion Nivolumab demonstrated higher, more durable responses but no difference in survival compared with ICC. OS should be interpreted with caution as it was likely impacted by an increased dropout rate before treatment, which led to crossover therapy in the ICC group, and by an increased proportion of patients in the nivolumab group with poor prognostic factors.

Abstract 2860: Improved clinical response in patients with advanced melanoma treated with nivolumab combined with ipilimumab compared to ipilimumab alone

Background: Blockade of the immune checkpoints PD-1 and CTLA-4 each results in improved overall survival in patients (pts) with metastatic melanoma using monotherapy. In a phase 1 dose-escalation study, dual inhibition of these pathways by nivolumab (NIVO) and ipilimumab (IPI) demonstrated encouraging antitumor activity.

Methods: Treatment-naïve pts with advanced melanoma were randomized (double-blind) 2:1 to IPI 3 mg/kg combined with either NIVO 1 mg/kg (NIVO+IPI combination group) or placebo (PBO; IPI alone group) every 3 weeks (Q3W) for 4 doses, followed by NIVO 3 mg/kg or PBO, respectively, Q2W until disease progression or unacceptable toxicity. Primary endpoint was investigator-assessed objective response rate (ORR) in BRAF wild-type (WT) pts. Secondary endpoints included progression-free survival (PFS), ORR in BRAF V600 mutation-positive (MT) pts, and safety.

Results: In BRAF WT pts, ORR was 60% (43/72) in the NIVO+IPI group vs 11% (4/37) in the IPI group (P<0.0001); complete response reported in 12 (17%) and 0 pts, respectively. Median change in target lesions was 57% reduction for NIVO+IPI vs 4% increase for IPI alone. Median duration of response was not reached in either group. In BRAF WT pts, median PFS was 8.9 months for NIVO+IPI; 4.7 months for IPI (HR 0.40, 95% CI 0.22-0.71; P = 0.0012). Similar results for ORR and PFS favoring the combination were observed in BRAF MT pts (Table). A higher rate of drug-related grade 3-4 adverse events was observed in the NIVO+IPI group compared to IPI (Table), leading to more frequent discontinuation. Pts who discontinued NIVO+IPI due to study drug toxicity had a 67% response rate; most continue to respond. Immune-mediated AEs were manageable by standard treatment interventions, and the majority resolved with immune-modulating medication.

Conclusion: NIVO+IPI significantly improved ORR and PFS compared to IPI alone in treatment-naïve pts with advanced melanoma, and had a manageable safety profile.

Efficacy (evaluated in all randomized patients)BRAF WTBRAF WTBRAF MTNIVO+IPIIPINIVO+IPIIPIRandomized patients, N72372310ORR,% (95% CI)59.7 (47.5-71.1)a10.8 (3.0-25.4)a43.5 (23.2-65.5)0 (0-30.8)Best overall response, n (%)Complete response12 (16.7)04 (17.4)0Partial response31 (43.1)4 (10.8)6 (26.1)0Stable disease10 (13.9)12 (32.4)5 (21.7)2 (20.0)Progressive disease10 (13.9)16 (43.2)5 (21.7)7 (70.0)Median PFS, mo (95% CI)8.9 (7.0, NE)4.7 (2.8, 5.3)7.4 (2.8, NE)2.7 (0.99, 5.4)HR, (95% CI)0.40 (0.22-0.71) P = 0.00120.33 (0.1, 0.9)bSafety (evaluated in all treated patients)Patients reporting AE, n (%)NIVO+IPI (N = 94)IPI (N = 46)Any GradeGrade 3-4Any GradeGrade 3-4Treatment-related AEs86 (91.5)48 (51.1)42 (91.3)9 (19.6)aP<0.0001; estimated odds ratio for objective response 12.23 (95% CI, 3.69-51.40)bDue to the small sample size in the BRAF MT subgroup, no P-value is provided NE = not estimable

Citation Format: F. Stephen Hodi, Michael A. Postow, Jason Chesney, Anna C. Pavlick, Caroline Robert, Kenneth Grossmann, David McDermott, Gerald Linette, Nicolas Meyer, Jeffrey Giguere, Sanjiv S. Agarwala, Montaser Shaheen, Marc S. Ernstoff, David R. Minor, April Salama, Matthew H. Taylor, Linda Rollin, Christine Horak, Paul Gagnier, Jedd D. Wolchok. Improved clinical response in patients with advanced melanoma treated with nivolumab combined with ipilimumab compared to ipilimumab alone. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2860. doi:10.1158/1538-7445.AM2015-2860

Phase III randomized clinical trial comparing tremelimumab with standard-of-care chemotherapy in patients with advanced melanoma

PURPOSE

In phase I/II trials, the cytotoxic T lymphocyte-associated antigen-4-blocking monoclonal antibody tremelimumab induced durable responses in a subset of patients with advanced melanoma. This phase III study evaluated overall survival (OS) and other safety and efficacy end points in patients with advanced melanoma treated with tremelimumab or standard-of-care chemotherapy.

PATIENTS AND METHODS

Patients with treatment-naive, unresectable stage IIIc or IV melanoma were randomly assigned at a ratio of one to one to tremelimumab (15 mg/kg once every 90 days) or physician's choice of standard-of-care chemotherapy (temozolomide or dacarbazine).

RESULTS

In all, 655 patients were enrolled and randomly assigned. The test statistic crossed the prespecified futility boundary at second interim analysis after 340 deaths, but survival follow-up continued. At final analysis with 534 events, median OS by intent to treat was 12.6 months (95% CI, 10.8 to 14.3) for tremelimumab and 10.7 months (95% CI, 9.36 to 11.96) for chemotherapy (hazard ratio, 0.88; P = .127). Objective response rates were similar in the two arms: 10.7% in the tremelimumab arm and 9.8% in the chemotherapy arm. However, response duration (measured from date of random assignment) was significantly longer after tremelimumab (35.8 v 13.7 months; P = .0011). Diarrhea, pruritus, and rash were the most common treatment-related adverse events in the tremelimumab arm; 7.4% had endocrine toxicities. Seven deaths in the tremelimumab arm and one in the chemotherapy arm were considered treatment related by either investigators or sponsor.

CONCLUSION

This study failed to demonstrate a statistically significant survival advantage of treatment with tremelimumab over standard-of-care chemotherapy in first-line treatment of patients with metastatic melanoma.

Phase II study of the farnesyltransferase inhibitor R115777 in advanced melanoma (CALGB 500104)

Background

Multiple farnesylated proteins are involved in signal transduction in cancer. Farnesyltransferase inhibitors (FTIs) have been developed as a strategy to inhibit the function of these proteins. As FTIs inhibit proliferation of melanoma cell lines, we undertook a study to assess the impact of a FTI in advanced melanoma. As farnesylated proteins are also important for T cell activation, measurement of effects on T cell function was also pursued.

Methods

A 3-stage trial design was developed with a maximum of 40 patients and early stopping if there were no responders in the first 14, or fewer than 2 responders in the first 28 patients. Eligibility included performance status of 0–1, no prior chemotherapy, at most 1 prior immunotherapy, no brain metastases, and presence of at least 2 cutaneous lesions amenable to biopsy. R115777 was administered twice per day for 21 days of a 28-day cycle. Patients were evaluated every 2 cycles by RECIST. Blood and tumor were analyzed pre-treatment and during week 7.

Results

Fourteen patients were enrolled. Two patients had grade 3 toxicities, which included myelosuppression, nausea/vomiting, elevated BUN, and anorexia. There were no clinical responses. All patients analyzed showed potent inhibition of FT activity (85-98%) in tumor tissue; inhibition of phosphorylated ERK and Akt was also observed. T cells showed evidence of FT inhibition and diminished IFN-γ production.

Conclusions

Despite potent target inhibition, R115777 showed no evidence of clinical activity in this cohort of melanoma patients. Inhibition of T cell function by FTIs has potential clinical implications.

Clinicaltrials.gov number NCT00060125

Health related quality of life outcomes for unresectable stage III or IV melanoma patients receiving ipilimumab treatment

BACKGROUND

In an international, randomized Phase III trial ipilimumab demonstrated a significant overall survival benefit in previously treated advanced melanoma patients. This report summarizes health-related quality of life (HRQL) outcomes for ipilimumab with/without gp100 vaccine compared to gp100 alone during the clinical trial's 12 week treatment induction period.

METHODS

The Phase III clinical trial (MDX010-20) was a double-blind, fixed dose study in 676 previously treated advanced unresectable stage III or IV melanoma patients. Patients were randomized 3:1:1 to receive either ipilimumab (3 mg/kg q3w x 4 doses) + gp100 (peptide vaccine; 1 mg q3w x 4 doses; ipilimumab plus gp100, n = 403); gp100 vaccine + placebo (gp100 alone, n = 136); or ipilimumab + placebo (ipilimumab alone, n = 137). The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) assessed HRQL. Baseline to Week 12 changes in EORTC QLQ-C30 function, global health status, and symptom scores were analyzed for ipilimumab with/without gp100 vaccine compared to gp100 alone. Mean change in scores were categorized "no change" (0-5), "a little" (5-10 points), "moderate" (10-20 points), and "very much" (>20).

RESULTS

In the ipilimumab plus gp100 and ipilimumab alone groups, mean changes from baseline to Week 12 generally indicated "no change" or "a little" impairment across EORTC QLQ-C30 global health status, function, and symptom subscales. Significant differences in constipation, favoring ipilimumab, were observed (p < 0.05). For ipilimumab alone arm, subscales with no or a little impairment were physical, emotional, cognitive, social function, global health, nausea, pain, dyspnea, constipation, and diarrhea subscales. For the gp100 alone group, the observed changes were moderate to large for global health, role function, fatigue, and for pain.

CONCLUSIONS

Ipilimumab with/without gp100 vaccine does not have a significant negative HRQL impact during the treatment induction phase relative to gp100 alone in stage III or IV melanoma patients.

TRIAL REGISTRATION

Clinicaltrials.gov identification number NCT00094653.

A study of paclitaxel, carboplatin, and bortezomib in the treatment of metastatic malignant melanoma: a phase 2 consortium study

BACKGROUND

Chemotherapy has not been reported to have a significant impact on survival for patients with metastatic melanoma. Bortezomib was shown to have additive/synergistic effects with several chemotherapeutic agents, including paclitaxel and platinum. A phase 1 trial of this 3-drug combination reported that 6 of 28 patients treated with bortezomib followed by paclitaxel and carboplatin achieved a partial response (including 2 of 5 patients with metastatic melanoma).

METHODS

A 2-stage phase 2 clinical trial was conducted to assess the antitumor activity of this 3-agent combination in patients with metastatic melanoma who had received at most 1 prior chemotherapy for metastatic disease. Treatment included bortezomib at a dose of 1.3 mg/m2 intravenously on Days 1, 4, and 8; paclitaxel at a dose of 175 mg/m2; and carboplatin at an area under the concentration (AUC) of 6 on Day 2 of a 21-day cycle. The primary endpoint of this trial was tumor response rate (TRR).

RESULTS

Seventeen eligible patients were enrolled. A median of 4 cycles were administered (range, 1-7 cycles). Three patients discontinued treatment due to persistent grade 4 (based on National Cancer Institute Common Terminology Criteria for Adverse Events [version 3.0]) neutropenia with grade 3 leukopenia (2 patients) or grade 4 pulmonary embolism (1 patient). Grade>or=3 toxicities included neutropenia (71%), leukopenia (41%), thrombocytopenia (29%), and arthralgia (12%). Two partial responses were observed (TRR, 11.8%). Four patients had stable disease at >12 weeks. The median progression-free survival was 3.2 months, and the median overall survival was 7.0 months.

CONCLUSIONS

Due to insufficient clinical efficacy, this trial did not proceed to second-stage accrual. The combination of paclitaxel, carboplatin, and bortezomib demonstrated limited clinical benefit and was associated with significant toxicity.

Efficacy of ipilimumab 10 mg/kg in advanced melanoma patients (pts) with good and poor prognostic factors

9036

Background: Ipilimumab is a fully human monoclonal antibody against cytotoxic T-lymphocyte antigen-4. In total, ∼50% of metastatic melanoma pts treated with 10 mg/kg ipilimumab are alive at 1 year (Wolchok et al. CRI-CVC annual meeting 2008. Oral presentation), and identifying prognostic factors may help select pts most likely to benefit from treatment. Factors predictive of poorer prognosis in melanoma include advanced stage of disease (ie, M1c), age 60+, gender (male), elevated baseline lactate dehydrogenase (LDH) levels, and lack of a prior response to therapy. In this pooled analysis, potential prognostic factors in pts with advanced melanoma treated with ipilimumab 10 mg/kg in 2 phase II studies (CA184–008, N=155 and -022, N=72) were explored. Methods: Ipilimumab 10 mg/kg was given every 3 weeks (Q3W) × 4 (induction); eligible pts could continue to receive ipilimumab Q12W starting at week (Wk) 24 (maintenance). Response was based on modified World Health Organization criteria. Each variable was analyzed separately. Results: Disease control rate (complete/partial response [CR/PR] and stable disease) seems not to be associated with age (<65 yrs: 25.2%; ≥65 yrs: 32.9%), gender (male: 22.6%; female: 34.0%), M stage (M0: 33.3%; M1a: 41.0%; M1b: 26.4%; M1c: 23.6%), response to prior systemic therapy (yes: 32.5%; no: 26.7%), prior immunotherapy (yes: 21.6%; no: 35.3%), LDH >upper normal limit (UNL) (yes: 25.9%; no: 29.7%), or LDH >2×UNL (yes: 15.9%; no: 30.6%). Best overall response rate (CR or PR) was not associated with age (<65 yrs: 7.3%; ≥65 yrs: 7.9%), gender (male: 4.0%; female: 11.7%), M stage (M0: 8.3%; M1a: 15.4%; M1b: 5.7%; M1c: 5.7%), response to prior systemic therapy (yes: 12.5%; no: 6.4%), prior immunotherapy (yes: 3.2%; no: 12.7%), LDH >UNL (yes: 8.6%; no: 6.3%), or LDH >2×UNL (yes: 4.5%; no: 8.2%). Overall survival was not associated with age (median OS: <65 yrs: 11.6 mo; ≥65 yrs: 7.59 mo), M stage (median OS: M0: 21.9 mo; M1a: 15.7 mo; M1b: 15.4 mo; M1c: 6.6 mo), or response to prior systemic therapy (median OS: yes: 11.6 mo; no: 10.7 mo). Conclusions: Ipilimumab demonstrates clinical activity independent of negative prognostic factors, and may even benefit those pts with the worst prognosis.

[Table: see text]

Association between immune-related adverse events (irAEs) and disease control or overall survival in patients (pts) with advanced melanoma treated with 10 mg/kg ipilimumab in three phase II clinical trials

9034

Background: The monoclonal antibody ipilimumab targets cytotoxic T-lymphocyte antigen-4. The most common AEs associated with ipilimumab are irAEs, and both antitumor and irAE responses likely reflect its immune-mediated mechanism of action. In this report, a potential association between disease control (DC) or overall survival (OS) and irAEs in patients (pts) with advanced melanoma treated with 10 mg/kg ipilimumab in 3 Phase II clinical trials was explored. Methods: Across 3 Phase II studies (CA184008, 022, and 007), ipilimumab (10 mg/kg) was given every 3 weeks (Q3W) x 4 (induction); eligible pts could continue to receive ipilimumab Q12W starting at week (wk) 24 (maintenance). In study 022, pts were randomized to 0.3, 3, and 10 mg/kg groups, whereas study 008 was a single-arm trial of ipilimumab 10 mg/kg. In study 007, ipilimumab 10 mg/kg was administered either with placebo or daily prophylactic budesonide. Disease control (CR/PR/SD) was evaluated using modified World Health Organization (mWHO) and immune- related response criteria (Hodi FS, et al. J Clin Oncol 26: 2008 (May 20 suppl; abstr 3008). Association between DC and grade 0/1 vs. grade ≥2 irAEs was examined (studies 007, 008, and 022). Association between OS and irAEs which developed within 12 wks of ipilimumab treatment was also explored using landmark analyses from Day 81 (studies 008 and 022). Results: Across the 3 phase II studies, the rate of DC by mWHO in pts with grade 0/1 irAEs was 20–24% and in pts with grade ≥2 irAEs was 34–43%. The number of pts with DC was higher among those who experienced an irAE compared with those who did not, but DC was not statistically significantly associated with grade 0/1 vs grade ≥2 irAEs. For pts who lived up to Day 81 in studies 008 and 022, median OS (95% CI) from Day 81 was 14.8 mo (10.0–21.7) for any irAE and 8.21 mo (5.29–13.7) for no irAE within 12 weeks; median OS was 13.6 mo (5.78-NR) for any grade ≥2 irAE and 11.3 mo (7.95–15.8) for no grade ≥2 irAE within 12 weeks. Conclusions: DC and survival benefits with ipilimumab are observed among pts that develop an irAE and among pts that do not develop an irAE. Thus, pts who do not experience an irAE may still demonstrate clinical benefit with ipilimumab.

[Table: see text]

Ras-associated protein-1 regulates extracellular signal-regulated kinase activation and migration in melanoma cells: two processes important to melanoma tumorigenesis and metastasis

Melanoma is one of the most devastating malignancies with a rising incidence and lack of effective treatments for advanced disease. Constitutive activation of the mitogen-activated protein kinase (MAPK) pathway and altered expression of alpha(v)beta(3) integrin are critical for melanoma development and progression. Ras-associated protein-1 (Rap1), a Ras family member of the small GTPases, has emerged as a key mediator in these two important processes. In this study, we have shown Rap1 activation in cells derived from two human metastatic melanomas and also in three of seven cutaneous metastatic melanoma tissues. We found increased extracellular signal-regulated kinase (ERK) activity in the tumors with detected Rap1 activity that interestingly harbored neither BRAF nor N-Ras mutation, suggesting a role for Rap1 in ERK activation in vivo. We also showed Rap1 and ERK activation by both hepatocyte growth factor (HGF) and 8CPT-2Me-cAMP (an activator of Epac, a Rap1 guanine nucleotide exchange factor) in two human melanoma cell lines. In addition, the activation of ERK by HGF was reduced, at least in part, by small interfering RNAs against Rap1 and a dominant-negative Rap1. Finally, a functional role for Rap1 activation was shown by Rap1-induced alpha(v)beta(3) integrin activation and consequent increased melanoma cell migration in vitro. Taken together, these results show that Rap1 is involved in the activation of MAPK pathway and integrin activation in human melanoma and suggest a potential role for Rap1 in melanoma tumorigenesis and metastasis.

Randomized phase II study of dacarbazine with or without sorafenib in patients with advanced melanoma

8511

Background: Sorafenib (SOR), a potent and selective multi-kinase inhibitor, exerts its anti-tumor and anti-angiogenic effects via inhibition of VEGFR-1, -2, -3, PDGFR-a, -β, and Raf. Dacarbazine (DTIC) is an FDA-approved cytotoxic agent for advanced melanoma. Phase I/II results of SOR + DTIC were encouraging and prompted this randomized phase II study. Methods: This was a multi- center, double-blinded, placebo-controlled study; eligibility criteria included measurable disease by RECIST, no prior cytotoxic chemotherapy, and no active brain metastases. Advanced melanoma patients (pts) stratified by stage (unresectable III vs IVM1a/M1b vs M1c) and ECOG PS (0 vs 1) were randomized to receive DTIC 1,000 mg/m2 q 21 days + oral placebo (PL) or oral SOR 400 mg bid continuously until the occurrence of progressive disease or intolerable toxicity. The primary endpoint was progression-free survival (PFS) of DTIC+SOR vs DTIC+PL. Using a two-sided test with a = 0.05, 77 PFS events were needed to detect a hazard ratio (HR) of 0.5 (SOR/PL) with 86 % power. The secondary endpoint was overall survival and tertiary endpoints were objective response rate (ORR), time to progression, and duration of response. Results: 101 pts were enrolled over 12 months (51 DTIC+SOR, 50 DTIC+PL). Treatment arms were balanced for age (median 58 yrs), gender (male 70%), PS (ECOG 1 39%), stage (Stage IV M1c 52%) and baseline LDH (>ULN 29%). At the time of analysis by independent assessment, the median PFS of DTIC+PL vs DTIC+SOR was 11.7 wks (95% CI 6.1, 17.9) vs 21.1 wks (95% CI: 16, 28); HR 0.67 [p=0.07]; PFS rate at Day 180 was 18% vs 41%; and ORR was 12% vs 24%. Survival data are immature. Toxicities of Grade 3 or higher (DTIC+PL vs DTIC+SOR) included neutropenia (12% vs 33%), leukopenia (6% vs 14%), thrombocytopenia (18% vs 35%), thrombosis/embolism (0% vs 6%), hypertension (0 vs 8%), hand-foot skin reaction (0 vs 4%), and CNS hemorrhage (0% vs 8%). 3 of the 4 pts with CNS hemorrhage had new brain metastases. No treatment-related deaths occurred in either arm. Conclusions: DTIC+SOR was well tolerated and showed a strong efficacy trend compared with DTIC+PL in median PFS, PFS rate at 6 months and ORR in chemotherapy-naïve pts with advanced melanoma. This regimen warrants further evaluation in larger clinical trial settings.

No significant financial relationships to disclose.

Phase II study of the farnesyltransferase inhibitor R115777 in advanced melanoma: CALGB 500104

8014

Background: Ras-based signaling is thought to be critical in the genesis of melanoma. Farneslytransferase (FT) inhibitors (FTIs) have been developed as a pharmacologic strategy to inhibit Ras function. Additional farnesylated proteins are also important for the malignant process, and FTIs inhibit melanoma cell line proliferation in vitro. These considerations motivated the development of a phase II trial of the FTI R115777 in patients with melanoma. Farnesylated proteins are also important for T cell activation. The interest in future combinations of targeted agents and immunotherapeutics in this disease prompted analysis of T cell function ex vivo. Methods: A 3-stage design was pursued with a maximum of 40 patients planned and early stopping if there were no responders in the first 14, or fewer than 2 responders in the first 28 patients. Eligibility included intact organ function, PS≤1, no prior chemotherapy, at most 1 prior immunotherapy, no brain metastases, and presence of at least 2 cutaneous lesions amenable to excisional biopsy. R115777 (300 mg orally) was administered twice per day for 21 days of a 28-day cycle. Patients were evaluated every 2 cycles by RECIST criteria. Blood was obtained pre-treatment and during week 7 for analysis of HDJ-2 farnesylation and for T cell IFN-γ production in response to SEA. In addition, tumor biopsies were performed pre- and post-treatment when feasible to directly measure FT activity. Results: 14 patients were enrolled. 2 patients had grade 3 toxicities, which included myelosuppression, nausea/vomiting, elevated BUN, and anorexia. There were no clinical responses, and only 4 patients went on to a second course of treatment. All analyzed patients showed HDJ-2 gel shift in peripheral blood cells, as well as marked inhibition of FT activity (by 85–98%) in tumor tissue. T cell production of IFN-γ was also suppressed. Conclusions: Despite potent target inhibition, the FTI R115777 showed no evidence for clinical activity as a single agent in this cohort of 14 metastatic melanoma patients. Inhibition of T cell function has implications for future combination therapies and suggests the possibility for FTIs as candidate immunosuppressive agents. New therapeutic approaches for melanoma, or logically selected combination therapies, are needed.

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Molecular diagnostics in melanoma

Molecular pathology is rapidly evolving, featuring continuous technologic improvements that offer novel clinical opportunities for the recognition of disease predisposition, for identifying sub-clinical disease, for more accurate diagnosis, for selecting efficacious and non-toxic therapy, and for monitoring of disease outcome. Currently, the identification and prognosis of primary cutaneous melanoma is based on histologic factors (tumor depth and ulceration) and clinical factors (number of lymph node and/or distant metastases). However, metastasis can occur in patients with thin melanomas, and sentinel lymph node biopsy does not identify all patients at risk for distant metastasis. New markers exist that correlate with melanoma progression, which may aid in melanoma identification, prognostication, and detection of minimal residual disease/early recurrence. Moreover, not many therapeutic options exist for melanoma as no regimen prolongs survival. Emerging data with investigational therapies suggest that certain markers might play a crucial role in identifying patients who will respond to therapy or show utility in the monitoring the response to therapy. Herein, molecular diagnostics that can potentially benefit the individual melanoma patient will be discussed.

Comparison of the predictive accuracy of DNA array-based multigene classifiers across cDNA arrays and Affymetrix GeneChips

We examined how well differentially expressed genes and multigene outcome classifiers retain their class-discriminating values when tested on data generated by different transcriptional profiling platforms. RNA from 33 stage I-III breast cancers was hybridized to both Affymetrix GeneChip and Millennium Pharmaceuticals cDNA arrays. Only 30% of all corresponding gene expression measurements on the two platforms had Pearson correlation coefficient r >or= 0.7 when UniGene was used to match probes. There was substantial variation in correlation between different Affymetrix probe sets matched to the same cDNA probe. When cDNA and Affymetrix probes were matched by basic local alignment tool (BLAST) sequence identity, the correlation increased substantially. We identified 182 genes in the Affymetrix and 45 in the cDNA data (including 17 common genes) that accurately separated 91% of cases in supervised hierarchical clustering in each data set. Cross-platform testing of these informative genes resulted in lower clustering accuracy of 45 and 79%, respectively. Several sets of accurate five-gene classifiers were developed on each platform using linear discriminant analysis. The best 100 classifiers showed average misclassification error rate of 2% on the original data that rose to 19.5% when tested on data from the other platform. Random five-gene classifiers showed misclassification error rate of 33%. We conclude that multigene predictors optimized for one platform lose accuracy when applied to data from another platform due to missing genes and sequence differences in probes that result in differing measurements for the same gene.

Disinfection of Goldmann tonometers against human immunodeficiency virus type 1

Goldmann tonometer tips were inoculated with 5 X 10(5) IU of cell-free or cell-associated human immunodeficiency virus type 1 (lymphadenopathy virus type 1 isolate) or 10(4) plaque-forming units of herpes simplex virus type 1 (McKrae strain) or type 2 (Hicks strain). In an effort to mimic a "worst case" clinical scenario, each respective virus was allowed to air dry on the tonometer tip for 10 minutes. Inoculated tonometers were then (1) not treated, (2) wiped with a disposable (Kim-wipe) tissue or sterile gauze; (3) wiped with sterile gauze soaked with 3% hydrogen peroxide; or (4) wiped with a 70% isopropyl alcohol swab. The hydrogen peroxide treatment and the alcohol wipes both completely disinfected the tonometer tips for human immunodeficiency virus type 1 and herpes simplex virus types 1 and 2, whereas wiping with a sterile gauze or tissue was not effective. Wiping the Goldmann tonometer tip with an isopropyl alcohol swab and then allowing the alcohol to evaporate provides a ready and efficient means of inactivating these three enveloped viruses.

The immunologic response of congenitally athymic rats to Schistosoma mansoni infection. I. In vivo studies of resistance

The responses of congenitally athymic (Nu/Nu) rats to an initial exposure and to re-exposure to Schistosoma mansoni were compared to those manifested by thymic reconstituted (Nu/Nu*TxR), heterozygous littermate controls (Nu/+) and the highly characterized Fischer rat strain. Congenitally athymic rats rejected the developing worms of an initial infection more slowly than did thymic reconstituted or heterozygous animals. These latter responses were highly comparable to those demonstrated by the Fischer rat. In addition, the congenitally athymic rats manifested lower peripheral blood eosinophilia in response to infection. Resistance to reinfection in athymic animals was impaired and associated with a decreased immunoinflammatory histologic response to hepatic intravascular parasites and to eggs lodged in the hepatic vasculature. There was little evidence of inflammatory responses involving degranulating eosinophils, lymphocytes, or macrophages in the athymic rats. Finally, athymic animals produced antibody that was less capable of passively transferring resistance in adoptive-challenge experiments; however, antibody produced in heterozygous animals conferred significant resistance when adoptively transferred to athymic animals. These results suggest that resistance to initial and subsequent challenge by S. mansoni infections in the rat is highly reliant upon T-dependent mechanisms that result in the production of antibody-dependent, possibly cell-mediated resistance. Additional studies utilizing in vitro analysis of a variety of antibody functions to define the mechanisms of T-dependent immunologic resistance in the congenitally athymic rat are the subject of the accompanying manuscript.

The immunologic response of congenitally athymic rats to Schistosoma mansoni infection. I. In vivo studies of resistance

The responses of congenitally athymic (Nu/Nu) rats to an initial exposure and to re-exposure to Schistosoma mansoni were compared to those manifested by thymic reconstituted (Nu/Nu*TxR), heterozygous littermate controls (Nu/+) and the highly characterized Fischer rat strain. Congenitally athymic rats rejected the developing worms of an initial infection more slowly than did thymic reconstituted or heterozygous animals. These latter responses were highly comparable to those demonstrated by the Fischer rat. In addition, the congenitally athymic rats manifested lower peripheral blood eosinophilia in response to infection. Resistance to reinfection in athymic animals was impaired and associated with a decreased immunoinflammatory histologic response to hepatic intravascular parasites and to eggs lodged in the hepatic vasculature. There was little evidence of inflammatory responses involving degranulating eosinophils, lymphocytes, or macrophages in the athymic rats. Finally, athymic animals produced antibody that was less capable of passively transferring resistance in adoptive-challenge experiments; however, antibody produced in heterozygous animals conferred significant resistance when adoptively transferred to athymic animals. These results suggest that resistance to initial and subsequent challenge by S. mansoni infections in the rat is highly reliant upon T-dependent mechanisms that result in the production of antibody-dependent, possibly cell-mediated resistance. Additional studies utilizing in vitro analysis of a variety of antibody functions to define the mechanisms of T-dependent immunologic resistance in the congenitally athymic rat are the subject of the accompanying manuscript.