Karen A. Autio

Abiraterone acetate plus prednisone versus prednisone alone in chemotherapy-naive men with metastatic castration-resistant prostate cancer: patient-reported outcome results of a randomised phase 3 trial

BACKGROUND Abiraterone acetate plus prednisone significantly improves radiographic progression-free survival in asymptomatic or mildly symptomatic, chemotherapy-naive patients with metastatic castration-resistant prostate cancer compared with prednisone alone. We describe analyses of data for patient-reported pain and functional status in a preplanned interim analysis of a phase 3 trial. METHODS Between April 28, 2009, and June 23, 2010, patients with progressive, metastatic castration-resistant prostate cancer were enrolled into a multinational, double-blind, placebo-controlled trial. Patients were eligible if they were asymptomatic (score of 0 or 1 on item three of the Brief Pain Inventory Short Form [BPI-SF] questionnaire) or mildly symptomatic (score of 2 or 3) and had not previously received chemotherapy. Patients were randomly assigned (1:1) to receive oral abiraterone (1 g daily) plus prednisone (5 mg twice daily) or placebo plus prednisone in continuous 4-week cycles. Pain was assessed with the BPI-SF questionnaire, and health-related quality of life (HRQoL) with the Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire. We analysed data with prespecified criteria for clinically meaningful pain progression and deterioration in HRQoL. All patients who underwent randomisation were included in analyses. FINDINGS 1088 patients underwent randomisation: 546 were assigned to abiraterone plus prednisone and 542 to placebo plus prednisone. At the time of the second prespecified interim analysis, median follow-up was 22·2 months (IQR 20·2-24·8). Median time to progression of mean pain intensity was longer in patients assigned to abiraterone plus prednisone (26·7 months [95% CI 19·3-not estimable]) than in those assigned to placebo plus prednisone (18·4 months [14·9-not estimable]; hazard ratio [HR] 0·82, 95% CI 0·67-1·00; p=0·0490), as was median time to progression of pain interference with daily activities (10·3 months [95% CI 9·3-13·0] vs 7·4 months [6·4-8·6]; HR 0·79, 95% CI 0·67-0·93; p=0·005). Median time to progression of worst pain was also longer with abiraterone plus prednisone (26·7 months [95% CI 19·4-not estimable]) than with placebo plus prednisone (19·4 months [16·6-not estimable]), but the difference was not significant (HR 0·85, 95% CI 0·69-1·04; p=0·109). Median time to HRQoL deterioration was longer in patients assigned to abiraterone plus prednisone than in those assigned to placebo plus prednisone as assessed by the FACT-P total score (12·7 months [95% CI 11·1-14·0] vs 8·3 months [7·4-10·6]; HR 0·78, 95% CI 0·66-0·92; p=0·003) and by the score on its prostate-cancer-specific subscale (11·1 months [8·6-13·8] vs 5·8 months [5·5-8·3]; HR 0·70, 95% CI 0·60-0·83; p<0·0001). INTERPRETATION Abiraterone plus prednisone delays patient-reported pain progression and HRQoL deterioration in chemotherapy-naive patients with metastatic castration-resistant prostate cancer. These results provide further support for the efficacy of abiraterone in this population.

“High-Risk” Prostate Cancer: Classification and Therapy

Approximately 15% of patients with prostate cancer are diagnosed with high-risk disease. However, the current definitions of high-risk prostate cancer include a heterogeneous group of patients with a range of prognoses. Some have the potential to progress to a lethal phenotype that can be fatal, while others can be cured with treatment of the primary tumour alone. The optimal management of this patient subgroup is evolving. A refined classification scheme is needed to enable the early and accurate identification of high-risk disease so that more-effective treatment paradigms can be developed. We discuss several principles established from clinical trials, and highlight other questions that remain unanswered. This Review critically evaluates the existing literature focused on defining the high-risk population, the management of patients with high-risk prostate cancer, and future directions to optimize care.

Low Bone Mineral Density in Adolescents with β‐Thalassemia

Abstract: The pervasiveness of low bone mass (LBM) in β‐thalassemia (Thal) patients (pts) is escalating as the average life expectancy of these pts increases. Adolescence is a period of substantial bone accrual, which is crucial for future bone strength. Studies of LBM are prevalent among adults with Thal. However, limited information exists about bone accrual and LBM in adolescents with the disease. Thirty‐one pts with β‐Thal (26 Thal major [TM], 5 Thal intermedia [TI]), aged 9‐20 years (mean: 15.3 years), 14 males and 17 females, underwent measurement of spinal bone mineral density (BMD) by DEXA (Lunar, Prodigy). Height, weight, body mass index, and Tanner stage were assessed at the time of the BMD measurement. A total of 16.1% of the patients had normal bone mass (Z≥−1), 22.6% had reduced bone mass (Z=−1 to −2), and 61.3% had low bone mass (Z≤−2). BMD Z correlated with height and weight Z scores. Some 53.9% of subjects had normal gonadal function and 46.1% had induced puberty with gonadal steroids. BMD Z significantly worsened with age (P < .0001). However, there was no difference in the LBM prevalence between subjects with normal versus those with induced puberty: BMD Z was −2 or less in 71.4% of subjects with normal puberty versus 66.7% in those with induced puberty. Our results indicate a high prevalence of LBM among adolescents with Thal regardless of adequate transfusion and chelation regimens. Bone accrual was found to be suboptimal in adolescents with normal or induced puberty. Thus, calcium and vitamin D supplementation with antiresorptive therapies should be evaluated in the adolescent Thal pt with close monitoring of growth and sexual development.

Low bone mass in prepubertal children with thalassemia major: insights into the pathogenesis of low bone mass in thalassemia.

OBJECTIVE Low bone mass occurs frequently in the aging thalassemic population. However, limited information exists on bone mass in children with thalassemia major (TM) during their first decade of life. STUDY DESIGN Spinal bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DEXA) in 18 children (age 5.8 +/- 1.5 yr; M:F 8:10) with TM on hypertransfusion and iron chelation therapy. Serial BMD measurements were available for 11 of the 18 children. RESULTS Weight and height z scores were 0.81 +/- 4.2 and -0.47 +/- 1.7 respectively. At the first BMD, four (22.2%) patients presented with BMD z scores less than -2.5, seven (38.8%) had BMD z scores between -1 and -2.5, while the remaining seven (38.8%) had normal BMDs (z score above -1). The mean decline of BMD z score was -0.38/year (p = ns). BMD z scores correlated with height z scores (p = 0.039), but not with liver enzymes, serum ferritin levels, or thalassemia genotypes. CONCLUSIONS Low bone mass is present in most children with TM despite hypertransfusion and optimal chelation, adequate growth and lack of endocrine complications.

Targeting the androgen receptor in prostate and breast cancer: several new agents in development

Prostate cancer (PCa) and breast cancer (BCa) share similarities as hormone-sensitive cancers with a wide heterogeneity of both phenotype and biology. The androgen receptor (AR) is a hormone receptor involved in both benign and malignant processes. Targeting androgen synthesis and the AR pathway has been and remains central to PCa therapy. Recently, there has been increased interest in the role of the AR in BCa development and growth, with results indicating AR co-expression with estrogen, progesterone, and human epidermal growth factor receptors, across all intrinsic subtypes of BCa. Targeting the AR axis is an evolving field with novel therapies in development which may ultimately be applicable to both tumor types. In this review, we offer an overview of available agents which target the AR axis in both PCa and BCa and provide insights into the novel drugs in development for targeting this signaling pathway.

Monitoring the Clinical Outcomes in Advanced Prostate Cancer: What Imaging Modalities and Other Markers Are Reliable?

Effective patient care and efficient drug development require accurate tools to assess treatment effects. For metastatic castration-resistant prostate cancer (mCRPC), response biomarkers have historically been poorly reproducible, inaccurate, inconsistently applied, or only loosely associated with tangible clinical benefits such as survival. However, the field of response assessments for prostate cancer is maturing, in compliance with a rigorous process defined by analytic validation, clinical validation, and clinical qualification. For example, bone imaging with technetium-99m scintigraphy has historically been poorly used in prostate cancer clinical trials and routine patient care, and frequently has led to poor decision-making. However, contemporary clinical trial consensus criteria (Prostate Cancer Working Group 2 [PCWG2]) have standardized the definition of progression on bone scintigraphy and the clinical trials endpoint of radiographic progression-free survival (rPFS). A validated bone scan interpretation form captures the relevant data elements. rPFS and the forms have been undergoing prospective testing in multiple phase III studies. The first of these trials demonstrated a high degree of reproducibility and correlation with overall survival, and rPFS was used by the US Food and Drug Administration (FDA) for approval of abiraterone in chemotherapy-naïve mCRPC. Circulating tumor cells (CTC) are another class of assays with significant promise as response-indicator biomarkers. CTC enumeration has undergone analytic validation and has been FDA-cleared for monitoring patients with prostate cancer in conjunction with other clinical methods. It is not yet a surrogate for survival. Patient-reported outcomes (PROs) are direct indicators of patient benefit. The assays to measure PROs must undergo each of the steps of biomarker development, and are increasingly being standardized and used as clinical trial endpoints. In this review, we critically assess each of these classes of novel biomarkers--imaging, CTC, and PROs--in regard to the quality of data supporting their use to monitor clinical outcomes in advanced prostate cancer.

Safety, Antitumor Activity, and Immune Activation of Pegylated Recombinant Human Interleukin-10 (AM0010) in Patients With Advanced Solid Tumors

Purpose Interleukin-10 (IL-10) stimulates the expansion and cytotoxicity of tumor-infiltrating CD8+ T cells and inhibits inflammatory CD4+ T cells. Pegylation prolongs the serum concentration of IL-10 without changing the immunologic profile. This phase I study sought to determine the safety and antitumor activity of AM0010. Patients and Methods Patients with selected advanced solid tumors were treated with AM0010 in a dose-escalation study, which was followed by a renal cell cancer (RCC) dose-expansion cohort. AM0010 was self-administered subcutaneously at doses of 1 to 40 μg/kg once per day. Primary end points were safety and tolerability; clinical activity and immune activation were secondary end points. Results In the dose-escalation and -expansion cohorts, 33 and 18 patients, respectively, were treated with daily subcutaneous injection of AM0010. AM0010 was tolerated in a heavily pretreated patient population. Treatment-related adverse events (AEs) included anemia, fatigue, thrombocytopenia, fever, and injection site reactions. Grade 3 to 4 nonhematopoietic treatment-related AEs, including rash (n = 2) and transaminitis (n = 1), were observed in five of 33 patients. Grade 3 to 4 anemia or thrombocytopenia was observed in five patients. Most treatment-related AEs were transient or reversible. AM0010 led to systemic immune activation with elevated immune-stimulatory cytokines and reduced transforming growth factor beta in the serum. Partial responses were observed in one patient with uveal melanoma and four of 15 evaluable patients with RCC treated at 20 μg/kg (overall response rate, 27%). Prolonged stable disease of at least 4 months was observed in four patients, including one with colorectal cancer with disease stabilization for 20 months. Conclusion AM0010 has an acceptable toxicity profile with early evidence of antitumor activity, particularly in RCC. These data support the further evaluation of AM0010 both alone and in combination with other immune therapies and chemotherapies.

Therapeutic Strategies for Bone Metastases and Their Clinical Sequelae in Prostate Cancer

Opinion statementSkeletal metastases threaten quality of life, functionality, and longevity in patients with metastatic castration-resistant prostate cancer (mCRPC). Therapeutic strategies for bone metastases in prostate cancer can palliate pain, delay/prevent skeletal complications, and prolong survival. Pharmacologic agents representing several drug classes have demonstrated the ability to achieve these treatment goals in men with mCRPC. Skeletal-related events such as fracture and the need for radiation can be delayed using drugs that target the osteoclast/osteoblast pathway. Cancer-related bone pain can be palliated using beta-emitting bone-seeking radiopharmaceuticals such as samarium-153 EDTMP and strontium-89. Also, prospective randomized studies have demonstrated that cytotoxic chemotherapy can palliate bone pain. For the first time, bone-directed therapy has been shown to prolong survival using the novel alpha-emitting radiopharmaceutical radium-223. Given these multifold clinical benefits, treatments targeting bone metabolism, tumor-bone stromal interactions, and bone metastases themselves are now central elements of routine clinical care. Decisions about which agents, alone or in combination, will best serve the patient’s and clinician’s clinical goals is contingent on the treatment history to date, present disease manifestations, and symptomatology. Clinical trials exploring novel agents such as those targeting c-Met and Src are under way, using endpoints that directly address how patients feel, function, and survive.

Pain palliation measurement in cancer clinical trials: The US Food and Drug Administration perspective

Pain palliation resulting from antitumor therapy provides direct evidence of treatment benefit when combined with evidence of antitumor activity. The US Food and Drug Administration (FDA) previously issued guidance regarding the use of patient‐reported outcome (PRO) measures to support labeling claims. The purpose of this article is to identify common challenges and key design strategies when measuring pain palliation in antitumor therapy clinical trials that are consistent with PRO Guidance principles.

Prevalence of Pain and Analgesic Use in Men With Metastatic Prostate Cancer Using a Patient-Reported Outcome Measure

PURPOSE Contemporary tumor-directed therapies for metastatic castration-resistant prostate cancer (mCRPC) are approved to prolong life, but their effects on symptoms such as pain are less well understood as a result of the lack of analytically valid assessments of pain prevalence and severity, clinically meaningful definitions of therapeutic benefit, and methodologic standards of trial conduct. This study establishes pain characteristics in the mCRPC population using a PRO measure. MATERIALS AND METHODS Patients with prostate cancer participated in an anonymous survey at five US comprehensive cancer centers in the Prostate Cancer Clinical Trials Consortium that incorporated the Brief Pain Inventory (BPI), analgesic use, and interference with daily activities. Prevalence and severity of cancer-related pain and analgesic use were tabulated according to castration-resistant status and exposure to docetaxel chemotherapy. RESULTS Four hundred sixty-one patients with prostate cancer participated, of whom 147 had mCRPC involving bone (61% [89 of 147] docetaxel exposed, 39% [58 of 147] docetaxel naive). Pain of any level was more common among docetaxel-exposed versus docetaxel-naive patients with mCRPC (70% [62 of 89] v 38% [22 of 58], respectively; P<.001). BPI score≥4 was reported by 38% (34 of 89) of docetaxel-pretreated and 24% (14 of 58) of docetaxel-naive patients with mCRPC; 40% of these patients with pain intensity≥4 reported no current narcotic analgesic. CONCLUSION Pain prevalence and severity were higher in patients with prior docetaxel exposure. Analgesics were underutilized. These results provide a method for estimating accruals along the disease continuum, and for enabling design of trials appropriately powered to assess pain.