PSMA ADC monotherapy in patients with progressive metastatic castration-resistant prostate cancer following abiraterone and/or enzalutamide: Efficacy and safety in open-label single-arm phase 2 study.

BACKGROUND: Prostate-specific membrane antigen (PSMA) is a well-established therapeutic and diagnostic target overexpressed in both primary and metastatic prostate cancers. PSMA antibody-drug conjugate (PSMA ADC) is a fully human immunoglobulin G1 anti-PSMA monoclonal antibody conjugated to monomethylauristatin E, which binds to PSMA-positive cells and induces cytotoxicity. In a phase 1 study, PSMA ADC was well tolerated and demonstrated activity as measured by reductions in serum prostate-specific antigen (PSA) and circulating tumor cells (CTCs). To further assess PSMA ADC, we conducted a phase 2 trial in metastatic castration-resistant prostate cancer (mCRPC) subjects who progressed following abiraterone/enzalutamide (abi/enz) therapy. METHODS: A total of 119 (84 chemotherapy-experienced and 35 chemotherapy-naïve) subjects were administered PSMA ADC 2.5 or 2.3 mg/kg IV q3w for up to eight cycles. Antitumor activity (best percentage declines in PSA and CTCs from baseline and tumor responses through radiological imaging), exploratory biomarkers, and safety (monitoring of adverse events [AEs], clinical laboratory tests, and Eastern Cooperative Oncology Group performance status) were assessed. RESULTS: PSA declines ≥50% occurred in 14% of all treated (n = 113) and 21% of chemotherapy-naïve subjects (n = 34). CTC declines ≥50% were seen in 78% of all treated (n = 77; number of subjects with ≥5 CTCs at baseline and a posttreatment result) and 89% of chemotherapy-naïve subjects (n = 19); 47% of all treated and 53% of chemotherapy-naïve subjects had a transition from ≥5 to less than 5 CTCs/7.5 mL blood at some point during the study. PSA and CTC reductions were associated with high PSMA expression (CTCs or tumor tissue) and low neuroendocrine serum markers. In the chemotherapy-experienced group, the best overall radiologic response to PSMA ADC treatment was stable disease in 51 (60.7%) subjects; 5.7% of subjects in the chemotherapy-naïve group had partial responses. The most common treatment-related AEs ≥Common Terminology Criteria for AE (CTCAE) grade 3 were neutropenia, fatigue, electrolyte imbalance, anemia, and neuropathy. The most common serious AEs were dehydration, hyponatremia, febrile neutropenia, and constipation. Two subjects who received 2.5 mg/kg died of sepsis. CONCLUSIONS: PSMA ADC demonstrated some activity with respect to PSA declines, CTC conversions/reductions, and radiologic assessments in abi/enz treated mCRPC subjects. Clinically significant treatment-related AEs included neutropenia and neuropathy.

Long-term safety and survival with gefitinib in select patients with advanced non-small cell lung cancer: Results from the US IRESSA Clinical Access Program (ICAP).

BACKGROUND: This is the first report of long-term (>10 years) safety, tolerability, and survival data on patients with non-small cell lung cancer (NSCLC) who received treatment with gefitinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor. METHODS: Patients with advanced NSCLC (N = 191) who entered the IRESSA Clinical Access Program (ICAP) (June 2011 to January 2013) and had previously obtained a clinical benefit from gefitinib therapy (including patients who had received gefitinib since 2001) were analyzed for adverse events (AEs). A subset of patients (n = 79) underwent retrospective chart review to capture demographic, safety, and survival data. RESULTS: Seventy-five of 191 patients (39%) remained on long-term gefitinib therapy as of September 2016. Overall, serious AEs (SAEs) were reported in 64 patients (34%), the majority of which were attributed to underlying disease or comorbidities; only 3 patients (1.6%) had SAEs that were considered as possibly gefitinib-related. In the retrospective chart review cohort, 70% of patients were women; 58% were former smokers, and 30% were never-smokers; 56% were diagnosed with adenocarcinoma, and 13% were diagnosed with squamous carcinoma. Although EGFR mutational status was tested in only 17 patients (22%), it was assumed that most tumors were EGFR-mutation-positive. The median duration of gefitinib therapy was 11.1 years (7.8 years before and 3.5 years during ICAP), with 10-year and 15-year survival rates of 86% and 59%, respectively, from the initiation of therapy. CONCLUSIONS: A subset of long-term NSCLC survivors who were receiving gefitinib had an excellent long-term safety profile. Although it is assumed that most of these patients' tumors harbor EGFR mutations, molecular studies of available tumor specimens are planned to uncover the features that predict long-term survival. Cancer 2018;124:2407-14. © 2018 American Cancer Society.

Randomized Phase II Trial of Parsatuzumab (Anti-EGFL7) or Placebo in Combination with FOLFOX and Bevacizumab for First-Line Metastatic Colorectal Cancer.

LESSONS LEARNED: These negative phase II results for parsatuzumab highlight the challenges of developing an agent intended to enhance the efficacy of vascular endothelial growth factor inhibition without the benefit of validated pharmacodynamic biomarkers or strong predictive biomarker hypotheses.Any further clinical development of anti-EGFL7 is likely to require new mechanistic insights and biomarker development for antiangiogenic agents. BACKGROUND: EGFL7 (epidermal growth factor-like domain 7) is a tumor-enriched vascular extracellular matrix protein that supports endothelial cell survival. This phase II trial evaluated the efficacy of parsatuzumab (also known as MEGF0444A), a humanized anti-EGFL7 IgG1 monoclonal antibody, in combination with modified FOLFOX6 (mFOLFOX6) (folinic acid, 5-fluorouracil, and oxaliplatin) bevacizumab in patients with previously untreated metastatic colorectal cancer (mCRC). METHODS: One-hundred twenty-seven patients were randomly assigned to parsatuzumab, 400 mg, or placebo, in combination with mFOLFOX6 plus bevacizumab, 5 mg/kg. Treatment cycles were repeated every 2 weeks until disease progression or unacceptable toxicity for a maximum of 24 months, with the exception of oxaliplatin, which was administered for up to 8 cycles. RESULTS: The progression-free survival (PFS) hazard ratio was 1.17 (95% confidence interval [CI], 0.71-1.93; p = .548). The median PFS was 12 months for the experimental arm versus 11.9 months for the control arm. The hazard ratio for overall survival was 0.97 (95% CI, 0.46-2.1; p = .943). The overall response rate was 59% in the parsatuzumab arm and 64% in the placebo arm. The adverse event profile was similar in both arms. CONCLUSIONS: There was no evidence of efficacy for the addition of parsatuzumab to the combination of bevacizumab and chemotherapy for first-line mCRC. The Oncologist 2017;22:375-e30.

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.

Inherited susceptibility to lung cancer may be associated with the T790M drug resistance mutation in EGFR.

Somatic activating mutations in EGFR identify a subset of non-small cell lung cancer that respond to tyrosine kinase inhibitors. Acquisition of drug resistance is linked to a specific secondary somatic mutation, EGFR T790M. Here we describe a family with multiple cases of non-small cell lung cancer associated with germline transmission of this mutation. Four of six tumors analyzed showed a secondary somatic activating EGFR mutation, arising in cis with the germline EGFR mutation T790M. These observations implicate altered EGFR signaling in genetic susceptibility to lung cancer.

Adjuvant docetaxel and cyclophosphamide plus trastuzumab in patients with HER2-amplified early stage breast cancer: a single-group, open-label, phase 2 study.

BACKGROUND: Previous results suggest that docetaxel plus cyclophosphamide improves disease-free survival (DFS) and overall survival compared with doxorubicin plus cyclophosphamide in early stage breast cancer. We assessed the addition of 1 year of trastuzumab to a non-anthracycline regimen, docetaxel plus cyclophosphamide, in patients with HER2-amplified early stage breast cancer and examined whether this regimen was equally effective in patients with TOP2A-amplified and TOP2A-non-amplified disease. METHODS: This was an open-label, single-group, phase 2 study. Eligible patients were aged 18-75 years; had Eastern Cooperative Oncology Group performance status of 1 or less; HER2-amplified early stage breast cancer; operable, histologically confirmed, invasive carcinoma of the breast; adequate tumour specimen available for FISH analysis of TOP2A status; and adequate haematological, renal, hepatic, and cardiac function. Patients received four 21-day cycles of intravenous docetaxel 75 mg/m(2), plus intravenous cyclophosphamide 600 mg/m(2), plus intravenous trastuzumab 4 mg/kg (loading dose) on day 1 and 2 mg/kg on days 1, 8, and 15 during chemotherapy, followed by trastuzumab 6 mg/kg every three weeks for the remainder of 1 year. The primary endpoint was 2-year DFS in TOP2A-amplified and TOP2A-non-amplified patients; the primary analysis was done by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00493649. FINDINGS: 493 patients were enrolled between June 15, 2007, and Aug 5, 2009. After a median follow-up of 36·1 months (IQR 35·5-36·7), 2-year DFS was 97·8% (95% CI 94·2-99·2) and 2-year overall survival was 99·5% (95% CI 96·2-99·9) for the 190 patients with TOP2A-amplified disease; 2-year DFS was 97·9% (95% CI 94·9-99·1) and 2-year overall survival was 98·8% (95% CI 96·2-99·6) for the 248 patients with TOP2A-non-amplified disease; 55 patients were not assessable for TOP2A status. In the 486 patients who received at least one dose of study drug, the most common adverse events of any grade were fatigue (284 patients, 58·4%), neutropenia (250, 51·4%), and nausea (217, 44·7%). The most common grade 3-4 toxic effects were neutropenia (229, 47·1%), febrile neutropenia (30, 6·2%), fatigue (21, 4·3%), and diarrhoea (16, 3·3%). Cardiac dysfunction occurred in 29 (6·0%) patients (12 [2·5%] grade 1, 15 [3·1%] grade 2, and two [0·4%] grade 3). 23 patients had at least one study-related serious adverse event. 16 patients stopped trastuzumab because of cardiac dysfunction. INTERPRETATION: A short, four-cycle regimen of docetaxel and cyclophosphamide combined with trastuzumab could be an option for adjuvant treatment of women with lower risk HER2-amplified early breast cancer, irrespective of TOP2A status. FUNDING: Sanofi.

Overall survival with neratinib after trastuzumab-based adjuvant therapy in HER2-positive breast cancer (ExteNET): A randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: ExteNET showed that neratinib, an irreversible pan-HER tyrosine kinase inhibitor, given for 1 year after trastuzumab-based therapy significantly improved invasive disease-free survival in women with early-stage HER2-positive breast cancer. We report the final analysis of overall survival in ExteNET. METHODS: In this international, randomised, double-blind, placebo-controlled, phase 3 trial, women aged 18 years or older with stage 1-3c (amended to stage 2-3c) HER2-positive breast cancer who had completed neoadjuvant and adjuvant chemotherapy plus trastuzumab were eligible. Patients were randomly assigned to oral neratinib 240 mg/day or placebo for 1 year. Randomisation was stratified according to hormone receptor (HR) status (HR-positive vs. HR-negative), nodal status (0, 1-3 or 4+), and trastuzumab regimen (sequentially vs. concurrently with chemotherapy). Overall survival was analysed by intention to treat. ExteNET is registered (Clinicaltrials.gov: NCT00878709) and is complete. RESULTS: Between July 9, 2009, and October 24, 2011, 2840 women received neratinib (n = 1420) or placebo (n = 1420). After a median follow-up of 8.1 (IQR, 7.0-8.8) years, 127 patients (8.9%) in the neratinib group and 137 patients (9.6%) in the placebo group in the intention-to-treat population had died. Eight-year overall survival rates were 90.1% (95% CI 88.3-91.6) with neratinib and 90.2% (95% CI 88.4-91.7) with placebo (stratified hazard ratio 0.95; 95% CI 0.75-1.21; p = 0.6914). CONCLUSIONS: Overall survival in the extended adjuvant setting was comparable for neratinib and placebo after a median follow-up of 8.1 years in women with early-stage HER2-positive breast cancer.

Germline mutations and developmental mosaicism underlying EGFR-mutant lung cancer.

While the development of multiple primary tumors in smokers with lung cancer can be attributed to carcinogen-induced field cancerization, the occurrence of multiple primary tumors in individuals with EGFR-mutant lung cancer who lack known environmental exposures remains unexplained. We identified ten patients with early-stage, resectable non-small cell lung cancer who presented with multiple anatomically distinct EGFR-mutant tumors. We analyzed the phylogenetic relationships among multiple tumors from each patient using whole exome sequencing (WES) and hypermutable poly-guanine (poly-G) repeat genotyping, as orthogonal methods for lineage tracing. In two patients, we identified germline EGFR variants, which confer moderately enhanced signaling when modeled in vitro. In four other patients, developmental mosaicism is supported by the poly-G lineage tracing and WES, indicating a common non-germline cell-of-origin. Thus, developmental mosaicism and germline variants define two distinct mechanisms of genetic predisposition to multiple EGFR-mutant primary tumors, with implications for understanding their etiology and clinical management.

A randomized phase II trial of vismodegib versus placebo with FOLFOX or FOLFIRI and bevacizumab in patients with previously untreated metastatic colorectal cancer.

PURPOSE: Vismodegib, a Hedgehog pathway inhibitor, has preclinical activity in colorectal cancer (CRC) models. This trial assessed the efficacy, safety, and pharmacokinetics of adding vismodegib to first-line treatment for metastatic CRC (mCRC). EXPERIMENTAL DESIGN: Patients were randomized to receive vismodegib (150 mg/day orally) or placebo, in combination with FOLFOX or FOLFIRI chemotherapy plus bevacizumab (5 mg/kg) every 2 weeks until disease progression or intolerable toxicity. The primary endpoint was progression-free survival (PFS). Key secondary objectives included evaluation of predictive biomarkers and pharmacokinetic drug interactions. RESULTS: A total of 199 patients with mCRC were treated on protocol (124 FOLFOX, 75 FOLFIRI). The median PFS hazard ratio (HR) for vismodegib treatment compared with placebo was 1.25 (90% CI: 0.89-1.76; P = 0.28). The overall response rates for placebo-treated and vismodegib-treated patients were 51% (90% CI: 43-60) and 46% (90% CI: 37-55), respectively. No vismodegib-associated benefit was observed in combination with either FOLFOX or FOLFIRI. Increased tumor tissue Hedgehog expression did not predict clinical benefit. Grade 3 to 5 adverse events reported for more than 5% of patients that occurred more frequently in the vismodegib-treated group were fatigue, nausea, asthenia, mucositis, peripheral sensory neuropathy, weight loss, decreased appetite, and dehydration. Vismodegib did not alter the pharmacokinetics of FOLFOX, FOLFIRI, or bevacizumab. CONCLUSIONS: Vismodegib does not add to the efficacy of standard therapy for mCRC. Compared with placebo, treatment intensity was lower for all regimen components in vismodegib-treated patients, suggesting that combined toxicity may have contributed to lack of efficacy.

A phase 2 study of a fixed combination of uracil and ftorafur and leucovorin given orally in a twice-daily regimen to treat patients with recurrent metastatic breast cancer.

BACKGROUND: UFT, a combination of uracil and ftorafur, was developed to combine the cytotoxic effects of 5-fluorouracil (5-FU) with convenient oral dosing. Leucovorin is combined with UFT to further potentiate the effect of 5-FU on tumor cells. Orally administered UFT and leucovorin provide higher peak plasma concentrations of 5-FU and prolonged therapeutic 5-FU concentrations compared with continuous infusion of 5-FU. METHODS: Ninety-four patients with metastatic breast cancer who had been previously treated with anthracyclines and/or taxanes were treated with UFT and leucovorin, given orally, for the first 28 days of a 35-day cycle. The total daily dose of UFT was 300 mg/m(2), which was given in 2 divided doses every 12 hours. The primary endpoint was time to disease progression (TTP). Secondary objectives included overall tumor response rate (OR = complete response [CR] + partial response [PR]) and overall survival (OS). RESULTS: Of the 94 patients enrolled, 68 were evaluable for efficacy. Although no CRs were observed, 9 patients achieved PRs, for an OR of 13.2% in the evaluable population. The median TTP for the evaluable population was 10.3 weeks, and the proportion of patients free of disease progression at 6 months was 17%. The median OS was 61.6 weeks for all patients enrolled. The most common drug-related >or= grade 3 adverse events (graded using the National Cancer Institute Common Toxicity Criteria version 2) were diarrhea, asthenia, nausea, and dehydration. CONCLUSIONS: The combination of UFT and leucovorin administered orally in a twice-daily regimen was found to have modest activity. Grade 3 toxicities were manageable with appropriate dose adjustments in patients with metastatic breast cancer previously treated with anthracyclines and/or taxanes.

Phase II study of the anti-cytotoxic T-lymphocyte-associated antigen 4 monoclonal antibody, tremelimumab, in patients with refractory metastatic colorectal cancer.

PURPOSE: Safety and efficacy of tremelimumab (CP-675,206), a fully human anti-cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) monoclonal antibody, were assessed in patients with treatment-refractory colorectal cancer. PATIENTS AND METHODS: A single-arm, multicenter, phase II trial was conducted in patients with Eastern Cooperative Oncology Group performance status or= 180 days after enrollment. One patient (2%; 90% CI, < 1% to 10%) had a stable pelvic mass and substantial regression in an adrenal mass (partial response). This patient received five tremelimumab doses; response duration was 6 months (enrollment to disease progression, 15 months). CONCLUSION: Tremelimumab did not demonstrate clinically meaningful single-agent activity in this patient population, although the number of survivors at 6 months and the one patient with confirmed partial response are potentially interesting. Further study of tremelimumab in combination with other agents may be warranted.