Christine K. Gause

Safety and clinical activity of pembrolizumab for treatment of recurrent or metastatic squamous cell carcinoma of the head and neck (KEYNOTE-012): an open-label, multicentre, phase 1b trial

BACKGROUND Patients with recurrent or metastatic squamous cell carcinoma of the head and neck have few treatment options. We aimed to assess the safety, tolerability, and antitumour activity of pembrolizumab, a humanised anti-programmed death receptor 1 (PD-1) antibody, in patients with PD-L1-positive recurrent or metastatic squamous cell carcinoma of the head and neck. METHODS This study was an open-label, multicentre, phase 1b trial of patients with recurrent or metastatic squamous cell carcinoma of the head and neck. Patients were eligible for enrolment if they were aged 18 years or older, had a confirmed diagnosis of recurrent or metastatic squamous cell carcinoma of the head and neck, and had any level of PD-L1 expression (ie, at least 1% of tumour cells or stroma that were PD-L1-positive by immunohistochemistry). Patients received pembrolizumab 10 mg/kg intravenously every 2 weeks. Primary outcomes were safety in the per-protocol population and the proportion of patients with centrally reviewed overall response per Response Evaluation Criteria In Solid Tumors (RECIST, version 1.1). Overall response was analysed in the full analysis set, which was defined as all patients who had received at least one dose of pembrolizumab, had measurable disease at baseline, and one post-baseline scan or patients without a post-baseline scan who discontinued therapy because of disease progression or a drug-related adverse event. The study is registered with ClinicalTrials.gov, number NCT01848834 and is ongoing, but no longer enrolling patients. FINDINGS Of the 104 patients screened between June 7, 2013, and Oct 3, 2013, 81 (78%) were PD-L1-positive. Of these, 60 patients with PD-L1-positive squamous cell carcinoma of the head and neck were enrolled and treated: 23 (38%) were HPV-positive and 37 (62%) were HPV-negative. Pembrolizumab was well tolerated, with 10 (17%) of 60 patients having grade 3-4 drug-related adverse events, the most common of which were increases in alanine aminotransferase and in aspartate aminotransferase, and hyponatraemia, each occurring in two of 60 patients; one patient developed a grade 3 drug-related rash. 27 (45%) of 60 patients experienced a serious adverse event. There were no drug-related deaths. The proportion of patients with an overall response by central imaging review was 18% (eight of 45 patients; 95% CI 8-32) in all patients and was 25% (four of 16 patients; 7-52) in HPV-positive patients and 14% (four of 29 patients; 4-32) in HPV-negative patients. INTERPRETATION Pembrolizumab was well tolerated and demonstrated clinically meaningful antitumour activity in recurrent or metastatic squamous cell carcinoma of the head and neck, supporting further study of pembrolizumab as anticancer therapy for advanced head and neck cancers. FUNDING Merck & Co.

Vorinostat in combination with lenalidomide and dexamethasone in patients with relapsed or refractory multiple myeloma

The addition of vorinostat to lenalidomide/dexamethasone represents a novel combination therapy in multiple myeloma (MM), informed by laboratory studies suggesting synergy. This was a phase I, multicenter, open-label, non-randomized, dose-escalating study in patients with relapsed or relapsed and refractory MM. Clinical evaluation, electrocardiogram, laboratory studies and adverse events were obtained and assessed. The maximum-tolerated dose was not reached owing to a non-occurrence of two dose-limiting toxicities per six patients tested at any of the dosing levels. Patients tolerated the highest dose tested (Level 5) and this was considered the maximum administered dose: at 400 mg vorinostat on days 1–7 and 15–21, 25 mg lenalidomide on days 1–21 and 40 mg dexamethasone on days 1, 8, 15 and 22, per 28-day cycle. Drug-related adverse events were reported in 90% of patients serious adverse experiences were reported in 45% of the patients and 22% of all patients had adverse experiences considered, possibly related to study drug by the investigators. A confirmed partial response or better was reported for 14/30 patients (47%) evaluable for efficacy, including 31% of patients previously treated with lenalidomide. Vorinostat in combination with lenalidomide and dexamethasone proved tolerable with appropriate supportive care, with encouraging activity observed.

Impact of a prophylactic quadrivalent human papillomavirus (types 6, 11, 16, 18) L1 virus-like particle vaccine in a sexually active population of North American women

OBJECTIVE The purpose of this study was to inform policy regarding human papillomavirus (HPV) vaccination in North America. We measured the clinical impact of HPV-6/-11/-16/-18 vaccination in North American women. STUDY DESIGN The study enrolled 21,954 women, the majority aged 16-25, across 5 studies of a quadrivalent HPV vaccine or its HPV-16 vaccine prototype. The North American subjects (n = 5996) were pooled from these trials, and the prevalence of HPV-6/-11/-16/-18 exposure was measured. The impact of vaccination on the burden of anogenital HPV lesions in an intention-to-treat population (regardless of enrollment HPV status) was calculated. RESULTS At enrollment, the median age was 20 years; 13% of the women had had a Papanicolaou test abnormality, and 76% of the women had negative tests results for all 4 vaccine HPV types. With approximately 3 years of follow-up evaluations in the intention-to-treat population (regardless of enrollment HPV status), vaccination reduced the rate of HPV-16- and -18-related precancers and HPV-6/-11/-16/-18-related genital lesions by 66.4% (95% CI, 42.7%-81.1%) and 57.7% (95% CI, 27.3%-76.3%), respectively. CONCLUSION The administration of HPV vaccine to sexually active North American women reduced the burden of HPV-6/-11/-16/-18-related disease. Catch-up vaccination programs in this population are warranted.

Abstract PD5-1: Results from the phase 2 trial of ridaforolimus, dalotuzumab, and exemestane compared to ridaforolimus and exemestane in advanced breast cancer

Introduction: The combination of a mammalian target of rapamycin (mTOR) inhibitor and an aromatase inhibitor has been shown to significantly increase progression-free survival (PFS) in patients with estrogen receptor-positive (ER+) advanced or metastatic breast cancer. Ridaforolimus is an alternative mTOR inhibitor with high potency and specificity. We hypothesized that triplet therapy with ridaforolimus, dalotuzumab (a humanized monoclonal antibody targeting the IGF-1 receptor [IGFR]), and exemestane (R/D/E) would be more effective than doublet therapy with ridaforolimus and exemestane (R/E). Methods: This phase 2, randomized, open-label trial enrolled 80 postmenopausal patients who had high-proliferation (KI67 staining) ER+ breast cancer that had progressed following treatment with a nonsteroidal aromatase inhibitor. Patients received either triplet therapy, at the previously determined maximum tolerated dose of oral ridaforolimus 10 mg QD×5, dalotuzumab 10 mg/kg/week IV, and oral exemestane 25 mg/day (R/D/E, n=40), or doublet therapy with R 30 mg QD×5 and E 25 mg/day (R/E, n=40). Dose increases of R to 20 or 40 mg QD×5 were permitted in the R/D/E or R/E arms, respectively, in the absence of grade ≥2 stomatitis after cycle 1. The R dose could be reduced in either arm for toxicity. The primary endpoint was PFS in the ITT population by central review. Adverse events (AE) of clinical interest (Tier 1) included stomatitis, pneumonitis, hearing loss, and hyperglycemia. Results: Baseline characteristics were balanced between treatment groups. The median PFS was 23.3 (95% CI, 8.71, 38.43) weeks for R/D/E versus 31.9 (95% CI, 16.00, 39.29) weeks in the R/E arm (hazard ratio, 1.18; 80% CI, 0.81-1.72; P=0.565). All patients experienced at least one AE. 5 (12.8%) and 3 (7.5%) patients in the R/D/E and R/E arms, respectively, discontinued the study because of AE. Serious drug-related AE occurred in 2.6% of the R/D/E arm and 15% of the R/E arm. Dose modifications due to AE occurred in 10.3% and 50% in the R/D/E and R/E arms, respectively (difference -39.7%; 95% CI, -56.7, -20.4). Tier 1 AE were primarily grade 1-2 in severity. Stomatitis occurred in 76.9% (30/39 patients) in the R/D/E arm vs 95.0% (38/40 patients) in the R/E arm (P=0.021), and grade 3-4 stomatitis was similar between arms (23.1% vs 25%). Pneumonitis occurred in 5.1% vs 22.5% (P=0.027) and hearing loss occurred in 1 patient in each treatment arm (2.6% vs 2.5%), all grade 1-2. Hyperglycemia occurred at a similar rate in both treatment arms (28.2% vs 27.5%), with grade 3-4 events in 4 (10.3%) and 3 (7.5%) patients in the R/D/E and R/E arms, respectively. Conclusions: The combination of R 10 mg QD×5, D, and E did not improve PFS when compared to R 30 mg QD×5 plus E. The incidence rates of AE were lower in the R/D/E arm than the R/E arm for most categories of adverse events, likely because of the higher dose of R in the R/E arm. The efficacy reported for R/E in this study is similar to that reported in previous studies evaluating mTOR inhibitors in combination with exemestane in ABC. Overlapping toxicities and lower doses likely contributed to the lack of improved PFS with the addition of the IGFR inhibitor to this combination. Citation Format: Hope S Rugo, Olivier Tredan, Jungsil Ro, Serafin Morales, Antonino Musolino, Noemia Afonso, Marta Ferreira, Kyong Hwa Park, Javier Cortes, Antoinette R Tan, Joanne L Blum, Lamar Eaton, Christine K Gause, Adelle (Zhen) Wang, Ellie Im, David J Mauro, Jose Baselga. Results from the phase 2 trial of ridaforolimus, dalotuzumab, and exemestane compared to ridaforolimus and exemestane in advanced breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr PD5-1.

On Group Sequential Enrichment Design for Basket Trial

ABSTRACT Cancer is becoming a collection of “niche diseases” defined by the molecular subtypes. Such understanding forms the basis of the basket trial, which pools together multiple cohorts of patients with the same molecular subtype across different tumor indications and thus facilitates the development of targeted therapies. Efficient pruning is critical in basket designs as it ensures the internal consistency of the selected indications and improves the probability of success on the selected pool of indications. In this article, we consider pruning both inactive and extremely active indications and propose a group sequential enrichment design with testing procedures to both control the family-wise error rate (FWER) in the weak sense and maintain the power for basket trials with such pruning strategy. We compare the proposed design with a relevant design which prunes only unresponsive subgroups. The total misclassification rates and misclassification rates among truly unresponsive indications are smaller for the proposed design, while the average power is similar.

Abstract OT2-6-15: Efficacy and safety of vintafolide alone and vintafolide plus paclitaxel vs paclitaxel alone in advanced triple negative breast cancer subjects using etarfolatide subject selection

Background: Vintafolide (V) is a folic acid-vinca alkaloid small molecule drug conjugate that targets tumors that over-express the folate receptor (FR). 99mTc-etarfolatide (EC20) is a folate-targeted molecular imaging agent being developed to identify FR-positive tumors. Data suggest that triple negative breast cancers (TNBCs) expressing high levels of FR are likely to benefit from treatment with vintafolide. Trial design/Patient eligibility: This is a multicenter, randomized, open-label, Phase IIa trial in subjects with advanced TNBC. Patients will be evaluated for tumor specific expression of the FR using a EC20 SPECT/CT scan and classified as FR(100%) if 100% of RECIST 1.1 target lesions are FR-positive. Only FR(100%) patients are eligible for treatment and will be randomized in a 1:1:1 ratio to V alone, V + paclitaxel (P) or P alone. V will be administered at 2.5 mg IV 3x/week for 2 weeks on Days 1, 3, 5, 15, 17 and 19 of a 28-day cycle. P will be administered at 80 mg/m2 IV on Days 1, 8, 15, and 22. Specific aims: The primary endpoint for the trial is centrally assessed progression free survival (PFS). Secondary objectives include: assess the frequency of target tumors expressing FR(100%) vs FR(20-80%) vs FR(0%) in subjects with TNBC using EC20 SPECT scans; compare the clinical activity in subjects with advanced TNBC of V alone vs P and V + P vs P alone as measured by objective response rate (ORR), (complete response [CR] + partial response [PR]), clinical benefit rate (CBR; CR + PR + stable disease for ≥6 months), and overall survival; and assess the safety and tolerability of V alone vs P alone and V + P vs P alone in subjects with advanced TNBC. Statistical methods and target accrual: PFS and overall survival will be assessed in the intention to treat population using a stratified Cox model with Efron9s tie handling method, and Kaplan-Meier method for PFS and OS curve estimation, respectively, in each treatment group. Inferential comparisons between the arms will be tested using the stratified log-rank test at one sided alpha level of 5%. This study will randomize 34 subjects into each treatment group with total study duration of ∼16-17 months. The study has 80% power to demonstrate that either patients treated with V or patients treated with V + P combination have a higher median time to an event of PFS than subjects treated with P at an unadjusted one-sided, 5% alpha-level, if the underlying constant hazard ratio between treatment groups is 0.5 and median survival time of 2.6 months. First patient enrollment is targeted for October. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT2-6-15.