Abstract Background LEN is a multikinase inhibitor of VEGFR 1–3, FGFR 1–4, PDGFRα, RET, and KIT. PEMBRO is an anti-PD-1 antibody. We report final results of a cohort of patients (pts) with metastatic EC (data cutoff, Jan. 10, 2019) as part of an ongoing phase 1b/2 study evaluating LEN + PEMBRO in pts with selected solid tumours. Methods In this cohort of a multicenter, open-label study, pts with histologically confirmed metastatic EC and measurable disease who received ≤2 prior chemotherapies (unless discussed with the sponsor) were administered LEN (20 mg PO QD) plus PEMBRO (200 mg IV Q3W). Tumour assessments for the primary phase 2 endpoint (objective response rate at 24 weeks [ORRWK24]) and secondary endpoints were evaluated by investigators per immune-related (ir)RECIST. Secondary endpoints included ORR, progression-free survival, overall survival, and duration of response. Tumour responses were also assessed by independent imaging reviewers per irRECIST, RECIST 1.1, and modified RECIST 1.1, and by investigators per mRECIST 1.1. Results At data cutoff, 108 pts with previously treated (1 regimen: 53%; >1 regimen: 47%) EC (endometrioid: 51%; serous: 32%; FIGO grade 3: 70%) were enrolled and had a median follow-up of 18.7 months. 13% of pts had high microsatellite instability (MSI-H) or mismatch-repair deficient (dMMR) status. Efficacy outcomes are summarized in the table. Treatment-related adverse events (TRAEs) occurred in 105 (97%) pts (97 [90%] ≤ grade 3, 8 [7%] ≥ grade 4). TRAEs led to study-drug interruption of one or both drugs in 78 (72%) pts and dose reductions of LEN in 70 (65%) pts; 20 (19%) pts discontinued one or both drugs due to a TRAE. The most common ≥ grade 3 TRAEs were hypertension (32%), fatigue (8%), and diarrhea (7%). Conclusions The LEN + PEMBRO combination showed promising antitumor activity in metastatic EC regardless of MSI/MMR status. Treatment was generally well tolerated, and no new safety signals emerged. A phase 3 study in advanced EC is underway (NCT03517449). Table: 994O . Investigator assessment per irRECIST Previously treated EC Total (N = 108) Not MSI-H or dMMR (n = 94) MSI-H/dMMR (n = 11) ORRWK24, n (%) 95% CI 41 (38.0) 28.8–47.8 34 (36.2) 26.5–46.7 7 (63.6) 30.8–89.1 ORR, n (%) (95% CI) Complete response Partial response 42 (38.9) 29.7–48.7 8 (7.4) 34 (31.5) 35 (37.2) 27.5–47.8 7 (7.4) 28 (29.8) 7 (63.6) 30.8–89.1 1 (9.1) 6 (54.5) Median duration of response, months (95% CI) 21.2 (7.6–NR) NE (7.4–NR) 21.2 (7.3–NR) Kaplan-Meier estimate of duration of response ≥6 months, a n Probability (95% CI) 32 0.87 (0.72–0.95) 25 0.85 (0.67–0.93) 7 1.00 (NR–NR) Median progression-free survival, months (95% CI) 7.4 (5.3–8.7) 7.4 (5.0–7.6) 18.9 (4.0–NR) Median overall survival, months (95% CI) 16.7 (15.0–NR) 16.4 (13.5–25.9) NR (7.4–NR) Time to response (months), mean (SD) 2.6 (1.6) 2.5 (1.5) 2.9 (1.8) a Probabilities of patients achieving a duration of response ≥6 months were calculated using the Kaplan-Meier product-limit method and Greenwood formula. CI, confidence interval; dMMR, mismatch repair deficient; NR, not reached; SD, standard deviation. Clinical trial identification NCT02501096. Editorial acknowledgement Jeffrey K. Bratz, PhD of Oxford PharmaGenesis, Newtown, PA was funded by Eisai Inc. Legal entity responsible for the study Eisai Inc. Funding Eisai Inc. and Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA. Disclosure V. Makker: Non-remunerated activity/ies: AstraZeneca; Honoraria (self), Non-remunerated activity/ies: Eisai; Honoraria (self), Non-remunerated activity/ies: Merck; Non-remunerated activity/ies: Lilly; Honoraria (self), Non-remunerated activity/ies: Karyopharm; Honoraria (self), Non-remunerated activity/ies: Takeda; Non-remunerated activity/ies: Genentech. M.H. Taylor: Research grant / Funding (institution): BioAlta; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Bristol-Myers Squibb; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Array Biopharma; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Eisai; Honoraria (self), Travel / Accommodation / Expenses: Bayer; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: LOXO; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Blueprint; Honoraria (self), Advisory / Consultancy: Arquele; Honoraria (self), Advisory / Consultancy: Novartis. C. Aghajanian: Advisory / Consultancy: Tesaro; Advisory / Consultancy: Immunogen; Advisory / Consultancy, Research grant / Funding (self): Clovis; Honoraria (self): Mateon Therapeutics; Advisory / Consultancy: Cerulean Pharma; Research grant / Funding (self): Genentech. A. Oaknin: Travel / Accommodation / Expenses: Roche; Travel / Accommodation / Expenses: AstraZeneca; Research grant / Funding (institution), Travel / Accommodation / Expenses: PharmaMar; Research grant / Funding (institution), Travel / Accommodation / Expenses: Clovis Oncology; Honoraria (self), Research grant / Funding (institution): Tesaro; Honoraria (self), Research grant / Funding (institution): Immunogen; Research grant / Funding (institution): Eisai Ltd.; Research grant / Funding (institution): Merck Sharp & Dohme de Espana SA; Honoraria (self): Genmab; Research grant / Funding (institution): AbbVie Deutschland; Research grant / Funding (institution): Millennium Pharma; Research grant / Funding (institution): Regeneron Pharmaceuticals; Research grant / Funding (institution): Ability Pharmaceuticals; Research grant / Funding (institution): Advaxis Inc; Research grant / Funding (institution): Aeterna Zentaris; Research grant / Funding (institution): Amgen SA; Research grant / Funding (institution): Aprea Therapeutics AB; Research grant / Funding (institution): F. Hoffman - La Roche Ltd. M. Romeo Marin: Advisory / Consultancy: Tesoro; Advisory / Consultancy, Non-remunerated activity/ies: Roche; Speaker Bureau / Expert testimony: AstraZeneca. M.S. Brose: Honoraria (self): Eisai. D.E. Stepan: Full / Part-time employment: Formerly of Eisai Inc. C.E. Dutcus: Leadership role, Full / Part-time employment: Eisai Inc. J. Wu: Full / Part-time employment: Eisai Inc. E.V. Schmidt: Full / Part-time employment: Merck & Co Inc. R.J. Orlowski: Full / Part-time employment: Merck & Co Inc. P. Sachdev: Full / Part-time employment: Eisai Inc. R. Shumaker: Full / Part-time employment: Eisai Inc. A. Casado Herraez: Research grant / Funding (institution), Travel / Accommodation / Expenses: PharmaMar. All other authors have declared no conflicts of interest.

ownload tment of metastatic renal cell cancer (RCC) with antiangiogenic agents that block vascular endothelial h factor (VEGF) receptor 2 signaling produces tumor regression in a substantial fraction of patients; er, resistance typically develops within 6 to 12 months. The purpose of this study was to identify mor pathways involved in resistance. Treatment of mice bearing either 786-0 or A498 human RCC xenowith sorafenib or sunitinib produced tumor growth stabilization followed by regrowth despite ued drug administration analogous to the clinical experience. Tumors and plasma were harvested at of therapy and at the time of resistance to assess pathways that may be involved in resistance. Serial ion imaging, and plasma and tumor collections were obtained in mice treated with either placebo or ib alone or in combination with intratumoral injections of the angiostatic chemokine CXCL9. Sunitinib istration led to an early downmodulation of IFNγ levels as well as reduction of IFNγ receptor and stream angiostatic chemokines CXCL9 to 11 within the tumor. Intratumoral injection of CXCL9, gh producing minimal effects by itself, when combined with sunitinib resulted in delayed resistance accompanied by a prolonged reduction of microvascular density and tumor perfusion as measured by ion imaging relative to sunitinib alone. These results provide evidence that resistance to VEGF receptor y is due at least in part to resumption of angiogenesis in association with reduction of IFNγ-related therap angiostatic chemokines, and that this resistance can be delayed by concomitant administration of CXCL9. Mol Cancer Ther; 9(10); 2793–802. ©2010 AACR.

Introduction: ABT‐737 is a BH3 mimetic that selectively inhibits Bcl‐2, Bcl‐xL and Bcl‐w and has been shown to induce apoptosis in several tumor types. Mcl‐1 expression has been proposed as a potential mechanism of resistance to Mcl‐1. Sorafenib is an oral multikinase inhibitor that targets VEGFR2, PDGFR, B‐Raf and has also been shown to down modulate Mcl‐1. PLX4720 is a potent inhibitor of the V600E mutant B‐Raf which is an oncogenic activating mutation that is found in approximately 40–60% of patients with cutaneous melanoma. PLX4032, a similar and more bioavailable molecule than PLX4720, is currently in clinical development and was associated with clinical responses in patients with malignant melanoma in a phase I trial. Since we have previously shown that sorafenib has a synergistic effect when used in combination with ABT‐737, we set out to evaluate and compare the effects of sorafenib and PLX4720 alone and in combination with ABT‐737 on melanoma cell lines. Methods: The B‐Raf V600E mutant melanoma cell lines A375, A2058 and SKMEL5 were treated with DMSO, sorafenib (10 uM) or PLX4720 (1 uM) alone or in combination with ABT‐737 (5 uM). Cell lysates were prepared after 4 hours and probed with specific antibodies to detect the presence of vinculin, PARP, Mcl‐1, total Erk, and phosphorylated Erk (Thr202/Tyr204) using standardWestern Blot technique. In addition, cells treated for 24 hours were assessed for cytotoxic activity using propidium iodide staining followed by flow cytometeric analysis. Results: Results were broadly similar in all three cell lines tested. Both sorafenib and PLX4720, but not ABT‐737, were found to down‐modulate Mcl‐1 and the phosphorylation of Erk (pErk). The effect of PLX4720 on Erk phosphorylation was greater than the effect of sorafenib while, conversely, sorafenib‐downmodulation of Mcl‐1 was more profound than that of PLX4720. PARP cleavage was identified in ABT‐737 treated cells at a low level, however this was substantially enhanced in combination with either sorafenib or PLX4720. Cytotoxicity was greater in sorafenib‐treated cells than those treated with PLX4720. The effect of each treatment was enhanced, however, in combination with ABT‐737, which exhibited little to no single‐agent activity across all cell lines. The combination of sorafenib and ABT‐737 had the strongest cytotoxic effect of the treatments evaluated in each cell line. Conclusion: Both the multitargeted TKI sorafenib and the more specific V600E mutant B‐raf inhibitor PLX4720 enhance the cytotoxicity of the BH3‐mimetic ABT‐737 in melanoma cell lines. Our results suggest that ABT‐737‐mediated cytotoxicity is dependent on Mcl‐1 downmodulation. This is supported by the finding that the combination of sorafenib and ABT‐737 is more toxic than PLX4720 and ABT‐737 and is associated with a more effective reduction of Mcl‐1 levels in 4 hour lysates. Xenograft testing of these combinations is planned with the goal of translating the most successful combination into an early phase clinical trial. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B89.

8000 Background: Metastatic melanoma is associated with various measures of systemic and local immune suppression. We hypothesized that immune suppression in the regional LN basin exists and may facilitate melanoma progression. METHODS We collected portions of regional LNs from tumor uninvolved sentinel LNs (USLN) (remote from primary melanoma removal) and from macroscopically involved nodes (TILN) from therapeutic node dissections in successive melanoma patients. Lymphocytes were extracted, stained using surface and internal antibodies to T cell receptor zeta chain (TCRζ), T regulatory cells (CD4+CD25+ Fox 3p+) (Tregs) and tumor associated myeloid cells (CD11b+ CD14- CD15+) (TAMC), and analyzed via flow cytometer. Results from USLN specimens were compared with TILN. RESULTS 30 LNs (14 USLN/16 TILN) from 30 patients were evaluated. Median age of patients was 48 years (range 30-83); 20 were male. USLN patients were stage IB (12) or IIA (2); TILN patients were stage IIIB (5), IIIC (5), and IV (6). 7 patients with TILN and none with USLN have progressed. TILN had significantly less TCRζ chain expression than SLN (62% vs. 85%; p = 0.0001). This amounts to a localized decrease of 23% of TCRζ expression (95% CI 13%; 34%). No significant relationship between lymph node involvement and Treg or TAMC was documented. CONCLUSION Regional LN involvement with melanoma is associated with a significant reduction in lymphocyte TCRζ expression indicating immune suppression. The mechanism for this is uncertain, but does not appear to be related to changes in Tregs or TAMC (arginase producing cells). We plan to further investigate TCRζ expression in microscopically involved SLNs and SLNs removed at time of primary excision to see if immune changes precede macroscopic tumor involvement. Supported by Harvard Skin SPORE Project 5 and Immune Monitoring Core P50CA93683-01 No significant financial relationships to disclose.

Purpose: Renal cancer response to interleukin 2 (IL-2) therapy and patient survival has been correlated with tumor histology and carbonic anhydrase IX (CAIX) expression. In an effort to confirm and expand these observations, we examined CAIX expression in pathology specimens from renal cancer patients who had previously received IL-2 therapy. Experimental Design: Paraffin-embedded tissue sections of renal cancer were immunostained with the MN-75 monoclonal antibody to CAIX and expression levels were correlated with histologic findings and clinical outcome. Results: Tissue specimens were obtained from 66 patients; 27 of whom (41%) had responded to IL-2–based therapy. Fifty-eight specimens were assessed as clear cell, with 56, 33, and 4 having alveolar, granular, and papillary features, respectively. Twenty-four (36%), 31 (47%), and 11 (17%) were classified into good, intermediate, and poor prognosis groups according to the Upton pathology model. Forty-one specimens (62%) had high CAIX expression. Twenty-one of 27 (78%) responding patients had high CAIX expressing tumors compared with 20 of 39 (51%) nonresponders (odds ratio, 3.3; P = 0.04). Median survival was prolonged (P = 0.04) and survival >5 years was only seen in high CAIX expressers. In patients with intermediate pathologic prognosis, all nine responders had high CAIX expression versus 11 of 22 nonresponders. A resultant group with good pathologic prognosis alone or with intermediate pathologic prognosis and high CAIX contained 26 of 27 (96%) responders compared with 18 of 39 (46%) nonresponders (odds ratio, 30; P < 0.01) and exhibited longer median survival (P < 0.01). Conclusions: CAIX expression seems to be an important predictor of outcome in renal cell carcinoma patients receiving IL-2–based therapy and may enhance prognostic information obtained from pathology specimens.

s: Abstracts for the 20th Annual Scientific Meeting of the International Society for Biological Therapy of Cancer (Primary Authors are Italicized): CYTOKINES: BIOLOGY AND THERAPEUTICS

Abstract Myeloid suppressor cells with high arginase activity are found in tumors and spleen of mice with colon and lung cancer. These cells, described as macrophages or immature dendritic cells, deplete arginine and impair T cell proliferation and cytokine production. Although arginase activity has been described in cancer patients, it is thought to originate from tumor cells metabolizing arginine to ornithine needed to sustain rapid cell proliferation. The goal of this study was to determine whether myeloid suppressor cells producing high arginase existed in renal cell carcinoma patients. Peripheral blood mononuclear cells from 123 patients with metastatic renal cell carcinoma, prior to treatment, were found to have a significantly increased arginase activity. These patients had a markedly decreased cytokine production and expressed low levels of T cell receptor CD3ζ chain. Cell separation studies showed that the increased arginase activity was limited to a specific subset of CD11b+, CD14−, CD15+ cells with a polymorphonuclear granulocyte morphology and markers, instead of macrophages or dendritic cells described in mouse models. Furthermore, these patients had low levels of arginine and high levels of ornithine in plasma. Depletion of the CD11b+, CD14− myeloid suppressor cells reestablished T cell proliferation and CD3ζ chain expression. These results showed, for the first time, the existence of suppressor myeloid cells producing arginase in human cancer patients. In addition, it supports the concept that blocking arginase may be an important step in the success of immunotherapy.

s for the 19th Annual Scientific Meeting of the International Society for Biological Therapy of Cancer, San Francisco, California, November 4-7, 2004: Angiogenesis

PURPOSE:Dendritic cells (DCs) are potent antigen-presenting cells that are uniquely capable of inducing tumor-specific immune responses. We have conducted a Phase I trial in which patients with metastatic breast and renal cancer were treated with a vaccine prepared by fusing autologous tumor and DCs.EXPERIMENTAL DESIGN:Accessible tumor tissue was disrupted into single cell suspensions. Autologous DCs were prepared from adherent peripheral blood mononuclear cells that were obtained by leukapheresis and cultured in granulocyte macrophage colony-stimulating factor, interleukin 4, and autologous plasma. Tumor cells and DCs were cocultured in the presence of polyethylene glycol to generate the fusions. Fusion cells were quantified by determining the percentage of cells that coexpress tumor and DC markers. Patients were vaccinated with fusion cells at 3-week intervals and assessed weekly for toxicity, and tumor response was assessed at 1, 3, and 6 months after completion of vaccination.RESULTS:The vaccine was generated for 32 patients. Twenty-three patients were vaccinated with 1 x 10(5) to 4 x 10(6) fusion cells. Fusion cells coexpressed tumor and DC antigens and stimulated allogeneic T-cell proliferation. There was no significant treatment-related toxicity and no clinical evidence of autoimmunity. In a subset of patients, vaccination resulted in an increased percentage of CD4 and CD8+ T cells expressing intracellular IFN-gamma in response to in vitro exposure to tumor lysate. Two patients with breast cancer exhibited disease regressions, including a near complete response of a large chest wall mass. Five patients with renal carcinoma and one patient with breast cancer had disease stabilization.CONCLUSIONS:Our findings demonstrate that fusion cell vaccination of patients with metastatic breast and renal cancer is a feasible, nontoxic approach associated with the induction of immunological and clinical antitumor responses.

s for the 19th Annual Scientific Meeting of the International Society for Biological Therapy of Cancer, San Francisco, California, November 4-7, 2004: Mechanisms of Escape/Resistance

4747 Background: Thalidomide (thal) (Celgene) produces tumor responses in some pts with mRCC, but also causes dose dependent fatigue. EPO (Ortho Biotech Products) improves overall quality of life [QOL] in cancer pts by raising hemoglobin (hgb) and reducing fatigue. We added EPO to thal in an effort to enhance its tolerability and efficacy. Methods: Pts with mRCC refractory to immune Rx were randomized to thal (100mg/d) or thal (100mg/d) + EPO (40,000 IU/wk). The dose of thal was escalated by 100mg/wk to 1g or MTD and EPO to 60,000 IU/wk in pts who failed to develop an hgb increase of 1g/dl after 4 wks. Tumor response was assessed by CT scan every 12 wks and QOL (FACT-An and Linear Analog scale) at baseline and q 4 wks for 24 wks. Results: To date, 25 patients (16 M, 9 F); median age 60 yrs (range 36–78); median prior Rx 2 (range 0–4); median number of metastatic sites 3.5 (range 1–7); median Motzer prognostic score 1 (range 0–3) have been enrolled since 4/11/01. 13 have received thal and 12 thal + EPO. Pts on thal had an MTD range from 100–700 (median 200), duration of Rx 2–59 wks (median 8 wks), mean baseline hgb (11.47 g/dl) and hgb variation from baseline range -3.3 to +1.8 (median -1.1 g/dl). Pts on thal + EPO had an MTD range from 100–800 (median 350), duration of Rx 1–119 wks (median 9 wks), mean baseline hgb (10.68 g/dl) and hgb variation from baseline -1.8 to +3.9 (median +0.95 g/dl). The mean change in hgb has been greater for pts on the thal + EPO arm (P=0.08, CI 1.062) Side effects (grade 1–2) including fatigue (80%), constipation (72%), N/V (52%), and neuropathy (40%) have occurred equally between arms. No responses (CR/PR) have been seen in either arm but 3 pts (thal [1pt], thal + EPO [2pts]) had SD lasting 24–119+ wks. So far, 21 of 25 pts have come off the study at or before wk 12 due to disease progression. Conclusions: Addition of EPO to thal produced an improvement in baseline hgb. However, this improvement has not reached statistical significance. The effect of this rise in hgb on QOL will be analyzed at the completion of the study. Rapid disease progression in this poor prognosis pt population limits the ability to determine the impact of EPO on the clinical efficacy of thal at present. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Celgene Celgene Ortho Biotech

2553 Background: rhIL-18, a member of the Th-1 inducing family of cytokines, has demonstrated anti-tumor activity in a variety of preclinical tumor models. Methods: In an ongoing phase I dose-escalation study, rhIL-18 (SB485232) was administered as a 2 hour infusion daily for 5 consecutive days to patients (pts) with solid tumors. Doses ranging from 3–1000 μg/kg/day were planned. The objectives were to determine tolerability, define a biologically effective dose, and assess pharmacokinetics, immunogenicity, immunomodulatory and anti-tumor activity of rhIL-18. Pts with detectable anti-SB-485232 antibodies at screening were excluded. Results: Twenty-six pts {metastatic renal cell carcinoma (21), advanced melanoma (4), Hodgkin's lymphoma (1)}were treated at dose levels up to1000 μg/kg/day . Two pts were withdrawn from the study: 1 pt at 10 μg/kg/day due to rapidly progressive disease and 1 pt at 100 μg/kg/day due to hypotension with bradycardia, a dose-limiting toxicity. This cohort was expanded to 6 pts with no further dose-limiting toxicities. Drug-related adverse event data are available for 25 pts: Grade (G) 1–2 fever (n=19), chills (n=14), rash (n=3) nausea/vomiting (n=8); G1 myalgia (n=3); G1–2 neutropenia (n=11), G1–3 lymphopenia (n=16), G1–2 thrombocytopenia (n=4), G1 elevated AST (n=4), G1–2 elevated ALT (n=5), G1 hypocalcemia (n=3), G1–2 hypoalbuminemia (n=12). Five pts developed antibodies to SB-485232. Increases in neopterin (24/25 pts), GM-CSF (25/25 pts), IL-18 BP (25/25 pts), sFas/L(22/25 pts), and INFγ (15/25 pts) were observed. Upregulation of FasL on NK, CD8+, and CD4+ cells as well as of CD69 on CD8+ cells was observed. Evidence of clinical activity was observed in two patients (metastatic melanoma and renal cell carcinoma) treated at 100 μg/kg/day. Conclusions: rhIL-18 administered as a single cycle was well tolerated. Preliminary data demonstrate evidence of immunomodulatory and clinical activity. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration GlaxoSmithKline

s for the 19th Annual Scientific Meeting of the International Society for Biological Therapy of Cancer, San Francisco, California, November 4-7, 2004: Cancer Biometrics

CNI-1493, an inhibitor of proinflammatory cytokines, was studied in a Phase I trial in melanoma and renal cancer patients receiving high-dose interleukin 2 (IL-2). Objectives of the study were to define the maximum tolerated dose (MTD) and toxicity of CNI-1493, to assess its pharmacological effects, and to define its pharmacokinetics. Twenty-four patients were treated in sequential cohorts with CNI-1493 doses from 2 through 32 mg/m2 daily. Patients first received only CNI-1493 daily for 5 days. After a 9-day rest, patients received two 5-day courses of IL-2 of 600,000 IU/kg every 8 h for up to 14 doses/course plus daily CNI-1493; courses were separated by a 9-day rest period. CNI-1493 administered alone was well tolerated at doses through 32 mg/m2; MTD was not reached. The only clinical toxicity attributed to CNI-1493 was occasional injection-site phlebitis. Grade 1 creatinine increases occurred in 1 of 7 patients at 4 mg/m2, in 1 of 1 patients at 25 mg/m2, and in 3 of 6 patients at 32 mg/m2 CNI-1493 alone. In combination with high-dose IL-2, CNI-1493 at > or = 25 mg/m2 seemed to exacerbate IL-2-induced nephrotoxicity: grade 3 or 4 creatinine increases developed in 3 of 6 patients at 25 or 32 mg/m2, as compared with 1 of 16 patients at doses < or = 16 mg/m2. The MTD for CNI-1493 given with high-dose IL-2 was 16 mg/m2. The dose-limiting toxicity of IL-2 was hypotension in 63% of patients; overall tolerance to IL-2 was not improved by CNI-1493. However, relative to changes seen in a reference group receiving high-dose IL-2 alone, at doses > or = 4 mg/m2 CNI-1493 did show evidence of pharmacological activity as an inhibitor of tumor necrosis factor production.

PURPOSE:The Cytokine Working Group performed a randomized phase II trial of two outpatient biochemotherapy regimens to identify an outpatient regimen with high antitumor activity and less toxicity than inpatient regimens which might be compared with chemotherapy or inpatient biochemotherapy regimens in future phase III trials.PATIENTS AND METHODS:Eighty-one patients with metastatic malignant melanoma received dacarbazine 250 mg/m(2)/d intravenously (IV) and cisplatin 25 mg/m(2)/d IV on days 1, 2, and 3, plus interferon (IFN) alfa-2b 5 mU/m(2) subcutaneously (SC) on days 6, 8, 10, 13, and 15, given every 28 days. Interleukin-2 (IL-2) was given daily on days 6 to 10 and 13 to 15. In group 1, IV IL-2 was given at 18.0 MU/m(2), and in group 2, SC IL-2 was given at 5.0 mU/m(2).RESULTS:In group 1 (IV IL-2), there were five complete responses (CRs) and 11 partial responses (PRs) among 44 patients (objective response rate [ORR], 36%; 95% confidence interval [CI], 22% to 51%). In group 2 (SC IL-2), there was one CR and five PRs among the 36 patients (ORR, 17%; 95% CI, 4% to 29%). The median survival was 10.7 months in group 1 and 7.3 months in group 2. Eleven patients in group 1 and four patients in group 2 remain alive as of the last follow-up. Toxicities in both groups were similar. No patient required hospitalization for neutropenic fever.CONCLUSION:Biochemotherapy has activity in these outpatient regimens with acceptable toxicity. The antitumor activity observed with the IV IL-2 regimen seems similar to that of inpatient biochemotherapy regimens. If inpatient biochemotherapy regimens develop an established role in the management of melanoma, future phase III trial comparisons with this outpatient IV IL-2 regimen would be appropriate.

IL-12 plays a pivotal role in the stimulation of immune responses against intracellular infections. This role is manifested in the increased susceptibility to atypical mycobacterial and salmonella infections among individuals whose lymphocytes lack expression of IL-12Rβ1. Here, we report on a patient with Mycobacterium avium infection, recurrent Staphylococcus aureus sinusitis, and multiple adverse drug reactions whose T cells were unable to produce IFN-γ or proliferate in response to IL-12 despite the expression of wild-type IL-12Rβ1 and IL-12Rβ2. The defect in these functional responses to IL-12 was selective, as cytolytic activity induced by IL-12 was intact, and lymphocytes were responsive to stimulation by IL-2. An examination of cytokine signaling revealed that STAT4 and extracellular regulated kinase 1 (ERK1) activation by IL-12 was intact, whereas the activation of STAT1, -3, and -5 by IL-12 was lost. This impairment of STAT activation was specific for IL-12, as STAT activation by IL-2, IL-15, and IFN-γ was unaffected. These findings demonstrate that the activation of STAT4 alone is not sufficient for IL-12-induced IFN-γ production and proliferation and suggest that other STATs play a role in these responses to IL-12. While the etiology of the impaired IL-12 signaling in this patient has not yet been elucidated, the absence of mutations in IL-12Rβ1 or IL-12Rβ2 and the preservation of STAT4 activation raise the possibility that there may be a mutation in an as yet undiscovered component of the IL-12 signaling complex that is normally required for the recruitment and activation of STAT1, -3, and -5.