Contribution of tumour and immune cells to PD-L1 expression as a predictive biomarker in metastatic triple-negative breast cancer: exploratory analysis from KEYNOTE-119

The efficacy of pembrolizumab monotherapy versus chemotherapy increased with increasing programmed death ligand 1 (PD-L1) expression, as quantified by combined positive score (CPS; PD-L1 expression on both tumour cells and immune cells) in patients with previously treated metastatic triple-negative breast cancer (mTNBC) in the phase 3 KEYNOTE-119 study. This exploratory analysis was conducted to determine whether the expression of PD-L1 on tumour cells contributes to the predictive value of PD-L1 CPS in mTNBC. PD-L1 expression in tumour samples was assessed using PD-L1 IHC 22C3 pharmDx and quantified using both CPS and tumour proportion score (TPS; PD-L1 expression on tumour cells alone). Calculated immune cell density (CID) was defined as CPS minus TPS. The ability of each scoring method (CPS, TPS, and CID) to predict clinical outcomes with pembrolizumab was evaluated. With pembrolizumab, the area under the receiver operating characteristic curve was 0.69 (95% CI = 0.58-0.80) for CPS, 0.55 (95% CI = 0.46-0.64) for TPS, and 0.67 (95% CI = 0.56-0.77) for CID. After correction for cutoff prevalence, CPS performed as well as, if not better than, CID with respect to predicting objective response rate, progression-free survival, and overall survival. Data from this exploratory analysis suggest that, although PD-L1 expression on immune cells alone is predictive of response to programmed death 1 blockade in mTNBC, adding tumour PD-L1 expression assessment (i.e. CPS, which combines immune cell and tumour cell PD-L1 expression) may improve prediction. PD-L1 CPS thus remains an effective and broadly applicable uniform scoring system for enriching response to programmed death 1 blockade with pembrolizumab in mTNBC as well as other tumour types.

Ribociclib plus Endocrine Therapy in Early Breast Cancer

BACKGROUND

Ribociclib has been shown to have a significant overall survival benefit in patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer. Whether this benefit in advanced breast cancer extends to early breast cancer is unclear.

METHODS

In this international, open-label, randomized, phase 3 trial, we randomly assigned patients with HR-positive, HER2-negative early breast cancer in a 1:1 ratio to receive ribociclib (at a dose of 400 mg per day for 3 weeks, followed by 1 week off, for 3 years) plus a nonsteroidal aromatase inhibitor (NSAI; letrozole at a dose of 2.5 mg per day or anastrozole at a dose of 1 mg per day for ≥5 years) or an NSAI alone. Premenopausal women and men also received goserelin every 28 days. Eligible patients had anatomical stage II or III breast cancer. Here we report the results of a prespecified interim analysis of invasive disease-free survival, the primary end point; other efficacy and safety results are also reported. Invasive disease-free survival was evaluated with the use of the Kaplan-Meier method. The statistical comparison was made with the use of a stratified log-rank test, with a protocol-specified stopping boundary of a one-sided P-value threshold of 0.0128 for superior efficacy.

RESULTS

As of the data-cutoff date for this prespecified interim analysis (January 11, 2023), a total of 426 patients had had invasive disease, recurrence, or death. A significant invasive disease-free survival benefit was seen with ribociclib plus an NSAI as compared with an NSAI alone. At 3 years, invasive disease-free survival was 90.4% with ribociclib plus an NSAI and 87.1% with an NSAI alone (hazard ratio for invasive disease, recurrence, or death, 0.75; 95% confidence interval, 0.62 to 0.91; P = 0.003). Secondary end points - distant disease-free survival and recurrence-free survival - also favored ribociclib plus an NSAI. The 3-year regimen of ribociclib at a 400-mg starting dose plus an NSAI was not associated with any new safety signals.

CONCLUSIONS

Ribociclib plus an NSAI significantly improved invasive disease-free survival among patients with HR-positive, HER2-negative stage II or III early breast cancer. (Funded by Novartis; NATALEE ClinicalTrials.gov number, NCT03701334.).

Impact of pembrolizumab versus chemotherapy on health-related quality of life in patients with metastatic triple-negative breast cancer: results from the phase 3 randomised KEYNOTE-119 study

BACKGROUND

In KEYNOTE-119 (ClinicalTrials.gov, NCT02555657), overall survival (primary end-point) was similar between pembrolizumab and chemotherapy in patients with previously treated metastatic triple-negative breast cancer (TNBC), although the pembrolizumab treatment effect increased with tumour PD-L1 expression. We report results of prespecified health-related quality of life (HRQoL) analyses from KEYNOTE-119.

METHODS

Eligible patients were randomised 1:1 to pembrolizumab 200 mg Q3W intravenously for up to 35 cycles or treatment of physician's choice per local/country guidelines. Prespecified exploratory end-points were the change from baseline in HRQoL (EORTC QLQ-C30, QLQ-BR23) and to characterise utilities (EQ-5D-3L). Time to deterioration (TTD) was the time from start of treatment to first onset of a ≥10-point worsening from baseline.

RESULTS

HRQoL analyses included 187 patients with tumour PD-L1 combined positive score (CPS) ≥10. Changes from baseline at 6 weeks (primary analysis time point) were directionally better with pembrolizumab versus chemotherapy for QLQ-C30 GHS/QoL (between-group difference in least-squares mean scores of 4.21 [95% CI, -1.38 to 9.80]), QLQ-C30 functional scales (physical, role, cognitive, social), QLQ-C30 symptom scales/items (fatigue, nausea/vomiting, dyspnoea, appetite loss), and QLQ-BR23 symptom scales/items (systemic therapy side-effects, upset by hair loss). Median TTD was directionally longer for pembrolizumab versus chemotherapy for QLQ-C30 QHS/QoL (4.3 versus 1.7 months), QLQ-C30 nausea/vomiting (7.7 versus 4.8 months), and QLQ-BR23 systemic therapy side-effects (6.1 versus 3.4 months). Minimal treatment differences were observed for other HRQoL end-points.

CONCLUSIONS

HRQoL results were consistent with clinical outcomes and appeared to be driven by results for patients with tumour PD-L1 CPS ≥10.

Pembrolizumab plus Chemotherapy in Advanced Triple-Negative Breast Cancer

BACKGROUND

In an interim analysis of this phase 3 trial, the addition of pembrolizumab to chemotherapy resulted in longer progression-free survival than chemotherapy alone among patients with advanced triple-negative breast cancer whose tumors expressed programmed death ligand 1 (PD-L1) with a combined positive score (CPS; the number of PD-L1-staining tumor cells, lymphocytes, and macrophages, divided by the total number of viable tumor cells, multiplied by 100) of 10 or more. The results of the final analysis of overall survival have not been reported.

METHODS

We randomly assigned patients with previously untreated locally recurrent inoperable or metastatic triple-negative breast cancer in a 2:1 ratio to receive pembrolizumab (200 mg) every 3 weeks plus the investigator's choice of chemotherapy (nanoparticle albumin-bound paclitaxel, paclitaxel, or gemcitabine-carboplatin) or placebo plus chemotherapy. The primary end points were progression-free survival (reported previously) and overall survival among patients whose tumors expressed PD-L1 with a CPS of 10 or more (the CPS-10 subgroup), among patients whose tumors expressed PD-L1 with a CPS of 1 or more (the CPS-1 subgroup), and in the intention-to-treat population. Safety was also assessed.

RESULTS

A total of 847 patients underwent randomization: 566 were assigned to the pembrolizumab-chemotherapy group, and 281 to the placebo-chemotherapy group. The median follow-up was 44.1 months. In the CPS-10 subgroup, the median overall survival was 23.0 months in the pembrolizumab-chemotherapy group and 16.1 months in the placebo-chemotherapy group (hazard ratio for death, 0.73; 95% confidence interval [CI], 0.55 to 0.95; two-sided P = 0.0185 [criterion for significance met]); in the CPS-1 subgroup, the median overall survival was 17.6 and 16.0 months in the two groups, respectively (hazard ratio, 0.86; 95% CI, 0.72 to 1.04; two-sided P = 0.1125 [not significant]); and in the intention-to-treat population, the median overall survival was 17.2 and 15.5 months, respectively (hazard ratio, 0.89; 95% CI, 0.76 to 1.05 [significance not tested]). Adverse events of grade 3, 4, or 5 that were related to the trial regimen occurred in 68.1% of the patients in the pembrolizumab-chemotherapy group and in 66.9% in the placebo-chemotherapy group, including death in 0.4% of the patients in the pembrolizumab-chemotherapy group and in no patients in the placebo-chemotherapy group.

CONCLUSIONS

Among patients with advanced triple-negative breast cancer whose tumors expressed PD-L1 with a CPS of 10 or more, the addition of pembrolizumab to chemotherapy resulted in significantly longer overall survival than chemotherapy alone. (Funded by Merck Sharp and Dohme; KEYNOTE-355 ClinicalTrials.gov number, NCT02819518.).

Territorial manifestation features of multiple primary malignant neoplasms in carriers of germline mutations in the BRCA 1 gene in Republic of Bashkortostan

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Background: Recent advances in the diagnostic and therapeutic fields of oncology have increased the life expectancy of cancer patients, and therefore carriers of germline mutations, who are at high risk of developing a malignant neoplasm, also have a higher risk of developing a second synchronous or metachronous malignant tumor. The aim of this work is to study the features of the development of primary multiple malignant neoplasms in patients with germline mutations in the repair genes. Methods: Among all treated in the Republican Clinical Oncological Dispensary patients germline mutations in the repair genes were detected in 225 persons. Mutations were determined by polymerase chain reaction (PCR). The material of the study was a sample of venous blood taken from a patient on an empty stomach. A diagnostic panel was used to detect the most common mutations in Russia in the BRCA1 (5382insC, 4153delA, 300T > G, 185delAG, 2080delA, 3819delGTAAA) and BRCA2 (6174delT) genes. In the absence of a mutation, the study was carried out by the next generation sequencing (NGS) method. Results: After a molecular genetic study from 2014 to 2021, we determined the spectrum of germline mutations in residents of the Republic of Bashkortostan: BRCA 1 - c.5266dupC, c.3143delG, c.5161C > T, c.5382 insC, c.3819delGTAAA, c. 300T > G, c.5136G > A, 185delAG, 4153delA, 2080delA; BRCA 2 - c.6621_6622del, p.39-1_39delGA, c.961_962insAA. Among carriers of germinal mutations, primary multiple cancer was registered in 14.6% (33/225) of patients with mutations in the BRCA 1 genes. The following mutations were identified in patients with primary multiple malignant neoplasms: c.5382 insC and c.3819delGTAAA in the BRCA gene 1. The first primary breast cancer was registered in 10.6% (24/225) of patients, ovarian cancer in 1.8% (4/225), gastric cancer in 0.4% (1/225), primary multiple synchronous breast and ovarian cancer in 1.8% (4/225). In carriers of germinal mutations, manifestations of the first primary cancer were observed at the age of 29 to 60 years. The manifestation of the second primary cancer was registered in 2-18 years after the manifestation of the first primary cancer. Twenty-two patients subsequently developed a second primary breast cancer and 11 patients developed ovarian cancer. Also, 6 patients had a manifestation of the third primary cancer of the breast, ovaries or stomach in 8-26 years after the manifestation of the second primary cancer. Conclusions: Primary multiple cancer in carriers of germline mutations in the Republic of Bashkortostan was observed in 14.6% (33/225) of patients with mutations in the BRCA 1 genes. The period of manifestation of a secondary malignant tumor ranged from 2 to 18 years. This study plays an important role in the process of optimizing screening for multiple primary malignant neoplasms for carriers of germline mutations.

Abstract GS1-02: Final results of KEYNOTE-355: Randomized, double-blind, phase 3 study of pembrolizumab + chemotherapy vs placebo + chemotherapy for previously untreated locally recurrent inoperable or metastatic triple-negative breast cancer

Background: In the phase 3 KEYNOTE-355 trial (NCT02819518), pembrolizumab (pembro) combined with chemotherapy (chemo) showed statistically significant improvements in OS and PFS compared to placebo + chemo in patients with previously untreated locally recurrent inoperable or metastatic TNBC whose tumors expressed PD-L1 with a combined positive score (CPS) ≥10. There were no statistically significant differences between treatment groups in the CPS ≥1 population, and statistical significance was not tested in the ITT population due to the prespecified testing strategy. Here, we compare outcomes in subgroups of patients by additional CPS cut-offs to the primary results of KEYNOTE-355. Methods: 847 patients with measurable disease per RECIST v1.1, ECOG PS 0-1, and ≥6 month disease-free interval were randomized 2:1 to pembro + chemo (nab-paclitaxel 100 mg/m2 days 1, 8, and 15 every 28 days; paclitaxel 90 mg/m2 days 1, 8, and 15 every 28 days; or gemcitabine 1000 mg/m2 + carboplatin AUC 2 days 1 and 8 every 21 days) or placebo + chemo for up to 35 administrations of pembro/placebo or until progression/intolerable toxicity. Patients were stratified by chemo type (taxane or gemcitabine-carboplatin), PD-L1 status (CPS ≥1 or <1), and prior neoadjuvant/adjuvant treatment with same-class chemo (yes or no). Dual primary endpoints were OS and PFS (RECIST v1.1, blinded independent central review) in patients with PD-L1-positive tumors (CPS ≥10 and ≥1) and in the ITT population. Hazard ratios (HRs) and 95% CIs in the additional CPS subgroups were based on an unstratified Cox model. Results: At the time of the final analysis (data cutoff, June 15, 2021), the median time from randomization to data cutoff was 44 months. Baseline characteristics of the CPS 1-9, 10-19, and ≥20 subgroups were generally similar to those of the ITT population. In the primary analyses, the HRs (95% CI) for OS were 0.73 (0.55-0.95) in the CPS ≥10 subgroup, 0.86 (0.72-1.04) in the CPS ≥1 subgroup, and 0.89 (0.76-1.05) in the ITT population; HRs (95% CI) for PFS were 0.66 (0.50-0.88), 0.75 (0.62-0.91), and 0.82 (0.70-0.98), respectively. Efficacy data are presented for the additional CPS subgroups in the Table. For OS, results in the CPS 1-9 subgroup showed comparable efficacy for pembro + chemo and placebo + chemo; however, results in the CPS 10-19 and CPS ≥20 subgroups showed a similar treatment benefit with the addition of pembro. Results for PFS were generally consistent with those observed for OS.

Conclusions: These results provide support that CPS ≥10 is a reasonable cut-off to define the population of patients with metastatic TNBC expected to derive treatment benefit from pembro + chemo.

Table. Efficacy in additional subgroups of patients by PD-L1 CPSCPS subgroupTreatmentMedian OS, mo (95% CI)OS HR (95% CI)*Median PFS, mo (95% CI)PFS HR (95% CI)*1-9†Pembro + Chemo. n = 20513.9. (12.2-16.6)1.09 (0.85-1.40)5.7. (5.4-7.4)0.85 (0.65-1.11)Placebo + Chemo n = 10815.5. (12.4-17.6)5.6. (5.3-7.6)10-19†Pembro + Chemo. n = 8020.3. (15.2-29.0)0.71 (0.46-1.09)9.9. (7.4-11.8)0.70 (0.44-1.09)Placebo + Chemo n = 3917.6. (10.3-25.8)7.6. (5.3-9.7)≥20‡Pembro + Chemo. n = 14024.0 (19.0-28.3)0.72 (0.51-1.01)9.2 (7.6-11.8)0.62 (0.44-0.88)Placebo + Chemo n = 6415.6. (12.3-20.8)5.4 (3.9-7.2)*Analyses based on an unstratified Cox model. †Post-hoc analyses. ‡Prespecified exploratory analyses.

Citation Format: Javier Cortes, David W. Cescon, Hope S. Rugo, Zbigniew Nowecki, Seock-Ah Im, Mastura Md Yusof, Carlos Gallardo, Oleg Lipatov, Carlos Henrique Barrios, Jose Perez-Garcia, Hiroji Iwata, Norikazu Masuda, Marco Torregroza Otero, Erhan Gokmen, Sherene Loi, Zifang Guo, Xuan Zhou, Vassiliki Karantza, Wilbur Pan, Peter Schmid. Final results of KEYNOTE-355: Randomized, double-blind, phase 3 study of pembrolizumab + chemotherapy vs placebo + chemotherapy for previously untreated locally recurrent inoperable or metastatic triple-negative breast cancer [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 GS1-02.

Germinal mutations landscape, which is responsible for cancer predisposition in multinational Republic of Bashkortostan

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Background: In oncology hereditary forms of malignant neoplasms occupy a special position due to the frequent cases at a young age and poor prognostic factors. The aim of this work is to determine in cancer patients germinal mutations which are responsible for cancer predisposition. Methods: The study included patients with burdened family history or those with a manifestation of malignant neoplasm at a young age residing on the territory of multinational Republic of Bashkortostan. The patients were diagnosed with one of these diseases: breast cancer, prostate cancer, pancreatic cancer, gastric cancer, colon cancer. The study is based on analyses of the molecular genetic blood testing n cancer patients using real-time polymerase chain reaction (PCR) for detection of 8 widely spread mutations among Russian population: in BRCA 1 gene were detected such mutations as 185delAG, 4153delA, 5382insC, 3819delGTAAA, 3875delGTCT, 300T>G, 2080delA; in gene BRCA 2 - 6174delT. Blood samples of the rest amount of patients which proved no mutations by PCR method was tested by the “next-generation” sequencing method (NGS). Results: The results of the study showed territorial features of presence of germinal mutations of Russian multinational region. The results of the study aimed to reveal the spectrum and frequency of gene mutations characteristic for the particular region: BRCA 1 - c.5266dupC, c.3143delG, c.5161C>T, c.5382 insC, c.3819delGTAAA, c.300T>G, c.5136G>A, 185delAG, 4153delA, 2080delA; BRCA 2 - c.6621_6622del, с.39-1_39delGA, c.961_962insAA; CHEK2 - c.470T>C, c.444+1G>A; PALB2 - c.1592delT; RAD50 - c.2157delA; MLH1 - c.1637A>G; MSH6 - c.2554_2556del; STK11 - c.368A>G; MSH2 - c.815C>T. According to the mutation detection the patient consulted a geneticist for making a genealogic tree for future molecular genetics exam. Hereinafter the control group included relatives of patients who remain potential carriers of pathogenic mutations of the proband using Sanger sequencing method. When penetrate mutations are identified in healthy population, a set of measures is taken to prevent and early diagnose malignant tumors. Conclusions: The results of the study showed features of presence of each detected mutation which is characteristic for south-eastern part of the Russian multinational region. This study plays an important role in the process of optimization of screening of germinal mutation carriers among healthy population and as a result it helps to conduct prophylactic measures to early diagnose malignant neoplasms.

Pembrolizumab versus investigator-choice chemotherapy for metastatic triple-negative breast cancer (KEYNOTE-119): a randomised, open-label, phase 3 trial

BACKGROUND

Pembrolizumab showed durable antitumour activity and manageable safety in metastatic triple-negative breast cancer in the single-arm KEYNOTE-012 and KEYNOTE-086 trials. In this study, we compared pembrolizumab with chemotherapy for second-line or third-line treatment of patients with metastatic triple-negative breast cancer.

METHODS

KEYNOTE-119 was a randomised, open-label, phase 3 trial done at 150 medical centres (academic medical centres, community cancer centres, and community hospitals) in 31 countries. Patients aged 18 years or older, with centrally confirmed metastatic triple-negative breast cancer, Eastern Cooperative Oncology Group performance status of 0 or 1, who had received one or two previous systemic treatments for metastatic disease, had progression on their most recent therapy, and had previous treatment with an anthracycline or taxane were eligible. Patients were randomly assigned (1:1) using a block method (block size of four) and an interactive voice-response system with integrated web-response to receive intravenous pembrolizumab 200 mg once every 3 weeks for 35 cycles (pembrolizumab group), or to single-drug chemotherapy per investigator's choice of capecitabine, eribulin, gemcitabine, or vinorelbine (60% enrolment cap for each; chemotherapy group). Randomisation was stratified by PD-L1 tumour status (positive [combined positive score (CPS) ≥1] vs negative [CPS <1]) and history of previous neoadjuvant or adjuvant treatment versus de-novo metastatic disease at initial diagnosis. Primary endpoints were overall survival in participants with a PD-L1 combined positive score (CPS) of 10 or more, those with a CPS of 1 or more, and all participants; superiority of pembrolizumab versus chemotherapy was tested in all participants only if shown in those with a CPS of one or more. The primary endpoint was analysed in the intention-to-treat population; safety was analysed in the all-subjects-as-treated population. This Article describes the final analysis of the trial, which is now completed. This trial is registered with ClinicalTrials.gov, number NCT02555657.

FINDINGS

From Nov 25, 2015, to April 11, 2017, 1098 participants were assessed for eligibility and 622 (57%) were randomly assigned to receive either pembrolizumab (312 [50%]) or chemotherapy (310 [50%]). Median study follow-up was 31·4 months (IQR 27·8-34·4) for the pembrolizumab group and 31·5 months (27·8-34·6) for the chemotherapy group. Median overall survival in patients with a PD-L1 CPS of 10 or more was 12·7 months (95% CI 9·9-16·3) for the pembrolizumab group and 11·6 months (8·3-13·7) for the chemotherapy group (hazard ratio [HR] 0·78 [95% CI 0·57-1·06]; log-rank p=0·057). In participants with a CPS of 1 or more, median overall survival was 10·7 months (9·3-12·5) for the pembrolizumab group and 10·2 months (7·9-12·6) for the chemotherapy group (HR 0·86 [95% CI 0·69-1·06]; log-rank p=0·073). In the overall population, median overall survival was 9·9 months (95% CI 8·3-11·4) for the pembrolizumab group and 10·8 months (9·1-12·6) for the chemotherapy group (HR 0·97 [95% CI 0·82-1·15]). The most common grade 3-4 treatment-related adverse events were anaemia (three [1%] patients in the pembrolizumab group vs ten [3%] in the chemotherapy group), decreased white blood cells (one [<1%] vs 14 [5%]), decreased neutrophil count (one [<1%] vs 29 [10%]), and neutropenia (0 vs 39 [13%]). 61 (20%) patients in the pembrolizumab group and 58 (20%) patients in the chemotherapy group had serious adverse events. Three (<1%) of 601 participants had treatment-related adverse events that led to death (one [<1%] in the pembrolizumab group due to circulatory collapse; two [1%] in the chemotherapy group, one [<1%] due to pancytopenia and sepsis and one [<1%] haemothorax).

INTERPRETATION

Pembrolizumab did not significantly improve overall survival in patients with previously treated metastatic triple-negative breast cancer versus chemotherapy. These findings might inform future research of pembrolizumab monotherapy for selected subpopulations of patients, specifically those with PD-L1-enriched tumours, and inform a combinatorial approach for the treatment of patients with metastatic triple-negative breast cancer.

FUNDING

Merck Sharp & Dohme.

Abstract PD14-04: Contribution of tumor and immune cells to PD-L1 as a predictive biomarker in triple-negative breast cancer (TNBC): Analysis from KEYNOTE-119

Background: Pembrolizumab monotherapy did not significantly improve overall survival (OS) as second- or third-line treatment for metastatic TNBC vs chemotherapy in the randomized, open-label, phase 3 KEYNOTE-119 study (NCT02555657; N = 622). However, the benefit of pembrolizumab compared with chemotherapy appeared to be greater with increasing PD-L1 expression as quantified by combined positive score (CPS; defined as the number of PD-L1–staining cells [tumor cells, lymphocytes, macrophages] divided by the total number of viable tumor cells, multiplied by 100). In the current exploratory analysis, we aimed to determine whether expression of PD-L1 on tumor cells contributes to the value of PD-L1 as a predictive biomarker in metastatic TNBC.Methods: Patients with centrally confirmed TNBC and 1 or 2 prior systemic treatments for metastatic disease were enrolled in KEYNOTE-119. Patients were randomly assigned 1:1 to pembrolizumab 200 mg Q3W or investigator’s choice of single-agent chemotherapy (capecitabine, eribulin, gemcitabine, or vinorelbine). PD-L1 expression in tumor samples was assessed using PD-L1 IHC 22C3 pharmDx and quantified per tumor proportion score (TPS; defined as the percentage of PD-L1–expressing tumor cells [partial or complete membrane staining] relative to total number of tumor cells) and CPS. Quantitative immune cell density (QID) was defined as CPS minus TPS. QID isolates immune cells but may be truncated when TPS is high. The ability of each scoring method (TPS, CPS, and QID) to predict objective response rate (ORR) with pembrolizumab, including receiver operating characteristics (ROC) analysis, and OS hazard ratios (HRs; pembrolizumab vs chemotherapy) was evaluated.Results: Tumor samples were available for 601 patients (pembrolizumab, 309; chemotherapy, 292) in KEYNOTE-119. ORR was 9.7% (30/309) with pembrolizumab and 11.3% (33/292) with chemotherapy when PD-L1 expression status was not considered. In the pembrolizumab arm, the area under the ROC curve (AUROC; 95% CI) was 0.69 (0.58-0.80) for tumor samples scored for CPS, 0.66 (0.55-0.77) for QID, and 0.55 (0.46-0.64) for TPS. ROC analysis is shown in the Table. At each cutoff, QID had lower estimated sensitivity (ie, missed responders) and a lower Youden Index compared with CPS. The number of missed responders (of 30 total in the pembrolizumab arm) for QID relative to CPS were 2, 5, 5, 6, 2, and 2 at cutoffs of 1, 10, 20, 30, 40, and 50, respectively. Across all practical cutoffs, the OS HR tended to be slightly smaller for CPS than QID. At cutoffs corresponding to the upper percentiles of 10, 20, 40, and 60, OS HRs were 0.497, 0.658, 0.758, and 0.850, respectively, for CPS vs 0.572, 0.712, 0.814, and 0.863, respectively, for QID. QID appeared to be orthogonal to TPS (r = -0.03 for all 601 observations; r = -0.04 after eliminating 7 potentially truncated values).Conclusions: Trends estimated using KN119 suggest that tumor cell expression is an important component of PD-L1 as a predictive biomarker of pembrolizumab efficacy in metastatic TNBC. In this exploratory analysis, when immune cells alone were used to measure PD-L1 expression, a meaningful number of responders was missed and OS benefit trended toward higher HR estimates. Tumor and immune cell PD-L1 expression may represent distinct (presumably negative modulatory) mechanisms.

Table. ROC AnalysisCutoffCPS SensCPS SpecCPS YICPS PrevQID SensQID SpecQID YIQID PrevTPS SensTPS SpecTPS YITPS Prev010011001100110.8330.3660.1990.6540.7670.4160.1820.6020.3000.7890.0890.220100.5670.7170.2840.3110.4000.8140.2140.2070.2000.8920.0920.117200.5000.8490.3490.1840.3330.9250.2580.1000.1670.9320.0990.078300.3670.8920.2590.1330.1670.9570.1240.0550.1000.9430.0430.061400.2000.9350.1350.0780.1330.9860.1190.0260.0670.9530.0200.049500.2000.9570.1570.0580.1330.9930.1260.0190.0670.9680.0340.036

Citation Format: Eric P. Winer, Oleg Lipatov, Seock-Ah Im, Anthony Goncalves, Eva Muñoz-Couselo, Keun Seok Lee, Zbigniew Nowecki, Peter Schmid, Kenji Tamura, Laura Testa, Isabell Witzel, Shoichiro Ohtani, Stephanie Hund, Karina Kulangara, Vassiliki Karantza, Jaime A. Mejia, Junshui Ma, Petar Jelinic, Lingkang Huang, Kenneth Emancipator, Javier Cortes. Contribution of tumor and immune cells to PD-L1 as a predictive biomarker in triple-negative breast cancer (TNBC): Analysis from KEYNOTE-119 [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD14-04.

Abstract PS12-01: Pembrolizumab versus chemotherapy for previously treated metastatic triple-negative breast cancer (KEYNOTE-119): Efficacy in patients with lung or liver metastases

Background: KEYNOTE-119 (NCT02555657) is a randomized, open-label phase 3 study of pembrolizumab (pembro) monotherapy vs single-agent chemotherapy (chemo) in patients with previously treated metastatic triple-negative breast cancer (mTNBC). The results showed directionally favorable improvement in overall survival (OS) with pembro compared to chemo in patients with PD-L1−positive tumors, although statistical superiority was not demonstrated. The pembro treatment effect increased with PD-L1 enrichment, as measured by the combined positive score (CPS). Since treatment outcomes may vary by location of metastasis, we performed a retrospective, exploratory analysis to evaluate the efficacy of pembro vs chemo among patients with lung or liver metastasis at baseline enrolled in KEYNOTE-119.

Methods: Patients with centrally confirmed TNBC, 1-2 prior systemic treatments for metastatic disease, documented progression on most recent therapy and prior treatment with an anthracycline and/or taxane were randomized 1:1 to pembro 200 mg Q3W or single-agent chemo per investigator’s choice of capecitabine, eribulin, gemcitabine, or vinorelbine (60% enrollment cap for each). Patients were stratified by PD-L1 status (CPS &lt;1 vs ≥1) and history of prior neoadjuvant/adjuvant treatment vs de novo metastatic disease at initial diagnosis. Primary study end points were OS in patients with PD-L1 CPS ≥10, patients with CPS ≥1, and all patients.

Results: Overall, 622 patients were randomized in KEYNOTE-119 (pembro, n=312; chemo, n=310); median follow-up was 31 months at the April 11, 2019 data cutoff date. At baseline, 403 (65%) patients had lung metastasis and 173 (28%) had liver metastasis. Pembro did not improve OS vs chemo in patients with lung or liver metastases in the ITT population, although the HRs decreased as tumor PD-L1 expression increased, with the greatest benefit observed in patients with PD-L1 CPS ≥20 tumors (Table). Similar trends were observed for progression-free survival, objective response rate, and duration of response. In both treatment groups, presence of liver metastases at baseline was associated with shorter OS as compared to absence of liver metastases at baseline; this trend was not observed for lung metastases. Results should be interpreted with caution due to modest patient sample size in some subgroups.

Conclusion: Among patients with previously treated mTNBC who had lung or liver metastases for whom prognosis is typically poor, pembro monotherapy showed a benefit vs single-agent chemo in patients with increasing PD-L1 tumor enrichment. These findings are consistent with the results from the global study population.

Table. Analysis of Overall SurvivalITTCPS ≥1CPS ≥10CPS ≥20NMedian, mo (95% CI)HR (95% CI)NMedian, mo (95% CI)HR (95% CI)NMedian, mo (95% CI)HR (95% CI)NMedian, mo (95% CI)HR (95% CI)Patients With Lung MetastasesPembro2009.8 (7.4-11.7)0.99 (0.80-1.23)12710.6 (8.1-12.5)0.85 (0.65-1.10)5612.8 (9.3-17.2)0.80 (0.53-1.18)3117.0 (11.7-27.1)0.55 (0.32-0.95)Chemo20311.4 (8.7-13.1)13110.4 (7.2-12.7)6311.9 (7.3-14.9)3413.0 (7.2-15.8)Patients Without Lung MetastasesPembro11210.3 (8.3-13.6)0.92 (0.69-1.23)7610.8 (8.9-15.7)0.89 (0.63-1.26)4012.1 (8.6-16.4)0.79 (0.47-1.31)2612.8 (7.8-23.0)0.63 (0.32-1.24)Chemo10710.2 (7.2-12.7)719.9 (7.0-13.5)3511.3 (7.0-15.7)1810.5 (5.2-15.7)Patients With Liver MetastasesPembro876.5 (4.7-9.3)1.04 (0.76-1.43)577.7 (4.2-9.9)1.02 (0.69-1.51)2410.3 (6.2-16.4)0.78 (0.44-1.39)1310.7 (6.2-19.0)0.69 (0.31-1.53)Chemo866.5 (5.4-8.4)546.5 (5.4-7.8)317.2 (5.2-11.6)207.5 (2.9-14.7)Patients Without Liver MetastasesPembro22510.9 (9.2-12.6)0.95 (0.78-1.17)14612.4 (10.5-14.2)0.82 (0.64-1.05)7213.0 (10.1-17.2)0.80 (0.55-1.16)4416.0 (11.4-27.1)0.57 (0.33-0.95)Chemo22412.6 (10.6-13.9)14812.6 (9.8-13.6)6712.7 (9.8-15.8)3214.3 (8.3-16.8)

Citation Format: Eric Winer, Oleg Lipatov, Seock-Ah Im, Anthony Goncalves, Keun Seok Lee, Peter Schmid, Laura Testa, Isabell Witzel, Shoichiro Ohtani, NIcholas Turner, Stefania Zambelli, Nadia Harbeck, Fabrice Andre, Rebecca Dent, Jianxin Lin, Vassiliki Karantza, Jaime Mejia, Javier Cortes. Pembrolizumab versus chemotherapy for previously treated metastatic triple-negative breast cancer (KEYNOTE-119): Efficacy in patients with lung or liver metastases [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS12-01.

Abstract GS3-01: Additional efficacy endpoints from the phase 3 KEYNOTE-355 study of pembrolizumab plus chemotherapy vs placebo plus chemotherapy as first-line therapy for locally recurrent inoperable or metastatic triple-negative breast cancer

Background: Pembrolizumab (pembro) monotherapy showed durable antitumor activity and manageable safety in patients (pts) with metastatic triple-negative breast cancer (TNBC) in the KEYNOTE-012, -086, and -119 studies. In a prespecified interim analysis of KEYNOTE-355 (NCT02819518), pembro combined with chemotherapy (chemo) showed a statistically significant improvement in PFS versus chemo alone in pts with previously untreated locally recurrent inoperable or metastatic TNBC whose tumors expressed PD-L1 CPS ≥10 (HR for progression or death, 0.65, 95% CI, 0.49-0.86; one-sided P=0.0012 [prespecified statistical criterion was alpha=0.00411 at this interim analysis]). Additionally, pembro + chemo was generally well tolerated, with no new safety signals. Here, we examine PFS outcomes for each chemo partner and present key secondary endpoints from KEYNOTE-355.

Methods: 847 pts with measurable disease per RECIST v1.1, ECOG PS 0-1, and ≥6 mo DFI were randomized 2:1 to pembro + chemo (nab-paclitaxel 100 mg/m2 days 1, 8, and 15 every 28 days; paclitaxel 90 mg/m2 days 1, 8, and 15 every 28 days; or gemcitabine 1000 mg/m2 + carboplatin AUC 2 days 1 and 8 every 21 days) or pbo + chemo for up to 35 administrations of pembro/pbo or until progression/intolerable toxicity. Steroid premedication for paclitaxel was given according to local guidelines and practices, and was not restricted by the protocol. Crossover between arms was not allowed. Pts were stratified by chemo type (taxane vs gemcitabine/carboplatin), PD-L1 status (CPS ≥1 vs &lt;1), and prior (neo)adjuvant treatment with same-class chemo (yes vs no). Dual primary endpoints are PFS (RECIST v1.1, blinded independent central review) and OS in pts with PD-L1 positive tumors (CPS ≥10 and ≥1) and in all pts. Secondary endpoints include ORR, DCR (CR + PR + SD ≥24 weeks), and DOR. The PFS treatment effect was assessed in subgroups descriptively using HRs and 95% CIs; although subgroup analysis by on-study chemo were pre-specified, the trial was not powered to compare efficacy among treatment groups by different chemo regimens.

Results: As of Dec 11 2019, median follow-up was 25.9 mo for pembro + chemo (n=566) and 26.3 mo for pbo + chemo (n=281). The HR for PFS favored pembro regardless of choice of chemo or CPS population (Table). Results for the key secondary endpoints of ORR, DCR, and DOR favored pembro + chemo, with the treatment effect increasing as CPS increased (Table).

Conclusion: In subgroup analysis, PFS with pembro + chemo compared to pbo + chemo in pts with metastatic TNBC was improved regardless of chemo partner. A trend toward improved efficacy with PD-L1 enrichment with pembro + chemo was observed for ORR, DCR and DOR endpoints. These data further support the potential of pembro + chemo as a first-line treatment option for metastatic TNBC.

CPS ≥ 10CPS ≥ 1All ptsPembro + ChemoPbo + ChemoPembro + ChemoPbo + ChemoPembro + Chemo|Pbo + ChemoN = 220N = 103N = 425N = 211N = 566N = 281PFS, mo median (95% CI)9.7 (7.6 - 11.3)5.6 (5.3 - 7.5)7.6 (6.6 - 8.0)5.6 (5.4 - 7.4)7.5 (6.3 - 7.7)5.6 (5.4 - 7.3)HR (95% CI)0.65 (0.49 - 0.86)0.74 (0.61 - 0.90)0.82 (0.69 - 0.97)PFS by on-study chemo, (n [%)) mo median(95% CI)Nab-Paclitaxel(63 [28.6%]) 9.9(36 [35.0%]) 5.5(130 [30.6%]) 6.3(74 [35.1%)) 5.3(173 [30.6%]) 7.5(95 [33.8%]) 5.4HR (95% CI)0.57 (0.34 - 0.95)0.66 (0.26 - 0.82)0.69 (0.51 - 0.93)Paclitaxel(33 [15.0%]) 9.6(11 [10.7%]) 3.6(62 [14.6%]) 9.4(22 [10.4%]) 3.8(82 [14.5%]) 8.0(32 [11.4%]) 3.8HR (95% CI)0.33 (0.14 - 0.76)0.46 (0.26 - 0.82)0.57 (0.35 - 0.93)Gemcitabine-Carboplatin(124 [56.4%]) 8.0(56 [54.4%]) 7.2(233 [54.8%]) 7.5(115 [54.5%]) 7.5(311 [54.9%]) 7.4(154 [54.8%]) 7.4HR (95% CI)0.77 (0.53 - 1.11)0.86 (0.66 - 1.11)0.93 (0.74 - 1.16)ORR, % (95% CI)53.2 (46.4 - 59.9)39.8 (30.3 - 49.9)45.2 (40.4 - 50.0)37.9 (31.3 - 44.8)41.0 (36.9 - 45.2)35.9 (30.3 - 41.9)DCR, % (95% CI)65.0 (58.3 - 71.3)54.4 (44.3 - 64.2)58.6 (53.7 - 63.3)53.6 (46.6 - 60.4)56.0 (51.8 - 60.1)51.6 (45.6 - 57.6)DOR, mo, median (range)19.3 (1.6+ - 29.8)7.3 (1.5 - 32.5+)10.1 (1.0+ - 29.8)6.5 (1.5 - 32.5+)10.1 (1.0+ - 29.8)6.4 ( 1.5 - 32.5+)"+" indicates there is no progressive disease by the time of last disease assessment.

Citation Format: Hope S. Rugo, Peter Schmid, David W. Cescon, Zbigniew Nowecki, Seock-Ah Im, Mastura Md Yusof, Carlos Gallardo, Oleg Lipatov, Carlos Henrique Barrios, Jose Perez-Garcia, Hiroji Iwata, Norikazu Masuda, Marco Torregroza Otero, Erhan Gokmen, Sherene Loi, Zifang Guo, Jing Zhao, Vassiliki Karantza, Gursel Aktan, Javier Cortes. Additional efficacy endpoints from the phase 3 KEYNOTE-355 study of pembrolizumab plus chemotherapy vs placebo plus chemotherapy as first-line therapy for locally recurrent inoperable or metastatic triple-negative breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr GS3-01.

Pembrolizumab plus chemotherapy versus placebo plus chemotherapy for previously untreated locally recurrent inoperable or metastatic triple-negative breast cancer (KEYNOTE-355): a randomised, placebo-controlled, double-blind, phase 3 clinical trial

BACKGROUND

Pembrolizumab monotherapy showed durable antitumour activity and manageable safety in patients with metastatic triple-negative breast cancer. We aimed to examine whether the addition of pembrolizumab would enhance the antitumour activity of chemotherapy in patients with metastatic triple-negative breast cancer.

METHODS

In this randomised, placebo-controlled, double-blind, phase 3 trial, done in 209 sites in 29 countries, we randomly assigned patients 2:1 with untreated locally recurrent inoperable or metastatic triple-negative breast cancer using a block method (block size of six) and an interactive voice-response system with integrated web-response to pembrolizumab (200 mg) every 3 weeks plus chemotherapy (nab-paclitaxel; paclitaxel; or gemcitabine plus carboplatin) or placebo plus chemotherapy. Randomisation was stratified by type of on-study chemotherapy (taxane or gemcitabine-carboplatin), PD-L1 expression at baseline (combined positive score [CPS] ≥1 or <1), and previous treatment with the same class of chemotherapy in the neoadjuvant or adjuvant setting (yes or no). Eligibility criteria included age at least 18 years, centrally confirmed triple-negative breast cancer; at least one measurable lesion; provision of a newly obtained tumour sample for determination of triple-negative breast cancer status and PD-L1 status by immunohistochemistry at a central laboratory; an Eastern Cooperative Oncology Group performance status score 0 or 1; and adequate organ function. The sponsor, investigators, other study site staff (except for the unmasked pharmacist), and patients were masked to pembrolizumab versus saline placebo administration. In addition, the sponsor, the investigators, other study site staff, and patients were masked to patient-level tumour PD-L1 biomarker results. Dual primary efficacy endpoints were progression-free survival and overall survival assessed in the PD-L1 CPS of 10 or more, CPS of 1 or more, and intention-to-treat populations. The definitive assessment of progression-free survival was done at this interim analysis; follow-up to assess overall survival is continuing. For progression-free survival, a hierarchical testing strategy was used, such that testing was done first in patients with CPS of 10 or more (prespecified statistical criterion was α=0·00411 at this interim analysis), then in patients with CPS of 1 or more (α=0·00111 at this interim analysis, with partial alpha from progression-free survival in patients with CPS of 10 or more passed over), and finally in the intention-to-treat population (α=0·00111 at this interim analysis). This study is registered with ClinicalTrials.gov, NCT02819518, and is ongoing.

FINDINGS

Between Jan 9, 2017, and June 12, 2018, of 1372 patients screened, 847 were randomly assigned to treatment, with 566 patients in the pembrolizumab-chemotherapy group and 281 patients in the placebo-chemotherapy group. At the second interim analysis (data cutoff, Dec 11, 2019), median follow-up was 25·9 months (IQR 22·8-29·9) in the pembrolizumab-chemotherapy group and 26·3 months (22·7-29·7) in the placebo-chemotherapy group. Among patients with CPS of 10 or more, median progression-free survival was 9·7 months with pembrolizumab-chemotherapy and 5·6 months with placebo-chemotherapy (hazard ratio [HR] for progression or death, 0·65, 95% CI 0·49-0·86; one-sided p=0·0012 [primary objective met]). Median progression-free survival was 7·6 and 5·6 months (HR, 0·74, 0·61-0·90; one-sided p=0·0014 [not significant]) among patients with CPS of 1 or more and 7·5 and 5·6 months (HR, 0·82, 0·69-0·97 [not tested]) among the intention-to-treat population. The pembrolizumab treatment effect increased with PD-L1 enrichment. Grade 3-5 treatment-related adverse event rates were 68% in the pembrolizumab-chemotherapy group and 67% in the placebo-chemotherapy group, including death in <1% in the pembrolizumab-chemotherapy group and 0% in the placebo-chemotherapy group.

INTERPRETATION

Pembrolizumab-chemotherapy showed a significant and clinically meaningful improvement in progression-free survival versus placebo-chemotherapy among patients with metastatic triple-negative breast cancer with CPS of 10 or more. These findings suggest a role for the addition of pembrolizumab to standard chemotherapy for the first-line treatment of metastatic triple-negative breast cancer.

FUNDING

Merck Sharp & Dohme Corp, a subsidiary of Merck & Co, Inc.

KEYNOTE-355: Randomized, double-blind, phase III study of pembrolizumab + chemotherapy versus placebo + chemotherapy for previously untreated locally recurrent inoperable or metastatic triple-negative breast cancer

1000

Background: Pembrolizumab (pembro) monotherapy showed promising antitumor activity and manageable safety in patients (pts) with metastatic TNBC in KEYNOTE-012, -086 and -119. KEYNOTE-355 (ClinicalTrials.gov, NCT02819518) compared pembro + chemotherapy (chemo) vs placebo (pbo) + chemo for previously untreated locally recurrent inoperable or metastatic TNBC. Methods: Pts with ≥6 mo DFI were randomized 2:1 to pembro + chemo (nab-paclitaxel; paclitaxel; or gemcitabine/carboplatin) or pbo + chemo for up to 35 administrations of pembro/pbo or until progression/intolerable toxicity. Pts were stratified by chemo type (taxane vs gemcitabine/carboplatin), PD-L1 status (CPS ≥1 vs <1), and prior (neo)adjuvant treatment with same-class chemo (yes vs no). Dual primary endpoints are PFS (RECIST v1.1, blinded independent central review) and OS by tumor PD-L1 expression (CPS ≥10 and ≥1) and in all pts. PFS was estimated using the Kaplan-Meier method. Stratified log-rank tests were used to assess treatment group differences. HR and 95% CIs were based on a stratified Cox regression model. AEs were monitored throughout the study and graded per NCI CTCAE v4.0. Results: As of Dec 11 2019, median follow-up was 17.5 mo for pembro + chemo (n=566) and 15.5 mo for chemo (n=281). Pembro + chemo significantly improved PFS vs chemo alone in pts with CPS ≥10 tumors (Table), meeting one of the protocol-defined primary objectives. Although the boundary for a statistically significant benefit of pembro + chemo in pts with CPS ≥1 tumors was not met and formal testing in ITT was not performed, the pembro treatment effect increased with PD-L1 enrichment (Table). OS follow-up is ongoing. Grade 3-5 treatment-related AE rates were 68.1% with pembro + chemo (2 deaths) vs 66.9% with chemo (0 deaths); rates of grade 3-4 immune-mediated AEs and infusion reactions were 5.5% vs 0%. Clinical trial information: NCT02819518 . Conclusion: Pembro combined with several chemo partners showed a statistically significant and clinically meaningful improvement in PFS vs chemo alone in pts with previously untreated locally recurrent inoperable or metastatic TNBC whose tumors expressed PD-L1 (CPS ≥10). Pembro + chemo was generally well tolerated, with no new safety concerns. [Table: see text]

Association of tumor mutational burden (TMB) and clinical outcomes with pembrolizumab (pembro) versus chemotherapy (chemo) in patients with metastatic triple-negative breast cancer (mTNBC) from KEYNOTE-119

1013

Background: In the randomized, open-label, phase 3 KEYNOTE-119 study (NCT02555657) , OS was not significantly different with pembro monotherapy versus chemo in second- or third-line settings for mTNBC; however, the pembro treatment effect increased with increasing PD-L1 enrichment. We evaluated the association of TMB with efficacy of pembro monotherapy versus chemo in patients with previously treated mTNBC. Methods: Patients with centrally confirmed TNBC and 1 or 2 prior systemic treatments for metastatic disease were enrolled. Patients were randomly assigned 1:1 to pembro 200 mg Q3W or single-agent chemo per investigator’s choice of capecitabine, eribulin, gemcitabine, or vinorelbine. Association of TMB, as measured by FoundationOne CDx (Foundation Medicine), with response was an exploratory objective evaluated using receiver operator characteristic (ROC) analysis, logistic regression (ORR), and Cox regression (OS; PFS) within treatment arms; estimates of efficacy based on TMB cutpoint used a prespecified cutpoint of 10 mut/Mb. Results: TMB data were available for 253/601 (42.1%) treated patients (pembro, n = 132; chemo, n = 121); baseline characteristics were similar to that of the overall study population. One-sided P values for the association of TMB and clinical outcomes in pembro-treated patients were 0.154 for ORR, 0.014 for PFS, and 0.018 for OS; the area under the ROC curve ([AUROC] 95% CI) for predicting ORR was 0.58 (0.43-0.73). Two-sided P values for the association of TMB and clinical outcomes in chemo-treated patients were 0.114 for ORR, 0.478 for PFS, and 0.906 for OS; AUROC (95% CI) was 0.43 (0.27-0.59). Twenty-six patients had TMB ≥10 mut/Mb. Thus, the prevalence of TMB ≥10 mut/Mb was ~10%. Outcomes based on TMB cutpoint are reported in the Table. Conclusions: Data from this exploratory analysis from KEYNOTE-119 suggest a potential positive association between TMB and clinical benefit with pembro but not chemo in patients with mTNBC. Although precision is limited by sample size and the number of patients with TMB ≥10 mut/Mb, ORR and HRs for OS suggested a trend towards increased benefit with pembro versus chemo in patients with TMB ≥10 mut/Mb. Clinical trial information: NCT02555657 . [Table: see text]

Abstract P1-18-08: Trazimera (a trastuzumab biosimilar) in HER2-positive metastatic breast cancer: Long-term safety and overall survival data

Background: Trazimera™ (PF-05280014) is a trastuzumab biosimilar. This multinational, randomized, double-blind, parallel-group study (NCT01989676) compared Trazimera with reference trastuzumab (Herceptin®) sourced from the EU (Herceptin-EU), each plus paclitaxel, in the first-line treatment of HER2-positive metastatic breast cancer (MBC). Equivalence between the two groups was previously demonstrated for the primary efficacy endpoint of objective response rate, evaluating responses achieved by Week 25 and confirmed by Week 33 (Pegram et al, Br J Cancer 2019). Furthermore, using data collected up to 378 days after randomization, there were no notable differences in progression-free survival, overall survival (OS), safety, or immunogenicity. Here, we report additional cumulative safety and OS data collected up to 5 years after the first patient was screened. Methods: Eligible patients were randomized 1:1 to receive intravenous Trazimera or Herceptin-EU, each plus paclitaxel. Randomization was stratified by prior trastuzumab exposure and estrogen receptor status. Trazimera or Herceptin-EU treatment could continue until objective disease progression per RECIST 1.1. In addition to evaluating safety and OS in the overall study population, we assessed safety in the subgroup of patients still ongoing in the study after Day 378 (including only adverse events starting after this time point). We also compared time to discontinuation from Trazimera or Herceptin-EU. Results: Of 707 patients randomized (Trazimera, n=352; Herceptin-EU, n=355), 83 (11.7%) were ongoing in the study as of the data cutoff on February 25, 2019 (Trazimera, n=41 [11.6%]; Herceptin-EU, n=42 [11.8%]). Overall, 637 (90.1%) patients discontinued trastuzumab treatment (Trazimera, n=319 [90.6%]; Herceptin-EU, n=318 [89.6%]). The most frequent reason for discontinuing trastuzumab was objective progression (Trazimera, n=245 [69.6%]; Herceptin-EU, n=245 [69.0%]). Estimated median time to discontinuation from trastuzumab was 12.25 months for Trazimera and 12.06 months for Herceptin-EU (stratified hazard ratio [HR] 1.014; 95% confidence interval [CI] 0.867-1.186; log-rank P=0.569). In total, 58 (16.5%) patients in the Trazimera group and 67 (18.9%) patients in the Herceptin-EU group died. There was no statistically significant difference in OS (stratified HR 0.888; 95% CI 0.624-1.264; log-rank P=0.254). Estimated 2-year survival rates were 82.26% for Trazimera and 77.50% for Herceptin-EU; corresponding estimated 3-year rates were 77.17% and 75.33%. Among patients who received treatment (Trazimera, n=349; Herceptin-EU, n=353), there were no notable differences in incidences of treatment-emergent adverse events (TEAEs; 98.3% vs. 96.6%), grade 3 or higher TEAEs (40.7% vs. 42.5%), or serious TEAEs (19.2% vs. 19.3%). Rates of cardiac failure (1.4% vs. 2.8%), infusion-related reaction (IRR; 9.7% vs. 9.1%), and decreased ejection fraction (13.2% vs. 13.0%) were similar. Comparable proportions of patients had ≥1 occasion of an absolute decrease in left ventricular ejection fraction of ≥16% from baseline (6.3% vs. 5.4%) or ≥10% from baseline and below the lower limit of normal (4.0% vs. 5.1%). In the subgroup ongoing after Day 378 (Trazimera, n=265; Herceptin-EU, n=264), rates of cardiac failure (0.0% vs. 1.1%), IRR (0.0% vs. 0.8%), and decreased ejection fraction (3.4% vs. 4.2%) remained balanced. Conclusion: Long-term safety and OS data were consistent with previous results from this ongoing comparative study of Trazimera and Herceptin-EU, demonstrating no clinically meaningful differences between treatment groups. These results represent the longest known follow-up data reported for a trastuzumab biosimilar study in patients with HER2-positive MBC. Funding: This study was sponsored by Pfizer.

Citation Format: Rubi K Li, Oleg Lipatov, Hryhoriy Adamchuk, Vladimir Vladimirov, Eduardo Yanez, Patricia Banchero, Amy Freyman, Fiona Hilton, Alexandra Thiele, Alicia Vana. Trazimera (a trastuzumab biosimilar) in HER2-positive metastatic breast cancer: Long-term safety and overall survival data [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-18-08.

Clinical considerations of the role of palbociclib in the management of advanced breast cancer patients with and without visceral metastases

Background

This report assesses the efficacy and safety of palbociclib plus endocrine therapy (ET) in women with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer (ABC) with or without visceral metastases.

Patients and methods

Pre- and postmenopausal women with disease progression following prior ET (PALOMA-3; N = 521) and postmenopausal women untreated for ABC (PALOMA-2; N = 666) were randomized 2 : 1 to ET (fulvestrant or letrozole, respectively) plus palbociclib or placebo. Progression-free survival (PFS), safety, and patient-reported quality of life (QoL) were evaluated by prior treatment and visceral involvement.

Results

Visceral metastases incidence was higher in patients with prior resistance to ET (58.3%, PALOMA-3) than in patients naive to ET in the ABC setting (48.6%, PALOMA-2). In patients with prior resistance to ET and visceral metastases, median PFS (mPFS) was 9.2 months with palbociclib plus fulvestrant versus 3.4 months with placebo plus fulvestrant [hazard ratio (HR), 0.47; 95% confidence interval (CI), 0.35–0.61], and objective response rate (ORR) was 28.0% versus 6.7%, respectively. In patients with nonvisceral metastases, mPFS was 16.6 versus 7.3 months, HR 0.53; 95% CI 0.36–0.77. In patients with visceral disease and naive to ET in the advanced disease setting, mPFS was 19.3 months with palbociclib plus letrozole versus 12.9 months with placebo plus letrozole (HR 0.63; 95% CI 0.47–0.85); ORR was 55.1% versus 40.0%; in patients with nonvisceral disease, mPFS was not reached with palbociclib plus letrozole versus 16.8 months with placebo plus letrozole (HR 0.50; 95% CI 0.36–0.70). In patients with prior resistance to ET with visceral metastases, palbociclib plus fulvestrant significantly delayed deterioration of QoL versus placebo plus fulvestrant, whereas patient-reported QoL was maintained with palbociclib plus letrozole in patients naive to endocrine-based therapy for ABC.

Conclusions

Palbociclib plus ET prolonged mPFS in patients with visceral metastases, increased ORRs, and in patients previously treated for ABC, delayed QoL deterioration, presenting a standard treatment option among patients with visceral metastases amenable to endocrine-based therapy.

Clinical trial registration

NCT01942135, NCT01740427

Palbociclib plus letrozole as first-line therapy in estrogen receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer with extended follow-up

PURPOSE

In the initial PALOMA-2 (NCT01740427) analysis with median follow-up of 23 months, palbociclib plus letrozole significantly prolonged progression-free survival (PFS) in women with estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) [hazard ratio (HR) 0.58; P < 0.001]. Herein, we report results overall and by subgroups with extended follow-up.

METHODS

In this double-blind, phase 3 study, post-menopausal women with ER+/HER2- ABC who had not received prior systemic therapy for their advanced disease were randomized 2:1 to palbociclib-letrozole or placebo-letrozole. Endpoints include investigator-assessed PFS (primary), safety, and patient-reported outcomes (PROs).

RESULTS

After a median follow-up of approximately 38 months, median PFS was 27.6 months for palbociclib-letrozole (n = 444) and 14.5 months for placebo-letrozole (n = 222) (HR 0.563; 1-sided P < 0.0001). All subgroups benefited from palbociclib treatment. The improvement of PFS with palbociclib-letrozole was maintained in the next 2 subsequent lines of therapy and delayed the use of chemotherapy (40.4 vs. 29.9 months for palbociclib-letrozole vs. placebo-letrozole). Safety data were consistent with the known profile. Patients' quality of life was maintained.

CONCLUSIONS

With approximately 15 months of additional follow-up, palbociclib plus letrozole continued to demonstrate improved PFS compared with placebo plus letrozole in the overall population and across all patient subgroups, while the safety profile remained favorable and quality of life was maintained. These data confirm that palbociclib-letrozole should be considered the standard of care for first-line therapy in patients with ER+/HER2- ABC, including those with low disease burden or long disease-free interval. Sponsored by Pfizer; ClinicalTrials.gov: NCT01740427.

Efficacy of tivozanib treatment after sorafenib in patients with advanced renal cell carcinoma: crossover of a phase 3 study

Background:

Tivozanib is a selective inhibitor of vascular endothelial growth factor receptors 1, 2 and 3 tyrosine kinases. This open-label, crossover clinical study (AV-951–09-902) provided access to tivozanib for patients who progressed on sorafenib in TIVO-1, comparing tivozanib with sorafenib in patients with advanced renal cell carcinoma (RCC).

Methods:

Patients enrolled in this single-arm, phase 2 crossover study were previously randomised to sorafenib on TIVO-1, progressed and then crossed over to tivozanib. Patients received tivozanib (1.5 mg/day orally; 3 weeks on/1 week off) within 4 weeks after their last sorafenib dose.

Findings:

Crossover patients were exposed to tivozanib for a median of eight cycles. From the start of tivozanib treatment, median progression-free survival was 11.0 months (95% confidence interval [CI]: 7.3–12.7) and median overall survival was 21.6 months (95% CI: 17.0–27.6). Best overall response was partial response in 29 (18%) patients and stable disease in 83 (52%) patients, with a median duration of response of 15.2 and 12.7 months, respectively. About 77% of patients experienced adverse events, most frequently hypertension (26%), followed by diarrhoea (14%) and fatigue (13%); 53% of patients had treatment-related adverse events, including 24% grade ≥3. About 9% and 16% of patients had dose reductions and dose interruptions due to adverse events, respectively. A total of 30% of patients had serious adverse events, and 4% had treatment-related serious adverse events.

Interpretation:

This crossover study of patients with advanced RCC demonstrated potent tivozanib anti-tumour activity. Safety and tolerability profiles were acceptable and consistent with the established adverse event profile of tivozanib.

Abstract P5-21-03: Palbociclib (PAL) + letrozole (LET) as first-line therapy in estrogen receptor–positive (ER+)/human epidermal growth factor receptor 2–negative (HER2−) advanced breast cancer (ABC): Efficacy and safety updates with longer follow-up across patient subgroups

BACKGROUND: Endocrine therapy (ET) has been the primary first-line (1L) therapy for ER+ ABC. In the PALOMA-2 study (NCT01740427), PAL (P)+LET (L) significantly prolonged progression-free survival (PFS; HR=0.58, P&lt;.001) after a median 23 mo follow-up (FU) (Finn et al. NEJM 2016). Here we report more mature PFS overall and in subgroups, with (w/) longer FU. The study is ongoing for overall survival FU.

METHODS: Postmenopausal pts w/ ER+/HER2- ABC and no prior systemic therapy in the ABC setting were randomized 2:1 to P (125 mg/d) + L (2.5 mg QD) or placebo (PBO) + L. Key endpoints: investigator-assessed PFS and safety. Median PFS (mPFS) was estimated (intent-to-treat population).

RESULTS: 666 pts (444, P+L; 222, PBO+L) were enrolled. Arms were well balanced: visceral (48%)/nonvisceral (52%) disease and prior ET (56%)/no prior ET (44%). After a median FU of 38 mo w/ P+L and 37 mo w/ PBO+L, mPFS was 27.6 and 14.5 mo, respectively, in the overall population (HR=0.56, P&lt;.0001; Table).

TABLE. mPFS overall and by relevant subgroupsP+LPBO+LP+L vs PBO+LmPFS, mo (95% CI)mPFS, mo (95% CI)HR (95% CI)P* Overall27.6 (22.4–30.3)14.5 (12.3–17.1)0.56 (0.46–0.69)&lt;.0001 Measurable disease23.7 (19.3–27.6)14.5 (12.3–18.5)0.63 (0.50–0.79)&lt;.0001 Nonmeasurable disease36.2 (27.6?NE)16.5 (8.3–19.6)0.39 (0.25–0.60)&lt;.0001 Visceral19.3 (16.4–24.2)12.3 (8.4–16.4)0.62 (0.47–0.81)&lt;.0005 Nonvisceral35.9 (27.7–NE)17.0 (13.8–24.8)0.50 (0.37–0.67)&lt;.0001 Bone only†36.2 (27.6–NE)11.2 (8.2–22.0)0.41 (0.26–0.63)&lt;.0001 Not bone only24.2 (19.4–27.7)14.5 (12.9–18.5)0.62 (0.50–0.78)&lt;.0001 De novo metastatic27.9 (22.1–33.4)22.0 (13.9–27.4)0.61 (0.44–0.85)&lt;.005 Prior ET24.2 (18.8–27.6)11.2 (8.4–14.5)0.54 (0.42–0.71)&lt;.0001 No prior ET30.3 (24.5–35.7)21.9 (15.9–27.4)0.59 (0.43–0.80)&lt;.0005 Nonvisceral36.2 (27.9–NE)27.6 (19.1–35.6)0.59 (0.38–0.92)&lt;.01 Visceral23.7 (16.8–30.3)13.9 (10.2–22.2)0.55 (0.36–0.85)&lt;.005 Disease sites130.4 (24.8–NE)16.5 (11.0–22.1)0.52 (0.36–0.75)&lt;.0005228.1 (19.4–NE)16.3 (11.0–27.4)0.57 (0.37–0.89)&lt;.01323.7 (19.2–27.6)13.8 (8.8–17.0)0.61 (0.46–0.82)&lt;.0005NE=not estimable. *Not adjusted for multiple analyses; 1-sided P values. †Per tumor site.

All subgroups benefited from addition of P to L. Notably, pts w/ low disease burden (bone only, nonvisceral disease, few disease sites) derived significant PFS benefit, including those w/ both nonvisceral disease and no prior ET (mPFS, 36.2 vs 27.6 mo; HR=0.59, P&lt;.01). Importantly, median time from randomization to start of 2nd subsequent systemic anticancer therapy was 39 vs 29 mo for P+L vs PBO+L (HR=0.72, P&lt;.005). There were no new safety signals w/ longer FU.

CONCLUSIONS: This is the longest FU of a phase 3 study of a cyclin-dependent kinase 4/6 inhibitor for ABC. P+L continues to consistently improve PFS vs PBO+L across all subgroups while toxicity remains manageable; notably P+L delays time to starting 2nd subsequent anticancer therapies by 10 mo. Pts w/ low disease burden or sensitivity to ET alone had PFS &gt;3 y (significant vs PBO+L), demonstrating the clinical benefit of P+ET. These data confirm P+L should be a 1L therapy option for pts w/ HR+/HER2- ABC.

Funding: Pfizer

Citation Format: Rugo HS, Finn RS, Dieras V, Ettl J, Lipatov O, Joy A, Harbeck N, Castrellon A, Lu DR, Mori A, Gauthier ER, Huang C, Gelmon KA, Slamon DJ. Palbociclib (PAL) + letrozole (LET) as first-line therapy in estrogen receptor–positive (ER+)/human epidermal growth factor receptor 2–negative (HER2−) advanced breast cancer (ABC): Efficacy and safety updates with longer follow-up across patient subgroups [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-03.

Randomized, double-blind study comparing proposed biosimilar LA-EP2006 with reference pegfilgrastim in breast cancer

AIM

This randomized, double-blind trial compared proposed biosimilar LA-EP2006 with reference pegfilgrastim in women receiving chemotherapy for breast cancer (PROTECT-1).

PATIENTS & METHODS

Women (≥18 years) were randomized to receive LA-EP2006 (n = 159) or reference (n = 157) pegfilgrastim (Neulasta(®), Amgen) for ≤6 cycles of (neo)-adjuvant TAC chemotherapy. Primary end point was duration of severe neutropenia (DSN) during cycle 1 (number of consecutive days with absolute neutrophil count <0.5 × 10(9)/l) with equivalence confirmed if 90% and 95% CIs were within a ±1 day margin.

RESULTS

For DSN, LA-EP2006 was equivalent to reference (difference: 0.07 days; 90% CI: -0.09-0.23; 95% CI: -0.12-0.26).

CONCLUSION

LA-EP2006 and reference pegfilgrastim showed no clinically meaningful differences regarding efficacy and safety in breast cancer patients receiving chemotherapy.

Abstract P6-14-03: Genome wide association study (GWAS) to identify variants conferring ramucirumab-associated hypertension in the ROSE/TRIO-012 breast cancer trial

Background: In a candidate single nucleotide polymorphism (SNP) association study, we previously identified VEGFR-1 and VEGFR-2 SNPs strongly associated with treatment emergent hypertension (HT) in the ramucirumab (RAM) and docetaxel (Doc) arm in the ROSE/TRIO-012 study, a double-blinded multinational phase III trial that randomized 1,144 patients with advanced breast cancer to receive first-line Doc in combination with RAM or placebo (Mackey et al, JCO Jan 10, 2015:141-148; Mackey et al, JCO, Volume 33, Issue 15_suppl, May 20, 2015: 547). However, candidate SNP studies limit the number of genes for interrogation and a more comprehensive genome wide search may identify critical variants associated with the phenotype of HT. Preliminary analysis indicated that patients experiencing HT with RAM showed better overall survival (Mackey JR, et al (2015). Reply to H. Lee, et al. JCO; in press). These observations provide the potential to identify those patients with genetic variants for predisposition to RAM-associated HT to inform therapeutic decisions.

Methods: Genotyping of samples is underway using Affymetrix SNP 6.0 arrays. Genotype data will be filtered for deviations from Hardy Weinberg Equilibrium and minor allele frequency of &gt;0.05. Study subjects (n=792) provided ethics-committee approved prospective consent for this genetic study of whom 478 subjects were allocated RAM + Doc arm. Toxicity grades 0-1 (n= 394 controls; low toxicity) vs. grade &gt;2 (n= 84 cases, high toxicity) is our binary outcome. Dominant genotypic model is assumed. Chi-square test, FDR and/or 10000 permutation tests will be employed (Golden Helix-SVS v8.3) and p&lt;0.05 considered statistically significant. Population stratification will be identified (EIGENSTRAT) and association statistics will be corrected using Eigenvectors along with age as covariates. Fine mapping of loci showing significant associations will be attempted using imputation tools.

Results and conclusions: We expect up to 700,000 SNPs to be retained after filtering based on our previous breast cancer GWAS analyses (Damaraju et al. Cancer Research (suppl); Vol 70 (24), page 258s, 2010 and Sehrawat et al Hum Genet. 2011 Oct;130(4):529-37) and 30,000 SNPs to show significance at a nominal p-value (0.05); these will be analysed for regions of high linkage disequilibrium to narrow down potential loci showing association with HT to serve as candidate markers in further independent validation studies. Cumulative dose to adverse events will be considered in the analysis. Identified loci will be interrogated for potential genes in the flanking regions with biological relevance based on pathway analysis. Identified variants from candidate SNP and GWAS may allow developing predictive tools to enable stratification of patients for therapies. The analysis is expected to be completed by mid- November, 2015.

Citation Format: Mackey JR, Lipatov O, Martín M, Webster M, Hegg R, Verma S, Ramos-Vázquez M, Fresco R, Thireau F, Houé V, Press MF, Kumaran M, Damaraju S. Genome wide association study (GWAS) to identify variants conferring ramucirumab-associated hypertension in the ROSE/TRIO-012 breast cancer trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-14-03.

Abstract P1-10-01: A randomized, double-blind trial to compare the efficacy and safety of proposed biosimilar pegfilgrastim (LA-EP2006) with reference pegfilgrastim in patients with breast cancer (PROTECT1)

Background: An abbreviated pathway for biological products shown to be biosimilar to the reference product exists in Europe and the US. The randomized PROTECT1 trial compared the efficacy and safety of the proposed biosimilar pegfilgrastim with reference pegfilgrastim.

Methods: In this multinational, prospective, double-blind trial, chemotherapy-naïve women aged ≥18 years with histologically proven breast cancer received up to 6 cycles of (neo)-adjuvant TAC chemotherapy (docetaxel 75 mg/m2, doxorubicin 50 mg/m2, cyclophosphamide 500 mg/m2). Patients were randomized to a single 6 mg SC injection of the proposed biosimilar pegfilgrastim (LA-EP2006) or the reference (Neulasta®) on day 2 of each cycle. Primary endpoint was duration of severe neutropenia (DSN) during Cycle 1, defined as number of consecutive days with an absolute neutrophil count (ANC) &lt;0.5 x 109/L. The study was powered at 90% and had a hierarchical testing procedure utilizing a ±1 day margin to test for equivalence (2-sided 95% confidence interval [CI]) and a subsequent −0.6 day non-inferiority margin (1-sided 97.5% CI) for DSN during Cycle 1. DSN was analyzed with an ANCOVA model adjusted for treatment, chemotherapy, region and baseline ANC. Secondary efficacy assessments were: time to ANC recovery, ANC nadir, incidence of febrile neutropenia, number of days of fever, frequency of infections and mortality due to infection. Safety was assessed at 4 weeks and 6 months after the last pegfilgrastim administration. Immunogenicity was assessed by testing for neutralizing anti-pegfilgrastim antibodies.

Results: A total of 316 patients were randomized and included in the full analysis set (LA-EP2006: n=159; reference: n=157). Baseline demographics were similar in both groups (mean±SD age: LA-EP2006 49.9±9.53, reference 50.5±10.87 years; breast cancer stage II-III: LA-EP2006 n=155 [97.5%], reference n=151 [96.2%]). Mean±SD DSN in Cycle 1 was 0.75±0.88 days with LA-EP2006 and 0.83±0.90 days with reference, with a treatment difference of 0.07 days (95% CI: −0.12, 0.26); LA-EP2006 was both equivalent and non-inferior to the reference. There were no clinically meaningful differences between LA-EP2006 and reference in incidence of febrile neutropenia (3.8% vs 7.0% in Cycle 1, 5.7% vs 7.6% across all cycles), days with fever, depth of ANC nadir in Cycle 1, time to ANC recovery in Cycle 1, or frequency of infections in Cycle 1 and across all cycles. Treatment-emergent adverse events (TEAEs) were similar across groups and consistent with the known safety profile of pegfilgrastim. Most frequently reported TEAEs related to treatment were musculoskeletal and connective tissue disorders (LA-EP2006 4.4%, reference 5.7%). Serious TEAEs were reported in 10.1% of LA-EP2006 and 13.4% of reference patients. No neutralizing anti-pegfilgrastim antibodies were detected.

Conclusions: Proposed biosimilar pegfilgrastim (LA-EP2006) met the primary endpoint demonstrating both equivalence and non-inferiority to the reference. LA-EP2006 and the reference are similar with no clinically meaningful differences regarding efficacy and safety in breast cancer patients receiving (neo)-adjuvant myelosuppressive chemotherapy.

Citation Format: Harbeck N, Zbarskaya I, Lipatov O, Frolova M, Udovitsa D, Topuzov E, Ganea-Motan DE, Nakov R, Singh P, Rudy A, Blackwell K. A randomized, double-blind trial to compare the efficacy and safety of proposed biosimilar pegfilgrastim (LA-EP2006) with reference pegfilgrastim in patients with breast cancer (PROTECT1). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-10-01.

Primary results of ROSE/TRIO-12, a randomized placebo-controlled phase III trial evaluating the addition of ramucirumab to first-line docetaxel chemotherapy in metastatic breast cancer

PURPOSE

Currently, antiangiogenic strategies in metastatic breast cancer have demonstrated modest improvements in progression-free survival (PFS) but not improved quality or duration of survival, warranting evaluation of new agents in a placebo-controlled setting. Ramucirumab is a human immunoglobulin G1 antibody that binds vascular endothelial growth factor receptor-2 and blocks ligand-stimulated activation. The ROSE/TRIO-012 trial evaluated ramucirumab with docetaxel in unresectable, locally recurrent, or metastatic breast cancer.

PATIENTS AND METHODS

In this double-blind, placebo-controlled, randomized, multinational phase III trial, 1,144 patients with human epidermal growth factor receptor 2 (HER2) -negative breast cancer who had not received cytotoxic chemotherapy in the advanced setting were randomly assigned at a two-to-one ratio to receive docetaxel 75 mg/m(2) plus ramucirumab 10 mg/kg or docetaxel 75 mg/m(2) plus placebo once every 3 weeks. Treatment continued until disease progression, unacceptable toxicity, or other withdrawal criteria. Patients were stratified by previous taxane therapy, visceral metastasis, hormone receptor status, and geographic region. An independent data monitoring committee oversaw the trial. The primary end point was investigator-assessed PFS.

RESULTS

Median PFS in patients treated with ramucirumab plus docetaxel was 9.5 months, compared with 8.2 months in patients who received placebo plus docetaxel (hazard ratio [HR], 0.88; P = .077). Median overall survival was 27.3 months in patients who received ramucirumab plus docetaxel, compared with 27.2 months in patients who received placebo plus docetaxel (HR, 1.01; P = .915). Toxicities seen at significantly higher rates in patients receiving ramucirumab included fatigue, hypertension, febrile neutropenia, palmar-plantar erythrodysesthesia syndrome, and stomatitis.

CONCLUSION

Addition of ramucirumab to docetaxel in HER2-negative advanced breast cancer did not meaningfully improve important clinical outcomes.

Ramucirumab plus paclitaxel versus placebo plus paclitaxel in patients with previously treated advanced gastric or gastro-oesophageal junction adenocarcinoma (RAINBOW): a double-blind, randomised phase 3 trial

BACKGROUND

VEGFR-2 has a role in gastric cancer pathogenesis and progression. We assessed whether ramucirumab, a monoclonal antibody VEGFR-2 antagonist, in combination with paclitaxel would increase overall survival in patients previously treated for advanced gastric cancer compared with placebo plus paclitaxel.

METHODS

This randomised, placebo-controlled, double-blind, phase 3 trial was done at 170 centres in 27 countries in North and South America, Europe, Asia, and Australia. Patients aged 18 years or older with advanced gastric or gastro-oesophageal junction adenocarcinoma and disease progression on or within 4 months after first-line chemotherapy (platinum plus fluoropyrimidine with or without an anthracycline) were randomly assigned with a centralised interactive voice or web-response system in a 1:1 ratio to receive ramucirumab 8 mg/kg or placebo intravenously on days 1 and 15, plus paclitaxel 80 mg/m(2) intravenously on days 1, 8, and 15 of a 28-day cycle. A permuted block randomisation, stratified by geographic region, time to progression on first-line therapy, and disease measurability, was used. The primary endpoint was overall survival. Efficacy analysis was by intention to treat, and safety analysis included all patients who received at least one treatment with study drug. This trial is registered with ClinicalTrials.gov, number NCT01170663, and has been completed; patients who are still receiving treatment are in the extension phase.

FINDINGS

Between Dec 23, 2010, and Sept 23, 2012, 665 patients were randomly assigned to treatment-330 to ramucirumab plus paclitaxel and 335 to placebo plus paclitaxel. Overall survival was significantly longer in the ramucirumab plus paclitaxel group than in the placebo plus paclitaxel group (median 9·6 months [95% CI 8·5-10·8] vs 7·4 months [95% CI 6·3-8·4], hazard ratio 0·807 [95% CI 0·678-0·962]; p=0·017). Grade 3 or higher adverse events that occurred in more than 5% of patients in the ramucirumab plus paclitaxel group versus placebo plus paclitaxel included neutropenia (133 [41%] of 327 vs 62 [19%] of 329), leucopenia (57 [17%] vs 22 [7%]), hypertension (46 [14%] vs eight [2%]), fatigue (39 [12%] vs 18 [5%]), anaemia (30 [9%] vs 34 [10%]), and abdominal pain (20 [6%] vs 11 [3%]). The incidence of grade 3 or higher febrile neutropenia was low in both groups (ten [3%] vs eight [2%]).

INTERPRETATION

The combination of ramucirumab with paclitaxel significantly increases overall survival compared with placebo plus paclitaxel, and could be regarded as a new standard second-line treatment for patients with advanced gastric cancer.

FUNDING

Eli Lilly and Company.

Tivozanib versus sorafenib as initial targeted therapy for patients with metastatic renal cell carcinoma: results from a phase III trial

PURPOSE

Tivozanib is a potent and selective tyrosine kinase inhibitor of vascular endothelial growth factor receptor 1 (VEGFR1), -2, and -3. This phase III trial compared tivozanib with sorafenib as initial targeted therapy in patients with metastatic renal cell carcinoma (RCC).

PATIENTS AND METHODS

Patients with metastatic RCC, with a clear cell component, prior nephrectomy, measurable disease, and 0 or 1 prior therapies for metastatic RCC were randomly assigned to tivozanib or sorafenib. Prior VEGF-targeted therapy and mammalian target of rapamycin inhibitor were not permitted. The primary end point was progression-free survival (PFS) by independent review.

RESULTS

A total of 517 patients were randomly assigned to tivozanib (n = 260) or sorafenib (n = 257). PFS was longer with tivozanib than with sorafenib in the overall population (median, 11.9 v 9.1 months; hazard ratio [HR], 0.797; 95% CI, 0.639 to 0.993; P = .042). One hundred fifty-six patients (61%) who progressed on sorafenib crossed over to receive tivozanib. The final overall survival (OS) analysis showed a trend toward longer survival on the sorafenib arm than on the tivozanib arm (median, 29.3 v 28.8 months; HR, 1.245; 95% CI, 0.954 to 1.624; P = .105). Adverse events (AEs) more common with tivozanib than with sorafenib were hypertension (44% v 34%) and dysphonia (21% v 5%). AEs more common with sorafenib than with tivozanib were hand-foot skin reaction (54% v 14%) and diarrhea (33% v 23%).

CONCLUSION

Tivozanib demonstrated improved PFS, but not OS, and a differentiated safety profile, compared with sorafenib, as initial targeted therapy for metastatic RCC.

Adjuvant bevacizumab-containing therapy in triple-negative breast cancer (BEATRICE): primary results of a randomised, phase 3 trial

BACKGROUND

The addition of bevacizumab to chemotherapy improves progression-free survival in metastatic breast cancer and pathological complete response rates in the neoadjuvant setting. Micrometastases are dependent on angiogenesis, suggesting that patients might benefit from anti-angiogenic strategies in the adjuvant setting. We therefore assessed the addition of bevacizumab to chemotherapy in the adjuvant setting for women with triple-negative breast cancer.

METHODS

For this open-label, randomised phase 3 trial we recruited patients with centrally confirmed triple-negative operable primary invasive breast cancer from 360 sites in 37 countries. We randomly allocated patients aged 18 years or older (1:1 with block randomisation; stratified by nodal status, chemotherapy [with an anthracycline, taxane, or both], hormone receptor status [negative vs low], and type of surgery) to receive a minimum of four cycles of chemotherapy either alone or with bevacizumab (equivalent of 5 mg/kg every week for 1 year). The primary endpoint was invasive disease-free survival (IDFS). Efficacy analyses were based on the intention-to-treat population, safety analyses were done on all patients who received at least one dose of study drug, and plasma biomarker analyses were done on all treated patients consenting to biomarker analyses and providing a measurable baseline plasma sample. This trial is registered with ClinicalTrials.gov, number NCT00528567.

FINDINGS

Between Dec 3, 2007, and March 8, 2010, we randomly assigned 1290 patients to receive chemotherapy alone and 1301 to receive bevacizumab plus chemotherapy. Most patients received anthracycline-containing therapy; 1638 (63%) of the 2591 patients had node-negative disease. At the time of analysis of IDFS, median follow-up was 31·5 months (IQR 25·6-36·8) in the chemotherapy-alone group and 32·0 months (27·5-36·9) in the bevacizumab group. At the time of the primary analysis, IDFS events had been reported in 205 patients (16%) in the chemotherapy-alone group and in 188 patients (14%) in the bevacizumab group (hazard ratio [HR] in stratified log-rank analysis 0·87, 95% CI 0·72-1·07; p=0·18). 3-year IDFS was 82·7% (95% CI 80·5-85·0) with chemotherapy alone and 83·7% (81·4-86·0) with bevacizumab and chemotherapy. After 200 deaths, no difference in overall survival was noted between the groups (HR 0·84, 95% CI 0·64-1·12; p=0·23). Exploratory biomarker assessment suggests that patients with high pre-treatment plasma VEGFR-2 might benefit from the addition of bevacizumab (Cox interaction test p=0·029). Use of bevacizumab versus chemotherapy alone was associated with increased incidences of grade 3 or worse hypertension (154 patients [12%] vs eight patients [1%]), severe cardiac events occurring at any point during the 18-month safety reporting period (19 [1%] vs two [<0·5%]), and treatment discontinuation (bevacizumab, chemotherapy, or both; 256 [20%] vs 30 [2%]); we recorded no increase in fatal adverse events with bevacizumab (four [<0·5%] vs three [<0·5%]).

INTERPRETATION

Bevacizumab cannot be recommended as adjuvant treatment in unselected patients with triple-negative breast cancer. Further follow-up is needed to assess the potential effect of bevacizumab on overall survival.

AVEREL: a randomized phase III Trial evaluating bevacizumab in combination with docetaxel and trastuzumab as first-line therapy for HER2-positive locally recurrent/metastatic breast cancer

PURPOSE The AVEREL trial [A Study of Avastin (Bevacizumab) in Combination With Herceptin (Trastuzumab)/Docetaxel in Patients With HER2-Positive Metastatic Breast Cancer] evaluated first-line bevacizumab-containing therapy for human epidermal growth factor receptor 2 (HER2) -positive locally recurrent/metastatic breast cancer (LR/MBC). PATIENTS AND METHODS Patients with measurable/evaluable HER2-positive LR/MBC who had not received trastuzumab or chemotherapy for LR/MBC were stratified by prior adjuvant trastuzumab, prior (neo)adjuvant taxane, hormone receptor status, and measurable disease and were randomly assigned to receive docetaxel 100 mg/m(2) plus trastuzumab 8 mg/kg loading dose followed by 6 mg/kg either with bevacizumab 15 mg/kg or without bevacizumab, all administered every 3 weeks. The primary end point was progression-free survival (PFS). Additional end points included overall survival, response rate (RR), safety, quality of life, and translational research. Results Baseline characteristics of the 424 patients were balanced between treatment arms. Most patients had visceral metastases, 43% had a disease-free interval less than 12 months, and 85% had measurable disease. Median follow-up was 26 months. The hazard ratio for investigator-assessed PFS was 0.82 (95% CI, 0.65 to 1.02; P = .0775; median PFS, 13.7 v 16.5 months in the non-bevacizumab and bevacizumab arms, respectively; PFS events in 72%). The Independent Review Committee-assessed PFS hazard ratio was 0.72 (95% CI, 0.54 to 0.94; P = .0162; median PFS, 13.9 v 16.8 months, respectively; PFS events in 53%). The RR was 70% versus 74%, respectively (P = .3492). Grade ≥ 3 febrile neutropenia and hypertension were more common with bevacizumab-containing therapy. High baseline plasma vascular endothelial growth factor A (VEGF-A) concentrations were associated with greater bevacizumab benefit (not statistically significant). CONCLUSION Combining bevacizumab with docetaxel and trastuzumab did not significantly improve investigator-assessed PFS. The potential predictive value of plasma VEGF-A is consistent with findings in HER2-negative LR/MBC, warranting prospective evaluation.

Pathological features of advanced gastric cancer (GC): Relationship to human epidermal growth factor receptor 2 (HER2) positivity in the global screening programme of the ToGA trial

4556

Background: HER2 positivity is thought to be a negative prognostic factor in GC, correlating with poor survival rates. Reported HER2-positivity rates in GC have varied widely (6–35%). The ToGA trial is evaluating the addition of trastuzumab (Herceptin) to chemotherapy in HER2-positive advanced GC. It is the first randomised Phase III trial to provide prospective information on HER2-positivity rates in GC. Enrollment is complete, with 3,883 patients screened in 24 countries. The pathological features of GC and the relationship with HER2 positivity will be examined. Methods: Advanced GC tumour samples were centrally screened by immunohistochemistry (IHC; HercepTest) and fluorescence in situ hybridisation (FISH; PharmDx) in parallel. A HER2-scoring system modified from the protocol in breast cancer (BC) was used: a score of IHC 3+ and/or FISH positive was defined as HER2 positive. Results: Final data showed an overall HER2-positivity rate of 22.1% evaluated from 3807 patients. The HER2-positivity rate was similar between Europe (23.6%) and Asia (23.5%). HER2-positivity rates were higher in gastro-oesophageal junction (GEJ) than stomach cancer (33.2% vs 20.9%; p<0.001) and in intestinal than diffuse/mixed cancer (32.2% vs 6.1%/20.4%; p<0.001). This is reflected in above-average HER2-positivity rates in countries with the highest GEJ:stomach cancer ratios (France 0.56 [HER2 positivity 26.9%]; Germany 0.53 [23.7%]; UK 0.33 [25.8%]) and intestinal:diffuse cancer ratios (UK 3.4 [HER2 positivity 25.8%]; Australia 2.6 [32.8%]; Japan 2.8 [27.8%]). The modified HER2-scoring system showed concordance between IHC and FISH results of 87.5%. In BC most IHC 0/1 samples are FISH negative but, in ToGA, the frequency of IHC 0/1 samples testing FISH positive was almost as high as IHC 2/FISH-positive samples (23% vs 26%). Conclusions: The overall HER2-positivity rate in advanced GC in ToGA is 22.1%. Variations in tumour location and type mostly explain the difference in HER2-positivity rates between countries. Efficacy data will enable further evaluation of the clinical significance of HER2 IHC and FISH scoring patterns.

[Table: see text]

RIBBON-1: Randomized, double-blind, placebo-controlled, phase III trial of chemotherapy with or without bevacizumab (B) for first-line treatment of HER2-negative locally recurrent or metastatic breast cancer (MBC)

1005

Background: B in combination with weekly paclitaxel or docetaxel (D) as 1st-line therapy for MBC has improved progression-free survival (PFS) compared with the respective taxane alone in two large Phase III trials. This study investigated the addition of B to standard 1st-line chemotherapy regimens for MBC. Methods: Patients were randomized in 2:1 ratio to receive B + chemotherapy or placebo (pl) + chemotherapy. Prior to randomization, investigators chose capecitabine (Cap) (2000 mg/m2 x 14d), taxane (T) (nab-paclitaxel [260 mg/m2] or D [75 or 100 mg/m2], q3wk), or anthracycline (Ant)-based chemotherapy (q3wk). B or pl was administered at 15 mg/kg q3wk. Key eligibility criteria included MBC or locally-recurrent disease, no prior cytotoxic treatment, ECOG PS 0 or 1, HER2-negative disease and no CNS metastases. The primary endpoint was investigator-assessed PFS. Secondary endpoints included overall survival (OS), objective response rate (ORR), independent review of PFS, and safety. At progression, all patients were eligible for B with 2nd line chemotherapy. The Cap cohort and the pooled T or Ant (T + Ant) cohort were independently powered and analyzed in parallel using two-sided stratified log-rank test (Cap: 80% power to detect HR=0.75; T + Ant: 90% power to detect HR=0.7). Results: RIBBON-1 enrolled 1237 patients (Cap, 615; T, 307; Ant, 315) from 12/05 to 8/07 in 22 countries with a median follow-up of 15.6 months in the Cap cohort and 19.2 months in the T + Ant cohort. The results are summarized below. OS data are limited with only 33% of events. Safety was consistent with results of prior B trials. Conclusions: The addition of B to Cap, T; or Ant-based chemotherapy regimens used in 1st-line treatment of MBC resulted in statistically-significant improvement in PFS with a safety profile comparable to prior Phase III studies.

[Table: see text]

[Table: see text]

A phase II study of picoplatin (pico) as second-line therapy for patients (pts) with small cell lung cancer (SCLC) who have resistant or refractory disease or have relapsed within 180 days of completing first-line, platinum (plat)-containing chemotherapy

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Background: Pico is a sterically hindered plat analogue designed to overcome plat resistance with improved safety and efficacy. In >600 pts pico had single-agent activity in lung, prostate, ovarian and other malignancies with rare significant nephro-, oto-, or neurotoxicity (∼2% grade 3 and 0% grade 4). In a previous phase 2 study of single agent pico as 2nd line therapy in SCLC, 4 of 48 pts (8%) had a partial response and 21 (44%) stable disease. Median survival was 27.0 (95% CI = 16–35) wks. This multi-center phase 2 trial was designed to confirm the activity of pico as 2nd line monotherapy for plat-resistant SCLC. Methods: Pts with SCLC who either 1) failed or progressed through 1st line plat-containing chemo (refractory disease), or 2) initially responded to 1st line plat-containing chemo and then relapsed/ progressed within 3 months (resistant disease), or 3) initially responded and then relapsed/progressed between 90 to 180 days (sensitive, relapsed 90 to 180 days), had measurable disease and ECOG PS 0–2 were treated with pico, 150 mg/m2 iv over1–2 hrs, q 21 days. Tumor response was assessed q 6 wks. Adverse events (AEs) were graded using the NCI CTCAE. Results: 77 pts received pico (45 refractory, 27 resistant, 5 sensitive). The median number of cycles received was 2 (mean = 2.9). The most frequently reported AEs of any severity were thrombocytopenia (39% of pts), anemia (35%), neutropenia (22%), nausea (20%), emesis (14%) and dyspnea (25%). Neutropenic fever occurred in 1 pt; there were no treatment related deaths. One pt had grade 3 neuropathy; there was no grade 3 or 4 ototoxicity or nephrotoxicity. Median overall survival is 28.1 (95% CI = 26–37) wks. Median progression free survival is 9.3 (95% CI = 7–12) wks. Of 63 pts with at least 1 post-treatment assessment of disease status, 33 (52%) had stable disease. Conclusion: Median survival compares favorably with other therapeutic options and toxicity is reduced in pico treated SCLC pts who have failed prior plat-containing first-line chemo or who have progressed within 180 days of first-line chemo. A phase III trial to confirm these results has been initiated.

No significant financial relationships to disclose.