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

Predictors of long-term response to abiraterone in patients with metastastic castration-resistant prostate cancer: a retrospective cohort study

We aimed to identify clinical predictors of long-term response to abiraterone (defined as >12 months drug exposure) in a retrospective cohort of metastatic castration-resistant prostate cancer patients treated in post-docetaxel setting at 24 Italian centers. The Cox proportional hazards model was used to analyze the association between clinical features and the duration of drug exposure. Results were expressed as hazard ratios (HR) with associated 95% confidence intervals (CI). A total of 143 patients met the inclusion criteria. Their median age was 73 years, median Gleason score 8 and median abiraterone exposure 20 months. At the univariate analysis, a significant correlation with the duration of abiraterone exposure was found for Gleason score (HR 0.82, 95% CI 0.71-0.96; p=0.012), PSA (HR 1.10, 95% CI 1.03-1.18; p=0.08) and lactic dehydrogenase levels (HR 1.22, 95% CI 1.02-1.46; p=0.027), while the association between lower alkaline phosphatase levels and treatment duration was marginally significant (HR 1.07, 95% CI 0.99-1.16; p=0.074). Only PSA and Gleason score were predictive of long-term treatment duration in the multivariate analysis. No other clinical factors resulted to be predictive of sustained response to abiraterone, including metastatic disease at diagnosis and visceral disease, suggesting that all subgroups of patients may derive a substantial clinical benefit from abiraterone treatment. These findings need to be validated in prospective, larger studies

Impact of second-line cetuximab-containing therapy in patients with KRAS wild-type metastatic colorectal cancer: results from the ITACa randomized clinical trial

Abstract The ITACa trial was designed to define the role of cetuximab (Cet) and bevacizumab (Bev) in combination with standard chemotherapy (CT, FOLFIRI or FOLFOX4) as first- and second-line treatment in metastatic colorectal cancer. All patients with WT KRAS tumors who had been enrolled in the first-line trial were randomized onto two independent second-line trials: CT or CT + Cet (study 2A) and CT + Bev or CT + Bev + Cet (study 2B). Patients with mutated KRAS were not eligible for randomization and were treated with CT alone (study 2A) or CT + Bev (study 2B). The primary endpoint was progression-free survival (PFS). 48 and 56 KRAS WT patients were randomized while 31 and 40 KRAS mutated patients were treated without randomization. Study 2A: median PFS was 3.4 (95%CI 2.3–4.6) and 6.2 (95%CI 4.3–7.8) months for the CT and CT + Cet arms, respectively, with a hazard ratio (HR) = 0.64 (95%CI 0.35–1.16, p = 0.144). Study 2B: median PFS was 7.7 (95%CI 4.1–10.1) and 4.9 (95%CI 3.2–7.0) months for CT + Bev and CT + Cet + Bev arms, respectively, with a HR = 1.31 (95%CI 0.76–2.26, p = 0.330). Notwithstanding limitations due to the small sample size, among patients with WT KRAS the addition of Cet to second-line CT increased PFS, whereas the addition of Cet to CT + Bev was associated with worse PFS

Cabozantinib in the elderly with metastatic renal cell carcinoma undergoing geriatric G8 screening test: A prospective multicenter observational study (ZEBRA/MEET-URO 9)

Background: Cabozantinib (CABO) is an oral tyrosine kinase inhibitor registered for the treatment of metastatic renal cell carcinoma (mRCC) for the first or subsequent lines. Tolerability in real world elderly patients is poorly documented. G8 is a short test for vulnerability gaining increased interest as a screening tool for trials in geriatric oncology. Methods: ZEBRA/MEET-URO 9 was a prospective multicenter study of safety and activity of CABO administered to pts ≥70 years with mRCC, either in the first or subsequent lines of treatment, until progression or unacceptable toxicity. All pts underwent G8 score at baseline, with a cut-off for vulnerability of 14 or below. Data on tolerability and activity were collected prospectively after signature of informed consent. Results: A total of 104 pts started CABO at 13 Italian Centers, 38,5% as first line. Median age was 75.8 yrs (range 70.2-87.4 yrs, 26 pts ≥80 yrs), 73.1% males. IMDC score was good 19.2%, intermediate 53.9%, poor 26.9%. Primary tumor had been removed in 82.7% of pts, histology was clear cell 78.8%, papillary 8.7%, chromophobe 5.8%, unclassified 6.7%. G8 score was ≤14 in 65.4% of pts. Up-front dose reduction of CABO was more frequent in pts with low G8 score (79.4 vs 41.7%, p=0.003), but eventually the majority of pts (91.4%) underwent dose reductions of CABO. After a median treatment of 6.4 months (0.5-26.1 months), 38.4% of pts developed G3-4 toxicities, 22.1% interrupted treatment due to adverse events, 2.8% (3 pts) died due to cardiovascular or thromboembolic events. Median PFS was 7.6 months (95% CI=5.8-12.6 months) in first line, 10.0 months (5.8-15.6) in second or further lines, median OS was 20.1 months (11.1-not reached) and 15.6 months (12.5-not reached), respectively. G8 score ≤14 did not correlate with rate of temporary interruptions >7 days, hospitalization, incidence of G3-5 toxicities, as well as with PFS. Pts with G8 score ≤14 had a trend for reduced OS, but difference was not statistically significant both in the first and further lines of treatment. Conclusions: Screening G8 test was positive in more than a half of pts, underlying the need for detailed geriatric assessment and increased clinical monitoring of such patients. A G8 score ≤14 correlated with up-front dose reduction of CABO but not with G3-5 toxicities probably due to the high rates of dose reductions in the whole cohort. Correlation between low G8 score and OS could not be demonstrated in this population

Patient-reported outcomes with olaparib plus abiraterone versus placebo plus abiraterone for metastatic castration-resistant prostate cancer: a randomised, double-blind, phase 2 trial

Background Results of this double-blind, phase 2 trial showed patients with metastatic castration-resistant prostate cancer given olaparib plus abiraterone versus placebo plus abiraterone had significantly improved progression-free survival. Here, we present an exploratory analysis of pain and health-related quality of life (HRQOL). Methods This double-blind, randomised, placebo-controlled, phase 2 trial was conducted across 41 urological oncology sites in 11 countries in Europe and North America. Eligible patients were aged 18 years or older, had metastatic castration-resistant prostate cancer, and had previously received docetaxel and up to one additional line of previous chemotherapy. Metastatic castration-resistant prostate cancer was defined as increasing prostate-specific antigen (PSA) concentration or other signs of disease progression despite androgen-deprivation therapy and serum testosterone concentrations at castrate levels (≤50 ng/dL), and with at least one metastatic lesion on bone scan, CT, or MRI. Eligible patients were randomly assigned (1:1) to receive oral olaparib (300 mg twice per day) plus oral abiraterone (1000 mg once a day) and oral prednisone or prednisolone (5 mg twice a day) or placebo plus abiraterone (1000 mg once a day) and prednisone or prednisolone (5 mg twice a day). Randomisation was done without stratification and by use of an interactive voice or web response system. A randomised treatment kit ID number was assigned sequentially to each patient as they became eligible. The primary endpoint (radiographic progression-free survival) has previously been reported. HRQOL was a prespecified exploratory patient-reported outcome. Patients were asked to complete the Brief Pain Inventory-Short Form (BPI-SF), single-item worst bone pain, Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire, and EuroQol-5 five-dimension five level (EQ-5D-5L) assessment at baseline, at weeks 4, 8, and 12, then every 12 weeks until treatment discontinuation. Prespecified outcomes were change from baseline in BPI-SF worst pain, single-item worst bone pain and FACT-P Total Outcome Index (TOI) scale scores, time to deterioration in BPI-SF worst pain and worst bone pain, and assessment of the EQ-5D-5L pain and discomfort domain. All analyses were exploratory and done in the full analysis set (all randomly assigned patients, including patients who were randomly assigned but did not subsequently go on to receive study treatment), with the exception of mean baseline and total change from baseline analyses, for which we used the population who had a valid baseline and at least one post-baseline assessment. This trial is registered with Clinicaltrials.gov, NCT01972217, and is no longer recruiting patients. Findings Between Nov 25, 2014, and July 14, 2015, 171 patients were assessed for eligibility. 29 patients were excluded, and 142 were enrolled and randomly assigned to receive olaparib and abiraterone (n=71) or placebo and abiraterone (n=71). Data cutoff was Sept 22, 2017. Median follow-up was 15·9 months (IQR 8·1–25·5) in the olaparib plus abiraterone group and 24·5 months (8·1–27·6) in the placebo plus abiraterone group. Questionnaire compliance was generally high (43–100%). Least-squares mean changes from baseline in BPI-SF worst pain, single-item worst bone pain, and FACT-P TOI remained stable across all visits for patients in both treatment groups. Adjusted mean change in FACT-P TOI from baseline across all visits was −0·10 (95% CI −2·50 to 2·71) in the olaparib plus abiraterone group and −1·20 (−4·15 to 1·74) in the placebo plus abiraterone group (difference 1·30, 95% CI −2·70 to 5·30; p=0·52). Time to deterioration in pain was similar in both groups (BPI-SF worst pain HR 0·90 [95% CI 0·62–1·32], p=0·30; worst bone pain HR 0·85 [0·59–1·22], p=0·18). Improvement rates in the pain and discomfort domain of the EQ-5D-5L were similar in both groups from baseline to week 48, beyond which a higher proportion of patients in the olaparib plus abiraterone arm reported an improvement compared to the placebo plus abiraterone group. Interpretation In these prespecified exploratory analyses, there was no significant difference in pain or HRQOL when olaparib was added to abiraterone. In this phase 2 trial, a statistically significant radiographic progression-free survival benefit was observed with the olaparib plus abiraterone combination. These results suggest that the improved survival benefits observed when combining olaparib with abiraterone does not result in different HRQOL compared with placebo plus abiraterone. Phase 3 studies are required to validate these results

Association among metabolic syndrome, inflammation, and survival in prostate cancer

Metabolic syndrome (MS) and inflammation (INF) alterations are among the factors involved in cancer progression. The study aimed to assess the relationship between MS and INF and its effect on progression-free/overall survival (PFS/OS) in metastatic castration-resistant prostate cancer (mCRPC) treaed with abiraterone or enzalutamide

Effectiveness of abiraterone acetate plus prednisone in chemotherapy-naïve patients with metastatic castration-resistant prostate cancer in a large prospective real-world cohort: the ABItude study

Real-world data on chemotherapy-naïve patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone plus prednisone are limited, largely deriving from small retrospective studies

Effects of abiraterone acetate plus prednisone on bone turnover markers in chemotherapy-naïve mCRPC patients after ADT failure: a prospective analysis of the italian real-world study ABITUDE

Background: Bone remodeling is disrupted in metastatic disease, which affects > 70% of metastatic castration-resistant prostate cancer (mCRPC) patients. As a result, abnormal levels of specific bone turnover biomarkers (BTMs) are released. In this prospective ancillary analysis of the Italian real-world study ABITUDE, four markers were measured during abiraterone acetate plus prednisone (AAP) treatment in chemotherapy-naïve mCRPC men failing androgen-deprivation therapy. Methods: Patients were enrolled if a blood sample was obtained before the first administration of abiraterone (baseline); ad-hoc blood samples were withdrawn during routine tests after 3, 6, and 12 months. A centralized lab measured bone alkaline phosphatase (BALP, osteoblast activity marker), type-I collagen-C-telopeptide (CTX-1, bone resorption marker), parathyroid hormone (PTH) and vitamin D (vitD). At each time point, intra-patient variations vs baseline were compared by the signed-rank test (statistical significance: P-value < 0.05). Results: Of 481 patients enrolled in ABITUDE, 186 (median age: 76 [range: 53-93] years) met the substudy criteria: 74.7% had bone metastases, 11.8% were on bone-targeted therapies (BTT) and 14.0% on vitD supplementation. BALP decreased significantly at month 6 (P = 0.0010) and 12 (P < 0.0001) and CTX-1 at month 6 (P = 0.0028); PTH increased at month 3 (P < 0.0001); no significant difference in vitD levels was observed. Similar findings were observed in BTT-untreated patients. The reduction in BALP and CTX-1 levels was more pronounced in patients with than without bone metastases; in the latter group, no significant variation in BALP and CTX-1 levels was observed. Conclusions: AAP seems to exert an effect on the microenvironment of metastatic but not of normal bone, which likely contributes to its antitumoral activity