A phase 1b study of trebananib in combination with pegylated liposomal doxorubicin or topotecan in women with recurrent platinum-resistant or partially platinum-sensitive ovarian cancer

Antiangiogenic Strategies in Epithelial Ovarian Cancer: Mechanism, Resistance, and Combination Therapy

Angiogenesis is one of the hallmarks of cancer and plays a crucial role in carcinogenesis and progression of epithelial ovarian cancer. Antiangiogenic agent is the first approved targeted agent in ovarian cancer. Anti-angiogenic agents mainly include agents target VEGF/VEGFR pathway, such as bevacizumab and agents target receptor tyrosine kinase, and non-VEGF/VEGFR targets of angiogenesis. Antiangiogenic agents demonstrate certain effects in ovarian cancer treatment either as monotherapy or combined with chemotherapy. Unfortunately, antiangiogenic agents, such as bevacizumab, integrated into the ovarian cancer treatment paradigm do not increase cures. Thus, the benefits of anti-angiogenic agents must be carefully weighed against the cost and associated toxicities. Antiangiogenic agents drug resistance and short of predictive biomarkers are main obstacles in ovarian cancer treatment. A combination of poly (ADP-ribose) polymerase inhibitors or immune checkpoint inhibitors might be great strategies to overcome resistance as well as enhance anti-tumor activity of anti-angiogenic drugs. Predictive biomarkers of antiangiogenic agents are in urgent need.

First-in-human, dose-escalation, phase 1 study of anti-angiopoietin-2 LY3127804 as monotherapy and in combination with ramucirumab in patients with advanced solid tumours

BACKGROUND

This is the first-in-human study of novel anti-angiopoietin-2 (Ang-2) monoclonal antibody LY3127804 as monotherapy and in combination with ramucirumab in advanced solid tumours.

METHODS

Patients received intravenous LY3127804 monotherapy (4, 8, 12, 16, 20 and 27 mg/kg) in part A; LY3127804 (8, 12, 16, 20 and 27 mg/kg) with 8 mg/kg ramucirumab in part B; and LY3127804 (20 mg/kg) with 12 mg/kg ramucirumab in part C. Treatments were administered every 2 weeks (Q2W) during 28-day cycles. Dose-escalation was based on cycle 1 dose-limiting toxicities (DLTs).

RESULTS

Sixty-two patients were treated in part A (n = 20), part B (n = 35) and part C (n = 7). Constipation, diarrhoea and fatigue were the most common treatment-emergent adverse events (TEAEs) in part A; hypertension and peripheral oedema were the most frequent TEAE in parts B and C. No DLT was observed and maximum tolerated dose for LY3127804 was not reached. Four patients achieved partial response with combination therapy (clear cell endometrial carcinoma, cervix squamous cell carcinoma, carcinoma of unknown primary and gastroesophageal junction carcinoma), 29 achieved stable disease, and 24 had progressive disease.

CONCLUSIONS

LY3127804 monotherapy and its combination with ramucirumab are well tolerated. LY3127804 20 mg/kg was the recommended Phase 2 dose.

Targeted therapies in gynecological cancers: a comprehensive review of clinical evidence

Advanced and recurrent gynecological cancers are associated with poor prognosis and lack of effective treatment. The developments of the molecular mechanisms on cancer progression provide insight into novel targeted therapies, which are emerging as groundbreaking and promising cancer treatment strategies. In gynecologic malignancies, potential therapeutic targeted agents include antiangiogenic agents, poly (ADP-ribose) polymerase (PARP) inhibitors, tumor-intrinsic signaling pathway inhibitors, selective estrogen receptor downregulators, and immune checkpoint inhibitors. In this article, we provide a comprehensive review of the clinical evidence of targeted agents in gynecological cancers and discuss the future implication.

Angiopoietin-1 and Angiopoietin-2 Inhibitors: Clinical Development

PURPOSE OF REVIEW

The purpose of this review is to discuss the current understanding of the Tie2-angiopoietin system and its role in tumor growth and metastasis. This review also focuses on preclinical and clinical data published to date that have evaluated Tie2-angiopoietin inhibition.

RECENT FINDINGS

Tie2 inhibition has shown significant promise in preclinical models, notable for decreased tumor burden and fewer sites of metastatic disease across various malignancies. However, data from human clinical trials have shown more mixed results. Trebananib, rebastanib, and MEDI3617 are the three Tie2-angiopoietin inhibitors that have been most widely evaluated in phase I and II trials. Further investigation into these therapies is ongoing. The Tie2-angiopoietin pathway continues to show promise in preclinical and some clinical trials, including studies on recurrent or metastatic breast and renal cell carcinomas. Further evaluation of these therapies, however, is warranted to better understand their optimal clinical utility.

Peptibodies: An elegant solution for a long-standing problem

Chimeric proteins composed of a biologically active peptide and a fragment crystallizable (Fc) domain of immunoglobulin G (IgG) are known as peptibodies. They present an extended half-life due to neonatal Fc receptor (FcRn) salvage pathway, a decreased renal clearance rate owing to its increased size (≈70 kDa) and, depending on the peptide used in the design of the peptibody, an active-targeting moiety. Also, the peptides therapeutic activity is boosted by the number of peptides in the fusion protein (at least two peptides) and to some peptides' alterations. Peptibodies are mainly obtained through recombinant DNA technology. However, to improve peptide properties, "unnatural" changes have been introduced to the original peptides' sequence, for instance, the incorporation of D- or non-natural amino acid residues or even cyclization thus, limiting the application of genetic engineering in the production of peptibodies, since these peptides must be obtained via chemical synthesis. This constrains prompted the development of new methods for conjugation of peptides to Fc domains. Another challenge, subject of intense research, relates to the large-scale production of such peptibodies using these new techniques, which can be minimized by their proved value. To date, two peptibodies, romiplostim and dulaglutide, have been approved and stay as the standard of care in their areas of action. Furthermore, a considerable number of peptibodies are currently in preclinical and clinical development.

Phase 2 and biomarker study of trebananib, an angiopoietin-blocking peptibody, with and without bevacizumab for patients with recurrent glioblastoma

BACKGROUND

Angiopoietins contribute to tumor angiogenesis and may be upregulated as a compensatory factor after vascular endothelial growth factor (VEGF) blockade. The authors performed a phase 2 and biomarker study to evaluate trebananib, an angiopoietin 1 and angiopoietin 2 blocking peptibody, with and without bevacizumab in patients with recurrent glioblastoma.

METHODS

Forty-eight patients who had bevacizumab-naive, recurrent glioblastoma were treated with trebananib (30 mg/kg weekly) as single agent (n = 11) or combined with bevacizumab (n = 37). The primary endpoint was 6-month progression-free survival rate as determined by investigator review. Circulating biomarker levels were assessed before and after study therapy.

RESULTS

Trebananib was well tolerated as monotherapy and did not enhance bevacizumab-associated toxicity. Trebananib had no single-agent activity, and all treated patients exhibited progressive disease within 2 months. The 6-month progression-free survival rate for trebananib plus bevacizumab was 24.3% (95% confidence interval [CI], 12.1%-38.8%); whereas the median overall survival was 9.5 months (95% CI, 7.5-4.7 months), and the 12-month overall survival rate was 37.8% (95% CI, 22.6%-53.0%). Baseline and post-treatment changes in circulating vascular VEGF and interleukin-8 levels were correlated with survival among patients who received trebananib plus bevacizumab.

CONCLUSIONS

Angiopoietin 1 and angiopoietin 2 inhibition with trebananib was ineffective as monotherapy and did not enhance the ability of VEGF blockade with bevacizumab to improve the outcomes of patients with recurrent glioblastoma. Cancer 2018;124:1438-48. © 2017 American Cancer Society.

The era of bioengineering: how will this affect the next generation of cancer immunotherapy?

Background

Immunotherapy consists of activating the patient’s immune system to fight cancer and has the great potential of preventing future relapses thanks to immunological memory. A great variety of strategies have emerged to harness the immune system against tumors, from the administration of immunomodulatory agents that activate immune cells, to therapeutic vaccines or infusion of previously activated cancer-specific T cells. However, despite great recent progress many difficulties still remain, which prevent the widespread use of immunotherapy. Some of these limitations include: systemic toxicity, weak immune cellular responses or persistence over time and most ultimately costly and time-consuming procedures.

Main body

Synthetic and natural biomaterials hold great potential to address these hurdles providing biocompatible systems capable of targeted local delivery, co-delivery, and controlled and/or sustained release. In this review we discuss some of the bioengineered solutions and approaches developed so far and how biomaterials can be further implemented to help and shape the future of cancer immunotherapy.

Conclusion

The bioengineering strategies here presented constitute a powerful toolkit to develop safe and successful novel cancer immunotherapies.

A Pharmacokinetic and Safety Study of Trebananib, an Fc-Fusion Peptibody, in Patients With Advanced Solid Tumors and Varying Degrees of Renal Dysfunction

Clearance of trebananib (AMG 386), a 64-kD antiangiogenic peptibody, has been associated with estimated glomerular filtration rate (eGFR). We prospectively evaluated trebananib pharmacokinetics and safety/tolerability in advanced solid tumor patients with varying degrees of renal function. Patients were assigned to normal renal function, mild, moderate, or severe renal dysfunction cohorts based on eGFR, received trebananib 15 mg/kg i.v. weekly, and underwent week 1 and week 5 pharmacokinetic and weekly safety assessments. For 28 patients, trebananib clearance decreased from normal renal function (1.52 mL/hr/kg), to mild (1.20 mL/hr/kg), moderate (0.79 mL/hr/kg), and severe (0.53 mL/hr/kg) renal dysfunction (P ≤ 0.001). Treatment-related adverse events showed no association with clearance. Trebananib clearance was proportional to eGFR and unrelated to pretreatment protein excretion. These data confirm a role for renal clearance of a recombinant peptibody with molecular weight <69 kD and support a longer dosing interval for patients with severe renal dysfunction.

ENGOT-ov-6/TRINOVA-2: Randomised, double-blind, phase 3 study of pegylated liposomal doxorubicin plus trebananib or placebo in women with recurrent partially platinum-sensitive or resistant ovarian cancer

AIMS

Trebananib, a peptide-Fc fusion protein, inhibits angiogenesis by inhibiting binding of angiopoietin-1/2 to the receptor tyrosine kinase Tie2. This randomised, double-blind, placebo-controlled phase 3 study evaluated whether trebananib plus pegylated liposomal doxorubicin (PLD) improved progression-free survival (PFS) in patients with recurrent epithelial ovarian cancer.

METHODS

Women with recurrent ovarian cancer (platinum-free interval ≤12 months) were randomised to intravenous PLD 50 mg/m² once every 4 weeks plus weekly intravenous trebananib 15 mg/kg or placebo. PFS was the primary end-point; key secondary end-points were objective response rate (ORR) and duration of response (DOR). Owing to PLD shortages, enrolment was paused for 13 months; the study was subsequently truncated.

RESULTS

Two hundred twenty-three patients were enrolled. Median PFS was 7.6 months (95% CI, 7.2-9.0) in the trebananib arm and 7.2 months (95% CI, 4.8-8.2) in the placebo arm, with a hazard ratio of 0.92 (95% CI, 0.68-1.24). However, because the proportional hazards assumption was not fulfilled, the standard Cox model did not provide a reliable estimate of the hazard ratio. ORR in the trebananib arm was 46% versus 21% in the placebo arm (odds ratio, 3.43; 95% CI, 1.78-6.64). Median DOR was improved (trebananib, 7.4 months [95% CI, 5.7-7.6]; placebo, 3.9 months [95% CI, 2.3-6.5]). Adverse events with a greater incidence in the trebananib arm included localised oedema (61% versus 32%), ascites (29% versus 9%) and vomiting (45% versus 33%).

CONCLUSIONS

Trebananib demonstrated anticancer activity in this phase 3 study, indicated by improved ORR and DOR. Median PFS was not improved. No new safety signals were identified.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01281254.

Targeted antiangiogenic agents in combination with cytotoxic chemotherapy in preclinical and clinical studies in sarcoma

Sarcomas are a heterogeneous group of mesenchymal malignancies. In recent years, studies have demonstrated that inhibition of angiogenic pathways or disruption of established vasculature can attenuate the growth of sarcomas. However, when used as monotherapy in the clinical setting, these targeted antiangiogenic agents have only provided modest survival benefits in some sarcoma subtypes, and have not been efficacious in others. Preclinical and early clinical data suggest that the addition of conventional chemotherapy to antiangiogenic agents may lead to more effective therapies for patients with these tumors. In the current review, the authors summarize the available evidence and possible mechanisms supporting this approach.

Targeted therapy in ovarian cancer

Among female-specific cancers worldwide, ovarian cancer is the leading cause of death from gynecologic malignancy in the western world. Despite radical surgery and initial high response rates to first-line chemotherapy, up to 70% of patients experience relapses with a median progression-free survival of 12-18 months. There remains an urgent need for novel targeted therapies to improve clinical outcomes in ovarian cancer. This review aims to assess current understanding of targeted therapy in ovarian cancer and evaluate the evidence for targeting growth-dependent mechanisms involved in its pathogenesis. Of the many targeted therapies currently under evaluation, the most promising strategies developed thus far are antiangiogenic agents and PARP inhibitors.

Efficacy of trebananib (AMG 386) in treating epithelial ovarian cancer

INTRODUCTION

Epithelial ovarian cancer (EOC) is the leading cause of death among gynecologic cancers. The majority of women are diagnosed with advanced stage disease. It is considered a chemosensitive cancer with a high initial response rate to first-line platinum and taxane-based chemotherapy. However, most patients with advanced EOC will relapse with subsequent resistance to conventional chemotherapy and ultimately succumb to their disease. Therefore, new therapeutic agents and strategies are desperately needed to improve the outcomes in patients with advanced EOC.

AREAS COVERED

This review focuses on the use of Trebananib (a non-VEGF-dependent angiogenesis pathway inhibitor) in EOC. Angiogenesis has been recognized as an important process promoting EOC growth and metastasis. Targeting angiogenesis in EOC have been developed and studied with demonstrated clinical efficacy. Bevacizumab, a humanized monoclonal antibody, that targets vascular endothelial growth factor A (VEGF-A), has been the most well evaluated molecular targeted therapy in the treatment of advanced and recurrent EOC with proven clinical efficacy. However, VEGF-dependent angiogenesis pathway inhibitors are often associated with serious toxicities and drug resistance ultimately develops. Hence, new therapeutic approach targeting the angiopoietin-Tie-2 complex pathway (a non-VEGF-dependent angiogenesis pathway) has gained interest over the past few years as an alternative strategy to overcome VEGF-dependent anti-angiogenesis-related toxicity and resistance.

EXPERT OPINION

Targeting angiopoietin-Tie-2 pathway represents a promising alternative approach to tumor anti-angiogenesis with a distinct toxicity profile from the VEGF-dependent pathway inhibitors. However, there are still many questions to be answered regarding the optimal treatment schedules, maintenance regimens, duration of maintenance therapy, and the best combination strategy. Currently there is no reliable surrogate molecular, cellular, or genetic marker that would definitively predict response to anti-angiogenic therapy. Identification of certain relevant and predictive biomarkers in the future may optimize treatment's efficacy by distinguishing the subset group of patients with EOC that would derive the most benefit from existing antiangiogenic treatment regimens.

Topotecan synergizes with CHEK1 (CHK1) inhibitor to induce apoptosis in ovarian cancer cells

Background

Topotecan (TPT) is a therapeutic option for women with platinum-resistant or -refractory ovarian cancer. However, the dose-limiting toxicity of TPT is myelosuppression. This led us to seek a combination treatment to augment TPT anti-cancer activity in a cancer-targeted manner. Ovarian serous cancers, a major subtype, show dysregulated DNA repair pathway and often display a high level of CHEK1 (CHK1), a cell cycle regulator and DNA damage sensor. CHEK1 inhibitors are a novel approach to treatment, and have been used as single agents or in combination chemotherapy in many cancers.

Methods

We evaluated the cellular effects of TPT in a panel of high grade serous (HGS) and non-HGS ovarian cancer cells. We then determined IC50s of TPT in the absence and presence of CHEK1 inhibitor, PF477736. Synergism between TPT and PF477736 was calculated based on cellular viability assays. Cytotoxic effect of the combined treatment was compared with apoptotic activities by Caspase3/7 activity assay and Western blotting of cleaved-PARP1 and γH2AX.

Results

Non-HGS ovarian cancer cells were generally more sensitive to TPT treatment compared to HGS ovarian cancer cells. When combined with CHEK1 inhibitor, TPT potently and synergistically inhibited the proliferation of HGS ovarian cancer cells. This dramatic synergism in cellular toxicity was consistent with increases in markers of apoptosis.

Conclusions

Our findings suggest that the addition of CHEK1 inhibitor increases the response of ovarian cancer cells to TPT. Furthermore, reduced dosages of both drugs achieved maximal cytotoxic effects by combining TPT with CHEK1 inhibitor. This strategy would potentially minimize side effects of the drugs for extended clinical benefit.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1231-z) contains supplementary material, which is available to authorized users.

Advances in anti-angiogenic agents for ovarian cancer treatment: The role of trebananib (AMG 386)

Ovarian cancer is a multifaceted and genomically complex disease and has emerged as leading cause of death among gynecological malignancies. Gold-standard treatment consisted of cytoreductive surgery and paclitaxel-carboplatin chemotherapy. Recently, promising results of randomized trials have definitively confirmed the importance of angiogenesis in oncogenesis and ovarian cancer behavior, by showing a significant prolongation of progression-free survival with the addiction of an angiogenesis inhibitor to standard treatment in the first and second line setting. Research over the years has sequentially provided a rapidly broadening signaling landscape and many drugs targeting different signaling pathways of angiogenesis have been developed and investigated. Recently accumulating scientific evidence has started to shed light on the efficacy of AMG 386, a new peptibody reported to neutralize the interaction between angiopoietins (Ang1/2) and their Tie2 receptors, thus representing a promising alternative, both in terms of efficacy and toxicity profile and is considerably under investigation. The aim of this review is to summarize the recent researches and clinical progresses of AMG 386 as a novel target agent in ovarian cancer.