Accelerating the development of genetically engineered cellular therapies: a framework for extrapolating data across related products.

BACKGROUND: Significant advancements have been made in the field of cellular therapy as anti-cancer treatments, with the approval of chimeric antigen receptor (CAR)-T cell therapies and the development of other genetically engineered cellular therapies. CAR-T cell therapies have demonstrated remarkable clinical outcomes in various hematological malignancies, establishing their potential to change the current cancer treatment paradigm. Due to the increasing importance of genetically engineered cellular therapies in the oncology treatment landscape, implementing strategies to expedite development and evidence generation for the next generation of cellular therapy products can have a positive impact on patients. METHODS: We outline a risk-based methodology and assessment aid for the data extrapolation approach across related genetically engineered cellular therapy products. This systematic data extrapolation approach has applicability beyond CAR-T cells and can influence clinical development strategies for a variety of immune therapies such as T cell receptor (TCR) or genetically engineered and other cell-based therapies (e.g., tumor infiltrating lymphocytes, natural killer cells and macrophages). RESULTS: By analyzing commonalities in manufacturing processes, clinical trial designs, and regulatory considerations, key learnings were identified. These insights support optimization of the development and regulatory approval of novel cellular therapies. CONCLUSIONS: The field of cellular therapy holds immense promise in safely and effectively treating cancer. The ability to extrapolate data across related products presents opportunities to streamline the development process and accelerate the delivery of novel therapies to patients.

Olaparib monotherapy for Asian patients with a germline BRCA mutation and HER2-negative metastatic breast cancer: OlympiAD randomized trial subgroup analysis.

The OlympiAD Phase III study (NCT02000622) established the clinical benefits of olaparib tablet monotherapy (300 mg twice daily) over chemotherapy treatment of physician's choice (TPC) in patients with a germline BRCA1/2 mutation (gBRCAm) and human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer who had received ≤2 chemotherapy lines in the metastatic setting. Here, we report pre-specified analyses of data from Asian (China, Japan, Korea and Taiwan) patients in the study. All patients were randomized 2:1 to olaparib tablets (300 mg twice daily) or single-agent chemotherapy TPC (21-day cycles of either capecitabine, eribulin or vinorelbine). The primary endpoint was progression-free survival assessed by blinded independent central review. The prevalence of gBRCAm in the OlympiAD Asian subgroup screened for study recruitment was 13.5%. Patient demographics and disease characteristics of the Asian subgroup (87/302 patients) were generally well balanced between treatment arms. Asian patients in the olaparib arm achieved longer median progression-free survival, assessed by blinded independent central review, versus the chemotherapy TPC arm (5.7 vs 4.2 months; HR = 0.53 [95% CI: 0.29-0.97]), which was consistent with findings in the global OlympiAD study population. Findings on secondary efficacy and safety/tolerability outcome measures in Asian patients were also similar to those observed in the global OlympiAD study population. The OlympiAD study was not powered to detect race-related differences between treatment groups; however, the consistency of our findings with the global OlympiAD study population suggests that previously reported findings are generalizable to Asian patients.

Olaparib for Metastatic Castration-Resistant Prostate Cancer.

BACKGROUND: Multiple loss-of-function alterations in genes that are involved in DNA repair, including homologous recombination repair, are associated with response to poly(adenosine diphosphate-ribose) polymerase (PARP) inhibition in patients with prostate and other cancers. METHODS: We conducted a randomized, open-label, phase 3 trial evaluating the PARP inhibitor olaparib in men with metastatic castration-resistant prostate cancer who had disease progression while receiving a new hormonal agent (e.g., enzalutamide or abiraterone). All the men had a qualifying alteration in prespecified genes with a direct or indirect role in homologous recombination repair. Cohort A (245 patients) had at least one alteration in BRCA1, BRCA2, or ATM; cohort B (142 patients) had alterations in any of 12 other prespecified genes, prospectively and centrally determined from tumor tissue. Patients were randomly assigned (in a 2:1 ratio) to receive olaparib or the physician's choice of enzalutamide or abiraterone (control). The primary end point was imaging-based progression-free survival in cohort A according to blinded independent central review. RESULTS: In cohort A, imaging-based progression-free survival was significantly longer in the olaparib group than in the control group (median, 7.4 months vs. 3.6 months; hazard ratio for progression or death, 0.34; 95% confidence interval, 0.25 to 0.47; P<0.001); a significant benefit was also observed with respect to the confirmed objective response rate and the time to pain progression. The median overall survival in cohort A was 18.5 months in the olaparib group and 15.1 months in the control group; 81% of the patients in the control group who had progression crossed over to receive olaparib. A significant benefit for olaparib was also seen for imaging-based progression-free survival in the overall population (cohorts A and B). Anemia and nausea were the main toxic effects in patients who received olaparib. CONCLUSIONS: In men with metastatic castration-resistant prostate cancer who had disease progression while receiving enzalutamide or abiraterone and who had alterations in genes with a role in homologous recombination repair, olaparib was associated with longer progression-free survival and better measures of response and patient-reported end points than either enzalutamide or abiraterone. (Funded by AstraZeneca and Merck Sharp & Dohme; PROfound ClinicalTrials.gov number, NCT02987543.).

Patient-reported outcomes in patients with a germline BRCA mutation and HER2-negative metastatic breast cancer receiving olaparib versus chemotherapy in the OlympiAD trial.

BACKGROUND: The phase III OlympiAD study (NCT02000622) showed a statistically significant progression-free survival benefit with olaparib versus chemotherapy treatment of physician's choice (TPC) in patients with a germline BRCA mutation and human epidermal growth factor receptor 2-negative metastatic breast cancer. From this study, we report the effect of olaparib on health-related quality of life (HRQoL). METHODS: Patients were randomised 2:1 to olaparib monotherapy (300 mg twice daily) or single-agent TPC. The primary HRQoL end-point was mean change from baseline in the two-item global health status/QoL score determined from patient-completed European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30-item module (EORTC QLQ-C30) questionnaires and assessed using a mixed model for repeated measures. Symptoms and functioning domains, best overall response and time to deterioration of QoL were also evaluated. RESULTS: Overall questionnaire compliance rates were 93.2% for olaparib and 76.3% for TPC. Between-treatment global health status/QoL comparison showed a significant improvement in the olaparib arm versus the TPC arm, with mean change of 3.9 (standard deviation 1.2) versus -3.6 (2.2), a difference of 7.5 points (95% confidence interval [CI]: 2.48, 12.44; P = 0.0035). A higher proportion of patients in the olaparib arm showed a best overall response of 'improvement' in global health status/QoL (33.7% vs 13.4%). Median time to global health status/QoL deterioration was not reached in olaparib patients and was 15.3 months for TPC patients (hazard ratio: 0.44 [95% CI: 0.25, 0.77]; P = 0.004). For EORTC QLQ-C30 symptoms and functioning subscales, only nausea/vomiting symptom score was worse in the olaparib arm than in the TPC arm (across all visits compared with baseline). CONCLUSION: HRQoL was consistently improved for patients treated with olaparib, compared with chemotherapy TPC.

Pharmacokinetic Effects and Safety of Olaparib Administered with Endocrine Therapy: A Phase I Study in Patients with Advanced Solid Tumours.

INTRODUCTION: The PARP inhibitor olaparib is efficacious as monotherapy and has potential application in combination with endocrine therapy for the treatment of breast cancer. This phase I study assessed the safety and pharmacokinetic (PK) profiles of olaparib combined with tamoxifen, anastrozole or letrozole in patients with advanced solid tumours. METHODS: During part A, PK profiles were assessed in three consecutive treatment periods: (1) olaparib (tablet) 300 mg bid, days 1-5 followed by a 4-day washout; (2) cohort 1, tamoxifen 60 mg loading dose qd days 10-13, 20 mg qd days 14-26; cohort 2, anastrozole 1 mg qd days 10-19; cohort 3, letrozole 2.5 mg qd days 10-38; (3) as for period 2, with concomitant olaparib 300 mg bid for 5 days. Patients could then enter part B and receive olaparib monotherapy (300 mg bid continuously). Safety was assessed in parts A and B until 12 months after the last patient entered part B. RESULTS: Seventy-nine patients (20.3% with breast cancer) received treatment in part A; 72 completed part A and 69 entered part B. Anastrozole and letrozole had no effect on the PK profile of olaparib and vice versa. Co-administration with tamoxifen produced a modest decrease in exposure to olaparib [geometric least-squares mean (GLSmean) Cmax,ss and AUC0-τ decreased by 20% (90% CI 0.71-0.90) and 27% (0.63-0.84), respectively]. Exposure to tamoxifen was slightly increased when combined with olaparib [GLSmean Cmax,ss and AUC0-τ increased by 13% (1.06-1.22) and 16% (1.11-1.21), respectively]; however, the 90% CI fell within the 0.7-1.43 boundary and there were no changes in exposure to tamoxifen metabolites. The safety profile for olaparib alone and in combination with the antihormonal therapies was acceptable. CONCLUSIONS: The combination of olaparib and either anastrozole, letrozole or tamoxifen was generally well tolerated, with no clinically relevant PK interactions identified. FUNDING: AstraZeneca. CLINICAL TRIAL REGISTRATION: NCT02093351.

Olaparib combined with abiraterone in patients with metastatic castration-resistant prostate cancer: a randomised, double-blind, placebo-controlled, phase 2 trial.

BACKGROUND: Patients with metastatic castration-resistant prostate cancer and homologous recombination repair (HRR) mutations have a better response to treatment with the poly(ADP-ribose) polymerase inhibitor olaparib than patients without HRR mutations. Preclinical data suggest synergy between olaparib and androgen pathway inhibitors. We aimed to assess the efficacy of olaparib plus the androgen pathway inhibitor abiraterone in patients with metastatic castration-resistant prostate cancer regardless of HRR mutation status. METHODS: We carried out this double-blind, randomised, placebo-controlled phase 2 trial at 41 urological oncology sites in 11 countries across Europe and North America. Eligible male patients were aged 18 years or older with metastatic castration-resistant prostate cancer who had previously received docetaxel and were candidates for abiraterone treatment. Patients were excluded if they had received more than two previous lines of chemotherapy, or had previous exposure to second-generation antihormonal drugs. Patients were randomly assigned (1:1) using an interactive voice or web response system, without stratification, to receive oral olaparib 300 mg twice daily or placebo. All patients received oral abiraterone 1000 mg once daily and prednisone or prednisolone 5 mg twice daily. Patients and investigators were masked to treatment allocation. The primary endpoint was investigator-assessed radiographic progression-free survival (rPFS; based on Response Evaluation Criteria in Solid Tumors version 1.1 and Prostate Cancer Clinical Trials Working Group 2 criteria). Efficacy analyses were done in the intention-to-treat population, which included all randomly assigned patients, and safety analyses included all patients who received at least one dose of olaparib or placebo. This trial is registered with ClinicalTrials.gov, number NCT01972217, and is no longer recruiting patients. FINDINGS: Between Nov 25, 2014, and July 14, 2015, 171 patients were assessed for eligibility. Of those, 142 patients were randomly assigned to receive olaparib and abiraterone (n=71) or placebo and abiraterone (n=71). The clinical cutoff date for the final analysis was Sept 22, 2017. Median rPFS was 13·8 months (95% CI 10·8-20·4) with olaparib and abiraterone and 8·2 months (5·5-9·7) with placebo and abiraterone (hazard ratio [HR] 0·65, 95% CI 0·44-0·97, p=0·034). The most common grade 1-2 adverse events were nausea (26 [37%] patients in the olaparib group vs 13 [18%] patients in the placebo group), constipation (18 [25%] vs eight [11%]), and back pain (17 [24%] vs 13 [18%]). 38 (54%) of 71 patients in the olaparib and abiraterone group and 20 (28%) of 71 patients in the placebo and abiraterone group had grade 3 or worse adverse events, including anaemia (in 15 [21%] of 71 patients vs none of 71), pneumonia (four [6%] vs three [4%]), and myocardial infarction (four [6%] vs none). Serious adverse events were reported by 24 (34%) of 71 patients receiving olaparib and abiraterone (seven of which were related to treatment) and 13 (18%) of 71 patients receiving placebo and abiraterone (one of which was related to treatment). One treatment-related death (pneumonitis) occurred in the olaparib and abiraterone group. INTERPRETATION: Olaparib in combination with abiraterone provided clinical efficacy benefit for patients with metastatic castration-resistant prostate cancer compared with abiraterone alone. More serious adverse events were observed in patients who received olaparib and abiraterone than abiraterone alone. Our data suggest that the combination of olaparib and abiraterone might provide an additional clinical benefit to a broad population of patients with metastatic castration-resistant prostate cancer. FUNDING: AstraZeneca.

Olaparib for Metastatic Breast Cancer in Patients with a Germline BRCA Mutation.

BACKGROUND: Olaparib is an oral poly(adenosine diphosphate-ribose) polymerase inhibitor that has promising antitumor activity in patients with metastatic breast cancer and a germline BRCA mutation. METHODS: We conducted a randomized, open-label, phase 3 trial in which olaparib monotherapy was compared with standard therapy in patients with a germline BRCA mutation and human epidermal growth factor receptor type 2 (HER2)-negative metastatic breast cancer who had received no more than two previous chemotherapy regimens for metastatic disease. Patients were randomly assigned, in a 2:1 ratio, to receive olaparib tablets (300 mg twice daily) or standard therapy with single-agent chemotherapy of the physician's choice (capecitabine, eribulin, or vinorelbine in 21-day cycles). The primary end point was progression-free survival, which was assessed by blinded independent central review and was analyzed on an intention-to-treat basis. RESULTS: Of the 302 patients who underwent randomization, 205 were assigned to receive olaparib and 97 were assigned to receive standard therapy. Median progression-free survival was significantly longer in the olaparib group than in the standard-therapy group (7.0 months vs. 4.2 months; hazard ratio for disease progression or death, 0.58; 95% confidence interval, 0.43 to 0.80; P<0.001). The response rate was 59.9% in the olaparib group and 28.8% in the standard-therapy group. The rate of grade 3 or higher adverse events was 36.6% in the olaparib group and 50.5% in the standard-therapy group, and the rate of treatment discontinuation due to toxic effects was 4.9% and 7.7%, respectively. CONCLUSIONS: Among patients with HER2-negative metastatic breast cancer and a germline BRCA mutation, olaparib monotherapy provided a significant benefit over standard therapy; median progression-free survival was 2.8 months longer and the risk of disease progression or death was 42% lower with olaparib monotherapy than with standard therapy. (Funded by AstraZeneca; OlympiAD ClinicalTrials.gov number, NCT02000622 .).

Bone-related Parameters are the Main Prognostic Factors for Overall Survival in Men with Bone Metastases from Castration-resistant Prostate Cancer.

BACKGROUND: Previous studies have reported on prognostic factors for castration-resistant prostate cancer (CRPC); however, most of these studies were conducted before docetaxel chemotherapy was approved for CRPC. OBJECTIVE: To evaluate the prognostic value of multiple parameters in men with bone metastases due to CRPC using a contemporary dataset. DESIGN, SETTING, AND PARTICIPANTS: The analysis included 1901 patients with metastatic CRPC enrolled in an international, multicenter, randomized, double-blind phase 3 trial conducted between May 2006 and October 2009. OUTCOME MEASURES AND STATISTICAL ANALYSIS: We developed multivariate validated Cox proportional hazards models and nomograms to estimate 12-mo and 24-mo survival probabilities and median survival time. RESULTS AND LIMITATIONS: The median (95% confidence interval) overall survival was 20 (18, 21) mo. The final model included 12 of the 15 potential prognostic variables evaluated (concordance index 0.72). Seven bone-related variables were associated with longer survival in the final model: alkaline phosphatase ≤143 U/l (p<0.0001); bone-specific alkaline phosphatase (BSAP) <146 U/l (p<0.0001); corrected urinary N-telopeptide (uNTx) ≤50 nmol/mmol (p=0.0008); mild or no pain (Brief Pain Inventory-Short Form [BPI-SF] score ≤4) (p<0.0001); no previous skeletal-related event (SRE; p=0.0002); longer time from initial diagnosis to first bone metastasis (p<0.0001); and longer time from first bone metastasis to randomization (p<0.0001). Other significant predictors of improved survival included prostate-specific antigen (PSA) level <10 ng/ml (p<0.0001), hemoglobin >128g/l (p<0.0001), absence of visceral metastases (p<0.0001), Eastern Co-operative Oncology Group (ECOG) score ≤1 (p=0.017), and younger age (p=0.008). Nomograms were generated based on the parameters included in the final validated models (with/without uNTx and BSAP). One limitation was that lactate dehydrogenase (LDH) levels, a known prognostic factor, were not available in this study. CONCLUSIONS: Bone-related parameters are strong prognostic variables for overall survival in patients with bone metastases from CRPC. PATIENT SUMMARY: Survival time is variable in patients with bone metastases from prostate cancer. We found that factors related to bone help to predict how long a patient will live.

Denosumab and bone metastasis-free survival in men with nonmetastatic castration-resistant prostate cancer: exploratory analyses by baseline prostate-specific antigen doubling time.

PURPOSE: Denosumab, an anti-RANK ligand monoclonal antibody, significantly increases bone metastasis-free survival (BMFS; hazard ratio [HR], 0.85; P = .028) and delays time to first bone metastasis in men with nonmetastatic castration-resistant prostate cancer (CRPC) and baseline prostate-specific antigen (PSA) ≥ 8.0 ng/mL and/or PSA doubling time (PSADT) ≤ 10.0 months. To identify men at greatest risk for bone metastasis or death, we evaluated relationships between PSA and PSADT with BMFS in the placebo group and the efficacy and safety of denosumab in men with PSADT ≤ 10, ≤ 6, and ≤ 4 months. PATIENTS AND METHODS: A total of 1,432 men with nonmetastatic CRPC were randomly assigned 1:1 to monthly subcutaneous denosumab 120 mg or placebo. Enrollment began February 2006; primary analysis cutoff was July 2010, when approximately 660 men were anticipated to have developed bone metastases or died. RESULTS: In the placebo group, shorter BMFS was observed as PSADT decreased below 8 months. In analyses by shorter baseline PSADT, denosumab consistently increased BMFS by a median of 6.0, 7.2, and 7.5 months among men with PSADT ≤ 10 (HR, 0.84; P = .042), ≤ 6 (HR, 0.77; P = .006), and ≤ 4 months (HR, 0.71; P = .004), respectively. Denosumab also consistently increased time to bone metastasis by PSADT subset. No difference in survival was observed between treatment groups for the overall study population or PSADT subsets. CONCLUSION: Patients with shorter PSADT are at greater risk for bone metastasis or death. Denosumab consistently improves BMFS in men with shorter PSADT and seems to have the greatest treatment effects in men at high risk for progression.

Treatment-induced bone loss and fractures in cancer patients undergoing hormone ablation therapy: efficacy and safety of denosumab.

Hormone ablation therapy (HALT) for breast or prostate cancer accelerates the development of osteoporosis in both men and women by causing estrogen deficiency, which increases the risk for fracture by promoting bone resorption mediated by osteoclasts. Denosumab, a fully human monoclonal antibody that inhibits osteoclast formation and function, increases bone mass in patients undergoing hormone ablation therapy. In the HALT study of 1,468 men with prostate cancer on androgen-deprivation therapy, denosumab significantly reduced the risk of new vertebral fractures, increased bone mineral density (BMD), and reduced markers of bone turnover. In a study of 252 women with breast cancer undergoing adjuvant aromatase inhibitor (AI) therapy, denosumab increased BMD at 12 and 24 months, overall and in all patient subgroups. The overall rates of adverse events were similar to placebo. Clinicians should consider fracture risk assessment and therapies such as denosumab to increase bone mass in patients on hormone ablation therapy who are at high risk for fracture.

The development of denosumab for the treatment of diseases of bone loss and cancer-induced bone destruction.

Denosumab is a fully human monoclonal antibody against RANK ligand (RANKL), an essential cytokine for the formation, function, and survival of osteoclasts. The role of excessive RANKL as a contributor to conditions characterized by bone loss or bone destruction has been well studied. With its novel mechanism of action, denosumab offers a significant advance in the treatment of postmenopausal osteoporosis; bone loss associated with hormone ablation therapy in women with breast cancer and men with prostate cancer; and the prevention of skeletal-related events in patients with bone metastases from solid tumors by offering clinical benefit to these patients in need.

Sarcopenia during androgen-deprivation therapy for prostate cancer.

PURPOSE: To characterize changes in lean body mass (LBM) in men with prostate cancer receiving androgen-deprivation therapy (ADT). PATIENTS AND METHODS: We prospectively evaluated LBM in a prespecified substudy of a randomized controlled trial of denosumab to prevent fractures in men receiving ADT for nonmetastatic prostate cancer. LBM was measured by total-body dual-energy x-ray absorptiometry at study baseline and at 12, 24, and 36 months. The analyses included 252 patients (132, denosumab; 120, placebo) with a baseline and at least one on-study LBM assessment. Patients were stratified by age (< 70 v ≥ 70 years) and by ADT duration (≤ 6 v > 6 months). RESULTS: Median ADT duration was 20.4 months at study baseline. Mean LBM decreased significantly from baseline, by 1.0% at month 12 (95% CI, 0.4% to 1.5%; P < .001; n = 248), by 2.1% at month 24 (95% CI, 1.5% to 2.7%; P < .001; n = 205), and by 2.4% at month 36 (95% CI, 1.6% to 3.2%; P < .001; n = 168). Men age ≥ 70 years (n = 127) had significantly greater changes in LBM at all measured time points than younger men. At 36 months, LBM decreased by 2.8% in men age ≥ 70 years and by 0.9% in younger men (P = .035). Men with ≤ 6 months of ADT at study entry (n = 36) had a greater rate of decrease in LBM compared with men who had received more than 6 months of ADT at study entry (3.7% v 2.0%; P = .0645). CONCLUSION: In men receiving ADT, LBM decreased significantly after 12, 24, and 36 months.

Denosumab and bone-metastasis-free survival in men with castration-resistant prostate cancer: results of a phase 3, randomised, placebo-controlled trial.

BACKGROUND: Bone metastases are a major cause of morbidity and mortality in men with prostate cancer. Preclinical studies suggest that osteoclast inhibition might prevent bone metastases. We assessed denosumab, a fully human anti-RANKL monoclonal antibody, for prevention of bone metastasis or death in non-metastatic castration-resistant prostate cancer. METHODS: In this phase 3, double-blind, randomised, placebo-controlled study, men with non-metastatic castration-resistant prostate cancer at high risk of bone metastasis (prostate-specific antigen [PSA] ≥8·0 µg/L or PSA doubling time ≤10·0 months, or both) were enrolled at 319 centres from 30 countries. Patients were randomly assigned (1:1) via an interactive voice response system to receive subcutaneous denosumab 120 mg or subcutaneous placebo every 4 weeks. Randomisation was stratified by PSA eligibility criteria and previous or ongoing chemotherapy for prostate cancer. Patients, investigators, and all people involved in study conduct were masked to treatment allocation. The primary endpoint was bone-metastasis-free survival, a composite endpoint determined by time to first occurrence of bone metastasis (symptomatic or asymptomatic) or death from any cause. Efficacy analysis was by intention to treat. The masked treatment phase of the trial has been completed. This trial was registered at ClinicalTrials.gov, number NCT00286091. FINDINGS: 1432 patients were randomly assigned to treatment groups (716 denosumab, 716 placebo). Denosumab significantly increased bone-metastasis-free survival by a median of 4·2 months compared with placebo (median 29·5 [95% CI 25·4-33·3] vs 25·2 [22·2-29·5] months; hazard ratio [HR] 0·85, 95% CI 0·73-0·98, p=0·028). Denosumab also significantly delayed time to first bone metastasis (33·2 [95% CI 29·5-38·0] vs 29·5 [22·4-33·1] months; HR 0·84, 95% CI 0·71-0·98, p=0·032). Overall survival did not differ between groups (denosumab, 43·9 [95% CI 40·1-not estimable] months vs placebo, 44·8 [40·1-not estimable] months; HR 1·01, 95% CI 0·85-1·20, p=0·91). Rates of adverse events and serious adverse events were similar in both groups, except for osteonecrosis of the jaw and hypocalcaemia. 33 (5%) patients on denosumab developed osteonecrosis of the jaw versus none on placebo. Hypocalcaemia occurred in 12 (2%) patients on denosumab and two (<1%) on placebo. INTERPRETATION: This large randomised study shows that targeting of the bone microenvironment can delay bone metastasis in men with prostate cancer. FUNDING: Amgen Inc.

Denosumab and changes in bone turnover markers during androgen deprivation therapy for prostate cancer.

Androgen deprivation therapy (ADT) for prostate cancer increases fracture risk, decreases bone mineral density, and increases bone turnover markers (BTMs) including serum type 1 C-telopeptide (sCTX), tartrate-resistant alkaline phosphatase 5b (TRAP-5b), and procollagen-1 N-terminal telopeptide (P1NP). In a prespecified exploratory analysis of a phase 3, multicenter, double-blind study, we evaluated the effects of denosumab (60 mg subcutaneously every 6 months for 3 years) versus placebo (1468 patients, 734 in each group) on BTM values. BTMs were measured at baseline, month 1, and predose at months 6, 12, 24, and 36 in the overall population. BTMs at month 1 are also reported for subgroups based on age (< 70 years versus ≥ 70 years), prior duration of ADT (≤ 6 months versus > 6 months), and baseline BTM (≤ median versus > median BTM values). Treatment with denosumab provided a rapid and sustained decrease of BTM values compared with placebo. The median change in sCTX levels at month 1 was -90% in the denosumab group and -3% in the placebo group (p < 0.0001). The median change in TRAP-5b levels at month 1 was -55% in the denosumab group and -3% in the placebo group (p < 0.0001). The maximal median change in P1NP was -64% in the denosumab group and -11% in the placebo group, (p < 0.0001). Significantly greater decreases in BTM for denosumab were also seen in subgroup analyses based on age, prior ADT treatment, and baseline BTM values. Suppression of bone turnover markers was consistent with marked increases in bone mineral density reported previously.

Denosumab versus zoledronic acid for treatment of bone metastases in men with castration-resistant prostate cancer: a randomised, double-blind study.

BACKGROUND: Bone metastases are a major burden in men with advanced prostate cancer. We compared denosumab, a human monoclonal antibody against RANKL, with zoledronic acid for prevention of skeletal-related events in men with bone metastases from castration-resistant prostate cancer. METHODS: In this phase 3 study, men with castration-resistant prostate cancer and no previous exposure to intravenous bisphosphonate were enrolled from 342 centres in 39 countries. An interactive voice response system was used to assign patients (1:1 ratio), according to a computer-generated randomisation sequence, to receive 120 mg subcutaneous denosumab plus intravenous placebo, or 4 mg intravenous zoledronic acid plus subcutaneous placebo, every 4 weeks until the primary analysis cutoff date. Randomisation was stratified by previous skeletal-related event, prostate-specific antigen concentration, and chemotherapy for prostate cancer within 6 weeks before randomisation. Supplemental calcium and vitamin D were strongly recommended. Patients, study staff, and investigators were masked to treatment assignment. The primary endpoint was time to first on-study skeletal-related event (pathological fracture, radiation therapy, surgery to bone, or spinal cord compression), and was assessed for non-inferiority. The same outcome was further assessed for superiority as a secondary endpoint. Efficacy analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00321620, and has been completed. FINDINGS: 1904 patients were randomised, of whom 950 assigned to denosumab and 951 assigned to receive zoledronic acid were eligible for the efficacy analysis. Median duration on study at primary analysis cutoff date was 12·2 months (IQR 5·9-18·5) for patients on denosumab and 11·2 months (IQR 5·6-17·4) for those on zoledronic acid. Median time to first on-study skeletal-related event was 20·7 months (95% CI 18·8-24·9) with denosumab compared with 17·1 months (15·0-19·4) with zoledronic acid (hazard ratio 0·82, 95% CI 0·71-0·95; p = 0·0002 for non-inferiority; p = 0·008 for superiority). Adverse events were recorded in 916 patients (97%) on denosumab and 918 patients (97%) on zoledronic acid, and serious adverse events were recorded in 594 patients (63%) on denosumab and 568 patients (60%) on zoledronic acid. More events of hypocalcaemia occurred in the denosumab group (121 [13%]) than in the zoledronic acid group (55 [6%]; p<0·0001). Osteonecrosis of the jaw occurred infrequently (22 [2%] vs 12 [1%]; p = 0·09). INTERPRETATION: Denosumab was better than zoledronic acid for prevention of skeletal-related events, and potentially represents a novel treatment option in men with bone metastases from castration-resistant prostate cancer. FUNDING: Amgen.

Clinical development of anti-RANKL therapies for treatment and prevention of bone metastasis.

The clinical sequelae from bone metastases, termed skeletal-related events, are among the most frequent and debilitating complications in patients with advanced cancer. Bone metastases are characterized by pathologically increased osteoclast activity, and accumulating evidence indicates that tumor cells interact within the bone to stimulate the RANK-RANK ligand (RANKL) pathway. RANKL is an essential mediator of osteoclast formation, function, and survival. Because of the central role of RANKL in cancer-induced bone destruction, the inhibition of RANKL has the potential to result in the reduction of pathologic bone resorption. Denosumab is a fully human monoclonal antibody specific for RANKL that inhibits the formation, activation, and survival of osteoclasts. This in turn decreases bone resorption and reduces cancer-induced bone destruction. As a result of its unique and specific mechanism of action, denosumab is being investigated for use in patients with advanced malignancies involving bone to prevent the occurrence of skeletal-related events.

Effects of denosumab on bone mineral density in men receiving androgen deprivation therapy for prostate cancer.

PURPOSE: In a recently completed 3-year, randomized, double-blind study, denosumab, a fully human monoclonal antibody against receptor activator of nuclear factor kappaB ligand, significantly increased bone mineral density and decreased new vertebral fractures in men receiving androgen deprivation therapy for prostate cancer. We conducted subgroup analyses to evaluate the relationships between subject characteristics and the effects of denosumab on bone mineral density at multiple skeletal sites. MATERIALS AND METHODS: A total of 1,468 subjects were randomized 1:1 to receive 60 mg subcutaneous denosumab every 6 months or placebo for 36 months. In these analyses we evaluated the effects of denosumab on bone mineral density at the lumbar spine, total hip and distal 1/3 radius (substudy of 309 subjects) during 36 months in specific subgroups according to age, duration and type of prior androgen deprivation therapy, bone mineral density T score, weight, body mass index, bone turnover marker levels and prevalent vertebral fractures. RESULTS: After 36 months denosumab significantly increased bone mineral density of the lumbar spine, total hip and distal 1/3 radius by 7.9%, 5.7% and 6.9%, respectively, compared with placebo (p <0.0001 for each comparison). Denosumab significantly increased bone mineral density to a degree similar to that observed in the overall analysis for every subgroup including older men as well as those with prevalent fractures, lower baseline bone mineral density, and higher serum C-telopeptide and tartrate-resistant alkaline phosphatase 5b. Mean increases in bone mineral density at each skeletal site were greatest for men with the highest levels of serum C-telopeptide and tartrate-resistant alkaline phosphatase 5b. CONCLUSIONS: Denosumab significantly and consistently increased bone mineral density at all skeletal sites and in every subgroup, including men at greatest risk for bone loss and fractures.