Abstract PD17-05: Development and Validation of a Composite Biomarker Predictive of Palbociclib + Endocrine Treatment Benefit in Early Breast Cancer: PENELOPE-B and PALLAS Trials

Background: The PENELOPE-B (NCT01864746) and PALLAS (NCT02513394) trials are large prospective, randomized, phase III trials that evaluated adjuvant palbociclib (PAL) + endocrine treatment (ET) vs ET in patients with hormone receptor–positive/human epidermal growth factor receptor 2–negative (HER2–) early breast cancer (EBC). Both studies did not meet the primary endpoint of improving invasive disease-free survival (iDFS). We conducted biomarker analyses to identify patients who might benefit from PAL + ET in EBC. Methods: Resected tumor tissue was collected from consenting patients. Gene expression analyses were conducted using the HTG EdgeSeq Oncology Biomarker Panel including 2549 genes. Based on 91 genes from the HTG panel, the intrinsic molecular subtypes were calculated using Absolute Intrinsic Molecular Subtyping (AIMS). Potential predictive treatment biomarkers were established in PENELOPE-B (n=906 with resected tissue) as the development set using an outcome-oriented approach based on iDFS with a selection procedure that maximized the log-rank statistic to estimate a standard Z score–based optimal cutoff. Independent validation was conducted on PALLAS (n=2085; PENELOPE-B-like with resected tissue and HTG data). Hazard ratios and corresponding 95% CIs were calculated using the Cox proportional hazards model, and iDFS distributions between treatment arms were compared using the log-rank test. Interaction between treatment and biomarker status was assessed. Results: Patient baseline characteristics were well balanced, with no differences in iDFS between the intent-to-treat set and the biomarker set for both trials. Approximately 73% of patients (PENELOPE-B [n=663] and PALLAS [n=1516]) had luminal A subtypes whereas only 7.1 % (PENELOPE-B [n=64]) and 8.3 % (PALLAS [n=172]) had a luminal B subtype. AIMS subtypes showed overall similar prognostic patterns for iDFS between PENELOPE-B and PALLAS. The biomarker-defined subgroup found in PENELOPE-B with optimal cutoff demonstrated a preferential benefit from PAL + ET (n=364 [96 events]; hazard ratio [95% CI], 0.63 [0.42, 0.95]; P=0.025). Independent validation of the PALLAS subgroup using the pre-defined optimal cutoff confirmed a significant benefit from PAL + ET (n=916 [70 events]; 0.55 [0.34–0.90]; P=0.015) while not in the rest of the patients (interaction p=0.0025). Significant treatment effects remained (0.55 [0.34–0.89]; P=0.015) after adjusting for the randomization stratification factors of PALLAS. Conclusions: The composite predictive biomarker defined from PENELOPE-B was independently validated in a prospectively defined retrospective analysis of a subset of patients selected from PALLAS. The composite biomarker identified a subset of EBC patients deriving benefit from the addition of PAL to ET. This patient stratification approach can potentially be applied to future adjuvant clinical trials for treatment of hormone receptor–positive/HER2– EBC.

Citation Format: Sibylle Loibl, Carsten Denkert, Yuan Liu, Erik S. Knudsen, Angela DeMichele, Zhe Zhang, Julia Teply-Szymanski, Martin Filipits, Peter A. Fasching, Michael Gnant, Shibing Deng, Marija Balic, Federico Rojo, Mark Watson, Chetan Deshpande, Nicholas Turner, Otto Metzger, Kathy Puyana Theall, Agnieszka Witkiewicz, Olga Valota, W. Fraser Symmans, Erica L. Mayer. Development and Validation of a Composite Biomarker Predictive of Palbociclib + Endocrine Treatment Benefit in Early Breast Cancer: PENELOPE-B and PALLAS Trials [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD17-05.

Abstract P5-13-36: Germline BRCA1/2 and other predisposition genes in high-risk early-stage HR+/HER2- breast cancer (BC) patients treated with endocrine therapy (ET) with or without palbociclib: A secondary analysis from the PENELOPE-B study

Background: In high-risk hormone-receptor (HR)+/HER2- BC patients germline (g) mutations can be found in approximately 14% in BRCA1/2 and in BRCA1/2 and other BC predisposition genes in 20% (Pohl-Rescigno E, et al. JAMA Oncol 2020). In metastatic BC CDK4/6 inhibitors may have greater activity in patients with a BRCA mutation detected in ctDNA (André F, et al. J Clin Oncol 2020). The PENELOPE-B trial did not to show an improved invasive disease-free survival (iDFS) by adding palbociclib to ET in high-risk HR+/HER2- BC (Loibl S, et al. J Clin Oncol 2021). Methods: Blood samples from 898 of 1250 PENELOPE-B patients were available. 445 patients were sampled following a case-cohort design (220 cases defined as patients with any event during follow-up and 225 randomly selected patients without any event [non-cases]) and analyzed for germline variants in BRCA1/2 and 16 non-BRCA1/2 cancer predisposition genes (ATM, BARD1, BRIP1, CDH1, CHEK2, FANCM, MRE11A, NBN, PALB2, PTEN, RAD50, RAD51C, RAD51D, STK11, TP53, XRCC2) by targeted next generation sequencing (NGS). The primary definition of mutational status was the prevalence of a pathogenic mutation (mt) in one or more analyzed BC predisposition genes. Statistical analyses for time-to-event endpoints (iDFS, distant disease-free survival [DDFS], and overall survival [OS]) were based on inverse probability weighting: weighted Cox proportional hazard models and Kaplan-Meier estimates were used. Results: 442 of 445 patients (placebo arm: 104 cases and 105 non-cases; palbociclib arm: 114 cases and 119 non-cases) were successfully analyzed for mutational status. A total of 42 (9.5%) patients (placebo arm: 9.1%; palbociclib arm: 9.9%) carried any mutation. 15 (3.4%) patients had a gBRCA1/2 mt (one of whom carried a gATM mt and one a gCHEK2 mt in addition to gBRCA2 mt) and 29 (6.6%) had mutations in one of the other BC predisposition genes (n=8 CHEK2, n=7 PALB2, n=5 ATM, n=2 RAD50, n=1 for BARD1, FANCM, MRE11A, RAD51C, RAD51D, TP53 and n=1 both RAD51D and BRIP1). The mutational status with respect to all genes analyzed showed no significant correlation to clinical baseline variables. With regard to gBRCA1 and gBRCA2 genes only, the mutational status significantly correlated with age but not with other clinical variables: all 15 (100%) gBRCA mt carriers were younger than 50 years compared to 238 (56%) wildtype (wt) patients (p=0.002). The iDFS rate after 3 years was 80.9% in patients with any mutation and 79.5% in patients without. Mutational status (mt vs. wt) based on all genes analyzed was not prognostic (iDFS: hazard ratio 1.015, 95%CI 0.558-1.784; DDFS: 0.970, 95%CI 0.521-1.758; OS: 0.768, 95%CI 0.274-1.615). Neither the mutated patients had a benefit from palbociclib treatment (palbociclib vs placebo; iDFS: hazard ratio 0.766, 95%CI 0.263-3.022; DDFS: 0.897, 95%CI 0.275-3.489; OS: 0.666, 95%CI 0.063-5.671) nor the wt patients (iDFS: hazard ratio 0.918, 95%CI 0.650-1.303; DDFS: 0.966, 95%CI 0.679-1.393; OS: 0.901, 95%CI 0.573-1.433); interaction tests for treatment arm/mutational status for all time-to-event endpoints were not statistically significant. Analysis in the subgroups of patients by gBRCA1/2 showed similar results but had less statistical power. Conclusions: In this case-cohort analysis of 442 patients enrolled in the PENELOPE-B trial, the detection of BC predisposition genes was lower than expected with 10%. This is probably due to the low rate of gBRCA1/2 carriers (3.4%), which could be influenced by the selection criteria of the trial. Patients with gBRCA1/2 or other BC disposition genes had a comparable outcome to non-carriers in the PENELOPE-B trial.

Citation Format: Sibylle Loibl, Jan Hauke, Karen Gelmon, Frederik Marmé, Corinna Ernst, Miguel Martin, Michael Untch, Hervé Bonnefoi, Erik Knudsen, Seock-Ah Im, Angela DeMichele, Laura Van’t Veer, Sung-Bae Kim, Harry Bear, Nicole McCarthy, Nicholas Turner, Agnieszka Witkiewicz, Federico Rojo, Peter A Fasching, José A García-Sáenz, Catherine M Kelly, Toralf Reimer, Masakazu Toi, Hope S Rugo, Carsten Denkert, Michael Gnant, Andreas Makris, Yuan Liu, Olga Valota, Bärbel Felder, Karsten Weber, Valentina Nekljudova, Eric Hahnen. Germline BRCA1/2 and other predisposition genes in high-risk early-stage HR+/HER2- breast cancer (BC) patients treated with endocrine therapy (ET) with or without palbociclib: A secondary analysis from the PENELOPE-B study [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-13-36.

A Phase Ib Study of Axitinib in Combination with Crizotinib in Patients with Metastatic Renal Cell Cancer or Other Advanced Solid Tumors

Lessons Learned.

The combination of axitinib and crizotinib has a manageable safety and tolerability profile, consistent with the profiles of the individual agents when administered as monotherapy.

The antitumor activity reported here for the combination axitinib/crizotinib does not support further study of this combination treatment in metastatic renal cell carcinoma given the current treatment landscape.

Background.

Vascular endothelial growth factor (VEGF) inhibitors have been successfully used to treat metastatic renal cell carcinoma (mRCC); however, resistance eventually develops in most cases. Tyrosine protein kinase Met (MET) expression increases following VEGF inhibition, and inhibition of both has shown additive effects in controlling tumor growth and metastasis. We therefore conducted a study of axitinib plus crizotinib in advanced solid tumors and mRCC.

Methods.

This phase Ib study included a dose‐escalation phase (starting doses: axitinib 3 mg plus crizotinib 200 mg) to estimate maximum tolerated dose (MTD) in patients with solid tumors and a dose‐expansion phase to examine preliminary efficacy in treatment‐naïve patients with mRCC. Safety, pharmacokinetics, and biomarkers were also assessed.

Results.

No patients in the dose‐escalation phase (n = 22) experienced dose‐limiting toxicity; MTD was estimated to be axitinib 5 mg plus crizotinib 250 mg. The most common grade ≥3 adverse events were hypertension (18.2%) and fatigue (9.1%). In the dose‐expansion phase, overall response rate was 30% (95% confidence interval [CI], 11.9–54.3), and progression‐free survival was 5.6 months (95% CI, 3.5–not reached).

Conclusion.

The combination of axitinib plus crizotinib, at estimated MTD, had a manageable safety profile and showed evidence of modest antitumor activity in mRCC.

Axitinib versus placebo as an adjuvant treatment of renal cell carcinoma: results from the phase III, randomized ATLAS trial

Background

The ATLAS trial compared axitinib versus placebo in patients with locoregional renal cell carcinoma (RCC) at risk of recurrence after nephrectomy.

Patients and methods

In a phase III, randomized, double-blind trial, patients had >50% clear-cell RCC, had undergone nephrectomy, and had no evidence of macroscopic residual or metastatic disease [independent review committee (IRC) confirmed]. The intent-to-treat population included all randomized patients [≥pT2 and/or N+, any Fuhrman grade (FG), Eastern Cooperative Oncology Group status 0/1]. Patients (stratified by risk group/country) received (1 : 1) oral twice-daily axitinib 5 mg or placebo for ≤3 years, with a 1-year minimum unless recurrence, occurrence of second primary malignancy, significant toxicity, or consent withdrawal. The primary end point was disease-free survival (DFS) per IRC. A prespecified DFS analysis in the highest-risk subpopulation (pT3, FG ≥ 3 or pT4 and/or N+, any T, any FG) was conducted.

Results

A total of 724 patients (363 versus 361, axitinib versus placebo) were randomized from 8 May 2012, to 1 July 2016. The trial was stopped due to futility at a preplanned interim analysis at 203 DFS events. There was no significant difference in DFS per IRC [hazard ratio (HR) = 0.870; 95% confidence interval (CI) : 0.660-1.147; P = 0.3211). In the highest-risk subpopulation, a 36% and 27% reduction in risk of a DFS event (HR; 95% CI) was observed per investigator (0.641; 0.468-0.879; P = 0.0051), and by IRC (0.735; 0.525-1.028; P = 0.0704), respectively. Overall survival data were not mature. Similar adverse events (AEs; 99% versus 92%) and serious AEs (19% versus 14%), but more grade 3/4 AEs (61% versus 30%) were reported for axitinib versus placebo.

Conclusions

ATLAS did not meet its primary end point; however, improvement in DFS per investigator was seen in the highest-risk subpopulation. No new safety signals were reported.

Trial registration number

NCT01599754.

Phase III Trial of Adjuvant Sunitinib in Patients with High-Risk Renal Cell Carcinoma: Exploratory Pharmacogenomic Analysis

PURPOSE

In the S-TRAC trial, adjuvant sunitinib prolonged disease-free survival (DFS) versus placebo in patients with loco-regional renal cell carcinoma at high risk of recurrence after nephrectomy. An exploratory analysis evaluated associations between SNPs in several angiogenesis- or hypoxia-related genes and clinical outcomes in S-TRAC.

PATIENTS AND METHODS

Blood samples were genotyped for 10 SNPs and one insertion/deletion mutation using TaqMan assays. DFS was compared using log-rank tests for each genotype in sunitinib versus placebo groups and between genotypes within each of three (sunitinib, placebo, and combined sunitinib plus placebo) treatment groups. P values were unadjusted.

RESULTS

In all, 286 patients (sunitinib, n = 142; placebo, n = 144) were genotyped. Longer DFS [HR; 95% confidence interval (CI)] was observed with sunitinib versus placebo for VEGFR1 rs9554320 C/C (HR 0.44; 95% CI, 0.21-0.91; P = 0.023), VEGFR2 rs2071559 T/T (HR 0.46; 95% CI, 0.23-0.90; P = 0.020), and eNOS rs2070744 T/T (HR 0.53; 95% CI, 0.30-0.94; P = 0.028). Shorter DFS was observed for VEGFR1 rs9582036 C/A versus C/C with sunitinib, placebo, and combined therapies (P ≤ 0.05), and A/A versus C/C with sunitinib (P = 0.022). VEGFR1 rs9554320 A/C versus A/A was associated with shorter DFS in the placebo (P = 0.038) and combined (P = 0.006) groups.

CONCLUSIONS

Correlations between VEGFR1 and VEGFR2 SNPs and longer DFS with sunitinib suggest germline SNPs are predictive of improved outcomes with adjuvant sunitinib in patients with renal cell carcinoma. Independent validation studies are needed to confirm these findings.

Validation of the 16-Gene Recurrence Score in Patients with Locoregional, High-Risk Renal Cell Carcinoma from a Phase III Trial of Adjuvant Sunitinib

Purpose: Adjuvant sunitinib prolonged disease-free survival (DFS; HR, 0.76) in patients with locoregional high-risk renal cell carcinoma (RCC) in the S-TRAC trial (ClinicalTrials.gov NCT00375674). The 16-gene Recurrence Score (RS) assay was previously developed and validated to estimate risk for disease recurrence in patients with RCC after nephrectomy. This analysis further validated the prognostic value of RS assay in patients from S-TRAC and explored the association of RS results with prediction of sunitinib benefit.Patients and Methods: The analysis was prospectively designed with prespecified genes, algorithm, endpoints, and analytical methods. Primary RCC was available from 212 patients with informed consent; primary analysis focused on patients with T3 RCC. Gene expression was quantitated by RT-PCR. Time to recurrence (TTR), DFS, and renal cancer-specific survival (RCSS) were analyzed using Cox proportional hazards regression.Results: Baseline characteristics were similar between patients with and those without RS results, and between the sunitinib and placebo arms among patients with RS results. RS results predicted TTR, DFS, and RCSS in both arms, with the strongest results observed in the placebo arm. When high versus low RS groups were compared, HR for recurrence was 9.18 [95% confidence interval (CI), 2.15-39.24; P < 0.001) in the placebo arm; interaction of RS results with treatment was not significant.Conclusions: The strong prognostic performance of the 16-gene RS assay was confirmed in S-TRAC, and the RS assay is now supported by level IB evidence. RS results may help identify patients at high risk for recurrence who may derive higher absolute benefit from adjuvant therapy. Clin Cancer Res; 24(18); 4407-15. ©2018 AACR.

Sunitinib in Patients With Metastatic Renal Cell Carcinoma: Clinical Outcome According to International Metastatic Renal Cell Carcinoma Database Consortium Risk Group

BACKGROUND

Sunitinib malate, a targeted tyrosine kinase inhibitor, is standard of care for metastatic renal cell carcinoma (mRCC) and serves as the active comparator in several ongoing mRCC clinical trials. In this analysis we report benchmarks for clinical outcomes on the basis of International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk groups for patients treated with sunitinib for mRCC in a first-line setting.

MATERIALS AND METHODS

A retrospective analysis was performed on data from sunitinib-treated patients (n = 375) in the pivotal phase III trial of sunitinib versus interferon-α as first-line treatment for mRCC. Objective response rates (ORRs) were determined from independently reviewed radiologic assessments. The Kaplan-Meier method was used to estimate median progression-free survival (PFS) and median overall survival (OS) according to patient risk group.

RESULTS

Median PFS (95% confidence interval [CI]) was 14.1 (13.4-17.1), 10.7 (10.5-12.5), 2.4 (1.1-4.7), and 10.6 (8.1-10.9) months in sunitinib-treated patients in the IMDC favorable (n = 134), intermediate (n = 205), poor (n = 34), and intermediate + poor (n = 239) risk groups, respectively. Median OS (95% CI) was 23.0 (19.8-27.8), 5.1 (4.3-9.9), and 20.3 (16.8-23.0) months in sunitinib-treated patients in IMDC intermediate, poor, and intermediate + poor risk groups, respectively, and was not reached in the favorable risk group (>50% of patients were alive at data cutoff). ORRs (95% CI) was 53.0% (44.2%-61.7%), 33.7% (27.2%-40.6%), 11.8% (3.3%-27.5%), and 30.5% (24.8%-36.8%) in sunitinib-treated patients in IMDC favorable, intermediate, poor, and intermediate + poor risk groups, respectively.

CONCLUSION

Results of this retrospective analysis show differences in patient outcomes for PFS, OS, and ORR on the basis of IMDC prognostic risk group assignment for patients with mRCC.

Regional Differences in Efficacy, Safety, and Biomarkers for Second-Line Axitinib in Patients with Advanced Hepatocellular Carcinoma: From a Randomized Phase II Study

BACKGROUND

An unmet need exists for treatment of patients with advanced hepatocellular carcinoma (HCC) who progress on or are intolerant to sorafenib. A global randomized phase II trial (ClinicalTrial.gov No. NCT01210495) of axitinib, a vascular endothelial growth factor receptor 1-3 inhibitor, in combination with best supportive care (BSC) did not prolong overall survival (OS) over placebo/BSC, but showed improved progression-free survival in some patients. Subgroup analyses were conducted to identify potential predictive/prognostic factors.

METHODS

The data from this phase II study were analyzed for the efficacy and safety of axitinib/BSC in patients from Asia versus non-Asia versus Asian subgroups (Japan, Korea, or mainland China/Hong Kong/Taiwan) and predictive/prognostic values of baseline microRNAs and serum soluble proteins, using the Cox proportional hazards model.

RESULTS

Of 202 patients, 78 were from non-Asia and 124 from Asia (37 Japanese, 36 Korean, and 51 Chinese). No significant differences in OS were found between axitinib/BSC and placebo/BSC in non-Asians, Asians, or Asian subgroups. However, in an exploratory analysis, axitinib/BSC showed favorable OS in Asians, especially Japanese, when patients intolerant to prior antiangiogenic therapy were excluded from the data set. Axitinib/BSC was well tolerated by non-Asians and Asians alike. The presence of 4 circulating microRNAs, including miR-5684 and miR-1224-5p, or a level lower than or equal to the median protein level of stromal cell-derived factor 1 at baseline was significantly associated with longer OS in axitinib/BSC-treated Asians or non-Asians.

CONCLUSIONS

Axitinib/BSC did not prolong survival over placebo/BSC in non-Asians, Asians, or Asian subgroups, but favorable OS with axitinib/BSC was observed in a subset of Japanese patients. A patient population that excludes sorafenib-intolerant patients might potentially be more suitable for clinical trials of new agents in advanced HCC. Since these results are very preliminary, further investigation is warranted. The potential predictive/prognostic value of several baseline microRNAs and soluble proteins identified in this study would require validation in prospective studies on a large cohort of patients.

Phase III trial of adjuvant sunitinib in patients with high-risk renal cell carcinoma: Exploratory pharmacogenomic analysis

576

Background: In the phase III S-TRAC trial, adjuvant sunitinib (SU) prolonged disease-free survival (DFS) vs placebo (PBO) in patients with locoregional renal cell carcinoma at high risk of recurrence after nephrectomy (median 6.8 vs 5.6 y; hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.59–0.98; P= 0.03). An exploratory analysis evaluated associations between single nucleotide polymorphisms (SNPs) in angiogenesis-related genes and clinical outcomes in S-TRAC. Methods: Prospectively collected blood samples were genotyped for 10 SNPs and 1 insertion/deletion mutation with TaqMan assays. DFS was compared with a log-rank test for each SNP genotype in SU vs PBO arms and between SNP genotypes within each arm. P-values are unadjusted for multiplicity comparison. Results: Of 615 patients, 286 (142 SU; 144 PBO) were analyzed. There were generally no genotype frequency deviations from the Hardy-Weinberg equilibrium, but linkage disequilibrium was seen between VEGFA rs699947 and rs833061 on chromosome 6 (D′ = 1.000, r2 = 0.979). Longer DFS was observed with SU vs PBO for VEGFR1 rs9554320 C/C (median: not reached [NR] vs 5.56 y; HR 0.44, 95% CI 0.21–0.91; P= 0.023), VEGFR2 rs2071559 T/T (median: NR vs 4.47 y; HR 0.46, 95% CI 0.23–0.90; P= 0.020), and eNOS rs2070744 T/T (median: 7.07 vs 3.44 y; HR 0.53, 95% CI 0.30–0.94; P= 0.028), with a trend for VEGFR1 rs9582036 A/A (median: NR in both arms; P= 0.054) and SH3GL2 rs10963287 C/T (median: NR vs 5.35 y; P= 0.088). Shorter DFS was observed for VEGFR1 rs9582036 C/A vs C/C in the SU, PBO, and combined arms ( P< 0.05); for A/A vs common, the association was only seen in the SU arm ( P= 0.022). VEGFR1 rs9554320 A/C was associated with shorter DFS vs A/A in the PBO ( P= 0.038) and combined arm ( P= 0.006), with a trend in the SU arm ( P= 0.051). VEGFR2 rs1870377 T/T was associated with longer DFS vs A/A in the combined arms, but not in the PBO arm (n = 7 with A/A genotype in the SU arm precluded statistical tests). Conclusions: Correlations between common VEGFR1 and VEGFR2 SNPs and longer DFS with SU suggest germline SNPs are predictive of improved outcomes with adjuvant SU. Due to the exploratory nature of this analysis, prospective validation studies are needed to confirm these findings. Clinical trial information: NCT00375674.

Sunitinib in patients with metastatic renal cell carcinoma: Clinical outcome according to IMDC risk group

4584

Background: In a phase III study (NCT00083889), treatment-naïve patients (pts) with metastatic renal cell carcinoma (mRCC) of all prognostic risk groups were treated with sunitinib or interferon-α (IFN-α). Since sunitinib has become the reference standard of care and serves as the comparator in multiple randomized trials sometimes restricted to prespecified risk groups, a retrospective analysis of outcome according to prognostic group from the phase III study was performed. Methods: Investigator-assessed efficacy data were analyzed for pts based on risk group (International mRCC Database Consortium [IMDC] criteria). The objective was to determine objective response rate (ORR), median progression-free survival (mPFS), and median overall survival (mOS) benchmarks by risk group. Results: Of sunitinib-treated pts, 134 were favorable, 205 were intermediate, and 34 were poor risk. The median sunitinib treatment duration/median number of cycles was 16.7 mo/12 cycles, 11.0 mo/8 cycles and 2.6 mo/2.0 cycles for favorable-, intermediate-, and poor-risk pts, respectively. ORR, PFS, and OS benchmarks for sunitinib-treated pts are shown in the Table. In sunitinib-treated intermediate-risk pts with 1 vs 2 risk factors, respectively: ORR was 43.3% vs 40.8%, mPFS (95% confidence interval [95% CI]) was 11.2 (9.7–13.6) vs 8.5 (5.6–10.7) mo, and mOS (95% CI) was 28.2 (23.0–not estimable) vs 16.3 (13.2–19.4) mo. Conclusions: This retrospective analysis provides ORR, PFS, and OS benchmarks for current and future clinical trial interpretation in mRCC pts with different prognostic risk treated with sunitinib. [Table: see text]

Phase III trial of adjuvant sunitinib in patients with high-risk renal cell carcinoma (RCC): Validation of the 16-gene Recurrence Score in stage III patients

4508

Background: Adjuvant therapy with sunitinib (SU) compared with placebo (PBO) prolonged disease-free survival (DFS) in 615 patients (pts) with high-risk RCC (hazard ratio [HR] 0.76; P= 0.03) in the S-TRAC trial. The 16-gene Recurrence Score (RS) was developed and validated to predict risk of recurrence of RCC after nephrectomy in 2 cohorts of stage I–III pts (Rini et al., Lancet Oncol 2015;16:676-85). We present further validation of RS results in high-risk stage III pts from S-TRAC. Methods: The study was prospectively designed with prespecified genes, algorithm, endpoints, analytical methods, and analysis plan using primary RCC tissues from 212 evaluable pts with informed consent. Gene expression was quantitated by RT-PCR; primary analysis focused on stage III (n = 193 pts). Time to recurrence (TTR) and DFS were analyzed using Cox proportional hazard regression. Results: Baseline characteristics were similar in SU and PBO arms and in pts with and without gene expression data; effect of SU was numerically similar to that in the entire trial (DFS HR 0.78, 95% CI 0.48–1.24; P= 0.29). RS predicted TTR and DFS in both treatment arms with the strongest results observed in PBO arm where high RS group had significantly higher risk (Table). Interaction of RS with treatment was not significant (TTR P= 0.192; DFS P= 0.219); however, the number of events was relatively low. Conclusions: The prognostic value of the 16-gene assay was confirmed in S-TRAC. RS is now validated with consistent results in 2 separate studies (level IB evidence). RS results may help identify patients at high risk who could derive higher absolute benefit from adjuvant treatment. The predictive value of RS to select patients for adjuvant SU requires further investigation in independent adjuvant trials. [Table: see text]

Axitinib plus crizotinib in patients with advanced solid tumors and metastatic renal cell carcinoma (mRCC): Preliminary phase 1b results

2551

Background: Axitinib (AX) is a tyrosine kinase inhibitor (TKI) of vascular endothelial growth factor receptor (VEGFR) and a standard treatment for mRCC. Upregulation of mesenchymal-epithelial transition factor (c-MET) is implicated in resistance to VEGFR-directed therapy. An ongoing ph Ib study (NCT01999972) evaluated the safety and efficacy of AX + crizotinib (CZ), a TKI of c-MET, anaplastic lymphoma kinase (ALK), and ROS1. Methods: mRCC patients (pts) with advanced solid tumors were treated with AX + CZ in a dose escalation phase (DESC). After determining maximum tolerated dose (MTD) (modified toxicity probability interval), mRCC pts were enrolled into 2 cohorts in a dose expansion phase (DEXP). Cohort 1 (C1) was treatment-naïve and C2 had 1–2 prior therapies. The primary objectives were to assess the tolerability of AX + CZ, to obtain the MTD, and to select the recommended phase II dose. Results: As of Aug 5, 2016, 24 pts were screened and 22 pts treated in the DESC. Pts received AX 3 mg twice daily (BID) + CZ 200 mg BID (n = 5); AX 3 mg BID + CZ 250 mg BID (n = 3); AX 5 mg BID + CZ 200 mg BID (n = 4); or AX 5 mg BID + CZ 250 mg BID (n = 10) in a median 4 (range 1–23) cycles. There were no cycle 1 dose-limiting toxicities. One pt discontinued due to an AX-related alanine aminotransferase increase. Fifteen (68.2%) pts experienced Grade 3–4 adverse events (AEs), none in ≥2 pts; 1 pt had a Grade 5 AE (disease progression). AX 5 mg BID + CZ 250 mg BID was established as the MTD. Most frequent AEs in the MTD group were fatigue (70.0%), nausea (70.0%) and diarrhea (60.0%). In the ongoing DEXP, 15 pts have been treated at the MTD (n = 11 in C1, and 4 C2). Response evaluation (RECIST) is ongoing, with 1 complete response (CR), 3 partial responses (PR) and 4 stable disease (SD) in 10 pts in C1, and 1 PR and 2 SD in 4 pts in C2. Overall, 10 (66.7%) pts experienced Grade 3–4 AEs and 1 pt had a Grade 5 AE (disease progression). Most frequent AEs (≥60% pts) were nausea and diarrhea. Conclusions: We have identified AX 5 mg BID + CZ 250 mg BID as the MTD for combination therapy. This regimen has manageable toxicities and exhibits antitumor activity in treatment-naïve and pretreated mRCC. Further studies in VEGFR, c-MET, ALK and ROS1 tumor types are warranted. Clinical trial information: NCT01999972.

Clinical Trial Simulations From a Model-Based Meta-Analysis of Studies in Patients With Advanced Hepatocellular Carcinoma Receiving Antiangiogenic Therapy

A mixed effect model describing median overall survival (mOS) in patients with advanced hepatocellular carcinoma (aHCC) treated with antiangiogenic therapy (AAT) was developed from literature data. Data were extracted from 59 studies, representing 4,813 patients. The final model included estimates of mOS after AAT (8.5 months) or placebo (7.1 months) administration. The mOS increased 21% when the AAT was sorafenib (SOR) or 42% when locoregional therapy was coadministered. The mOS decreased when patients received prior systemic therapy (↓7%) or concomitant chemotherapy (↓4%) or the percentage of patients with hepatitis B increased (↓∼0.4%/%). Clinical trial simulations of a phase II comparative trial predicted an mOS ratio (placebo:AAT) of 0.687 or 0.831, with a 65% or 22% probability of demonstrating superiority, for SOR or other AATs, respectively. Additionally, the 95% confidence interval (CI) of the simulated median mOS ratio for non‐SOR AATs was similar to the 95% CI of the hazard ratio (HR) observed in the trial.

Regional differences in efficacy/safety/biomarkers in a randomised study of axitinib in 2nd line patients (pts) with advanced hepatocellular carcinoma (HCC)

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Background: A randomised, double-blind phase II study of axitinib plus BSC [AXI] vs placebo plus BSC [PBO] was conducted in HCC pts after failure of one antiangiogenic therapy. Primary outcome was presented at ESMO 2014. No significant differences in overall survival (OS) between two arms were noted overall and in pre-specified subgroup analysis (non-Asian [nA] and Asian [A]). Interestingly, improvements favouring AXI (P < 0.01) were observed in secondary efficacy endpoints and retained among A. Methods: Exploratory efficacy/safety/biomarker analyses were performed by geographic region (nA; A; A subgroups: Japan/Korea [JK] and China/Hong Kong/Taiwan [CHT]) including: OS excluding pts intolerant to prior therapy; relationship between a subset of 26 baseline micro RNAs (miR) and AXI effect. Results: 78 nA pts (76% male, 60% with vascular invasion/extrahepatic spread) and 124 A pts (73JK/51CHT) (86% [84% JK, 90% CHT] male; 86% [82% JK, 92% CHT] with vascular invasion/extrahepatic spread) were randomized. In regional subgroups, OS HR excluding pts intolerant to prior therapy was: nA HR = 0.700 (95% CI 0.373–1.316; p = 0.1318) for AXI (45) vs PBO (16); A HR = 0.653 (95% CI 0.415–1.027; p = 0.0312) for AXI (76) vs PBO (35); JK HR = 0.479 (95% CI 0.250–0.918; p = 0.0118) for AXI (46) vs PBO (17); CHT HR = 0.918 (95% CI 0.480–1.756; p = 0.3954) for AXI (30) vs PBO (18). AXI safety profile was generally similar in regional subgroups. Differences were seen in dose modification pattern: dose reduction or discontinuation due to adverse events in 24% nA / 41% A / 51% JK / 26% CHT or in 39% nA / 22% A / 16% JK / 32% CHT, respectively. miR analysis for OS showed a trend of predictive and/or prognostic effect in overall population (e.g., let-7e-5p); a strong predictive effect of multiple miR (e.g., miR-3648) was seen in A but not in nA. Conclusions: AXI showed favorable OS vs PBO in nA and A, particularly in JK, when pts intolerant to prior therapy were excluded, suggesting that pts who progress on prior therapy are more suitable population for new agent studies in HCC. Appropriate dose modifications may also play a role in treatment duration. Baseline miR signature may have predictive value for AXI OS in A. Clinical trial information: NCT01210495.

A case for the use of receiver operating characteristic analysis of potential clinical efficacy biomarkers in advanced renal cell carcinoma

AIM

Assess patient-level utility of suggested pretreatment biomarkers of sunitinib in advanced renal cell carcinoma.

PATIENTS & METHODS

Kaplan-Meier analysis of data from a randomized, Phase II study (n = 292) suggested baseline predictive value for circulating soluble Ang-2 and MMP-2 and HIF-1α percentage of tumor expression. Using this dataset, the sensitivity, specificity and area under the curve (AUC) were calculated, using receiver operating characteristic (ROC) curves.

RESULTS

Based on a ROC (sensitivity vs 1 - specificity) threshold AUC value of >0.8, neither Ang-2 (0.67) nor MMP-2 (0.65), nor HIF-1α percentage of tumor expression (0.65), performed appropriately from a patient-selection standpoint.

CONCLUSION

To properly assess potential biomarkers, sensitivity and specificity characteristics should be obtained by ROC analysis.

Randomized phase II study of axitinib versus placebo plus best supportive care in second-line treatment of advanced hepatocellular carcinoma

BACKGROUND

The efficacy and safety of axitinib, a potent and selective vascular endothelial growth factor receptors 1-3 inhibitor, combined with best supportive care (BSC) was evaluated in a global, randomized, placebo-controlled phase II trial in patients with locally advanced or metastatic hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

Patients with HCC and Child-Pugh Class A who progressed on or were intolerant to one prior antiangiogenic therapy were stratified by tumour invasion (presence/absence of extrahepatic spread and/or vascular invasion) and region (Asian/non-Asian) and randomized (2:1) to axitinib/BSC (starting dose 5 mg twice-daily) or placebo/BSC. The primary end point was overall survival (OS).

RESULTS

The estimated hazard ratio for OS was 0.907 [95% confidence interval (CI) 0.646-1.274; one-sided stratified P = 0.287] for axitinib/BSC (n = 134) versus placebo/BSC (n = 68), with the median (95% CI) of 12.7 (10.2-14.9) versus 9.7 (5.9-11.8) months, respectively. Results of prespecified subgroup analyses in Asian versus non-Asian patients or presence versus absence of tumour invasion were consistent with the overall population. Improvements favouring axitinib/BSC (P < 0.01) were observed in secondary efficacy end point analyses [progression-free survival (PFS), time to tumour progression (TTP), and clinical benefit rate (CBR)], and were retained among Asian patients in the prespecified subgroup analyses. Overall response rate did not differ significantly between treatments and patient-reported outcomes favoured placebo/BSC. Most common all-causality adverse events with axitinib/BSC were diarrhoea (54%), hypertension (54%), and decreased appetite (47%). Baseline serum analyses identified potential new prognostic (interleukin-6, E-selectin, interleukin-8, angiopoietin-2, migration inhibitory factor, and c-MET) or predictive (E-selectin and stromal-derived factor-1) factors for survival.

CONCLUSIONS

Axitinib/BSC did not improve OS over placebo/BSC in the overall population or in stratification subgroups. However, axitinib/BSC resulted in significantly longer PFS and TTP and higher CBR, with acceptable toxicity in patients with advanced HCC.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01210495.

Abstract CT120: Axitinib safety and pharmacokinetics in Child-Pugh A and Child-Pugh B patients with advanced hepatocellular cancer

Introduction: Hepatobiliary excretion is the major elimination pathway for axitinib, an oral, potent, selective inhibitor of vascular endothelial growth factor receptors 1, 2 and 3, approved for second-line treatment of advanced renal cell carcinoma. A formal hepatic impairment (HI) study was previously conducted in subjects with Child-Pugh A (CPA) and Child-Pugh B (CPB) disease but who were otherwise healthy to evaluate the effect of mild and moderate HI on the pharmacokinetics (PK) of axitinib following a single 5 mg oral dose. The safety and PK of axitinib were further evaluated in CPA and CPB patients (pts) with advanced hepatocellular carcinoma (HCC) following continuous multiple axitinib dosing.

Methods: Two study portions (randomized double-blind portion of axitinib versus placebo, and non-randomized portion) were conducted in parallel in pts with advanced HCC after failure of one prior antiangiogenic therapy. In the non-randomized portion, the effect of HI on safety and PK were evaluated in HCC CPA (starting dose: 5 mg twice a day [BID]) and CPB (Score 7, starting dose: 2 mg BID) pts. This was also intended to identify the recommended starting dose of axitinib in HCC CPB pts. Serial PK samples up to 8 hour postdose were collected at steady state (Cycle 1 Day 15).

Results: Data from 15 CPA and 7 CPB pts were available for safety analysis. Most pts were male (n = 17) and Asian (n = 21). Overall, the most frequently reported all-causality treatment emergent adverse events (TEAE) in all, CPA and CPB pts were fatigue (63.6%, 80% and 28.6%), decreased appetite (54.5%, 46.7% and 71.4%), diarrhea (45.5%, 60% and 14.3%), hypertension (45.5%, 46.7% and 42.9%), and palmar-plantar erythrodysesthesia syndrome (45.5%, 53.3% and 28.6%). Overall, the most frequently reported Grade ≥3 TEAEs in all, CPA and CPB pts were hypertension (27.3%, 26.7% and 28.6%), fatigue (18.2%, 20% and 14.3%) and hyponatraemia (18.2%, 6.7% and 42.9%). One out of 6 evaluable CPB pts treated with 2 mg BID experienced Cycle 1 dose limiting toxicity (proteinuria; &gt;3.5 g/24 hours). PK samples were collected from 12 CPA and 7 CPB pts (AUC0-24 and CL/F reported for 8 CPA and 6 CPB pts, respectively). In CPA and CPB pts, the geometric mean (geometric% coefficient of variance [CV]) values for axitinib AUC0-24 were 311 (63) and 316 (118) ng.hr/mL, respectively. The geometric mean (geometric% CV) values for axitinib CL/F were 32.2 (63) and 12.7 (118) L/hour, respectively, indicating that axitinib CL/F is decreased with increasing HI.

Conclusions: The safety profile of axitinib in HCC CPA and CPB pts in this study was consistent with the known safety profile of axitinib. Axitinib plasma exposures were comparable in CPB pts receiving 2 mg BID axitinib and CPA pts receiving 5 mg BID axitinib. These data are in agreement with the previous single-dose HI study and further support that 2 mg BID is an appropriate axitinib starting dose for CPB pts with HCC.

Citation Format: Yoon-Koo Kang, Tara E. Seery, Mina Kato, Debasis Chakrabarti, Olga Valota, Ying Chen, Jie Tang, Yazdi K. Pithavala, Masatoshi Kudo. Axitinib safety and pharmacokinetics in Child-Pugh A and Child-Pugh B patients with advanced hepatocellular cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT120. doi:10.1158/1538-7445.AM2015-CT120

Phase I Study of Axitinib in Combination with Cisplatin and Capecitabine in Patients with Previously Untreated Advanced Gastric Cancer

PURPOSE

This phase I trial evaluated the question of whether the standard starting dose of axitinib could be administered in combination with therapeutic doses of cisplatin/capecitabine in patients with previously untreated advanced gastric cancer, and assessed overall safety, pharmacokinetics, and preliminary antitumor activity of this combination.

MATERIALS AND METHODS

Patients in dose level (DL) 1 received axitinib 5 mg twice a day (days 1 to 21) with cisplatin 80 mg/m(2) (day 1) and capecitabine 1,000 mg/m(2) twice a day (days 1 to 14) in 21-day cycles. Maximum tolerated dose (MTD) was the highest dose at which ≤ 30% of the first 12 patients experienced a dose-limiting toxicity (DLT) during cycle 1. Ten additional patients were enrolled and treated at the MTD in order to obtain additional safety and pharmacokinetic data.

RESULTS

Three DLTs occurred during cycle 1 in three (25%) of the first 12 patients: ruptured abdominal aortic aneurysm, acute renal failure, and > 5 consecutive days of missed axitinib due to thrombocytopenia. DL1 was established as the MTD, since higher DL cohorts were not planned. Common grade 3/4 non-hematologic adverse events in 22 patients treated at DL1 included hypertension (36.4%) and decreased appetite and stomatitis (18.2% each). Cisplatin/capecitabine slightly increased axitinib exposure; axitinib decreased capecitabine and 5-fluorouracil exposure. Eight patients (36.4%) each had partial response or stable disease. Median response duration was 9.1 months; median progression-free survival was 3.8 months.

CONCLUSION

In patients with advanced gastric cancer, standard doses of axitinib plus therapeutic doses of cisplatin and capecitabine could be administered in combination. Adverse events were manageable.

Phase I study of sunitinib plus capecitabine/cisplatin or capecitabine/oxaliplatin in advanced gastric cancer

BACKGROUND

We evaluated the maximum tolerated dose (MTD) and safety of sunitinib plus capecitabine/cisplatin (XP) or capecitabine/oxaliplatin (XELOX) in Korean patients with advanced gastric cancer (GC).

METHODS

Sunitinib (37.5 or 25 mg/day) was administered on a 2-week-on/1-week-off schedule with chemotherapy. Assessments included dose-limiting toxicity (DLT), safety, pharmacokinetics, and antitumor activity.

RESULTS

Twenty-eight patients received sunitinib/XP; 48 received sunitinib/XELOX. The MTDs were: sunitinib 25 mg/day, cisplatin 80 mg/m(2), and capecitabine 1,000 mg/m(2); sunitinib 37.5 mg/day, oxaliplatin 110 mg/m(2), and capecitabine 800 mg/m(2); and sunitinib 25 mg/day, oxaliplatin 110 mg/m(2), and capecitabine 1,000 mg/m(2). DLTs at the MTDs comprised grade (G) 4 febrile neutropenia plus G3 diarrhea (n = 1; sunitinib/XP), dose delays due to hematologic toxicity (n = 2; both sunitinib/XP), G3 bleeding (menorrhagia; n = 1; sunitinib/XELOX), and G3 increased alanine aminotransferase levels (n = 1; sunitinib/XELOX). There was a high frequency of G3/4 hematologic adverse events observed with both treatment regimens, particularly with sunitinib/XP. Frequent non-hematologic, G3/4 adverse events were nausea, stomatitis, and hypophosphatemia with sunitinib/XP and hypophosphatemia and pulmonary embolism with sunitinib/XELOX. No drug-drug interactions were apparent. At the MTDs, median progression-free survival was 6.4 months and 5.5-8.0 months for sunitinib/XP and sunitinib/XELOX, respectively; and the objective response rate was 46.7% and 43.5-45.5% for sunitinib/XP and sunitinib/XELOX, respectively.

CONCLUSIONS

At the MTD, sunitinib/XELOX had an acceptable safety profile in patients with advanced GC.

External validation of a sunitinib prognostic nomogram in patients (pts) with metastatic renal cell carcinoma (mRCC)

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Background: A nomogram was previously developed from pretreatment clinical features to predict the probability of achieving 12-month progression-free survival (PFS) with sunitinib in treatment (Tx)-naïve mRCC pts from a randomized, phase 3 trial (Cancer 2008;113:1552). Here, validation and update of this nomogram using pts from a phase 2 sunitinib mRCC study (Renal EFFECT Trial) is reported, as is evaluation of its usefulness for clinical decision making. Methods: The Tx-naïve mRCC pts included in the current analysis were randomized 1:1 to sunitinib 50 mg/d on a 4-weeks-on-2-weeks-off schedule (Schedule 4/2; n=146) or 37.5 mg/d on a continuous daily dosing (CDD) schedule (n=146). The variables included in the prior nomogram and used here for validation purposes were corrected serum calcium, number of metastatic sites, hemoglobin, prior nephrectomy, presence of lung and liver metastases, ECOG performance status, thrombocytosis, time from diagnosis to treatment, alkaline phosphatase, and lactate dehydrogenase. The nomogram was updated by removing prior nephrectomy as a variable, including baseline neutrophils and presence of bone metastases, and replacing thrombocytosis with baseline platelets. Validation of the existing and updated nomograms consisted of quantification of the discrimination with the concordance index. A decision curve analysis was used to examine whether this prediction model is useful for medical decision making. Results: With comparable pt characteristics and no significant difference in PFS (8.5 vs. 7.0 months; P=0.070) between the Schedule 4/2 and CDD arms of the phase 2 trial, the combined pt population (N=292) was used to validate the existing nomogram. The overall concordance index was 0.615. Based on the decision curve analysis, the existing nomogram has clinical utility when the probability of 12-month PFS exceeds 60%. Using Schedule 4/2 pts only, the concordance index was 0.594 for the updated nomogram; however, its utility showed more variability. Conclusions: The sunitinib nomogram has been validated in a similar pt cohort; however, its clinical utility may be limited and more research is needed to refine the tool further.

Randomized phase II trial of sunitinib on an intermittent versus continuous dosing schedule as first-line therapy for advanced renal cell carcinoma

PURPOSE

Sunitinib has shown antitumor activity with a manageable safety profile as metastatic renal cell carcinoma (RCC) treatment, when given by the standard intermittent schedule as well as a continuous daily dosing (CDD) schedule. A trial was conducted to compare the schedules.

PATIENTS AND METHODS

Patients with treatment-naive, clear cell advanced RCC were randomly assigned 1:1 to receive sunitinib 50 mg/d for 4 weeks followed by 2 weeks off treatment (schedule 4/2; n = 146) or 37.5 mg/d on the CDD schedule (n = 146) for up to 2 years. The primary end point was time to tumor progression.

RESULTS

Median time to tumor progression was 9.9 months for schedule 4/2 and 7.1 months for the CDD schedule (hazard ratio, 0.77; 95% CI, 0.57 to 1.04; P = .090). No significant difference was observed in overall survival (23.1 v 23.5 months; P = .615), commonly reported adverse events, or patient-reported kidney cancer symptoms. Schedule 4/2 was statistically superior to CDD in time to deterioration, a composite end point of death, progression, and disease-related symptoms (P = .034). CONCLUSION; There was no benefit in efficacy or safety for continuous dosing of sunitinib compared with the approved 50 mg/d dose on schedule 4/2. Given the numerically longer time to tumor progression with the approved 50 mg/d dose on schedule 4/2, adherence to this dose and schedule remains the treatment goal for patients with advanced RCC.

Ongoing phase I and II studies of novel anthracyclines

Many anthracyclines are currently in clinical development with the common aim of improving selectivity. This could be achieved by improving tumor drug delivery through the identification and development of molecules with new structure, prodrugs with low molecular weight for selective release and activation, prodrugs with high molecular weight conjugated to antibody with active targeting or macromolecules with enhanced permeability and retention. There are still interfering factors to be defined, in particular chemical, with degradation steps in tumor tissues, biological, related to tumor proteases, pharmacological, with inter-individual tumor differences in the extent of accumulation. Another way to improve selectivity is to activate the drug at the tumor site, a good example of which is provided by Nemorubicin (2\"-(S)-methoxymorpholinodoxorubicin hydrochloride) in hepatocellular carcinoma. The favorable characteristics of Nemorubicin in terms of broad spectrum of significant antitumor activity in liver malignancies models, lower cardiotoxicity than Doxorubicin, make Nemorubicin a promising third-generation anthracycline, suitable for intrahepatic administration.

Phase I/II trial of nemorubicin hydrochloride in combination with cisplatin is supported by new preclinical evidences of its mechanism of action

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Background: Nemorubicin hydrochloride (nemorubicin) is a non-conventional anthracycline in Phase II evaluation in hepatocellular carcinoma (HCC). Its mechanism of action is not fully elucidated. Although structurally related to doxorubicin, nemorubicin is a topoisomerase I inhibitor, overcomes anthracyclines resistance, is minimally cardiotoxic and is biotransformed by hepatic CYP3A4 into hundred times more cytotoxic metabolite. Phase I and II trials were conducted in Europe and China to test nemorubicin by hepatic intra-arterial (IHA) infusion in HCC patients (pts). The drug was well tolerated up to 600 mcg/m2 q4–6w; DLT was transient liver transaminase elevations. Overall, 57 HCC pts were evaluable for efficacy, with 11/57 confirmed liver CR/PRs (RR = 19.3%; 95% ci 10–31.9%) lasting 1–54+ months. Stable disease ≥ 3 months was observed in 17/57 (29.8%) pts, most with AJCC Stage III, IIIA and IVA. These data supported new trials of nemorubicin in HCC. Methods: To further characterize the mechanism of action of the drug, we generated cells (L1210) resistant to nemorubicin. Since resistant cells were more sensitive than the parental ones to UV irradiation, we reasoned that the nucleotide excision repair (NER) system might be involved in mediating the activity of nemorubicin. To test this hypothesis we used isogenic CHO cells proficient or deficient in excision repair cross-complementing (ERCC) genes, namely ERCC1 and ERCC6 genes. Results: In contrast with what is observed for most DNA damaging drugs that show resistance in the presence of high NER activity, nemorubicin is more cytotoxic in NER proficient than in deficient cells. This suggests that NER pathway plays a role in the cytotoxic effect of nemorubicin. Also, cells resistant to nemorubicin are NER-deficient and are highly sensitive to platinum derivatives and alkylating agents and synergism was found combining cisplatin with nemorubicin. Conclusions: Nemorubicin has a peculiar mechanism of action through the NER system providing the rationale for clinical combination studies with platinum derivatives. A Phase I/II trial of nemorubicin with cisplatin in HCC patients started in Italy at the end of 2005.

No significant financial relationships to disclose.

Predicting the maximum-tolerated dose of PNU-159548 (4-demethoxy-3'-deamino-3'-aziridinyl-4'-methylsulphonyl-daunorubicin) in humans using CFU-GM clonogenic assays and prospective validation

A haematotoxicity model was proposed by Parchment in 1998 to predict the maximum-tolerated dose (MTD) in humans of myelosuppressive antitumour agents by combining data from in vitro clonogenic assays on haematopoietic progenitors and in vivo systemic exposure data in animals. A prospective validation of this model in humans was performed with PNU-159548, a novel agent showing selective dose-limiting myelosuppression in animals. PNU-159548 and its main metabolite, PNU-169884, were tested in vitro on murine, canine and human colony forming units-granulocyte macrophages (CFU-GM) and in vivo on mice and dogs. The IC(90x) ratios (IC(x)=concentration inhibiting x% of colony growth) for CFU-GM and drug plasma protein binding were used to adjust the target plasma concentrations versus time curve (AUC) and predict the human MTD. The predicted MTD was compared with values achieved in phase I studies. Canine CFU-GM were 6-fold more sensitive (P<0.01) and murine CFU-GM 1.7-fold less sensitive (P<0.05) to PNU-159548 treatment than the human progenitors. PNU-169884 behaved similarly to PNU-159548. The predicted MTDs in humans calculated from data in mice and dogs were 15 and 38 mg/m(2), respectively. Overall, 61 patients were treated in two phase I studies, at doses ranging from 1.0 to 16 mg/m(2). Thrombocytopenia was dose-limiting with a MTD of 14 and 16 mg/m(2) in heavily and minimally pretreated/non-pretreated patients, respectively. Adjusting animal MTD data by means of the CFU-GM ratio between species can predict the human MTD with a good quantitative accuracy. Inhibition of common haemopoietic progenitors by PNU-159548 induced neutropenia/thrombocytopenia in animals and thrombocytopenia in patients, probably due to the higher sensitivity to the compound observed in human colony forming units-megakaryocyte (CFU-MK).

Phase I and pharmacokinetic studies of PNU-159548, a novel alkycycline, administered intravenously to patients with advanced solid tumours

PNU-159548 (4-demethoxy-3'-deamino-3'-aziridinyl-4'-methylsulphonyl-daunorubicin) is the lead compound of a novel class of cytotoxic agents (alkycyclines) with a unique mechanism of action combining DNA intercalation with alkylation of guanines in the DNA major groove. The objectives of two phase I studies were to assess the dose-limiting toxicities (DLTs), to determine the maximum tolerated dose (MTD) and to study the pharmacokinetics (PKs) of PNU-159548 and its active metabolite PNU-169884 when administered intravenously (i.v.) over 10 or 60 min to patients with advanced solid tumours. Patients were treated with escalating doses of PNU-159548, courses repeated every 21 days at doses ranging from 1.0 to 16 mg/m(2). For pharmacokinetic analysis, plasma sampling was performed during the first course and assayed using a validated high-performance liquid chromatographic assay with mass spectrometric detection. 69 patients received a total of 161 courses. The MTD was reached at 14 and 16 mg/m(2) in heavily (HP) and minimally pretreated/non-pretreated (MP) patients, respectively, with thrombocytopenia as the DLT. A hypersensitivity reaction was observed in 8 patients across all dose levels, characterised by fever with chills, erythema, facial oedema and dyspnoea. The PKs of PNU-159548 and PNU-169884 were linear over the dose range studied. A significant correlation was observed between the percentage decrease in platelet count and the AUC of PNU-159548. In these studies, the DLT of PNU-159548 was thrombocytopenia. The recommended dose for phase II studies of PNU-159548 is 12 and 14 mg/m(2) administered i.v. over 10 min, once every 21 days, in HP and MP patients, respectively.

A prolonged methoxymorpholino doxorubicin (PNU-152243 or MMRDX) infusion schedule in patients with solid tumours: a phase 1 and pharmacokinetic study

The aim of this phase I study was to assess feasibility, pharmacokinetics and toxicity of methoxymorpholino doxorubicin (MMRDX or PNU-152243) administered as a 3 h intravenous infusion once every 4 weeks. Fourteen patients with intrinsically anthracycline-resistant tumours received 37 cycles of MMRDX. The first cohort of patients was treated with 1 mg m(-2) of MMRDX. The next cohorts received 1.25 mg m(-2) and 1.5 mg m(-2) respectively. Common toxicity criteria (CTC) grade III/IV nausea and vomiting were observed in 1/18 cycles at 1.25 mg m(-2) and in 2/11 cycles at 1.5 mg m(-2). Transient elevation in transaminases up to CTC grade III was observed in 2/16 cycles at 1.25 mg m(-2) and 4/11 cycles at 1.5 mg m(-2). No cardiotoxicity was observed. At 1.25 mg m(-2) CTC grade IV neutropenia occurred in 1/17 cycles. At 1.5 mg m(-2) CTC grade III neutropenia was seen in 2/7 and grade IV in 3/7 evaluable cycles. Thrombocytopenia grade III was observed in 2/9 and grade IV in 1/9 evaluable cycles. One patient treated at 1.5 mg m(-2) died with neutropenic fever. Therefore, dose-limiting toxicity was reached and 1.25 mg m(-2) was considered the maximum tolerated dose for MMRDX as 3 h infusion. No tumour responses were observed. Pharmacokinetic parameters showed a rapid clearance of MMRDX from the circulation by an extensive tissue distribution. Renal excretion of the drug and its metabolite was negligible. In conclusion, prolongation of MMRDX infusion to 3 h does not improve the toxicity profile as compared with bolus administration.

Level of anti-mouse-antibody response induced by bi-specific monoclonal antibody OC/TR in ovarian-carcinoma patients is associated with longer survival

More than 60% of cancer patients injected with intact murine monoclonal antibody (MAb) develop a humoral response against the antigen even after a single dose. Analysis of a series of 35 ovarian-cancer patients entered in phase-I and -II clinical studies of T-cells retargeted with the bi-specific F(ab')2 OC/TR revealed: (i) a detectable human anti-mouse antibody (HAMA) response in 31/35 (88%) patients, with high HAMA levels (> or = 150 ng/ml) in 18/31 (58%) cases by the end of the treatment; (ii) no correlation between HAMA levels and the form of delivery of the mAb (OC/TR bound to T cells or bound plus soluble), time schedule or cumulative dose; (iii) an association between high HAMA levels and favorable clinical parameters and response to immunotherapy; and (iv) a significantly longer median survival probability in patients with high HAMA levels than in patients with lower HAMA levels, even when the sub-group of non-responder patients was considered. Evaluation of the anti-idiotypic response in HAMA-positive sera indicated that 11/17 sera showed high-titer (>6000) binding of OC/TR, as evaluated by a specific radioimmunoassay, and 15/18 and 16/16 sera specifically inhibited the binding of the MOv18 and anti-CD3 parental MAbs to ovarian-carcinoma cells and T lymphocytes respectively. Of 7 patients evaluated for duration of the HAMA response, 5 showed stable or even increased HAMA levels. The long-lasting HAMA response maintained an anti-idiotypic component, directed mainly against the alphaCD3 idiotype of bi-MAb OC/TR in 2 out of 3 cases tested.

Efficiency of T cell triggering by anti-CD3 monoclonal antibodies (mAb) with potential usefulness in bispecific mAb generation

T cell triggering can be achieved by monoclonal antibodies (mAbs) specific for the CD3/TcR complex. In the presence of appropriate costimulation and/or progression factors, such triggering permits the generation of effector cells for immunotherapy protocols involving the redirection of T cell lysis against tumor cells by mAbs bispecific for anti-CD3/anti-tumor cells (bs-mAbs). Focusing our analysis on the clinically relevant bs-mAb OC/TR, we found that bs-mAbs generated with the same anti tumor specificity, but two other anti-CD3 mAbs, TR66 and OKT3, have the same and a significantly lower lytic potential, respectively, compared with that of OC/TR. To evaluate the relevance of the anti-CD3 component, we examined several anti-CD3 mAbs with respect to binding parameters and the ability to trigger T lymphocytes. Competitive binding assays suggested that all anti-CD3 mAbs recognized the same or overlapping epitopes, although mAbs BMA030 and OC/TR bound with lower avidity than did alpha CD3 (the bivalent anti-CD3 mAb produced by the hybrid hybridoma OC/TR). TR66 and OKT3, as determined by measurement of the affinity constants. In all lymphocyte populations examined, which included resting peripheral blood mononuclear cells (PBMC), activated PBMC and T cell clones, OKT3, BMA033 and OC/TR failed to mobilize Ca2+ without cross-linking, whereas alpha CD3, in both murine and murine-human chimeric versions, TR66 and BMA030, did not require cross-linking. The ability to induce CD3 modulation was associated in part with the induction of Ca2+ fluxes. Despite the differences in the behavior of these mAbs in triggering the events that precede proliferation, all of them ultimately led to expression of the IL-2 receptor and to proliferation in T cells in the presence of accessory cells. Our data suggest that anti-CD3 mAbs that bind more rapidly (strong Ca2+ mobilizers) and more tightly under physiological conditions are good candidates for retargeting T cells in the bs-mAb clinical application.

Anti-idiotypic response to antigrowth factor receptor monoclonal antibodies

The immunogenicity of the idiotypic portions of two antigrowth factor receptor monoclonal antibodies (MAbs) was studied. Immunisation of allogeneic but not syngeneic mice with antihuman epidermal growth factor receptor (EGF-R) MAb MINT5 or anti-HER-2/neu MGR6 MAb elicited a detectable titre of circulating antibodies, particularly when the MAb was coupled with the keyhole limpet haemocyanin and administered together with Freund's adjuvant. The anti-Ab1 response to MAb MINT5 was slightly delayed as compared with the response obtained with MAb MGR6 and was mainly directed to the variable regions. In both cases, all anti-Ab1-positive sera specifically competed with the binding of homologous radiolabelled Ab1 to the relevant EGF-R+ or HER-2/neu+ target cells. Fusion of splenocytes from MINT5-immunised animals failed to produce MAb, whereas cell fusion was successful in generating a paratope-related MAb in the case of MGR6. The anti-MGR6 MAb-produced IdM6.4 inhibited the binding of MAb MGR6 on breast carcinoma cells, suggesting that it recognises an idiotope in or near the antigen combining site, and can be considered useful in the identification and purification of the Ab1 or its derivatives. We analysed whether a possible recognition of murine EGF-R by MAb MINT5 or a mimicry of EGF by the MAb idiotype prevented or delayed the development of an idiotypic cascade in mice. MINT5 inhibited human and murine EGF binding to the human EGF-R, whereas the anti-Ab1 response competed with MINT5 but not with murine EGF binding to A431 human epidermoid carcinoma cells. Moreover, MINT5 did not recognise the murine EGF-R. In a phase I clinical study, no detectable levels of human antimouse antibody response were observed in 5 of the 6 treated cancer patients. The ability of MAb MINT5 to block human EGF-R function, together with its low immunogenicity in patients, raise the possibility of its application in carcinoma immunotherapy.

In vitro and in vivo stability and anti-tumour efficacy of an anti-EGFR/anti-CD3 F(ab')2 bispecific monoclonal antibody

The in vitro and in vivo stability and anti-tumour efficacy of the anti-EGFR/anti-CD3 bispecific monoclonal antibody (biMAb), M26.1, were analysed. The interaction of the intact biMAb with Fc receptor I (Fc gamma RI) present on human leucocytes was not observed when the antibody was used as an F(ab')2 fragment. A CD8+ T-cell clone coated with M26.1 F(ab')2 was as effective as the intact biMAb in inducing IGROV1 target cell lysis when tested in a 51Cr-release assay. Variable levels of reduction of F(ab')2 to monovalent F(ab') were observed upon incubation with human ovarian cancer ascitic fluid (OCAF) or with human glioblastoma cavity fluid (GCF), but not with mouse or human sera. Activated lymphocytes coated with F(ab')2 and incubated in vitro with GCF or OCAF for 24 and 48 h respectively maintained their targeting. Thus, the F(ab')2, when present as a soluble molecule, but not when bound to T cells, might lose some functional activity as a consequence of partial reduction to F(ab'). In normal mice, M26.1 F(ab')2 retained full cytotoxic activity in the circulation, and clearance values were similar to those obtained with parental and other MAb F(ab')2. Treatment of IGROV1 tumour-bearing mice with activated human lymphocytes coated with the M26.1 F(ab')2 significantly prolonged survival of the animals compared with tumour-bearing untreated and control mice treated with lymphocytes or F(ab')2 alone. Together, these results suggest the clinical usefulness of bispecific M26.1 F(ab')2 as a targeting agent for local treatment of tumours such as glioma and ovarian cancers that express variable levels of epidermal growth factor receptor (EGFR).

Anti-tumor efficacy of an anti-epidermal-growth-factor-receptor monoclonal antibody and its F(ab')2 fragment against high- and low-EGFR-expressing carcinomas in nude mice

Monoclonal antibody (MAb) MINT5 specifically detects the epidermal-growth-factor receptor (EGFR). In vitro analyses of intact MINT5 (IgG1) and its F(ab')2 fragment indicated that both forms of the MAb inhibited binding of 125I-mEGF to EGFR, induced receptor internalization and blocked EGF-induced EGFR tyrosine-kinase activation in A431 cells. Both forms of the MAb also inhibited to the same extent the proliferation of the carcinoma cell lines A431 and IGROVI, despite the difference in EGFR levels on the cells. The detection of TGF alpha mRNA and the inhibition of cell growth in EGF-free conditions by anti-EGFR MAb indicated the involvement of an EGFR/TGF alpha autocrine/paracrine pathway in the in vitro growth of both cell lines. Analysis of mice xenotransplanted s.c. with A431 cells and treated with MINT5 revealed a block in A431 tumor take in 6 of 10 animals when intact MAb was administered from day 0 to day 11. On a molar basis, F(ab')2 at the same dose was ineffective, although at a 7-fold higher dose F(ab')2 reduced s.c. tumor growth by 80%. At the same dose, intact MINT5 MAb reduced s.c. growth of the EGFR-negative MeWo cell line by 5%. Survival of mice bearing IGROVI i.p. xenotransplants and treated locally with either form of MAb was significantly prolonged even when treatment was initiated on day 3. Corrected doses of intact and F(ab')2 fragment, which accounted for the difference in serum half-lives of the MAb forms, resulted in similar survival rates in the tumor-bearing mice. These pre-clinical results suggest that MINT5 MAb might be safely used for systemic therapy of EGFR-over-expressing tumors. Loco-regional therapy might be contemplated in the case of tumors with moderate/low EGFR expression.

Unidirectional potentiation of binding between two anti-FBP MAbs: evaluation of the involved mechanisms

The monoclonal antibody MOv19 directed to a folate binding protein shows temperature-dependent potentiation of binding of the noncompeting monoclonal antibody MOv18 to the relevant antigen, but the mechanism involved in this phenomenon had remained unclear. Use of chimeric versions of both monoclonal antibodies and the F(ab')2 and Fab fragments of MOv19 revealed an increment in MOv18 binding in all combinations irrespective of the origin of the Fc portion of the monoclonal antibody. The potentiating effect of bivalent MOv19 fragments on 125I-MOv18 binding was similar to that of the entire monoclonal antibody and occurred at saturating concentrations of both reagents at which monovalent binding prevails. Similarly, the monovalent fragment also induced a significant increase in MOv18 binding. However, the potentiation occurred only at very high concentrations of antibody fragment. Homologous inhibition was drastically reduced using MOv19 Fab fragment, suggesting a low binding stability of the monovalent reagent. Immunoblotting analysis and binding in the presence of exogenous purified folate binding protein indicated a cross-linking between soluble and cell surface molecules mediated by the bivalent monoclonal antibodies. The extent of the increase in MOv18 binding at 0 degrees C with high amounts of exogenous folate binding protein was lower than that obtained at 37 degrees C in the absence of added molecule. Release of 125I-MOv18 from the cell surface was significantly higher in the absence of MOv19 than in its presence.(ABSTRACT TRUNCATED AT 250 WORDS)