Prior VEGF Research Articles

INTEGRATE II: randomised phase III controlled trials of regorafenib containing regimens versus standard of care in refractory Advanced Gastro-Oesophageal Cancer (AGOC): a study by the Australasian Gastro-Intestinal Trials Group (AGITG)

BackgroundAdvanced gastro-oesophageal cancer (AGOC) carries a poor prognosis. No standard of care treatment options are available after first and second-line therapies. Regorafenib is an oral multi-targeted tyrosine kinase inhibitor targeting angiogenic, stromal, and oncogenic receptor tyrosine kinases. Regorafenib 160 mg daily prolonged progression free survival compared to placebo (INTEGRATE, phase 2). Regorafenib 80 mg daily in combination with nivolumab 3 mg/kg showed promising objective response rates (REGONIVO).Methods/designINTEGRATE II (INTEGRATE IIa and IIb) platform comprises two international phase III randomised controlled trials (RCT) with 2:1 randomisation in favor of experimental intervention. INTEGRATE IIa (double-blind) compares regorafenib 160 mg daily on days 1 to 21 of each 28-day cycle to placebo. INTEGRATE IIb (open label) compares REGONIVO, regorafenib 90 mg days 1 to 21 in combination with intravenous nivolumab 240 mg days 1 and 15 each 28-day cycle with investigator’s choice of chemotherapy (control). Treatment continues until disease progression or intolerable adverse events as per protocol. Eligible participants include adults with AGOC who have failed two or more lines of treatment. Stratification is by location of tumour (INTEGRATE IIa only), geographic region, prior VEGF inhibitor and prior immunotherapy use (INTEGRATE IIb only). Primary endpoint is overall survival. Secondary endpoints are progression free survival, objective response rate, quality of life, and safety. Tertiary/correlative objectives include biomarker and pharmacokinetic evaluation.DiscussionINTEGRATE II provides a platform to evaluate the clinical utility of regorafenib alone, as well as regorafenib in combination with nivolumab in treatment of participants with refractory AGOC.Trial registrationINTEGRATE IIa prospectively registered 1 April 2016 Australia New Zealand Clinical Trial Registry: ACTRN12616000420448 (ClinicalTrials.gov NCT02773524). INTEGRATE IIb prospectively registered 10 May 2021 ClinicalTrials.gov: NCT04879368.

INTEGRATE IIa: A randomised, double-blind, phase III study of regorafenib versus placebo in refractory advanced gastro-oesophageal cancer (AGOC)—A study led by the Australasian Gastro-intestinal Trials Group (AGITG).

LBA294 Background: AGOC has limited options after second-line therapy. Regorafenib (Rego), an oral multi-targeted tyrosine kinase inhibitor (TKI) targeting angiogenic, stromal and oncogenic receptor TKs, prolonged progression free survival (PFS) versus placebo (PBO) across all regions/subgroups in the INTEGRATE phase 2 randomised trial (JCO 2016 43(23):2728-2735). INTEGRATE IIa was designed to examine if Rego improves overall survival (OS). Methods: Double-blind placebo-controlled phase 3 trial comparing Rego + best supportive care (BSC) vs PBO + BSC using 2:1 randomisation, stratified by tumour location (GO junction vs gastric), geographic region (Asia vs rest of world), prior VEGF inhibitors (Y/N). Eligibility criteria: histologically/cytologically confirmed AGOC, evaluable metastatic/locally advanced disease, failure/intolerance of ≥ 2 prior lines of therapy with a platinum agent + fluoropyrimidine. Primary objective: OS in the whole study population. OS among Asian sub-population is a key secondary objective. Target of at least 221 events from 250 patients provides 80% power to detect an OS hazard ratio (HR) of 0.67. Pooled OS analysis incorporating INTEGRATE phase 2 data is also planned. Secondary endpoints include PFS, objective response rate, safety and quality of life. Results: 251 patients enrolled (Oct16 - Sep21) from 5 countries:157 from Asia (Korea, Taiwan, Japan);169 Rego and 82 PBO. After 238 events, median OS (in months) for Rego vs PBO was 4.5 vs 4.0 (HR 0.70 [95%CI: 0.53 to 0.92]; p = 0.011) in the whole study population, with a 12 mo survival of 19% vs 6%. Median PFS was 1.8 v 1.6 (HR = 0.52; [95%CI: 0.40-0.69]; p = < .0001). After pre-planned adjustment for multiplicity, there were no statistically significant differences across regions (Asia versus non-Asia) or other pre-specified subgroups. Pooled analysis median OS was 5.0 v 4.1 (HR 0.69 [95% CI:0.56 to 0.87]; p = 0.001). Rego toxicity was similar to previously reported. Conclusions: Rego improves survival compared with PBO in advanced refractory AGOC, offering a new treatment option. This result creates a therapeutic platform for combination studies. INTEGRATE IIb is an ongoing international randomised Phase 3 trial in pre-treated patients with AGOC comparing Rego + nivolumab to standard chemotherapy (NCT0487936). Clinical trial information: NCT02773524 .

Activity of tivozanib in non-clear cell renal cell carcinoma (nccRCC): Subgroup analysis from a phase 2 randomized discontinuation trial.

4542 Background: Non-clear cell renal cell carcinoma (nccRCC) is a blanket term for a collection of heterogenous and biologically diverse RCC histologies including (but not limited to) papillary, chromophobe and unclassified subtypes. Tivozanib is a selective VEGFR tyrosine kinase inhibitor with demonstrated activity in RCC with clear cell component. Here we report efficacy of tivozanib in a histologically diverse nccRCC subset included in a phase 2 study. Methods: We conducted a subgroup analysis of patients with nccRCC enrolled in the study 201 (NCT00502307), a phase 2 randomized discontinuation trial of tivozanib in patients with RCC who had no prior VEGF targeted treatment. Clinical outcomes including overall response rate (ORR), disease control rate (DCR, defined by CR+PR+SD), and progression free survival (PFS) were examined. Safety outcomes for all patients are reported in the original publication (Nosov, JCO 2012). Results: Of the 272 patients enrolled, 46 (16.9%) patients had nccRCC. [11 (4%) papillary, 2 (0.7%) chromophobe, 2 (0.7%) collecting duct, and 31 (11.4%) unclassified/mixed]. Of the 46 nccRCC patients, the ORR was 17.4% by investigator (INV) review and 15.2% by independent radiology review (IRR). The DCR was 80.4% by INV and IRR. The median PFS was 6.7 months (204 days) (95%CI: 125-366 days) by IRR (Figure 1). Of note, 14 patients with SD after 16 weeks on tivozanib were randomized to 12 weeks of placebo and may have progressed during that timeframe before unblinding and resuming tivozanib. Safety was not analyzed by histology but there were no new safety signals and was consistent with tivozanib labelling in the ITT population. Conclusions: Tivozanib demonstrated activity and a favorable safety profile in patients with nccRCC. This data adds to the body of evidence supporting VEGFR TKI use in advanced RCC including in non-clear cell histologies. Clinical trial information: NCT00502307. [Table: see text]

A phase 1b/2 study of batiraxcept (AVB-S6-500) in combination with cabozantinib in patients with advanced or metastatic clear cell renal cell (ccRCC) carcinoma who have received front-line treatment (NCT04300140).

4511 Background: AXL is up-regulated by hypoxia-inducible factor-1 signaling in both VHL-deficient and hypoxic tumor cells and plays a critical role in the metastatic phenotype of ccRCC. Batiraxcept is a recombinant fusion protein containing an extracellular region of human AXL combined with the human immunoglobulin G1 heavy chain (Fc), demonstrating highly potent, specific AXL inhibition. Methods: Batiraxcept at doses of 15 and 20 mg/kg, plus cabozantinib 60 mg daily, was evaluated using a 3+3 dose escalation study design. The primary objective was safety; secondary and exploratory objectives included identification of the recommended phase 2 dose (RP2D), overall response rate (ORR), and duration of response (DOR). Correlation of serum soluble AXL (sAXL)/GAS6 with ORR was evaluated. Key eligibility criteria include previously treated (2L+) ccRCC patients; prior treatment with cabozantanib was not allowed. sAXL/GAS6 was evaluated at baseline. Results: Data as of 4-February-2022, Phase 1b enrolled 26 patients, 16 patients treated with 15 mg/kg and 10 patients with 20 mg/kg dose of batiraxcept. Baseline characteristics: median age 60 (40-81); male 22 (85%); median prior line of therapy 1 (1-5); IMDC risk group of favorable 6 (23%); prior VEGF inhibitor 15 (58%); 100% with prior immunotherapy. At median follow up of 4.9 months, 92% (n=24) patients remained on the study. No dose limiting toxicities were observed at either 15 mg/kg or 20 mg/kg dose. Batiraxcept and cabozantinib related adverse events (AEs) occurred in 17 subjects (65%). Most common related AE include decreased appetite 31% (n=8), diarrhea and fatigue 23% (n=6). Grade 3 related AEs occurred in 4 patients (15%) including diarrhea, thromboembolism, hypertension, small bowel obstruction, and thrombocytopenia (n=1, 4% each) being most common. No grade 4 or 5 related AEs were observed. The ORR was 46% (n=12, partial response [PR]; Table). No patients had primary progressive disease. Among the patients who had baseline sAXL/GAS6 ratio of ≥ 2.3, the ORR was 67% (12/18). Regardless of baseline sAXL/GAS6 ratio, 3-month DOR was 100%; and 6-month progression free survival was 79%. Batiraxcept PK levels were similar across both doses and GAS6 levels suppressed through the dosing period. Conclusions: Batiraxcept plus cabozantinib is well tolerated. The RP2D of batiraxcept was identified as 15 mg/kg. Early efficacy signals were observed including 100% DOR at 3 months. Baseline sAXL/GAS6 may serve as a potential biomarker to enrich the population. Clinical trial information: NCT04300140. [Table: see text]

Phase 1 LITESPARK-001 (MK-6482-001) study of belzutifan in advanced solid tumors: Update of the clear cell renal cell carcinoma (ccRCC) cohort with more than 3 years of total follow-up.

4509 Background: Hypoxia-inducible factor 2α (HIF-2α) is a key oncogenic driver in RCC. Antitumor activity of the HIF-2α inhibitor belzutifan has been observed in RCC and is approved for treatment in patients (pts) with VHL disease who require therapy for associated RCC, CNS hemangioblastomas, or pNETs not requiring immediate surgery. Previous data from the phase 1 LITESPARK-001 trial (NCT02974738) designed to evaluate belzutifan in heavily pretreated RCC showed durable antitumor activity and an acceptable safety profile. After more than 3 years of follow-up for pts with ccRCC still receiving treatment, updated data are presented. Methods: Pts enrolled in the ccRCC cohort were previously treated with ≥1 therapy, had RECIST-measurable disease, ECOG PS score of 0 or 1, adequate organ function, and life expectancy of ≥6 months. Pts received oral belzutifan 120 mg once daily. The primary end point was safety. Secondary end points were ORR, DCR (CR + PR + SD), PFS, and DOR per RECIST v1.1 by investigator. The data cutoff date was July 15, 2021. Results: Of 55 pts enrolled in the ccRCC cohort, 9 (16%) remain on treatment as of the data cutoff date of July 15, 2021; the primary reason for discontinuation was progressive disease (n = 34; 62%). Pts received a median of 3 prior therapies (range, 1-9); 39 (71%) received prior VEGF and immunotherapy. Pts were followed while on treatment and for 30 days after the last dose for a median of 41.2 months (range, 38.2-47.7). Twenty-two pts (40%) experienced grade 3 TRAEs. The most common (≥10%) grade 3 TRAEs were anemia (n = 13; 24%) and hypoxia (n = 7; 13%). There were no grade 4 or 5 TRAEs. ORR was 25%, with 1 confirmed CR (2%) and 13 PRs (24%); DCR was 80%. Median DOR was not reached (range, 3.1+ to 37.9+ months); 8 of 14 responding pts (57%) remain in response as of the data cutoff date. Per IMDC risk, 4 of 13 pts with favorable risk achieved response (ORR = 31%; all PRs) and 10 of 42 pts with intermediate/poor risk achieved response (ORR = 24%; 1 CR, 9 PRs). DCR was 92% for pts with favorable risk and 76% for pts with intermediate/poor risk. For pts who received prior VEGF and immunotherapy, 8 of 39 pts achieved response (ORR = 21%; 1 CR; 7 PR); DCR was 74%. For the 16 pts who did not receive prior VEGF/immunotherapy, 6 achieved response (ORR = 38%; all PRs); DCR was 94%. Median PFS for the total cohort was 14.5 months (95% CI, 7.3-22.1); PFS rate at 156 weeks (̃36 months) was 34%. Conclusions: As seen after a median follow-up of > 3 years for pts still receiving treatment, belzutifan monotherapy continued to show a high rate of disease control and durable responses in previously treated pts with advanced ccRCC. Belzutifan exhibited a favorable safety profile, and no new safety signals were observed. In several phase 3 studies, belzutifan is being evaluated as monotherapy and combined therapy for ccRCC. Clinical trial information: NCT02974738.

Treatment outcomes in patients (pts) with metastatic renal cell carcinoma (mRCC) with sarcomatoid and/or rhabdoid (S/R) features after progressive disease (PD) on immune checkpoint therapy (ICT): The MD Anderson Cancer Center experience.

351 Background: S/R mRCC is an aggressive disease that is associated with improved response to ICT. Studies performed prior to the approval of ICT demonstrated poor outcomes of S/R RCC with VEGF targeted therapies (TT). Here, we report outcomes of pts with S/R mRCC treated with VEGF TT after PD on ICT. Methods: We retrospectively reviewed the records of pts with mRCC with sarcomatoid (S), rhabdoid (R), or sarcomatoid plus rhabdoid (S+R) features who received VEGF TT after PD on ICT. Clinical endpoints of interest were time on VEGF TT and OS from treatment initiation. Directed acyclic graphs were used to identify confounders for adjustment in regression models. Hazard ratios (HR) and 95% confidence intervals (95% CI) were calculated using multivariable Cox regression. Multivariable models adjusted for epithelial histology, IMDC risk, prior VEGF TT, and inclusion of cabozantinib in the post-ICT VEGF TT regimen. Results: 57 pts with metastatic S/R RCC (52 with clear cell and 5 with non-clear cell histology) received a VEGF TT after PD on ICT. 46% of pts received a VEGF TT prior to ICT. After PD on ICT, 67% of pts had IMDC intermediate-risk disease; the most commonly used VEGF TT were cabozantinib (44%), either sunitinib, pazopanib, or axitinib (24%), and a VEGF TT in combination with an ICT (21%). Pts with R RCC had significantly longer time on VEGF TT compared with S RCC (adjusted HR = 0.45, 95% CI 0.21-0.94, p = 0.034), whereas the OS comparison was inconclusive (adjusted HR = 0.77, 95% CI 0.36-1.62, p = 0.486). IMDC risk classification following ICT progression was predictive of OS (adjusted HR = 2.22, 95% CI 1.07-4.61, p = 0.032), whereas, its association with time on VEGF TT was less conclusive (adjusted HR = 1.78, 95% CI 0.88-3.60, p = 0.107). Conclusions: Patients with S/R mRCC derive clinical benefit from VEGF TT after progression on ICT, and it is similar to the benefit previously described for patients without S/R features. Our findings suggest that the type of S/R features present and IMDC risk score inform the clinical benefit that VEGF TT will produce in this setting.[Table: see text]

INTEGRATE IIb: A randomized phase III open label study of regorafenib + nivolumab versus standard chemotherapy in refractory advanced gastroesophageal cancer (AGOC).

TPS366 Background: Advanced Gastro-oesophageal Carcinoma (AGOC) has a poor prognosis, and there is no established standard treatment following failure of first- and second-line chemotherapy. Regorafenib (BAY 73-4506) is an investigational oral multi-targeted tyrosine kinase inhibitor (TKI) which targets angiogenic (VEGF, TIE-2), stromal (PDGF-β), and oncogenic (RAF, RET and KIT) receptor tyrosine kinases, and has shown activity in this setting. Single agent regorafenib prolonged progression free survival (PFS) versus placebo across all regions/subgroups in the INTEGRATE randomised phase 2 trial. Current options in refractory AOGC involves sequencing through chemotherapy with the latest active agent approved being trifluridine/tipiracil, TAS-102. Promising activity in refractory AOGC has been seen with the combination of regorafenib & nivolumab. INTEGRATE IIb–will compare the effectiveness of the combination of regorafenib & nivolumab in pre-treated patients with AGOC to current standard chemotherapy. Methods: Randomised phase III, open label study with 2:1 randomisation (RegoNivo : standard chemotherapy) and stratification by: Geographic region (Asia vs. Rest of World); Prior VEGF inhibitors (Yes vs No); Prior immunotherapy (Yes vs No). RegoNivo arm will receive 90mg (3x30mg) of regorafenib days 1-21 of each 28-day treatment cycle with intravenous nivolumab 240 mg day 1 of each 14 day cycle until disease progression or prohibitive adverse events as per protocol. The control arm will receive the investigator’s choice of the following chemotherapy; a taxane (paclitaxel or docetaxel), irinotecan or oral trifluridine/tipiracil (TAS102). Primary endpoint: OS. Secondary endpoints: PFS, response rate, quality of life, toxicity, exploratory correlative biomarkers. Clinical trial information: NCT04879368.

1438TiP INTEGRATE IIb: A randomised phase III open label study of regorafenib + nivolumab vs standard chemotherapy in refractory advanced gastro-oesophageal cancer (AGOC)

Advanced Gastro-oesophageal Carcinoma (AGOC) has a poor prognosis, and there is no established standard treatment following failure of first- and second-line chemotherapy. Regorafenib (BAY 73-4506) is an investigational oral multi-targeted tyrosine kinase inhibitor (TKI) which targets angiogenic (VEGF, TIE-2), stromal (PDGF-β), and oncogenic (RAF, RET and KIT) receptor tyrosine kinases, and has shown activity in this setting. Single agent regorafenib prolonged progression free survival (PFS) versus placebo across all regions/subgroups in the INTEGRATE randomised phase II trial. Current options in refractory AOGC involves sequencing through chemotherapy with the latest active agent approved being trifluridine/tipiracil, TAS-102. Promising activity in refractory AOGC has been seen with the combination of regorafenib & nivolumab. INTEGRATE IIb – will compare the effectiveness of the combination of regorafenib & nivolumab in pre-treated patients with AGOC to current standard chemotherapy. Randomised phase III, open label study with 2:1 randomisation (RegoNivo: standard chemotherapy) and stratification by: 1. Geographic region (Asia vs. Rest of World) 2. Prior VEGF inhibitors (Yes vs No) 3. Prior immunotherapy (Yes vs No) RegoNivo arm will receive 90mg (3x30mg) of regorafenib days 1-21 of each 28-day treatment cycle with intravenous nivolumab 240 mg day 1 of each 14 day cycle until disease progression or prohibitive adverse events as per protocol. The control arm will receive the investigator’s choice of the following chemotherapy; a taxane (paclitaxel or docetaxel), irinotecan or oral trifluridine/tipiracil (TAS102). Primary endpoint: OS. Secondary endpoints: PFS, response rate, quality of life, toxicity, exploratory correlative biomarkers. NCT04879368. Australasian Gastro-Intestinal Trials Group.

Diabetic macular edema shows a positive response to Aflibercept after previous unresponsive intravitreal Anti-VEGF and steroid therapy

To evaluate the efficacy of intravitreal aflibercept in diabetic macular edema unresponsive to prior intravitreal anti VEGF and steroid therapy.10 eyes were prospectively investigated. Each eye was treated with intravitreal aflibercept in case of central macular edema unresponsive to prior anti VEGF therapy and intravitreal steroid. Patient were evaluated preoperatively with BCVA, OCT and fundus evaluation and IOP and followed up at 15 days, 6 weeks. : Mean BCVA at presentation was 0.85 log MAR, and that improved to at 15 days and 45 days of intravitreal aflibercept, 0.65 log MAR and 0.52 log MAR. Mean central macular edema at presentation was 662.5 μm (380-905μm), after 15 days was 403μm (185-705μm) and after 45 days was 261.25μm (120-507 μm). Intravitreal aflibercept can be an option to treat unresponsive diabetic central macular edema.

A phase II/III randomized double-blind study of octreotide acetate LAR with axitinib versus octreotide acetate LAR with placebo in patients with advanced G1-G2 NETs of non-pancreatic origin (AXINET trial-GETNE-1107).

360 Background: Angiogenesis plays an important role in NET development and progression. Axitinib is a potent and selective VEGFR-1,2,3 inhibitor, with proven activity against several vascular-dependent solid tumors. The aim of this randomized, double-blind phase II/III study was to assess the efficacy of axitinib in patients with advanced G1-2 extra-pancreatic NETs. Methods: Eligible pts were randomized (1:1) to receive octreotide LAR (30 mg IM q4w) with axitinib (5 mg BID) or placebo BID until disease progression or unacceptable toxicity. Pteswere stratified by time from diagnosis to study entry ( > or < 12m), primary tumor site (GI tract vs non-GI) and Ki-67 index (< 5% vs > 5%). Prior therapy with SSA, IFN and up to 2 lines of systemic treatment was allowed, but not prior VEGF- or VEGFR-targeted drugs. Clinical and/or radiological disease progression within 12 months prior to study entry was required. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), time to progression, overall response rate (ORR), duration of response, biochemical response and safety. Results: 256 pts were randomized (106 in the Phase II part, and 150 additional pts in the Phase III part), 126 to axitinib and 130 to placebo. The main characteristics of the study population were: median age 61 years (range: 21-85), 52% male, PS 0-1 (64-35%), G1-2 (29%-71%), primary tumor site GI (40%)-Lung (17%)-Other (32%). Prior therapies included: SSA (46%), everolimus (13%), chemotherapy (13%), TACE (5%) and PRRT (2%). ORR was significantly higher in axitinib- vs placebo-treated patients (17.5% vs 3.8%, p = 0.0004). PFS per investigator assessment also favored axitinib vs placebo-treated patients, although the difference did not reach statistical significance (median PFS 17.2 vs 12.3 months, respectively, HR 0.816, p = 0.169). Grade 3-4 treatment-related AEs occurred more frequently in the axitinib vs placebo arm (52% vs 13.8%), and included hypertension (21% vs 6 %), cardiac disorders (3.2% vs 0.7%), diarrhoea (13% vs 1.5 %), asthenia (9% vs 3%) and nausea&vomiting (2% vs 0.7%). There were 3 treatment-related deaths, 1 in the axitinib arm (cardiac failure) and 2 in the placebo arm (myocardial infarction and hepatorenal syndrome). Conclusions: Although the study failed to demonstrate a significant PFS benefit per investigator assessment, axitinib in combination with octreotide LAR demonstrated activity and had a tolerable safety profile in patients with advanced G1-2 extra-pancreatic NETs. Data base cleaning and central blinded radiological PFS assessment are currently ongoing. Clinical trial information: NCT01744249.

Randomised Phase 3 Study of Regorafenib in Refractory Advanced Gastro-Oesophageal Cancer (AGOC) - INTEGRATE II

Abstract Background AGOC has a poor prognosis with limited benefits from treatments following failure of chemotherapy (CT). Regorafenib (BAY 73-4506)(REG) is an oral multi-kinase inhibitor targeting kinases involved in angiogenesis (VEGFR1-3, TIE-2), tumor microenvironment (PDGFR-β, FGFR), and oncogenesis (RAF, RET and KIT). INTEGRATE (phase 2) demonstrated REG effectiveness in prolonging PFS in AGOC pts, with a positive OS trend and less toxicity than other REG trials at the same doses. REG was effective across all regions/subgroups, with regional differences noted in magnitude of effect. INTEGRATE II (phase 3) will explore whether REG is effective in prolonging survival in all patients, and in the Asian sub-population Methods International randomised phase III, double-blind, placebo-controlled trial with 2:1 (REG:placebo)(PBO) randomisation and stratification by tumour location, geographic region, and prior VEGF inhibitors. Histologically confirmed AGOC patients, with evaluable metastatic or locally advanced disease refractory to/relapsed following at least 2 lines of CT, will receive best supportive care plus 160mg REG or matched placebo orally on days 1-21 of each 28 day cycle until disease progression or prohibitive adverse events. Primary endpoint is OS. Secondary endpoints: PFS, response rate, quality of life, safety, identification of prognostic/predictive biomarkers for study endpoints, and REG PK across geographical regions. 350 patients (50% from Asia, with at least 50 patients to be recruited from Japan) randomized in a 2:1 ratio will provide 90% power to detect a hazard ratio (HR) for OS of 0.67 with a 2-sided α of 0.05 assuming PBO median survival is 4.5 mos. The sample size accommodates an interim analysis undertaken once 2/3 of required events have occurred. Results 27 ANZ, 8 Canadian, 15 Korean, 5 Taiwanese, and 2 Japanese sites have been activated with 106 patients enrolled. Remaining Japanese/US sites expected to activate through Q1/Q2 2019.

912PD - Results of the phase II TRAXAR study: A randomized phase II trial of axitinib and TRC105 (TRAX) versus axitinib (AX) alone in patients with advanced or metastatic renal cell carcinoma (mRCC)

912PD - Results of the phase II TRAXAR study: A randomized phase II trial of axitinib and TRC105 (TRAX) versus axitinib (AX) alone in patients with advanced or metastatic renal cell carcinoma (mRCC)

Nivolumab in second or third line setting for the treatment of metastatic renal cell carcinoma (mRCC): The real-world experience from Guy’s Hospital.

624 Background: Nivolumab (Nivo) has been approved by the FDA for patients (pts) with mRCC who have received prior VEGF tyrosine kinase inhibition based on the Checkmate 025 study. However following various new anti-angiogenic therapies licensed over the past decade, optimal sequence of treatments in mRCC remains unknown. Methods: This is a retrospective review of mRCC pts who received nivo at Guy’s Hospital. Pts were divided based on treatment line setting. Clinical characteristics, response rate (RR), progression free survival (PFS), duration on treatment and safety are reported. Results: Between March 2016 and April 2018, 50 pts with mRCC received nivo, 25 as second line (2L) and 25 as third line treatment or beyond (3L+). In 2L setting, median age was 62 years and 68% were male. 76% had a nephrectomy, with a majority of clear cell (cc) histology (92%). 96% of pts had visceral metastases. 88% received pazopanib in the first line setting (1L). Median age for pts in 3L+ was 60 years and 88% were male. 60% had a nephrectomy and 80% had cc histology. 96% had visceral metastases. Pazopanib was given in 72% in 1L. RR was 28% and 16% in 2L and 3L+ respectively. Median duration of treatment was 4.3 months in 2L and 2.2 months in 3L+, with 11 patients (22%) still on treatment. Median follow-up time was 12.4 months in 2L and 9 months in 3L+. Median PFS was 4.8 months and 3.7 months respectively in 2L and 3L+ groups. Median OS was not reached in either group. Adverse events leading to treatment discontinuation occurred in 7 pts (14%). 5 pts experienced grade 3/4 toxicities (colitis, pneumonitis, hepatitis, arthritis and nephritis), with 4 pts in 3L+. Overall 22 pts received subsequent treatments: 8/25 (32%) had cabozantinib (cabo) and 4/25 (16%) were treated with axitinib following nivo given in 2L. For pts who received nivo in the 3L+ setting 7/25 (28%) received cabo and 2/25 (8%) had axitinib as subsequent therapy. Conclusions: Our real world data supports the efficacy and safety of nivo following VEGF inhibition for pts with mRCC. Nivo was associated with a trend towards superior clinical responses in the 2L setting. For the entire cohort no new safety signals were reported.

Immunotherapy for renal cell carcinoma - current status

Systemic treatment of metastatic renal cell carcinoma (mRCC) has substantially changed during the last 2 years due to approval of the immune-checkpoint inhibitor Nivolumab (Opdivo®) and new multikinase inhibitors (Cabozantinib, Lenvatinib, Tivozanib). The german kidney tumor guideline strongly recommends Nivolumab and Cabozantinib as 2nd line treatments after prior VEGF targeted therapy. CheckMate 025, the prospective randomized trial which led to approval of Nivolumab demonstrated improved overall survival (26 month vs. 19.7 month; hazard ratio 0.73; p = 0.0006) and response rate (26 % vs. 5 %) as well as a favorable toxicity profile compared with Everolimus. Currently, numerous combinations with PD-1/PD-L1 inhibitors are compared to Sunitinib as first line treatment of mRCC. Out of these CheckMate 214, a randomized phase-3 trial is the first to demonstrate a significant higher objective response rate (42 % vs. 27 %, p < 0.0001) and overall survival (Sunitinib 26.0 month, median for Nivo + Ipi has been not yet reached (28.2 - NR); Hazard ratio 0.63) for the combination of Nivolumab and the CTLA-4 antibody Ipilimumab in IMDC intermediate and high risk patients. Furthermore, CheckMate 214 shows better side effect profile and quality of life in patients receiving Nivolumab and Ipilimumab compared with Sunitinib. However, a considerable increase of immune related adverse events is associated with the immune combination therapy. Another randomized trial demonstrates improved progression-free survival for the combination of the PD-L1 inhibitor Atezolizumab and the VEGF antibody Bevacizumab in patients with PD-L1 positive tumors; this was found in all IMDC risk groups. Further phase-3 trials with "new" VEGFR-TKIs (Axitinib, Cabozantinib, Lenvatinib) and PD-1/PD-L1 inhibitor combinations are ongoing.In conclusion, the PD-1 immune checkpoint inhibitor Nivolumab will remain a standard treatment for patients with metastatic renal cell carcinoma after prior VEGF targeted therapy. Nivolumab in combination with Ipilimumab will become a standard 1st line option for patients with intermediate and high risk profile according to IMDC. Further data are required regarding PD-1/PD-L1 inhibitors in combination with Bevacizumab and VEGFR-TKIs, respectively, including overall survival and side effect profile.

Integrate II: A randomised phase 3 double-blind placebo-controlled study of regorafenib in refractory advanced gastro-oesophageal cancer (AGOC)—An international study organized by the Australasian Gastrointestinal Trials Group (AGITG).

TPS4136 Background: AGOC has a poor prognosis with no established standard treatment following failure of chemotherapy (CT). Regorafenib (BAY 73-4506)(REG) is an oral multi-kinase inhibitor targeting kinases involved in angiogenesis (VEGFR1-3, TIE-2), tumor microenvironment (PDGFR-β, FGFR), and oncogenesis (RAF, RET and KIT). INTEGRATE (phase 2) demonstrated REG was highly effective in prolonging PFS across a range of AGOC pts, with a positive OS trend. Regional differences were found in magnitude of effect, but REG was effective in all regions/subgroups. The phase 3 INTEGRATE II will explore whether REG is effective in prolonging survival in patients overall, and in the Asian sub-population. Methods: International (Australia/New Zealand (NHMRC CTC); Canada (CCTG), Korea, Japan, Taiwan, USA (ACCRU)) randomised phase III, double-blind, placebo-controlled trial with 2:1 (REG:placebo)(PBO) randomisation and stratification by: Location of tumour, Geographic region, prior VEGF inhibitors. Eligible patients (histologically confirmed AGOC), with evaluable metastatic or locally advanced disease refractory to, or relapsed following second line CT, will receive best supportive care plus 160mg REG or matched placebo orally on days 1-21 of each 28 day cycle until disease progression or prohibitive adverse events. Primary endpoint is OS. Secondary endpoints: PFS, response rate, quality of life, safety, identification of prognostic/predictive biomarkers for study endpoints, and REG PK across geographical regions. 350 patients (50% from Asia) randomized in a 2:1 ratio will provide 90% power to detect a hazard ratio (HR) for OS of 0.67 with a 2-sided α of 0.05 assuming PBO median survival is 4.5 mos. The sample size accommodates 2 interim analyses undertaken at 1/3 and 2/3 of required events. As of January 2017, 12 of 28 planned ANZ sites are open, with 4 patients enrolled. Regulatory approval has been received for 12 Canadian sites, and 12 Korean sites. Korean recruitment is expected to commence in February 2017. Regulatory submissions are pending in Taiwan, Japan, and the USA. Clinical trial information: NCT02773524.

Phase 2 Study of Bevacizumab and Temsirolimus After VEGFR TKI in Metastatic Renal Cell Carcinoma

BackgroundInhibiting VEGF and mammalian target of rapamycin (mTOR) pathways are standard treatment approaches for patients with metastatic renal cell carcinoma (mRCC). Here we report the activity and safety of the VEGF ligand inhibitor bevacizumab and the mTOR inhibitor temsirolimus combination in patients with clear cell (CC) and non-clear cell (NCC) mRCC whose disease had failed to respond to prior VEGF blockade. Patients and MethodsIn this phase 2 investigator-initiated multicenter study, patients received bevacizumab and temsirolimus. The primary end point was 4-month progression-free survival (PFS) rate. Secondary end points included overall response rate, median overall survival (OS), toxicity, and correlative studies of biomarkers downstream of mTOR. ResultsForty patients received at least 1 dose of therapy. Thirty-three (82.5%) had favorable/intermediate risk disease according to International Metastatic Renal Cell Carcinoma Database Consortium criteria, 13 (32.5%) with nccRCC histology. Nineteen (48.7%) had primary vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor (TKI)-refractory disease. The 4-month PFS rate was 65%. Overall median PFS and OS were 5.6 and 12.2 months. Median PFS and OS were 6.5 and 9.6 months in patients with primary VEGFR TKI-refractory disease, and 5.6 months and 13.1 months in patients with nccRCC. Dose reductions were needed in 80% of patients. Most frequent toxicities included fatigue, hypertension, dyslipidemia, and proteinuria. Dose discontinuation due to adverse events occurred in 27.5% of patients. Baseline tumor immunohistochemistry for phospho-S6 protein was not associated with clinical benefit. ConclusionCombining bevacizumab and temsirolimus in patients previously treated with VEGFR TKI was possible but with dose reductions and treatment discontinuations. This combination resulted in modest activity, including in patients with primary VEGF-refractory disease and NCC histology.

887P - Trc105 (Anti-Endoglin Antibody) in Combination with Bevacizumab (Bev) and As a Single Agent for Platinum Resistant Ovarian Cancer

ABSTRACT Aim: Endoglin (CD105) is an endothelial cell membrane receptor densely expressed on tumor vessels that is essential for angiogenesis and upregulated by hypoxia and VEGF inhibition. TRC105 is an anti-endoglin monoclonal antibody that potentiates BEV in preclinical models. Methods: Patients with advanced metastatic ovarian cancer, ECOG PS 0-1, and normal organ function were treated with escalating doses of IV TRC105 (3, 6, 8 or 10 mg/kg/wk) plus BEV at 15 mg/kg q3wk or 10 mg/kg q2wk (n = 11) or with 10 mg/kg/wk TRC105 as a single agent (n = 23). Patients were assessed for safety, pharmacokinetics and response. Results: TRC105 was well tolerated as a single agent in 23 patients with advanced platinum resistant ovarian cancer (median age = 63; median 2 prior therapies; range 1-5). The combination of TRC105 and BEV was well tolerated at the recommended single agent doses (10 mg/kg) when the initial dose of TRC105 was divided over two days to limit the frequency of headache. The concurrent administration of BEV and TRC105 did not otherwise potentiate known toxicities of TRC105 or BEV. Target TRC105 serum concentrations were achieved in all patients who received the combination or single agent TRC105 at 10 mg/kg. Mucocutaneous telangiectasia, a marker of TRC105 target modulation, was observed at higher rates with the combination of the two drugs (64% vs 35%; p = 0.15). Reductions in CA-125 were noted in 7 of 20 patients treated with TRC105 as a single agent and 7 of 11 treated with the combination, including 5 of 8 patients who received prior BEV or VEGF receptor tyrosine kinase inhibitor (VEGFR TKI) therapy. Radiographic reductions in tumor volume were observed in 7 of 11 patients (64%) treated with the combination including 4 of 8 patients who received prior BEV or VEGFR TKI, including two patients with PFS > 6 months; one of whom had a partial response by RECIST 1.1. Conclusions: TRC105 10 mg/kg wkly was well tolerated with and without BEV 10 mg/kg q2wk in patients with advanced platinum resistant ovarian cancer. The combination demonstrated activity in BEV and VEGFR TKI refractory patients. Disclosure: A.A. Garcia: The institution received funding for participating in the study; E.A. Alvarez: Dr. Alvarez receives compensation from TRACON Pharmaceuticals, Inc for service on the Safety Review Board Committee; D.S. Mendelson: Institution received funding to conduct the study; B.K. Seon: I am an inventor of TRC105. I do not own stock of TRACON Pharma. I am not a member on the advisory board or board of directors of TRACON Pharma. I had a corporate-sponsored research agreement with TRACON Pharma; D. Alvarez, B.J. Adams and C.P. Theuer: I am employed by TRACON Pharma and own stock in the company. M. Gordon: Institution received funding to conduct the study. All other authors have declared no conflicts of interest.

533P - Baton-Crc: a Phase 2 Randomized Trial Comparing Tivozanib (Tivo) + Mfolfox6 with Bevacizumab (Bev) + Mfolfox6 in Stage Iv Metastatic Colorectal Cancer (Mcrc)

ABSTRACT Aim: Tivo is a selective oral VEGF TKI with a long half-life and activity against all 3 VEGFRs. Preclinical data showed antitumor activity of tivo when added to chemotherapy (chemo). In a phase 1b study of tivo + mFOLFOX6 in mCRC and other GI cancers, partial responses were shown and the combination was well tolerated. Based on these results, a randomized, open-label, phase 2 trial of tivo + mFOLFOX6 (arm A) vs bev + mFOLFOX6 (arm B) in previously untreated mCRC was initiated. Methods: Eligible patients had no prior systemic chemo, no fluorouracil-containing adjuvant therapy in the previous 6 mo, and an ECOG PS ≤1. No prior VEGF therapy, including bev was permitted, nor a history of significant thromboembolic or vascular disorders within 6 mo before study entry. The primary end point was PFS by investigator radiologic assessment. Secondary end points included PFS by IRR, OS, ORR, DOR, TTF, and biomarker subgroup analysis of LDH; VEGF A, C, D; CD68; myeloid-derived gene signature and serum soluble cytokines. Subjects were randomized 2:1 and stratified by LDH, origin of cancer, and number of metastatic sites, and received mFOLFOX6 q2w on days 1 and 15 of each 28-day cycle with either tivo 1.5 mg qd for 21 days followed by 7 days off treatment or bev 5 mg/kg q2w. Results: Between 12/20/11 and 4/28/13, 265 subjects were randomized: 177 to arm A and 88 to arm B. A prespecified interim analysis included 95 PFS events and met prespecified futility criteria. mPFS (arm A vs arm B) was 9.4 mo vs 10.7 mo (P = .706); mORR: 45.2% vs 43.2% (P = .718). The overall safety profile was comparable between arms, but there were more drug-related ≥grade 3 treatment-emergent AEs in arm A (57.1% vs 35.6%), higher ALT or AST elevations >3 × ULN (16.6% vs 5.7%), and increase in grade for platelets (65.9% vs 43.7%). The most common toxicities included diarrhea, nausea, fatigue, neutropenia, and hypertension. Conclusions: The addition of tivo to mFOLFOX6 vs bev + mFOLFOX6 met prespecified futility criteria and resulted in comparable PFS, ORR, TTF, and DOR with an acceptable safety profile. At the interim analysis, there were no significant associations between serum/tumor biomarkers and outcomes. Disclosure: J.A. Bridgewater: • Advisory board: 2013, 1; I. Kiss: • Ad bds: Roche, Merck, Bayer • Speakers’ bureau: Roche, Merck, Amgen, Bayer, Sanofi; J. Chen, C. Sasse, S. Vossen, C. van Sant, H. Ball, A. Keating, A. Krisvoshik: Astellas employee • Stock • Salary; All other authors have declared no conflicts of interest.

Biomarker analysis from a phase III trial (GOLD) of dovitinib (Dov) versus sorafenib (Sor) in patients with metastatic renal cell carcinoma after one prior VEGF pathway–targeted therapy and one prior mTOR inhibitor therapy.

473 Background: In the GOLD trial, Dov did not improve progression-free survival (PFS) or overall survival (OS) over Sor. An exploratory objective of the study was to investigate plasma and tumor biomarkers to predict outcome. Methods: Plasma samples were obtained longitudinally throughout the study, and biomarkers were assessed by immunoassay. Primary archival tumor samples were assessed by immunohistochemistry. Log-rank tests, stratified by baseline MSKCC risk group, for difference in Kaplan-Meier curves between biomarker category (low/high based on &lt;/≥ median baseline values) within treatment arm were performed. Hazard ratios (HRs) were estimated from Cox proportional hazards models. Results: Plasma samples were available from 561 patients (Dov, n = 281; Sor, n = 280), and tumor samples were available from 341 patients (Dov, n = 181; Sor, n = 160). Baseline plasma biomarker levels were not predictive of Dov or Sor PFS or OS. However, strong prognostic effects, particularly for OS, were observed. High baseline cKIT and low baseline FGF2, HGF, PlGF, sVEGFR1, VEGFA, and VEGFD were associated with better OS for both Dov and Sor (Table). Changes from baseline in a number of plasma biomarkers were observed following treatment with Dov and Sor, consistent with VEGFR/FGFR inhibitory effects. Prognostic effects were also observed for low FGFR2 (PFS) and low FGF2 (OS) expression in archival tumors. Conclusions: Baseline plasma biomarkers are prognostic but not predictive in the third-line setting. Clinical trial information: NCT01223027. [Table: see text]

A phase I pharmacodynamic trial of sequential sunitinib with bevacizumab in patients with renal cell carcinoma and other advanced solid malignancies

Sunitinib treatment results in a compensatory increase in plasma VEGF levels. Acute withdrawal of sunitinib results in a proliferative withdrawal flare, primarily due to elevated VEGF levels. Concurrent sunitinib plus bevacizumab is poorly tolerated with high (37 %) incidence of microangiopathic hemolytic anemia (MAHA). We evaluated a sequential design administering bevacizumab during the sunitinib treatment break to suppress the sunitinib withdrawal flare. Patients with no prior VEGF treatment were enrolled in this study. All patients had target lesions amenable to serial FLT PET/CT imaging. Sunitinib 37.5 mg was given on days 1-28 every 6 weeks with bevacizumab 5 mg/kg on day 29. If safe and tolerable, sunitinib increased to 50 mg. FLT PET/CT scans would be obtained at baseline (D1), week 4, and week 6 to evaluate pharmacodynamics of the sequential combination. Sunitinib pharmacokinetics and total, free, and bound VEGF levels were obtained on each cycle at D1, pre-bevacizumab (D29), 4 h post-bevacizumab (D29H4), and day 42 (D42). Six patients enrolled in the safety cohort of sunitinib 37.5 mg plus bevacizumab (see Table). One patient experienced grade 1 MAHA, and after discussion with the Cancer Therapy Evaluation Program (CTEP), the trial was closed to further accrual. No imaging scans were obtained due to early closure. Total and free VEGF levels during cycle 1 Cycle 1 Total VEGF (pg/mL) Mean ± SD Free VEGF (pg/mL) Mean ± SD D1 80 ± 70 51 ± 47 D29 150 ± 62 103 ± 35 D29H4 10 ± 12 2 ± 5 D42 177 ± 34 97 ± 18 CONCLUSIONS: Subclinical MAHA was seen despite using sequential sunitinib with low-dose bevacizumab, and this combination was not feasible for further development. As predicted, VEGF levels increased during sunitinib exposure followed by a rapid decline after bevacizumab. Due to the long half-life of bevacizumab, we expected VEGF ligand suppression through D42, but instead observed a complete rebound in total/free VEGF levels by D42. The increase in VEGF at D42 was unexpected based on sunitinib alone and contrary to the hypothesis that we would block VEGF flare with low-dose bevacizumab. VEGF ligand production may increase as a result of bevacizumab, implying a robust host compensatory mechanism to VEGF signaling pathway inhibition. A greater understanding of the compensatory mechanism would aid future sequencing strategies of new agents.