Iain A. McNeish

Rethinking ovarian cancer: recommendations for improving outcomes.

There have been major advances in our understanding of the cellular and molecular biology of the human malignancies that are collectively referred to as ovarian cancer. At a recent Helene Harris Memorial Trust meeting, an international group of researchers considered actions that should be taken to improve the outcome for women with ovarian cancer. Nine major recommendations are outlined in this Opinion article.

“Re-educating” tumor-associated macrophages by targeting NF-κB

The nuclear factor κB (NF-κB) signaling pathway is important in cancer-related inflammation and malignant progression. Here, we describe a new role for NF-κB in cancer in maintaining the immunosuppressive phenotype of tumor-associated macrophages (TAMs). We show that macrophages are polarized via interleukin (IL)-1R and MyD88 to an immunosuppressive “alternative” phenotype that requires IκB kinase β–mediated NF-κB activation. When NF-κB signaling is inhibited specifically in TAMs, they become cytotoxic to tumor cells and switch to a “classically” activated phenotype; IL-12high, major histocompatibility complex IIhigh, but IL-10low and arginase-1low. Targeting NF-κB signaling in TAMs also promotes regression of advanced tumors in vivo by induction of macrophage tumoricidal activity and activation of antitumor activity through IL-12–dependent NK cell recruitment. We provide a rationale for manipulating the phenotype of the abundant macrophage population already located within the tumor microenvironment; the potential to “re-educate” the tumor-promoting macrophage population may prove an effective and novel therapeutic approach for cancer that complements existing therapies.

Paraneoplastic Thrombocytosis in Ovarian Cancer

BACKGROUND The mechanisms of paraneoplastic thrombocytosis in ovarian cancer and the role that platelets play in abetting cancer growth are unclear. METHODS We analyzed clinical data on 619 patients with epithelial ovarian cancer to test associations between platelet counts and disease outcome. Human samples and mouse models of epithelial ovarian cancer were used to explore the underlying mechanisms of paraneoplastic thrombocytosis. The effects of platelets on tumor growth and angiogenesis were ascertained. RESULTS Thrombocytosis was significantly associated with advanced disease and shortened survival. Plasma levels of thrombopoietin and interleukin-6 were significantly elevated in patients who had thrombocytosis as compared with those who did not. In mouse models, increased hepatic thrombopoietin synthesis in response to tumor-derived interleukin-6 was an underlying mechanism of paraneoplastic thrombocytosis. Tumor-derived interleukin-6 and hepatic thrombopoietin were also linked to thrombocytosis in patients. Silencing thrombopoietin and interleukin-6 abrogated thrombocytosis in tumor-bearing mice. Anti-interleukin-6 antibody treatment significantly reduced platelet counts in tumor-bearing mice and in patients with epithelial ovarian cancer. In addition, neutralizing interleukin-6 significantly enhanced the therapeutic efficacy of paclitaxel in mouse models of epithelial ovarian cancer. The use of an antiplatelet antibody to halve platelet counts in tumor-bearing mice significantly reduced tumor growth and angiogenesis. CONCLUSIONS These findings support the existence of a paracrine circuit wherein increased production of thrombopoietic cytokines in tumor and host tissue leads to paraneoplastic thrombocytosis, which fuels tumor growth. We speculate that countering paraneoplastic thrombocytosis either directly or indirectly by targeting these cytokines may have therapeutic potential. (Funded by the National Cancer Institute and others.).

A Phase I Study of OncoVEXGM-CSF, a Second-Generation Oncolytic Herpes Simplex Virus Expressing Granulocyte Macrophage Colony-Stimulating Factor

Purpose: To conduct a phase I clinical trial with a second-generation oncolytic herpes simplex virus (HSV) expressing granulocyte macrophage colony-stimulating factor (Onco VEXGM-CSF) to determine the safety profile of the virus, look for evidence of biological activity, and identify a dosing schedule for later studies. Experimental Design: The virus was administered by intratumoral injection in patients with cutaneous or s.c. deposits of breast, head and neck and gastrointestinal cancers, and malignant melanoma who had failed prior therapy. Thirteen patients were in a single-dose group, where doses of 106, 107, and 108 plaque-forming units (pfu)/mL were tested, and 17 patients were in a multidose group testing a number of dose regimens. Results: The virus was generally well tolerated with local inflammation, erythema, and febrile responses being the main side effects. The local reaction to injection was dose limiting in HSV-seronegative patients at 107 pfu/mL. The multidosing phase thus tested seroconverting HSV-seronegative patients with 106 pfu/mL followed by multiple higher doses (up to 108 pfu/mL), which was well tolerated by all patients. Biological activity (virus replication, local reactions, granulocyte macrophage colony-stimulating factor expression, and HSV antigen-associated tumor necrosis), was observed. The duration of local reactions and virus replication suggested that dosing every 2 to 3 weeks was appropriate. Nineteen of 26 patient posttreatment biopsies contained residual tumor of which 14 showed tumor necrosis, which in some cases was extensive, or apoptosis. In all cases, areas of necrosis also strongly stained for HSV. The overall responses to treatment were that three patients had stable disease, six patients had tumors flattened (injected and/or uninjected lesions), and four patients showed inflammation of uninjected as well as the injected tumor, which, in nearly all cases, became inflamed. Conclusions: Onco VEXGM-CSF is well tolerated and can be safely administered using the multidosing protocol described. Evidence of an antitumor effect was seen.

Interleukin-6 as a Therapeutic Target in Human Ovarian Cancer

Purpose: We investigated whether inhibition of interleukin 6 (IL-6) has therapeutic activity in ovarian cancer via abrogation of a tumor-promoting cytokine network. Experimental Design: We combined preclinical and in silico experiments with a phase 2 clinical trial of the anti-IL-6 antibody siltuximab in patients with platinum-resistant ovarian cancer. Results: Automated immunohistochemistry on tissue microarrays from 221 ovarian cancer cases showed that intensity of IL-6 staining in malignant cells significantly associated with poor prognosis. Treatment of ovarian cancer cells with siltuximab reduced constitutive cytokine and chemokine production and also inhibited IL-6 signaling, tumor growth, the tumor-associated macrophage infiltrate and angiogenesis in IL-6–producing intraperitoneal ovarian cancer xenografts. In the clinical trial, the primary endpoint was response rate as assessed by combined RECIST and CA125 criteria. One patient of eighteen evaluable had a partial response, while seven others had periods of disease stabilization. In patients treated for 6 months, there was a significant decline in plasma levels of IL-6–regulated CCL2, CXCL12, and VEGF. Gene expression levels of factors that were reduced by siltuximab treatment in the patients significantly correlated with high IL-6 pathway gene expression and macrophage markers in microarray analyses of ovarian cancer biopsies. Conclusion: IL-6 stimulates inflammatory cytokine production, tumor angiogenesis, and the tumor macrophage infiltrate in ovarian cancer and these actions can be inhibited by a neutralizing anti-IL-6 antibody in preclinical and clinical studies. Clin Cancer Res; 17(18); 6083–96. ©2011 AACR.

Rucaparib in relapsed, platinum-sensitive high-grade ovarian carcinoma (ARIEL2 Part 1): an international, multicentre, open-label, phase 2 trial

BACKGROUND Poly(ADP-ribose) polymerase (PARP) inhibitors have activity in ovarian carcinomas with homologous recombination deficiency. Along with BRCA1 and BRCA2 (BRCA) mutations genomic loss of heterozygosity (LOH) might also represent homologous recombination deficiency. In ARIEL2, we assessed the ability of tumour genomic LOH, quantified with a next-generation sequencing assay, to predict response to rucaparib, an oral PARP inhibitor. METHODS ARIEL2 is an international, multicentre, two-part, phase 2, open-label study done at 49 hospitals and cancer centres in Australia, Canada, France, Spain, the UK, and the USA. In ARIEL2 Part 1, patients with recurrent, platinum-sensitive, high-grade ovarian carcinoma were classified into one of three predefined homologous recombination deficiency subgroups on the basis of tumour mutational analysis: BRCA mutant (deleterious germline or somatic), BRCA wild-type and LOH high (LOH high group), or BRCA wild-type and LOH low (LOH low group). We prespecified a cutoff of 14% or more genomic LOH for LOH high. Patients began treatment with oral rucaparib at 600 mg twice per day for continuous 28 day cycles until disease progression or any other reason for discontinuation. The primary endpoint was progression-free survival. All patients treated with at least one dose of rucaparib were included in the safety analyses and all treated patients who were classified were included in the primary endpoint analysis. This trial is registered with ClinicalTrials.gov, number NCT01891344. Enrolment into ARIEL2 Part 1 is complete, although an extension (Part 2) is ongoing. FINDINGS 256 patients were screened and 206 were enrolled between Oct 30, 2013, and Dec 19, 2014. At the data cutoff date (Jan 18, 2016), 204 patients had received rucaparib, with 28 patients remaining in the study. 192 patients could be classified into one of the three predefined homologous recombination deficiency subgroups: BRCA mutant (n=40), LOH high (n=82), or LOH low (n=70). Tumours from 12 patients were established as BRCA wild-type, but could not be classified for LOH, because of insufficient neoplastic nuclei in the sample. The median duration of treatment for the 204 patients was 5·7 months (IQR 2·8-10·1). 24 patients in the BRCA mutant subgroup, 56 patients in the LOH high subgroup, and 59 patients in the LOH low subgroup had disease progression or died. Median progression-free survival after rucaparib treatment was 12·8 months (95% CI 9·0-14·7) in the BRCA mutant subgroup, 5·7 months (5·3-7·6) in the LOH high subgroup, and 5·2 months (3·6-5·5) in the LOH low subgroup. Progression-free survival was significantly longer in the BRCA mutant (hazard ratio 0·27, 95% CI 0·16-0·44, p<0·0001) and LOH high (0·62, 0·42-0·90, p=0·011) subgroups compared with the LOH low subgroup. The most common grade 3 or worse treatment-emergent adverse events were anaemia or decreased haemoglobin (45 [22%] patients), and elevations in alanine aminotransferase or aspartate aminotransferase (25 [12%]). Common serious adverse events included small intestinal obstruction (10 [5%] of 204 patients), malignant neoplasm progression (10 [5%]), and anaemia (nine [4%]). Three patients died during the study (two because of disease progression and one because of sepsis and disease progression). No treatment-related deaths occurred. INTERPRETATION In patients with BRCA mutant or BRCA wild-type and LOH high platinum-sensitive ovarian carcinomas treated with rucaparib, progression-free survival was longer than in patients with BRCA wild-type LOH low carcinomas. Our results suggest that assessment of tumour LOH can be used to identify patients with BRCA wild-type platinum-sensitive ovarian cancers who might benefit from rucaparib. These results extend the potential usefulness of PARP inhibitors in the treatment setting beyond BRCA mutant tumours. FUNDING Clovis Oncology, US Department of Defense Ovarian Cancer Research Program, Stand Up To Cancer-Ovarian Cancer Research Fund Alliance-National Ovarian Cancer Coalition Dream Team Translational Research Grant, and V Foundation Translational Award.

Arginine deprivation and argininosuccinate synthetase expression in the treatment of cancer

Arginine, a semi‐essential amino acid in humans, is critical for the growth of human cancers, particularly those marked by de novo chemoresistance and a poor clinical outcome. In addition to protein synthesis, arginine is involved in diverse aspects of tumour metabolism, including the synthesis of nitric oxide, polyamines, nucleotides, proline and glutamate. Tumoural downregulation of the enzyme argininosuccinate synthetase (ASS1), a recognised rate‐limiting step in arginine synthesis, results in an intrinsic dependence on extracellular arginine due to an inability to synthesise arginine for growth. This dependence on extracellular arginine is known as arginine auxotrophy. Several tumours are arginine auxotrophic, due to variable loss of ASS1, including hepatocellular carcinoma, malignant melanoma, malignant pleural mesothelioma, prostate and renal cancer. Importantly, targeting extracellular arginine for degradation in the absence of ASS1 triggers apoptosis in arginine auxotrophs. Several phase I/II clinical trials of the arginine‐lowering drug, pegylated arginine deiminase, have shown encouraging evidence of clinical benefit and low toxicity in patients with ASS1‐negative tumours. In part, ASS1 loss is due to epigenetic silencing of the ASS1 promoter in various human cancer cell lines and tumours, and it is this silencing that confers arginine auxotrophy. In relapsed ovarian cancer, this is associated with platinum refractoriness. In contrast, several platinum sensitive tumours, including primary ovarian, stomach and colorectal cancer, are characterised by ASS1 overexpression, which is regulated by proinflammatory cytokines. This review examines the prospects for novel approaches in the prevention, diagnosis and treatment of malignant disease based on ASS1 pathophysiology and its rate‐limiting product, arginine.

Randomized Phase II Placebo-Controlled Trial of Maintenance Therapy Using the Oral Triple Angiokinase Inhibitor BIBF 1120 After Chemotherapy for Relapsed Ovarian Cancer

PURPOSE Inhibiting angiogenesis is one of the most promising avenues for new therapies for ovarian cancer. We investigated the efficacy and safety of a novel agent, BIBF 1120, a triple angiokinase inhibitor, after chemotherapy for relapsed disease. PATIENTS AND METHODS We conducted a randomized, double-blind, controlled phase II trial in 83 patients who had just completed chemotherapy for relapsed ovarian cancer, with evidence of response, but at high risk of further early recurrence. The patients were randomly assigned to receive maintenance therapy using BIBF 1120 250 mg or placebo, twice per day, continuously for 36 weeks. End points were progression-free survival (PFS), toxicity, and overall survival. RESULTS Thirty-six-week PFS rates were 16.3% and 5.0% in the BIBF 1120 and placebo groups, respectively (hazard ratio, 0.65; 95% CI, 0.42 to 1.02; P = .06). Four patients continued on BIBF 1120, including two patients for another year or more. The proportion of patients with any grade 3 or 4 adverse events was similar between the groups (34.9% for BIBF 1120 v 27.5% for placebo; P = .49; mostly grade 3). However, more patients on BIBF 1120 experienced diarrhea, nausea, or vomiting (mainly grade 1 or 2 and no grade 4). There was a higher rate of grade 3 or 4 hepatotoxicity in patients on BIBF 1120 (51.2%) compared with patients on placebo (7.5%; P < .001), but this was rarely of clinical significance, and patients continued with the trial treatment. A single-level dose reduction to 150 mg was made in 15 patients, all on active drug. CONCLUSION BIBF 1120 is well tolerated and associated with a potential improvement in PFS. The observed treatment effect is sufficient to justify further study within a large phase III trial.

Low-risk persistent gestational trophoblastic disease: Outcome after initial treatment with low-dose methotrexate and folinic acid from 1992 to 2000

PURPOSE We have simplified the treatment of gestational trophoblastic disease (GTD) in order to reduce the number of patients exposed to potentially carcinogenic chemotherapy. Patients who score 0 to 8 on the Charing Cross scoring system are classified as low-risk and receive methotrexate (MTX) and folinic acid (FA), whereas those who score higher than 8 are classified as high-risk and receive the etoposide, methotrexate, and dactinomycin (EMA)/cyclophosphamide and vincristine (CO) regimen. PATIENTS AND METHODS Between 1992 and 2000, 485 women with GTD were commenced on MTX/FA at Charing Cross Hospital, London, United Kingdom. If patients developed MTX resistance or toxicity, treatment was altered according to the level of beta human chorionic gonadotropin (hCG). If serum hCG was < or = 100 IU/L, patients received dactinomycin; if hCG was greater than 100 IU/L, patients received EMA/CO. RESULTS The median duration of follow-up was 4.7 years. Overall survival was 100% and the relapse rate was 3.3% (16 of 485 patients). hCG values normalized in 324 (66.8%) of 485 patients with MTX alone, whereas 161 (33.2%) of 485 patients required a change in treatment, 11 because of MTX toxicity and 150 because of MTX resistance. Sixty-seven patients changed to dactinomycin, of whom 58 achieved normal hCG values, and nine required third-line chemotherapy with EMA/CO. hCG values normalized in 93 (98.9%) of 94 patients who changed directly to EMA/CO from MTX. CONCLUSION Single-agent dactinomycin has activity in patients with low-risk GTD who develop MTX resistance and whose hCG is low. Simplifying the stratification of GTD into two classes (low- and high-risk) does not compromise overall outcome and may reduce the risk of second tumors.

Phase I/II Study of Oncolytic HSVGM-CSF in Combination with Radiotherapy and Cisplatin in Untreated Stage III/IV Squamous Cell Cancer of the Head and Neck

Purpose: This study sought to define the recommended dose of JS1/34.5-/47-/GM-CSF, an oncolytic herpes simplex type-1 virus (HSV-1) encoding human granulocyte-macrophage colony-stimulating factor (GM-CSF), for future studies in combination with chemoradiotherapy in patients with squamous cell cancer of the head and neck (SCCHN). Experimental Design: Patients with stage III/IVA/IVB SCCHN received chemoradiotherapy (70 Gy/35 fractions with concomitant cisplatin 100 mg/m2 on days 1, 22, and 43) and dose-escalating (106, 106, 106, 106 pfu/mL for cohort 1; 106, 107, 107, 107 for cohort 2; 106, 108, 108, 108 for cohort 3) JS1/34.5-/47-/GM-CSF by intratumoral injection on days 1, 22, 43, and 64. Patients underwent neck dissection 6 to 10 weeks later. Primary end points were safety and recommended dose/schedule for future study. Secondary end points included antitumor activity (radiologic, pathologic). Relapse rates and survival were also monitored. Results: Seventeen patients were treated without delays to chemoradiotherapy or dose-limiting toxicity. Fourteen patients (82.3%) showed tumor response by Response Evaluation Criteria in Solid Tumors, and pathologic complete remission was confirmed in 93% of patients at neck dissection. HSV was detected in injected and adjacent uninjected tumors at levels higher than the input dose, indicating viral replication. All patients were seropositive at the end of treatment. No patient developed locoregional recurrence, and disease-specific survival was 82.4% at a median follow-up of 29 months (range, 19-40 months). Conclusions: JS1/34.5-/47-/GM-CSF combined with cisplatin-based chemoradiotherapy is well tolerated in patients with SCCHN. The recommended phase II dose is 106, 108, 108, 108. Locoregional control was achieved in all patients, with a 76.5% relapse-free rate so far. Further study of this approach is warranted in locally advanced SCCHN. Clin Cancer Res; 16(15); 4005–15. ©2010 AACR.