PIK3CA alterations and benefit with neratinib: analysis from the randomized, double-blind, placebo-controlled, phase III ExteNET trial.

BACKGROUND: Neratinib is an irreversible pan-HER tyrosine kinase inhibitor that inhibits PI3K/Akt and MAPK signaling pathways after HER2 receptor activation. The ExteNET study showed that neratinib significantly improved 5-year invasive disease-free survival (iDFS) in women who completed trastuzumab-based adjuvant therapy for early breast cancer (EBC). We assessed the prognostic and predictive significance of PIK3CA alterations in patients in ExteNET. METHODS: Participants were women aged ≥ 18 years (≥ 20 years in Japan) with stage 1-3c (modified to stage 2-3c in February 2010) operable breast cancer, who had completed (neo)adjuvant chemotherapy plus trastuzumab ≤ 2 years before randomization, with no evidence of disease recurrence or metastatic disease at study entry. Patients were randomized to oral neratinib 240 mg/day or placebo for 1 year. Formalin-fixed, paraffin-embedded primary tumor specimens underwent polymerase chain reaction (PCR) PIK3CA testing for two hotspot mutations in exon 9, one hot-spot mutation in exon 20, and fluorescence in situ hybridization (FISH) analysis for PIK3CA amplification. The primary endpoint (iDFS) was tested with log-rank test and hazard ratios (HRs) estimated using Cox proportional-hazards models. RESULTS: Among the intent-to-treat population (n = 2840), tumor specimens were available for PCR testing (991 patients) and PIK3CA FISH (702 patients). Overall, 262 samples were PIK3CA altered: 201 were mutated (77%), 52 (20%) were amplified, and 9 (3%) were mutated and amplified. iDFS was non-significantly worse in placebo-treated patients with altered vs wild-type PIK3CA (HR 1.34; 95% CI 0.72-2.50; P = 0.357). Neratinib's effect over placebo was significant in patients with PIK3CA-altered tumors (HR 0.41; 95% CI 0.17-0.90, P = 0.028) but not PIK3CA wild-type tumors (HR 0.72; 95% CI 0.36-1.41; P = 0.34). The interaction test was non-significant (P = 0.309). CONCLUSIONS: Although there was a greater absolute risk reduction associated with neratinib treatment of patients with PIK3CA-altered tumors in ExteNET, current data do not support PIK3CA alteration as a predictive biomarker of response to neratinib in HER2-positive EBC. TRIAL REGISTRATION: ClinicalTrials.gov , NCT00878709 . Trial registered April 9, 2009.

Neratinib after trastuzumab-based adjuvant therapy in patients with HER2-positive breast cancer (ExteNET): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: Neratinib, an irreversible tyrosine-kinase inhibitor of HER1, HER2, and HER4, has clinical activity in patients with HER2-positive metastatic breast cancer. We aimed to investigate the efficacy and safety of 12 months of neratinib after trastuzumab-based adjuvant therapy in patients with early-stage HER2-positive breast cancer. METHODS: We did this multicentre, randomised, double-blind, placebo-controlled, phase 3 trial at 495 centres in Europe, Asia, Australia, New Zealand, and North and South America. Eligible women (aged ≥18 years, or ≥20 years in Japan) had stage 1-3 HER2-positive breast cancer and had completed neoadjuvant and adjuvant trastuzumab therapy up to 2 years before randomisation. Inclusion criteria were amended on Feb 25, 2010, to include patients with stage 2-3 HER2-positive breast cancer who had completed trastuzumab therapy up to 1 year previously. Patients were randomly assigned (1:1) to receive oral neratinib 240 mg per day or matching placebo. The randomisation sequence was generated with permuted blocks stratified by hormone receptor status (hormone receptor-positive [oestrogen or progesterone receptor-positive or both] vs hormone receptor-negative [oestrogen and progesterone receptor-negative]), nodal status (0, 1-3, or ≥4), and trastuzumab adjuvant regimen (sequentially vs concurrently with chemotherapy), then implemented centrally via an interactive voice and web-response system. Patients, investigators, and trial sponsors were masked to treatment allocation. The primary outcome was invasive disease-free survival, as defined in the original protocol, at 2 years after randomisation. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00878709. FINDINGS: Between July 9, 2009, and Oct 24, 2011, we randomly assigned 2840 women to receive neratinib (n=1420) or placebo (n=1420). Median follow-up time was 24 months (IQR 20-25) in the neratinib group and 24 months (22-25) in the placebo group. At 2 year follow-up, 70 invasive disease-free survival events had occurred in patients in the neratinib group versus 109 events in those in the placebo group (stratified hazard ratio 0·67, 95% CI 0·50-0·91; p=0·0091). The 2-year invasive disease-free survival rate was 93·9% (95% CI 92·4-95·2) in the neratinib group and 91·6% (90·0-93·0) in the placebo group. The most common grade 3-4 adverse events in patients in the neratinib group were diarrhoea (grade 3, n=561 [40%] and grade 4, n=1 [<1%] vs grade 3, n=23 [2%] in the placebo group), vomiting (grade 3, n=47 [3%] vs n=5 [<1%]), and nausea (grade 3, n=26 [2%] vs n=2 [<1%]). QT prolongation occurred in 49 (3%) patients given neratinib and 93 (7%) patients given placebo, and decreases in left ventricular ejection fraction (≥grade 2) in 19 (1%) and 15 (1%) patients, respectively. We recorded serious adverse events in 103 (7%) patients in the neratinib group and 85 (6%) patients in the placebo group. Seven (<1%) deaths (four patients in the neratinib group and three patients in the placebo group) unrelated to disease progression occurred after study drug discontinuation. The causes of death in the neratinib group were unknown (n=2), a second primary brain tumour (n=1), and acute myeloid leukaemia (n=1), and in the placebo group were a brain haemorrhage (n=1), myocardial infarction (n=1), and gastric cancer (n=1). None of the deaths were attributed to study treatment in either group. INTERPRETATION: Neratinib for 12 months significantly improved 2-year invasive disease-free survival when given after chemotherapy and trastuzumab-based adjuvant therapy to women with HER2-positive breast cancer. Longer follow-up is needed to ensure that the improvement in breast cancer outcome is maintained. FUNDING: Wyeth, Pfizer, Puma Biotechnology.

A phase II study of bevacizumab and erlotinib as initial treatment for metastatic non-squamous, non-small cell lung cancer with serum proteomic evaluation.

BACKGROUND: Erlotinib alone or bevacizumab in combination with chemotherapy improve survival in patients with advanced non-small cell lung cancer. The current trial of erlotinib and bevacizumab was designed as an alternative to initial conventional chemotherapy for advanced lung cancer and a platform to explore selection factors. METHODS: Eligibility criteria included stage IIIB/IV or recurrent non-squamous, non-small cell lung cancer (NSNSCLC), no prior chemotherapy for metastatic disease, PS=0-1, and no history of brain metastases for the first 40 patients. An expansion cohort of an additional 10 patients allowed treated brain metastases. Patients received erlotinib 150 mg/day and bevacizumab 15 mg/kg/3 weeks until objective or symptomatic progression. Pretreatment serum was collected for blinded VeriStrat® evaluation. RESULTS: Fifty patients were accrued. The median age was 65 years, 10 were octogenarians, 37 had PS=1, 25 were female and 12 were never-smokers. Histologies were adenocarcinoma in 26 and unspecified in 24. Partial responses were observed in 12 (24%), stable in 30 (60%) and progressive disease in 8 (16%). The median time on therapy was 15.5 weeks. The median survival was 50.4 weeks with 1 and 2 years survivals of 50% and 21%, respectively. Only 38% of eligible patients received second line therapy, most often due to decline in PS. VeriStrat® analysis was performed in 42 subjects (Good 32, Poor 9, and Indeterminate 1). Significant differences based on VeriStrat® signature were noted in PFS (Good=18.9 weeks, Poor=6.3 weeks, p=0.0035) and overall survival (Good=71.4 weeks, Poor=19.9 weeks, p=0.0015). CONCLUSIONS: Survival in an unselected population of patients with NSNSCLC treated with bevacizumab and erlotinib approximated that expected with conventional chemotherapy. VeriStrat® analyses distinguished patients who were likely or unlikely to benefit from this combination.

Phase II study of gemcitabine and bevacizumab as first-line treatment in taxane-pretreated, HER2-negative, locally recurrent or metastatic breast cancer.

BACKGROUND: In first-line treatment of metastatic breast cancer, the best use of the available therapeutic agents is unclear. This study evaluated the efficacy and safety of combined therapy with bevacizumab and gemcitabine. PATIENTS: Women who were to undergo first-line treatment for locoregionally recurrent or metastatic breast cancer were eligible. Patients must have received a taxane-containing regimen in the neoadjuvant and/or adjuvant setting with a ≥ 12-month disease-free interval. METHODS: This was a single-arm, phase II trial. On day 1 of each 14-day cycle, patients received gemcitabine (2500 mg/m(2)) followed by bevacizumab (10 mg/kg). Patients were treated until complete response, progressive disease (PD), or intolerable toxicity. The primary endpoint was progression-free survival (PFS). RESULTS: Fifty-two women were enrolled and treated. The median PFS was 4.8 months (95% confidence interval [CI], 3.4-7.6), the 1-year overall survival rate was 68.7% (95% CI, 54.1%-79.5%), and the response rate was 21.4% (95% CI, 10.3%-36.8%). The clinical benefit rate was 35.7%. The median PFS in the triple-negative (n = 19) and non-triple-negative (n = 33) subsets was 3.9 months (95% CI, 2.7-11.7) and 4.9 months (95% CI, 3.4-8.1), respectively. The most common (all grades) drug-related adverse events (AEs) were nausea (51.9%), fatigue (46.2%), decreased appetite (25.0%), and anemia (25.0%). The most common grade 3 or grade 4 drug-related AEs were neutropenia (13.5%), leukopenia (11.5%), and hypertension (7.7%). CONCLUSION: Although the gemcitabine-bevacizumab doublet appears active, the median PFS was lower than expected. There were no unexpected safety signals at this dose and schedule of this combination.

A phase II study of weekly nanoparticle albumin-bound paclitaxel with or without trastuzumab in metastatic breast cancer.

INTRODUCTION: Weekly administration of nanoparticle albumin-bound (nab) paclitaxel as a first-line treatment for metastatic breast cancer (MBC) has not been fully investigated. The addition of trastuzumab, a monoclonal antibody against human epidermal growth factor receptor 2 (HER2), is less understood. This phase II study evaluated the efficacy and safety of weekly nab paclitaxel in the first-line MBC setting. Patients whose tumors overexpressed HER2 also received trastuzumab. PATIENTS AND METHODS: Patients with locally advanced or metastatic breast cancer received nab paclitaxel (125 mg/m(2)) by 30-minute intravenous infusion weekly for 3 of 4 weeks. Patients who were HER2-positive received concurrent trastuzumab. RESULTS: Seventy-two patients were enrolled; HER2 expression was detected in 22 patients. The overall response rate (ORR) was 42.2% (95% CI, 30%-55%); 5 patients had a complete response (CR) and 22 patients had a partial response (PR). Additionally, 17 patients experienced stable disease (SD), providing an overall benefit (CR + PR + SD) of 68.8%. Patients with HER2-positive tumors had an ORR of 52.4%; the ORR was 38.1% in the HER2-negative population (P = .3). Median progression-free survival was 14.5 months (range, 1-49.3 months) and survival rates at 1 year and 2 years were 69% and 62%, respectively. The most commonly observed toxicities were pain (64%), fatigue (58%), sensory neuropathy (54%), infection (46%), nausea (38%), alopecia (33%), and anemia (33%). CONCLUSION: Our findings demonstrate that weekly nab paclitaxel has a favorable safety profile and is well tolerated as a first-line treatment for MBC. An ORR of 42% and an overall benefit of 69% is extremely encouraging, particularly in the HER2-positive population where 52% of patients responded.

Randomized phase III study of exatecan and gemcitabine compared with gemcitabine alone in untreated advanced pancreatic cancer.

PURPOSE: Exatecan mesylate is a hexacyclic, water-soluble, topoisomerase-1 inhibitor. Exatecan has single-agent and combination activity with gemcitabine in advanced pancreatic cancer. A multicenter, randomized, phase III trial comparing exatecan plus gemcitabine versus gemcitabine alone in advanced pancreatic cancer was conducted. PATIENTS AND METHODS: Eligibility criteria included Karnofsky performance status > or = 60%, locally advanced or metastatic pancreatic adenocarcinoma, and no prior chemotherapy. Radiation alone for locally advanced disease was permitted. Patients were randomly assigned on a 1:1 basis. For the exatecan plus gemcitabine arm, exatecan 2.0 mg/m2 and gemcitabine 1,000 mg/m2 were administered on days 1 and 8, every 3 weeks. Gemcitabine alone was dosed at 1,000 mg/m2 up to 7 weeks in the first cycle, then once a week for the first 3 weeks of a 4-week cycle. Tumor assessment was performed every 6 weeks. The primary end point was overall survival. An intent-to-treat analysis was used. RESULTS: From August 2001 to January 2003, 349 patients were randomly assigned, 175 to exatecan plus gemcitabine and 174 to gemcitabine alone. Twenty-four patients (6.9%) were not treated. The median survival time was 6.7 months for exatecan plus gemcitabine and 6.2 months for gemcitabine alone (P = .52). One complete response (CR; < 1%) and 11 partial responses (PRs; 6.3%) were observed in the exatecan plus gemcitabine treatment group, and one CR (< 1%) and eight PRs (4.6%) were observed in the gemcitabine-alone group. Grade 3 and 4 toxicities were higher for the exatecan plus gemcitabine arm versus the gemcitabine alone arm; neutropenia (30% v 15%) and thrombocytopenia (15% v 4%). CONCLUSION: Exatecan plus gemcitabine was not superior to gemcitabine alone with respect to overall survival in the first-line treatment of advanced pancreatic cancer.

Phase III comparison of two irinotecan dosing regimens in second-line therapy of metastatic colorectal cancer.

PURPOSE: Randomized trials in fluorouracil (FU)-refractory colorectal cancer demonstrate significant survival advantages for patients receiving irinotecan. We prospectively compared the efficacy and tolerability of two irinotecan regimens (once a week for 4 weeks followed by a 2-week rest period [weekly] v once every 3 weeks) in such patients. PATIENTS AND METHODS: This multicenter, open-label, phase III study randomly assigned patients in a 1:2 ratio to irinotecan given either weekly (125 mg/m(2)) or once every 3 weeks (350 mg/m(2), or 300 mg/m(2) in patients who were >/= 70 years of age, who had Eastern Cooperative Oncology Group performance status equal to 2, or who had prior pelvic irradiation). RESULTS: With median follow-up of 15.8 months, there was no significant difference in 1-year survival (46% v 41%, respectively; P =.42), median survival (9.9 v 9.9 months, respectively; P =.43), or median time to progression (4.0 v 3.0 months, respectively; P =.54) between the two regimens. Grade 3/4 diarrhea occurred in 36% of patients treated weekly and in 19% of those treated once every 3 weeks (P =.002). Grade 3/4 neutropenia occurred in 29% of patients treated weekly and 34% of those treated once every 3 weeks (P =.35). Treatment-related mortality occurred in five patients (5.3%) receiving irinotecan weekly and three patients (1.6%) given therapy once every 3 weeks (P =.12). Global quality of life was not statistically different between treatment groups. CONCLUSION: Irinotecan schedules of weekly and of once every 3 weeks demonstrated similar efficacy and quality of life in patients with FU-refractory, metastatic colorectal cancer. The regimen of once every 3 weeks was associated with a significantly lower incidence of severe diarrhea.