Veliparib with frontline chemotherapy and as maintenance in Japanese women with ovarian cancer: a subanalysis of efficacy, safety, and antiemetic use in the phase 3 VELIA trial.

BACKGROUND: The phase 3 VELIA trial evaluated veliparib with carboplatin/paclitaxel and as maintenance in patients with high-grade serous ovarian carcinoma. METHODS: Patients with previously untreated stage III-IV high-grade serous ovarian carcinoma were randomized 1:1:1 to control (placebo with carboplatin/paclitaxel and placebo maintenance), veliparib-combination-only (veliparib with carboplatin/paclitaxel and placebo maintenance), or veliparib-throughout (veliparib with carboplatin/paclitaxel and veliparib maintenance). Randomization stratification factors included geographic region (Japan versus North America or rest of the world). Primary end point was investigator-assessed median progression-free survival. Efficacy, safety, and pharmacokinetics were evaluated in a subgroup of Japanese patients. RESULTS: Seventy-eight Japanese patients were randomized to control (n = 23), veliparib-combination-only (n = 30), and veliparib-throughout (n = 25) arms. In the Japanese subgroup, median progression-free survival for veliparib-throughout versus control was 27.4 and 19.1 months (hazard ratio, 0.46; 95% confidence interval, 0.18-1.16; p = 0.1 [not significant]). In the veliparib-throughout arm, grade 3/4 leukopenia, neutropenia, and thrombocytopenia rates were higher for Japanese (32%/88%/32%) versus non-Japanese (17%/56%/28%) patients. Grade 3/4 anemia rates were higher in non-Japanese (65%) versus Japanese (48%) patients. Early introduction of olanzapine during veliparib monotherapy maintenance phase may help prevent premature discontinuation of veliparib, via its potent antiemetic efficacy. CONCLUSIONS: Median progression-free survival was numerically longer in Japanese patients in the veliparib-throughout versus control arm, consistent with results in the overall study population. Pharmacokinetics were comparable between Japanese and non-Japanese patients. Data for the subgroup of Japanese patients were not powered to show statistical significance but to guide further investigation.

Veliparib with First-Line Chemotherapy and as Maintenance Therapy in Ovarian Cancer.

BACKGROUND: Data are limited regarding the use of poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitors, such as veliparib, in combination with chemotherapy followed by maintenance as initial treatment in patients with high-grade serous ovarian carcinoma. METHODS: In an international, phase 3, placebo-controlled trial, we assessed the efficacy of veliparib added to first-line induction chemotherapy with carboplatin and paclitaxel and continued as maintenance monotherapy in patients with previously untreated stage III or IV high-grade serous ovarian carcinoma. Patients were randomly assigned in a 1:1:1 ratio to receive chemotherapy plus placebo followed by placebo maintenance (control), chemotherapy plus veliparib followed by placebo maintenance (veliparib combination only), or chemotherapy plus veliparib followed by veliparib maintenance (veliparib throughout). Cytoreductive surgery could be performed before initiation or after 3 cycles of trial treatment. Combination chemotherapy was 6 cycles, and maintenance therapy was 30 additional cycles. The primary end point was investigator-assessed progression-free survival in the veliparib-throughout group as compared with the control group, analyzed sequentially in the BRCA-mutation cohort, the cohort with homologous-recombination deficiency (HRD) (which included the BRCA-mutation cohort), and the intention-to-treat population. RESULTS: A total of 1140 patients underwent randomization. In the BRCA-mutation cohort, the median progression-free survival was 34.7 months in the veliparib-throughout group and 22.0 months in the control group (hazard ratio for progression or death, 0.44; 95% confidence interval [CI], 0.28 to 0.68; P<0.001); in the HRD cohort, it was 31.9 months and 20.5 months, respectively (hazard ratio, 0.57; 95 CI, 0.43 to 0.76; P<0.001); and in the intention-to-treat population, it was 23.5 months and 17.3 months (hazard ratio, 0.68; 95% CI, 0.56 to 0.83; P<0.001). Veliparib led to a higher incidence of anemia and thrombocytopenia when combined with chemotherapy as well as of nausea and fatigue overall. CONCLUSIONS: Across all trial populations, a regimen of carboplatin, paclitaxel, and veliparib induction therapy followed by veliparib maintenance therapy led to significantly longer progression-free survival than carboplatin plus paclitaxel induction therapy alone. The independent value of adding veliparib during induction therapy without veliparib maintenance was less clear. (Funded by AbbVie; VELIA/GOG-3005 ClinicalTrials.gov number, NCT02470585.).

Progression-free survival by investigator versus blinded independent central review in newly diagnosed patients with high-grade serous ovarian cancer: Analysis of the VELIA/GOG-3005 trial.

OBJECTIVE: In the phase 3 VELIA/GOG-3005 trial, veliparib added to carboplatin-paclitaxel and continued as maintenance improved progression-free survival (PFS) compared to carboplatin-paclitaxel alone in patients with newly diagnosed ovarian carcinoma. Primary analysis of PFS was by investigator (INV) assessment, with a supplemental analysis of PFS by blinded independent central review (BICR). METHODS: Patients received veliparib or placebo with carboplatin-paclitaxel (6 cycles) and as maintenance (30 additional cycles). The primary analysis compared PFS in the veliparib-throughout arm to the carboplatin-paclitaxel only arm in the BRCA mutation (BRCAm), homologous recombination deficiency (HRD), and intention-to-treat (ITT) populations. Exploratory analyses of PFS in BRCA wildtype (BRCAwt), homologous recombination proficient (HRP), and HRD + BRCAwt populations were also performed. PFS per BICR and overall concordance rates between INV and BICR assessments were analyzed. RESULTS: Hazard ratios for PFS by INV and BICR were consistent in each of the primary analysis and exploratory populations. In the ITT population, median PFS per INV was 23.5 months in the veliparib-throughout arm versus 17.3 months in the control arm (hazard ratio [HR] 0.683, 95% confidence interval [CI] 0.562-0.831; P < 0.001). Median PFS by BICR was 29.3 months versus 19.2 months (HR 0.687, 95% CI 0.504-0.806). In the ITT population, the overall concordance rates between INV and BICR were 78% and 75% for the veliparib-throughout and control arms, respectively. CONCLUSIONS: Hazard ratios for PFS per BICR and per INV were consistent, with no suggestion of investigator bias. These findings support the reliability of PFS by INV in ovarian cancer trials.

Veliparib with carboplatin and paclitaxel in BRCA-mutated advanced breast cancer (BROCADE3): a randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: BRCA1 or BRCA2-mutated breast cancers are sensitive to poly(ADP-ribose) polymerase (PARP) inhibitors and platinum agents owing to deficiency in homologous recombination repair of DNA damage. In this trial, we compared veliparib versus placebo in combination with carboplatin and paclitaxel, and continued as monotherapy if carboplatin and paclitaxel were discontinued before progression, in patients with HER2-negative advanced breast cancer and a germline BRCA1 or BRCA2 mutation. METHODS: BROCADE3 was a randomised, double-blind, placebo-controlled, phase 3 trial done at 147 hospitals in 36 countries. Eligible patients (aged ≥18 years) had deleterious germline BRCA1 or BRCA2 mutation-associated, histologically or cytologically confirmed advanced HER2-negative breast cancer, an Eastern Cooperative Oncology Group performance status of 0-2, and had received up to two previous lines of chemotherapy for metastatic disease. Patients were randomly assigned (2:1) by interactive response technology by means of permuted blocks within strata (block size of 3 or 6) to carboplatin (area under the concentration curve 6 mg/mL per min intravenously) on day 1 and paclitaxel (80 mg/m2 intravenously) on days 1, 8, and 15 of 21-day cycles combined with either veliparib (120 mg orally twice daily, on days -2 to 5) or matching placebo. If patients discontinued carboplatin and paclitaxel before progression, they could continue veliparib or placebo at an intensified dose (300 mg twice daily continuously, escalating to 400 mg twice daily if tolerated) until disease progression. Patients in the control group could receive open-label veliparib monotherapy after disease progression. Randomisation was stratified by previous platinum use, history of CNS metastases, and oestrogen and progesterone receptor status. The primary endpoint was investigator-assessed progression-free survival per Response Evaluation Criteria in Solid Tumors version 1.1. Efficacy analyses were done by intention to treat, which included all randomly assigned patients with a centrally confirmed BRCA mutation, and safety analyses included all patients who received at least one dose of velilparib or placebo. This study is ongoing and is registered with ClinicalTrials.gov, NCT02163694. FINDINGS: Between July 30, 2014, and Jan 17, 2018, 2202 patients were screened, of whom 513 eligible patients were enrolled and randomly assigned. In the intention-to-treat population (n=509), 337 patients were assigned to receive veliparib plus carboplatin-paclitaxel (veliparib group) and 172 were assigned to receive placebo plus carboplatin-paclitaxel (control group). Median follow-up at data cutoff (April 5, 2019) was 35·7 months (IQR 24·9-43·6) in the veliparib group and 35·5 months (23·1-45·9) in the control group. Median progression-free survival was 14·5 months (95% CI 12·5-17·7) in the veliparib group versus 12·6 months (10·6-14·4) in the control group (hazard ratio 0·71 [95% CI 0·57-0·88], p=0·0016). The most common grade 3 or worse adverse events were neutropenia (272 [81%] of 336 patients in the veliparib group vs 143 [84%] of 171 patients in the control group), anaemia (142 [42%] vs 68 [40%]), and thrombocytopenia (134 [40%] vs 48 [28%]). Serious adverse events occurred in 115 (34%) patients in the veliparib group versus 49 (29%) patients in the control group. There were no study drug-related deaths. INTERPRETATION: The addition of veliparib to a highly active platinum doublet, with continuation as monotherapy if the doublet were discontinued, resulted in significant and durable improvement in progression-free survival in patients with germline BRCA mutation-associated advanced breast cancer. These data indicate the utility of combining platinum and PARP inhibitors in this patient population. FUNDING: AbbVie.

A first-in-human, phase 1, dose-escalation study of ABBV-176, an antibody-drug conjugate targeting the prolactin receptor, in patients with advanced solid tumors.

ABBV-176 is an antibody-drug conjugate composed of the humanized antibody h16f (PR-1594804) conjugated to a highly potent, cytotoxic cross-linking pyrrolobenzodiazepine dimer (PBD; SGD-1882) targeting the prolactin receptor (PRLR), which is overexpressed in several solid tumor types. This phase 1, dose-escalation study (NCT03145909) evaluated the safety, pharmacokinetics, and preliminary activity of ABBV-176 in patients with advanced solid tumors likely to exhibit elevated levels of PRLR. Patients received ABBV-176 once every 3 weeks. Dose escalation was by an exposure-adjusted, continual reassessment method. Dose-limiting toxicities (DLTs) were assessed from the first day of dosing until the next dose of ABBV-176 to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D). Nineteen patients received ABBV-176 at doses from 2.7-109.35 µg/kg. Patients enrolled had colorectal cancer (n = 11), breast cancer (n = 6), or adrenocortical carcinoma (n = 2). DLTs occurred in 4 patients and included thrombocytopenia (n = 2; both at 99.9-µg/kg dose level), neutropenia (n = 2; 78.3-µg/kg and 99.9-µg/kg dose levels), and pancytopenia (n = 1; 109.35-µg/kg dose level). The most common treatment-emergent adverse events related to ABBV-176 were thrombocytopenia, neutropenia, increased aspartate aminotransferase, nausea, fatigue, and pleural effusions. Effusions and edema were common, and timing of onset suggested possible cumulative ABBV-176 toxicity. Tumor expression of PRLR varied among patients enrolled and analyzed. No patient had an objective response. MTD was not formally determined, as identification of a tolerable dose was confounded by late-onset toxicities. ABBV-176 was associated with significant toxicity in this phase 1, dose-escalation study. Although cytopenias were often dose limiting, effusions and edema were also common and had late onset that suggested cumulative toxicity. No responses were observed, although data were available from a small number of patients with variable tumor PRLR expression. This study was terminated after the dosing of 19 patients.

A phase 1 study of PARP-inhibitor ABT-767 in advanced solid tumors with BRCA1/2 mutations and high-grade serous ovarian, fallopian tube, or primary peritoneal cancer.

Purpose This phase 1 study examined safety, pharmacokinetics (PK), and efficacy of the poly(ADP-ribose) polymerase (PARP) inhibitor ABT-767 in patients with advanced solid tumors and BRCA1/2 mutations or with high-grade serous ovarian, fallopian tube, or primary peritoneal cancer. Methods Patients received ABT-767 monotherapy orally until disease progression or unacceptable toxicity. Dose was escalated from 20 mg once daily to 500 mg twice daily (BID). Dose-limiting toxicities, recommended phase 2 dose (RP2D), food effect, objective response rate, and biomarkers predicting response were determined. Results Ninety-three patients were treated with ABT-767; 80 had a primary diagnosis of ovarian cancer. ABT-767 demonstrated dose-proportional PK up to 500 mg BID and half-life of ~2 h. Food had no effect on ABT-767 bioavailability. Most common grade 3/4 treatment-related adverse events were nausea, fatigue, decreased appetite, and anemia. Anemia showed dose-dependent increase. RP2D was 400 mg BID. Objective response rate by RECIST 1.1 was 21% (17/80) in all evaluable patients and 20% (14/71) in evaluable patients with ovarian cancer. Response rate by RECIST 1.1 and/or CA-125 was 30% (24/80) in patients with ovarian cancer. Mutations in BRCA1 or BRCA2, homologous recombination deficiency (HRD), and platinum sensitivity were associated with tumor response. Median progression-free survival was longer for HRD positive (6.7 months) versus HRD negative patients (1.8 months) with ovarian cancer. Conclusions ABT-767 had an acceptable safety profile up to the established RP2D of 400 mg BID and dose-proportional PK. Patients with BRCA1 or BRCA2 mutation, HRD positivity, and platinum sensitivity were more sensitive to ABT-767.

TAK1 targeting by glucocorticoids determines JNK and IkappaB regulation in Toll-like receptor-stimulated macrophages.

Glucocorticoids potently attenuate the production of inflammatory mediators by macrophages, a primary effector of innate immunity. Activation of different macrophage Toll-like receptors (TLRs) by their respective ligands presents a powerful system by which to evaluate stimulus-dependent glucocorticoid effects in the same cell type. Here, we test the hypothesis that glucocorticoids, acting through the glucocorticoid receptor, modulate macrophage activation preferentially depending upon the TLR-selective ligand and TLR adapters. We established that 2 adapters, Trif, MyD88, or both, determine the ability of glucocorticoids to suppress inhibitor of kappaB (IkappaB) degradation or Janus kinase (JNK) activation. Moreover, the sensitivity of transforming growth factor beta-activated kinase 1 (TAK1) activation to glucocorticoids determines these effects. These findings identify TAK1 as a novel target for glucocorticoids that integrates their anti-inflammatory action in innate immunity signaling pathways.

Generation of myometrium-specific Bmal1 knockout mice for parturition analysis.

Human and rodent studies indicate a role for circadian rhythmicity and associated clock gene expression in supporting normal parturition. The importance of clock gene expression in tissues besides the suprachiasmatic nucleus is emerging. Here, a Bmal1 conditional knockout mouse line and a novel Cre transgenic mouse line were used to examine the role of myometrial Bmal1 in parturition. Ninety-two percent (22/24) of control females but only 64% (14/22) of females with disrupted myometrial Bmal1 completed parturition during the expected time window of 5p.m. on Day 19 through to 9a.m. on Day 19.5 of gestation. However, neither serum progesterone levels nor uterine transcript expression of the contractile-associated proteins Connexin43 and Oxytocin receptor differed between females with disrupted myometrial Bmal1 and controls during late gestation. The data indicate a role for myometrial Bmal1 in maintaining normal time of day of parturition.

Exposure-Response Model With Time-Varying Predictors to Estimate the Effects of Veliparib in Combination With Carboplatin/Paclitaxel and as Monotherapy: Veliparib Phase 3 Study in BRCA-Mutated Advanced Breast Cancer (BROCADE3) Trial.

BRCA-Mutated Advanced Breast Cancer (BROCADE3) is a phase 3 study, evaluating veliparib in combination with carboplatin/paclitaxel with continuation as monotherapy if carboplatin/paclitaxel is discontinued in patients with germline BRCA1/2 mutation-associated, advanced human epidermal growth factor receptor 2-negative breast cancer. The objective of the current analysis was to characterize the veliparib exposure-response relationships for efficacy (progression-free survival [PFS]) and safety in this study. Exposure-efficacy analyses of PFS were conducted using Kaplan-Meier plots and cox proportional hazards (CPH) models using treatment alone or both treatment and exposure as time-dependent predictors to estimate the effect of veliparib in combination with carboplatin/paclitaxel and as monotherapy. The cox proportional hazards model with only treatment as the time-varying predictor estimated a statistically significant benefit of veliparib monotherapy compared to placebo monotherapy (hazard ratio, 0.49; 95%CI, 0.33-0.73) and a modest, non-statistically significant benefit (hazard ratio, 0.81; 95%CI, 0.62-1.05) of adding veliparib to carboplatin/paclitaxel. Inclusion of exposure as an additional time-varying predictor in the cox proportional hazards model indicated a flat exposure-response relationship between the veliparib exposure and PFS when veliparib was administered in combination with carboplatin/paclitaxel or as monotherapy. The exposure-safety analysis did not reveal any meaningful exposure-dependent trend in the incidence of adverse events of interest. These analyses support the dose regimen of veliparib (120 mg twice daily) in combination with carboplatin/paclitaxel and continuation of veliparib (300-400 mg twice daily) as monotherapy if carboplatin/paclitaxel were discontinued before disease progression in this patient population. This study is registered with ClinicalTrials.gov with a registration ID: NCT02163694.

Safety and efficacy of veliparib plus carboplatin/paclitaxel in patients with HER2-negative metastatic or locally advanced breast cancer: subgroup analyses by germline BRCA1/2 mutations and hormone receptor status from the phase-3 BROCADE3 trial.

PURPOSE: To evaluate efficacy and safety of veliparib combined with carboplatin/paclitaxel in patients with advanced human epidermal growth factor receptor 2 (HER2)-negative, germline BRCA (gBRCA)-associated breast cancer defined by hormone receptor (HR) and gBRCA1/2 mutation status. PATIENTS AND METHODS: In this phase-3, double-blind, placebo-controlled trial, patients (N = 509) with advanced HER2-negative breast cancer and gBRCA1/2 mutations were randomized 2:1 to receive veliparib plus carboplatin/paclitaxel or placebo plus carboplatin/paclitaxel. Patients who discontinued chemotherapy prior to disease progression continued receiving blinded veliparib/placebo monotherapy. The primary endpoint was investigator-assessed progression-free survival (PFS). Subgroup analyses of PFS stratified by HR and gBRCA1/2 mutation status were prespecified. RESULTS: In the intention-to-treat population, there were similar proportions of patients with gBRCA1 versus gBRCA2 mutations (51% vs 49%) and HR+ disease versus triple-negative breast cancer (TNBC) (52% vs 48%). Median PFS was longer in the veliparib arm compared with the placebo arm for all subgroups (HR+: 13.0 vs 12.5 months, hazard ratio (95% confidence interval (CI)): 0.69 (0.52, 0.93), p = 0.013; TNBC: 16.6 vs 14.1 months, hazard ratio (95% CI): 0.72 (0.52, 1.00), p = 0.052; gBRCA1: 14.2 vs 12.6 months, hazard ratio (95% CI): 0.75 (0.55, 1.03), p = 0.073; gBRCA2: 14.6 vs 12.6 months, hazard ratio (95% CI): 0.69 (0.50, 0.95); p = 0.021). Benefit was durable, with improved PFS rates at 2 years (HR+, 27.5% vs 15.3%; TNBC, 40.4% vs 25.0%) and 3 years (HR+, 17.5% vs 8.6%; TNBC, 35.3% vs 13.0%) in all subgroups. gBRCA status (BRCA1 vs BRCA2) did not substantially affect the carboplatin/paclitaxel ± veliparib toxicity profile. CONCLUSION: Veliparib plus carboplatin/paclitaxel resulted in durable benefit in subgroups defined by HR status or by gBRCA1 versus gBRCA2 mutation. Overall, addition of veliparib to carboplatin/paclitaxel was tolerable, and there were no clinically meaningful differences in adverse events between the gBRCA1 versus gBRCA2 and HR+ versus TNBC subgroups. TRIAL REGISTRATION: NCT02163694, https://clinicaltrials.gov/ct2/show/NCT02163694.

Efficacy and safety of first-line veliparib and carboplatin-paclitaxel in patients with HER2- advanced germline BRCA+ breast cancer: Subgroup analysis of a randomised clinical trial.

BACKGROUND: Addition of veliparib to carboplatin-paclitaxel, with continuation of veliparib monotherapy if carboplatin-paclitaxel was discontinued, improved progression-free survival (PFS) in patients with germline BRCA-associated locally advanced/metastatic HER2- breast cancer and ≤2 lines of previous cytotoxic therapy for metastatic disease in BROCADE3. A pre-planned subgroup analysis evaluated efficacy and safety in patients without previous cytotoxic therapy for metastatic disease. METHODS: Patients were randomised 2:1 to receive veliparib (120 mg orally BID) or placebo on days -2 to 5. Carboplatin (AUC 6) was administered on day 1, and paclitaxel (80 mg/m2) on days 1, 8 and 15 (21-day cycles). Patients discontinuing carboplatin-paclitaxel for reasons besides progression could continue veliparib/placebo monotherapy (300 mg BID, increasing to 400 mg BID if tolerated) until progression. The primary end-point was PFS assessed by investigator. RESULTS: Of 509 patients in the intention-to-treat population (98.6% female; mean age 47, standard deviation 11), 413 (81%) had no previous cytotoxic therapy for metastatic disease (274, veliparib; 139, placebo). In the first-line subgroup, median PFS was 16.6 months (95% confidence interval [CI] 13.4-18.7) versus 13.1 months (95% CI 11.4-14.5) for the veliparib versus control groups (hazard ratio 0.70, 95% CI 0.54-0.89, P = .004). More patients were alive and progression-free at 2 years (36% versus 23.2%) and 3 years (27.9% versus 13.3%) in the veliparib versus control group. Adverse events unrelated to progression leading to study drug discontinuation occurred in 25 (9.1%) and 8 (5.8%) patients. CONCLUSIONS: Veliparib with carboplatin-paclitaxel led to durable disease control among first-line patients, suggesting a benefit of this treatment approach in early lines. CLINICAL TRIAL REGISTRATION: NCT02163694.

Relevance of Platinum-free Interval and BRCA Reversion Mutations for Veliparib Monotherapy after Progression on Carboplatin/Paclitaxel for gBRCA Advanced Breast Cancer (BROCADE3 Crossover).

PURPOSE: Safety, efficacy, and exploratory biomarker analyses were evaluated in patients with advanced HER2-negative germline breast cancer susceptibility gene (gBRCA)-associated breast cancer enrolled in the BROCADE3 trial who received crossover veliparib monotherapy after disease progression on placebo plus carboplatin/paclitaxel. PATIENTS AND METHODS: Eligible patients (N = 513) were randomized 2:1 to veliparib plus carboplatin/paclitaxel or placebo plus carboplatin/paclitaxel; patients had variable platinum-free intervals (PFI) at progression. In the placebo arm, patients were eligible to receive crossover veliparib monotherapy (300-400 mg twice daily continuous). Antitumor activity and adverse events were assessed during crossover veliparib treatment. BRCA reversion mutations at crossover were analyzed retrospectively using next-generation sequencing on plasma circulating tumor DNA (ctDNA). RESULTS: Seventy-five patients in the placebo plus carboplatin/paclitaxel arm received ≥1 dose of crossover veliparib postprogression (mean treatment duration: 154 days). Eight of 50 (16%) patients with measurable disease had a RECIST v1.1 response. Activity was greater in patients with PFI ≥180 days compared with <180 days [responses in 23.1% (3/13) vs. 13.5% (5/37) of patients]. BRCA reversion mutations that restored protein function were detected in ctDNA from 4 of 28 patients tested, and the mean duration of crossover veliparib monotherapy was <1 month in these 4 patients versus 7.49 months in patients lacking reversion mutations. The most frequent adverse events were nausea (61%), vomiting (29%), and fatigue (24%). CONCLUSIONS: Crossover veliparib monotherapy demonstrated limited antitumor activity in patients who experienced disease progression on placebo plus carboplatin/paclitaxel. PFI appeared to affect veliparib activity. BRCA reversion mutations may promote cross-resistance and limit veliparib activity following progression on platinum.

Clock gene expression in gravid uterus and extra-embryonic tissues during late gestation in the mouse.

Evidence in humans and rodents suggests the importance of circadian rhythmicity in parturition. A molecular clock underlies the generation of circadian rhythmicity. While this molecular clock has been identified in numerous tissues, the expression and regulation of clock genes in tissues relevant to parturition is largely undefined. Here, the expression and regulation of the clock genes Bmal1, Clock, cryptochrome (Cry1/2) and period (Per1/2) was examined in the murine gravid uterus, placenta and fetal membranes during late gestation. All clock genes examined were expressed in the tissues of interest throughout the last third of gestation. Upregulation of a subset of these clock genes was observed in each of these tissues in the final two days of gestation. Oscillating expression of mRNA for a subset of the examined clock genes was detected in the gravid uterus, placenta and fetal membranes. Furthermore, bioluminescence recording on explants from gravid Per2::luciferase mice indicated rhythmic expression of PER2 protein in these tissues. These data demonstrate expression and rhythmicity of clock genes in tissues relevant to parturition indicating a potential contribution of peripheral molecular clocks to this process.

Exposure-response analysis to inform the optimal dose of veliparib in combination with carboplatin and paclitaxel in BRCA-mutated advanced breast cancer patients.

PURPOSE: Veliparib, a poly(ADP-ribose)-polymerase (PARP) 1 and 2 enzyme inhibitor, was administered at 120 mg twice daily (BID) for 7 days in a 21-day cycle with carboplatin/paclitaxel in the Phase 2 BROCADE study in patients with BRCA-deficient recurrent or metastatic breast cancer, a dose based on Phase 1 results. Population pharmacokinetic (PK) and exposure-response analyses were undertaken to retrospectively evaluate whether an optimal dose was used in BROCADE. METHODS: A population PK analysis was performed using data from 168 patients in BROCADE along with data from 288 subjects in another 5 studies. The relationship between veliparib exposure and efficacy variables (including progression-free survival [PFS] and objective response rate [ORR]) and safety variables (selected grade 3 or greater hematological adverse events) were analyzed. RESULTS: Veliparib PK parameters in BROCADE were comparable to the previous studies. Creatinine clearance on veliparib apparent clearance and lean body weight on veliparib apparent volume of distribution were identified as covariates. A trend of better efficacy (PFS and ORR) in the veliparib arm compared to placebo was observed. However, veliparib exposure-efficacy response was relatively flat with higher veliparib exposures not showing better efficacy. No exposure-response relationship was observed in grade 3 or greater hematological toxicities (anemia, neutropenia, leukopenia, and thrombocytopenia). CONCLUSIONS: The exposure-response analysis suggested that intermittent 7-day veliparib 120 mg BID dosing in a 21-day cycle provided additional efficacy without meaningfully impacting the safety and tolerability when co-administered with carboplatin and paclitaxel in patients with BRCA-deficient breast cancer. A higher dose of veliparib is unlikely to provide greater benefit in this combination in patients with BRCA-deficient recurrent or metastatic breast cancer.

Insights into parturition biology from genetically altered mice.

With the growing frequency of preterm birth, increased effort has been made to elucidate the physiology of normal and aberrant parturition. As with many developmental processes, the study of genetically altered mice has led to an increased understanding of mechanisms controlling the maintenance and resolution of pregnancy. Studies in genetically altered mice have implicated critical roles for both prostaglandin synthesis and degradation in luteolysis and the progression of labor. The importance of local modulation of progesterone activity to cervical ripening has also been demonstrated. Although a decline in levels of serum progesterone is a part of normal labor initiation in mice but not humans, murine labor without progesterone withdrawal has been reported in some cases. These findings emphasize the importance of other components of the parturition cascade that are shared in mice and humans and highlights the importance of an increased understanding of the physiology of mouse parturition.

Hypoxia regulates the expression of fatty acid-binding proteins in primary term human trophoblasts.

OBJECTIVE: Fatty acids (FAs) are essential for fetal development. Cellular FA uptake is modulated by fatty acid-binding proteins (FABPs). We hypothesized that hypoxia regulates the expression of FABPs in human trophoblasts. STUDY DESIGN: Primary term human trophoblasts were cultured for 72 hours in either standard (O2 = 20%) or hypoxic (O2 < 1%) conditions. FABP expression was interrogated using polymerase chain reaction and Western immunoblotting. Trophoblast lipid droplets were examined using dipyrromethene boron difluoride 493/503 staining. RESULTS: We detected the expression of FABP1, -3, -4, -5, and pm but not FABP2 or FABP6-9 subtypes in trophoblasts. Exposure to hypoxia markedly increased lipid droplet accumulation in trophoblasts. Consistent with this observation, hypoxia enhanced the expression of FABP1, -3, and -4. Lastly, agonists of peroxisome proliferator-activated receptor-gamma enhanced the expression of FABP1 and -4 in trophoblasts. CONCLUSION: Hypoxia enhances the expression of FABP1, -3, and -4 in term human trophoblasts, suggesting that FABPs support fat accumulation in the hypoxic placenta.

Preventing preterm birth: the past limitations and new potential of animal models.

The high rate of preterm birth in the USA and many other countries is a potential target for improving children's immediate health and reducing the medical problems they face as adults. The acute complications for infants born prematurely often require intensive care management and are followed by long-lasting cognitive, sensory, motor, and cardiovascular deficits that substantially limit adult capabilities and survival. The inability to effectively reduce preterm birth stems from the failure to understand normal mechanisms of parturition in humans. Although studies from several model organisms help define the physiology of maintenance and termination of pregnancy, there are fundamental differences between species. For example, species regulate their production of progesterone, the crucial hormone in sustaining pregnancy, differently. This limits the extent to which models can provide meaningful information about the physiological mechanisms of human gestation. The growing wealth of sequenced mammalian genomes, computational comparative genomic tools and systems biology approaches provides new potential to utilize the divergence of DNA sequences and physiology between species to understand the genetic underpinnings of preterm birth.

Impaired steroidogenesis and implantation failure in Bmal1-/- mice.

Evidence in humans and rodents suggests that normal circadian rhythmicity is important for supporting reproductive function. A molecular clock underlies circadian rhythmicity. Impaired fertility is observed in some genetically altered mice with deficiencies in genes of the molecular clock, suggesting a critical role for these genes in reproduction. Here we systematically characterize the reproductive phenotype of females deficient in the clock gene Bmal1. Bmal1(-/-) females are infertile. They exhibit progression through the estrous cycle, although these cycles are prolonged. Normal follicular development occurs in Bmal1(-/-) females, and healthy embryos of the expected developmental stage are found in the reproductive tract of Bmal1(-/-) females 3.5 d after mating to wild-type males. However, serum progesterone levels are significantly lower in Bmal1(-/-) vs. Bmal1(+/+/-) females on d 3.5 of gestation. Low progesterone levels in Bmal1(-/-) females are accompanied by decreased expression of steroidogenic acute regulatory protein in corpora lutea of Bmal1(-/-) vs. Bmal1(+/+/-) females. Whereas implantation of embryos is not observed in untreated or vehicle-treated Bmal1(-/-) females, exogenous administration of progesterone to Bmal1(-/-) females is able to reinstitute implantation. These data suggest that implantation failure due to impaired steroidogenesis causes infertility of Bmal1(-/-) females.

The PI3K/Akt pathway is present and functional in the preimplantation mouse embryo.

The PI3K/Akt signal transduction pathway is a well-known mediator of growth promoting and cell survival signals. While the expression and function of this pathway have been documented during early and late stages of the reproductive process, currently, there is no evidence demonstrating either the presence or function of the PI3K/Akt pathway in murine preimplantation embryos. We found, using confocal immunofluorescent microscopy and Western blot analysis, that the p 85 and p110 subunits of PI3K and Akt are expressed from the 1-cell through the blastocyst stage of murine preimplantation embryo development. These proteins were localized predominantly at the cell surface from the 1-cell through the morula stage. At a blastocyst stage, both PI3K and Akt exhibited an apical staining pattern in the trophectoderm cells. Interestingly, phosphorylated Akt was detected throughout murine preimplantation development, and its presence at the plasma membrane is a reflection of its activation status. Inhibition of Akt activity had significant effects on the normal physiology of the blastocyst. Specifically, inhibition of this pathway resulted in a reduction in insulin-stimulated glucose uptake. In addition, inhibiting Akt activity resulted in a significant delay in blastocyst hatching, a developmental step facilitating implantation. Finally, we established the presence of this pathway in trophoblast stem (TS) cells, a potentially useful in vitro model to study this signaling cascade. Taken together, these data are the first to demonstrate the presence and function of the PI3K/Akt pathway in mammalian preimplantation embryos.