Stephen P. Anthony

Phase III Trial Comparing Doxorubicin Plus Cyclophosphamide With Docetaxel Plus Cyclophosphamide As Adjuvant Therapy for Operable Breast Cancer

PURPOSE The combination of doxorubicin and cyclophosphamide (AC) is a standard adjuvant chemotherapy regimen. Studies of docetaxel and cyclophosphamide (TC) in metastatic breast cancer (MBC) showed promise in MBC. In 1997, we initiated a randomized adjuvant trial of TC compared with standard-dose AC with a primary end point of disease-free survival (DFS). PATIENTS AND METHODS Patients were eligible if they had stage I to III operable invasive breast cancer with complete surgical excision of the primary tumor. Between June 1997 and December 1999, 1,016 patients were randomly assigned to four cycles of either standard-dose AC (60 and 600 mg/m2, respectively; n = 510) or TC (75 and 600 mg/m2, respectively; n = 506), administered intravenously every 3 weeks as adjuvant chemotherapy. Radiation therapy (as indicated) and tamoxifen, for patients with hormone receptor-positive disease, were administered after completion of chemotherapy. RESULTS Both treatment groups (TC and AC) were well balanced with respect to major prognostic factors. Patients were observed through 2005 for a median of 5.5 years. At 5 years, DFS rate was significantly superior for TC compared with AC (86% v 80%, respectively; hazard ratio [HR] = 0.67; 95% CI, 0.50 to 0.94; P = .015). Overall survival rates for TC and AC were 90% and 87%, respectively (HR = 0.76; 95% CI, 0.52 to 1.1; P = .13). More myalgia, arthralgia, edema, and febrile neutropenia occurred on the TC arm; more nausea and vomiting occurred on the AC arm as well as one incident of congestive heart failure. CONCLUSION At 5 years, TC was associated with a superior DFS and a different toxicity profile compared with AC.

Structure-Guided Blockade of CSF1R Kinase in Tenosynovial Giant-Cell Tumor

BACKGROUND Expression of the colony-stimulating factor 1 (CSF1) gene is elevated in most tenosynovial giant-cell tumors. This observation has led to the discovery and clinical development of therapy targeting the CSF1 receptor (CSF1R). METHODS Using x-ray co-crystallography to guide our drug-discovery research, we generated a potent, selective CSF1R inhibitor, PLX3397, that traps the kinase in the autoinhibited conformation. We then conducted a multicenter, phase 1 trial in two parts to analyze this compound. In the first part, we evaluated escalations in the dose of PLX3397 that was administered orally in patients with solid tumors (dose-escalation study). In the second part, we evaluated PLX3397 at the chosen phase 2 dose in an extension cohort of patients with tenosynovial giant-cell tumors (extension study). Pharmacokinetic and tumor responses in the enrolled patients were assessed, and CSF1 in situ hybridization was performed to confirm the mechanism of action of PLX3397 and that the pattern of CSF1 expression was consistent with the pathological features of tenosynovial giant-cell tumor. RESULTS A total of 41 patients were enrolled in the dose-escalation study, and an additional 23 patients were enrolled in the extension study. The chosen phase 2 dose of PLX3397 was 1000 mg per day. In the extension study, 12 patients with tenosynovial giant-cell tumors had a partial response and 7 patients had stable disease. Responses usually occurred within the first 4 months of treatment, and the median duration of response exceeded 8 months. The most common adverse events included fatigue, change in hair color, nausea, dysgeusia, and periorbital edema; adverse events rarely led to discontinuation of treatment. CONCLUSIONS Treatment of tenosynovial giant-cell tumors with PLX3397 resulted in a prolonged regression in tumor volume in most patients. (Funded by Plexxikon; ClinicalTrials.gov number, NCT01004861.).

Phase I pharmacokinetic and pharmacodynamic study of the pan-PI3K/mTORC vascular targeted pro-drug SF1126 in patients with advanced solid tumours and B-cell malignancies

BACKGROUND SF1126 is a peptidic pro-drug inhibitor of pan-PI3K/mTORC. A first-in-human study evaluated safety, dose limiting toxicities (DLT), maximum tolerated dose (MTD), pharmacokinetics (PK), pharmacodynamics (PD) and efficacy of SF1126, in patients with advanced solid and B-cell malignancies. PATIENTS AND METHODS SF1126 was administered IV days 1 and 4, weekly in 28day-cycles. Dose escalation utilised modified Fibonacci 3+3. Samples to monitor PK and PD were obtained. RESULTS Forty four patients were treated at 9 dose levels (90-1110 mg/m(2)/day). Most toxicity was grade 1 and 2 with a single DLT at180 mg/m(2) (diarrhoea). Exposure measured by peak concentration (C(max)) and area under the time-concentration curve (AUC(0-)(t)) was dose proportional. Stable disease (SD) was the best response in 19 of 33 (58%) evaluable patients. MTD was not reached but the maximum administered dose (MAD) was 1110 mg/m(2). The protocol was amended to enrol patients with CD20+ B-cell malignancies at 1110 mg/m(2). A CLL patient who progressed on rituximab [R] achieved SD after 2 months on SF1126 alone but in combination with R achieved a 55% decrease in absolute lymphocyte count and a lymph node response. PD studies of CLL cells demonstrated SF1126 reduced p-AKT and increased apoptosis indicating inhibition of activated PI3K signalling. CONCLUSION SF1126 is well tolerated with SD as the best response in patients with advanced malignancies.

Phase II assessment of talabostat and cisplatin in second-line stage IV melanoma

BackgroundMetastatic melanoma is an incurable disease with an average survival of less than one year. Talabostat is a novel dipeptidyl peptidase inhibitor with immunostimulatory properties.MethodsThis phase II, open label, single arm study was conducted to evaluate the safety and efficacy of 75–100 mg/m2 cisplatin combined with 300–400 mcg talabostat bid for 6, 21-day cycles. The primary endpoint was overall response. The rate of complete responses, duration of overall objective response, progression-free survival (PFS), and overall survival were the secondary endpoints.ResultsSix objective partial responses were recorded in the 74 patients (8.1%) in the intention-to-treat population. Five of these responses involved the 40 evaluable patients (12.5%). Thirty-one percent of patients reported SAEs to the combination of talabostat and cisplatin.ConclusionAcceptable tolerability was observed in the intention-to-treat population and antitumor activity was observed in 12.5% of evaluable patients, which is not greater than historical expectation with cisplatin alone.

A Multicenter, Phase I, Dose-Escalation Study to Assess the Safety, Tolerability, and Pharmacokinetics of Etirinotecan Pegol in Patients with Refractory Solid Tumors

Purpose: This study was designed to establish the maximum tolerated dose (MTD) and to evaluate tolerability, pharmacokinetics, and antitumor activity of etirinotecan pegol. Experimental Design: Patients with refractory solid malignancies were enrolled and assigned to escalating-dose cohorts. Patients received 1 infusion of etirinotecan pegol weekly 3 times every 4 weeks (w × 3q4w), or every 14 days (q14d), or every 21 days (q21d), with MTD as the primary end point using a standard 3 + 3 design. Results: Seventy-six patients were entered onto 3 dosing schedules (58–245 mg/m2). The MTD was 115 mg/m2 for the w × 3q4w schedule and 145 mg/m2 for both the q14d and q21d schedules. Most adverse events related to study drug were gastrointestinal disorders and were more frequent at higher doses of etirinotecan pegol. Late onset diarrhea was observed in some patients, the frequency of which generally correlated with dose density. Cholinergic diarrhea commonly seen with irinotecan treatment did not occur in patients treated with etirinotecan pegol. Etirinotecan pegol administration resulted in sustained and controlled systemic exposure to SN-38, which had a mean half-life of approximately 50 days. Overall, the pharmacokinetics of etirinotecan pegol are predictable and do not require complex dosing adjustments. Confirmed partial responses were observed in 8 patients with breast, colon, lung (small and squamous cell), bladder, cervical, and neuroendocrine cancer. Conclusion: Etirinotecan pegol showed substantial antitumor activity in patients with various solid tumors and a somewhat different safety profile compared with the irinotecan historical profile. The MTD recommended for phase II clinical trials is 145 mg/m2 q14d or q21d. Clin Cancer Res; 19(1); 268–78. ©2012 AACR.

Loss of the tumor suppressor SMARCA4 in small cell carcinoma of the ovary, hypercalcemic type (SCCOHT)

Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT), is a rare and understudied cancer with a dismal prognosis. SCCOHTs infrequency has hindered empirical study of its biology and clinical management. However, we and others have recently identified inactivating mutations in the SWI/SNF chromatin remodeling gene SMARCA4 with concomitant loss of SMARCA4 protein in the majority of SCCOHT tumors.1–4 Here we summarize these findings and report SMARCA4 status by targeted sequencing and/or immunohistochemistry (IHC) in an additional 12 SCCOHT tumors, 3 matched germlines, and the cell line SCCOHT-1. We also report the identification of a homozygous inactivating mutation in the gene SMARCB1 in one SCCOHT tumor with wild-type SMARCA4, suggesting that SMARCB1 inactivation may also play a role in the pathogenesis of SCCOHT. To date, SMARCA4 mutations and protein loss have been reported in the majority of 69 SCCOHT cases (including 2 cell lines). These data firmly establish SMARCA4 as a tumor suppressor whose loss promotes the development of SCCOHT, setting the stage for rapid advancement in the biological understanding, diagnosis, and treatment of this rare tumor type.

Patient-reported Symptoms of Tenosynovial Giant Cell Tumors

Purpose Tenosynovial giant cell tumor (TGCT), a rare locally aggressive neoplasm of the synovium of joints and tendon sheaths, is associated with joint destruction, inflammation, pain, and swelling, in part due to colony-stimulating factor 1 receptor–bearing macrophages recruited to the tumor by genetic elevation of colony-stimulating factor 1 activity. The most common treatment is surgery, although promising pharmacologic treatments are in development. Patient-reported outcome (PRO) instruments are critical end points in demonstrating the clinical relevance of standard oncologic outcome measures and the overall impact of novel pharmacologic therapies in nonmalignant neoplastic conditions such as TGCT. The content validity of PROs relevant to patients with TGCT has not been formally investigated, and instruments to evaluate such outcomes do not exist for this condition. Methods PRO instruments of potential relevance were evaluated by using a literature review and by clinical and PRO experts. Patients with TGCT were recruited through clinical sites and the Internet for participation in qualitative research interviews to identify predominant symptoms and to test the relevance and content validity of several PRO measures. Select PRO measures were included in a Phase I clinical trial, and preliminary results of the PRO end points are reported descriptively. Findings Of the 22 subjects who participated in qualitative interviews, 73% were female, and their mean age was 42.5 years (range, 27–56 years). The TGCTs (19 diffuse and 3 localized) were located in the knee (n = 15), hip (n = 3), ankle (n = 2), elbow (n= 1), and forearm (n = 1). The most common symptoms cited were pain (82%), swelling (86%), stiffness (73%), reduced range of motion (64%), and joint instability (64%), which were consistent with clinical expert input and with the content of instruments chosen by PRO experts. The worst pain numeric rating scale, Patient Reported Outcomes Measurement Information System physical functioning items, and the Western Ontario and McMaster Universities Osteoarthritis Index, as well as a worst stiffness numeric rating scale developed for TGCT, were confirmed as meaningful measures of TGCT patient symptoms and were well understood in qualitative interviews. Results from the Phase I trial showed trends of improvement in both pain and stiffness over time. Implications This study is the first to gather information directly from patients with TGCT regarding their symptom experiences. Pain, stiffness, and physical functioning are important treatment outcomes in patients with TGCT. We have identified content-valid PRO measures of these concepts, which are included in an ongoing Phase III TGCT clinical trial with pexidartinib (PLX3397) (NCT02371369).

Molecular Characterization of a Patient's Small Cell Carcinoma of the Ovary of the Hypercalcemic Type.

Small cell carcinoma of the ovary of the hypercalcemic type (SCCOHT) is a very rare tumor type that mainly affects young women. We report a 21-year old woman with SCCOHT. The patient initially presented with stage T3AN1MX disease and treated with surgery. The patient then received 8 cycles of multi-agent chemotherapy including cisplatin, bleomycin, cyclophosphamide, doxorubicin, and etoposide. Upon relapse, the patient underwent total abdominal hysterectomy, followed by chemotherapy with gemcitabine. The patient subsequently received radiation therapy and chemotherapy with bevacizumab, irinotecan and docetaxel. She passed away approximately 5 months after the second surgery and with her prior permission an immediate autopsy was performed. We examined the gene expression and copy number profiles of the tumor tissue samples obtained from the autopsy and compared them to normal ovary tissues. Our results indicated that although this tumor did not harbor chromosomal abnormalities nor gene copy number changes, there were significant gene expression changes in a number of genes/pathways. More than 5,000 genes showed significant differential expression in the tumor when compared to normal ovary tissue. Pathway enrichment analysis further identified several pathways/processes including the Vitamin D receptor signaling and the hedgehog signaling pathways to be significantly dysregulated. The gene expression profiling also suggests a number of agents such as pazopanib, bortezomib, 5-azacytidine, and PARP inhibitors as treatment options to possibly explore in future trials against this disease.

506 Phase (Ph) 1/2a study of TSR-011, a potent inhibitor of ALK and TRK, in advanced solid tumors including crizotinib-resistant ALK positive non-small cell lung cancer

Background: Both intrinsic and acquired resistance mechanisms to ALK inhibitors have been observed in ALK rearranged (ALK+) non–small cell lung cancer (NSCLC). TSR-011 inhibits ALK (IC50=0.7nM), tropomyosin receptor kinase (TRK) A, B, and C (IC50<3nM), and tumor growth in vivo. Patients and Methods: A Ph 1/2a study is underway to evaluate safety, pharmacokinetics (PK), and preliminary efficacy of TSR-011. The ongoing Ph 1 is evaluating patients (pts) with ALK+ tumors, including those progressing on or naive to ALK inhibitor therapy (ALKi). Results: Forty-six pts with advanced cancer, including 19 ALK+ and 11 TRK+ pts, have been treated at total daily doses of 30 to 480 mg, administered 1, 2, or 3 times a day. Dose-limiting toxicities (dysesthesia, QTc prolongation) were observed above 120 mg/day daily dosing, but not with the fractionated dosing up to 120 mg/day. PK modeling showed that a fractionated schedule achieves sustained trough concentrations above the ALK IC50, and minimizes peak exposure associated with QTc prolongation. TSR-011 at the current dose level of 40 mg q8h is well tolerated. In evaluable ALK+ pts, 3/3 achieved a response at or above 120 mg total daily dose and 5/9 achieved disease stabilization for 7 months or longer at lower doses; investigation with the 40 mg q8h cohort continues. Duration on TSR-011 exceeded that of previous ALKi in a majority of patients with clinical benefit, up to 20 months longer than prior ALKi for a pt still continuing on study. Conclusions: TSR-011 is a well-tolerated, promising second-generation ALKi. Overall safety and ECG findings support further development of TSR-011 in pts with ALK+ NSCLC at a fractionated schedule. Development of a controlled release formulation is planned.

Enrichment of PI3K-AKT–mTOR pathway activation in hepatic metastases from breast cancer

Purpose: Little is known about the molecular signatures associated with specific metastatic sites in breast cancer. Using comprehensive multi-omic molecular profiling, we assessed whether alterations or activation of the PI3K–AKT–mTOR pathway is associated with specific sites of breast cancer metastasis. Experimental Design: Next-generation sequencing–based whole-exome sequencing was coupled with reverse-phase protein microarray (RPPA) functional signaling network analysis to explore the PI3K–AKT–mTOR axis in 32 pretreated breast cancer metastases. RPPA-based signaling data were further validated in an independent cohort of 154 metastatic lesions from breast cancer and 101 unmatched primary breast tumors. The proportion of cases with PI3K–AKT–mTOR genomic alterations or signaling network activation were compared between hepatic and nonhepatic lesions. Results: PIK3CA mutation and activation of AKT (S473) and p70S6K (T389) were detected more frequently among liver metastases than nonhepatic lesions (P < 0.01, P = 0.056, and P = 0.053, respectively). However, PIK3CA mutations alone were insufficient in predicting protein activation (P = 0.32 and P = 0.19 for activated AKT and p70S6K, respectively). RPPA analysis of an independent cohort of 154 tumors confirmed the relationship between pathway activation and hepatic metastasis [AKT (S473), mTOR (S2448), and 4EBP1 (S65); P < 0.01, P = 0.02, and P = 0.01, respectively]. Similar results were also seen between liver metastases and primary breast tumors [AKT (S473) P < 0.01, mTOR (S2448) P < 0.01, 4EBP1 (S65) P = 0.01]. This signature was lost when primary tumors were compared with all metastatic sites combined. Conclusions: Breast cancer patients with liver metastasis may represent a molecularly homogenized cohort with increased incidence of PIK3CA mutations and activation of the PI3K–AKT–mTOR signaling network. Clin Cancer Res; 23(16); 4919–28. ©2017 AACR.