Safety and Efficacy of Vicriviroc (MK-7690) in Combination With Pembrolizumab in Patients With Advanced or Metastatic Microsatellite Stable Colorectal Cancer.

Background: Pembrolizumab, a monoclonal antibody against PD-1, has shown limited efficacy in patients with microsatellite stable or mismatch repair proficient (MSS/pMMR) metastatic colorectal cancer (CRC). We evaluated vicriviroc (small-molecule C-C motif chemokine ligand 5 antagonist) plus pembrolizumab in patients with advanced or metastatic MSS/pMMR CRC.

Patients And Methods: This open-label, phase 2 trial (NCT03631407) enrolled adults with histologically confirmed, locally advanced, unresectable or metastatic CRC that was MSS per local assessment.

CXCR2 antagonist navarixin in combination with pembrolizumab in select advanced solid tumors: a phase 2 randomized trial.

C-X-C motif chemokine receptor 2 (CXCR2) has a role in tumor progression, lineage plasticity, and reduction of immune checkpoint inhibitor efficacy. Preclinical evidence suggests potential benefit of CXCR2 inhibition in multiple solid tumors. In this phase 2 study (NCT03473925), adults with previously treated advanced or metastatic castration-resistant prostate cancer (CRPC), microsatellite-stable colorectal cancer (MSS CRC), or non-small-cell lung cancer (NSCLC) were randomized 1:1 to the CXCR2 antagonist navarixin 30 or 100 mg orally once daily plus pembrolizumab 200 mg intravenously every 3 weeks up to 35 cycles.

A phase 1 study of veliparib (ABT-888) plus weekly carboplatin and paclitaxel in advanced solid malignancies, with an expansion cohort in triple negative breast cancer (TNBC) (ETCTN 8620).

Background: Veliparib is a poly-ADP-ribose polymerase (PARP) inhibitor, and it has clinical activity with every 3 weeks carboplatin and paclitaxel. In breast cancer, weekly paclitaxel is associated with improved overall survival. We aimed to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) of veliparib with weekly carboplatin and paclitaxel as well as safety, pharmacokinetics, and preliminary clinical activity in triple negative breast cancer (TNBC).

A phase 1 and pharmacodynamic study of chronically-dosed, single-agent veliparib (ABT-888) in patients with BRCA1- or BRCA2-mutated cancer or platinum-refractory ovarian or triple-negative breast cancer.

Purpose: BRCA1 or BRCA2 mutated cancers (BRCAmut) have intrinsic sensitivity to PARP inhibitors due to deficiency in homologous recombination-mediated DNA repair. There are similarities between BRCAmut and BRCAwt ovarian and basal-like breast cancers. This phase I study determined the recommended phase II dose (RP2D) and preliminary efficacy of the PARP inhibitor, veliparib (ABT-888), in these patients.

A phase I/II study of veliparib (ABT-888) with radiation and temozolomide in newly diagnosed diffuse pontine glioma: a Pediatric Brain Tumor Consortium study.

Background: A Pediatric Brain Tumor Consortium (PBTC) phase I/II trial of veliparib and radiation followed by veliparib and temozolomide (TMZ) was conducted in children with newly diagnosed diffuse intrinsic pontine glioma (DIPG). The objectives were to: (i) estimate the recommended phase II dose (RP2D) of veliparib with concurrent radiation; (ii) evaluate the pharmacokinetic parameters of veliparib during radiation; (iii) evaluate feasibility of intrapatient TMZ dose escalation; (iv) describe toxicities of protocol therapy; and (v) estimate the overall survival distribution compared with historical series.

Methods: Veliparib was given Monday through Friday b.

Optimal two-stage designs for exploratory basket trials.

The primary goal of an exploratory oncology clinical trial is to identify an effective drug for further development. To account for tumor indication selection error, multiple tumor indications are often selected for simultaneous testing in a basket trial. In this article, we propose optimal and minimax two-stage basket trial designs for exploratory clinical trials.

Clinical Pharmacokinetics and Mass Balance of Veliparib in Combination with Temozolomide in Subjects with Nonhematologic Malignancies.

Background And Objectives: Veliparib is an orally active potent poly(ADP-ribose) polymerase (PARP) inhibitor currently in phase III clinical trials in solid tumors. This phase I study evaluated the pharmacokinetics and mass balance of veliparib administered alone and in combination with temozolomide, and assessed any potential pharmacokinetic drug-drug interaction between veliparib and temozolomide.

Methods: This was an open-label, dose-escalation study of veliparib in combination with temozolomide in 42 subjects with nonhematologic malignancies.

Smoking History Predicts Sensitivity to PARP Inhibitor Veliparib in Patients with Advanced Non-Small Cell Lung Cancer.

Introduction: Tobacco-related NSCLC is associated with reduced survival and greater genomic instability. Veliparib, a potent poly(adenosine diphosphate-ribose) polymerase inhibitor, augments platinum-induced DNA damage. A phase 2 trial of untreated advanced NSCLC showed a trend for improved outcomes (hazard ratio [HR] = 0.

Randomized, Placebo-Controlled, Phase II Study of Veliparib in Combination with Carboplatin and Paclitaxel for Advanced/Metastatic Non-Small Cell Lung Cancer.

PARP plays an important role in DNA repair. Veliparib, a PARP inhibitor, enhances the efficacy of platinum compounds and has been safely combined with carboplatin and paclitaxel. The primary endpoint of this phase II trial determined whether addition of veliparib to carboplatin and paclitaxel improved progression-free survival (PFS) in previously untreated patients with advanced/metastatic non-small cell lung cancer.

A randomized Phase II study of veliparib with temozolomide or carboplatin/paclitaxel versus placebo with carboplatin/paclitaxel in BRCA1/2 metastatic breast cancer: design and rationale.

Veliparib is an orally administered poly(ADP-ribose) polymerase inhibitor that is being studied in Phase I-III clinical trials, including Phase III studies in non-small-cell lung cancer, ovarian cancer and breast cancer. Tumor cells with deleterious BRCA1 or BRCA2 mutations are deficient in homologous recombination DNA repair and are intrinsically sensitive to platinum therapy and poly(ADP-ribose) polymerase inhibitors. We describe herein the design and rationale of a Phase II trial investigating whether the addition of veliparib to temozolomide or carboplatin/paclitaxel provides clinical benefit over carboplatin/paclitaxel with placebo in patients with locally recurrent or metastatic breast cancer harboring a deleterious BRCA1 or BRCA2 germline mutation (Trial registration: EudraCT 2011-002913-12, NCT01506609).

Phase I Study of Veliparib (ABT-888) Combined with Cisplatin and Vinorelbine in Advanced Triple-Negative Breast Cancer and/or BRCA Mutation-Associated Breast Cancer.

Purpose: Cisplatin is synergistic with vinorelbine and the PARP inhibitor veliparib, and has antineoplastic activity in triple-negative breast cancer (TNBC) and BRCA mutation-associated breast cancer. This phase I study assessed veliparib with cisplatin and vinorelbine.

Experimental Design: A 3+3 dose-escalation design evaluated veliparib administered twice daily for 14 days with cisplatin (75 mg/m(2) day 1) and vinorelbine (25 mg/m(2) days 1, 8) every 21 days, for 6 to 10 cycles, followed by veliparib monotherapy.

A phase 1 study evaluating the pharmacokinetics and preliminary efficacy of veliparib (ABT-888) in combination with carboplatin/paclitaxel in Japanese subjects with non-small cell lung cancer (NSCLC).

Introduction: Veliparib is a potent, orally bioavailable PARP inhibitor that enhances efficacy of DNA-damaging chemotherapeutic agents. The study objectives were to determine the recommended phase 2 dose (RPTD) of veliparib plus carboplatin and paclitaxel, and assess pharmacokinetics (PK), tolerability, and preliminary efficacy in Japanese patients with solid tumors.

Methods: Carboplatin (AUC 6 mg/mL min) and paclitaxel (200 mg/m(2)) were administered on day 3 of a 21-day cycle.

Veliparib in combination with whole brain radiation therapy in patients with brain metastases: results of a phase 1 study.

Veliparib, a potent, oral PARP inhibitor, potentiates the antitumor activity of radiation therapy and crosses the blood-brain barrier. This was a phase 1 dose-escalation study evaluating the safety, and secondarily the antitumor activity of veliparib in combination with whole brain radiation therapy (WBRT) in patients with brain metastases, in order to power future trials. Patients with brain metastases from primary solid tumors were treated with WBRT (30.

A phase 1 study to evaluate effect of food on veliparib pharmacokinetics and relative bioavailability in subjects with solid tumors.

Purpose: A phase 1 study was conducted to evaluate the bioavailability and food effect of a new veliparib formulation in subjects with solid tumors.

Methods: Subjects (planned: Stage I, N = 20; Stage II, N = 16) received four regimens of a single oral dose of veliparib utilizing a group-sequential design. Subjects were administered single doses of 40 mg veliparib supplied as four 10 mg current formulation, four 10 mg new formulation and one 40 mg new formulation under fasting conditions and under non-fasting conditions.

A phase I trial of veliparib (ABT-888) and temozolomide in children with recurrent CNS tumors: a pediatric brain tumor consortium report.

Background: A phase I trial of veliparib (ABT-888), an oral poly(ADP-ribose) polymerase (PARP) inhibitor, and temozolomide (TMZ) was conducted in children with recurrent brain tumors to (i) estimate the maximum tolerated doses (MTDs) or recommended phase II doses (RP2Ds) of veliparib and TMZ; (ii) describe the toxicities of this regimen; and (iii) evaluate the plasma pharmacokinetic parameters and extent of PARP inhibition in peripheral blood mononuclear cells (PBMCs) following veliparib.

Methods: TMZ was given once daily and veliparib twice daily for 5 days every 28 days. Veliparib concentrations and poly(ADP-ribose) (PAR) levels in PBMCs were measured on days 1 and 4.

Targeting DNA repair with combination veliparib (ABT-888) and temozolomide in patients with metastatic castration-resistant prostate cancer.

Androgen receptor-mediated transcription is directly coupled with the induction of DNA damage, and castration-resistant tumor cells exhibit increased activity of poly (ADP-ribose) polymerase (PARP)-1, a DNA repair enzyme. This study assessed the efficacy and safety of low dose oral PARP inhibitor veliparib (ABT-888) and temozolomide (TMZ) in docetaxel-pretreated patients with metastatic castration-resistant prostate cancer (mCRPC) in a single-arm, open-label, pilot study. Patients with mCRPC progressing on at least one docetaxel-based therapy and prostate specific antigen (PSA) ≥ 2 ng/mL were treated with veliparib 40 mg twice daily on days 1-7 and TMZ once daily (150 mg/m(2)/day cycle 1; if well tolerated then 200 mg/m(2)/day cycle 2 onwards) on days 1-5 q28 days.

Population pharmacokinetic modeling of veliparib (ABT-888) in patients with non-hematologic malignancies.

Background And Objective: Veliparib (ABT-888) is a potent oral inhibitor of Poly(ADP-ribose) polymerase enzyme that is currently in development for the treatment of non-hematologic and hematologic malignancies. This analysis characterizes the population pharmacokinetics of veliparib, including developing a structural pharmacokinetic model and testing patient demographics and covariates for potential influence on veliparib pharmacokinetics in patients with non-hematologic malignancies.

Methods: The analysis dataset included 3,542 veliparib concentration values from 325 patients with non-hematologic malignancies enrolled in three phase I and one phase II studies.

Hit to Lead optimization of a novel class of squarate-containing polo-like kinases inhibitors.

A high throughput screening (HTS) hit, 1 (Plk1 K(i)=2.2 μM) was optimized and evaluated for the enzymatic inhibition of Plk-1 kinase. Molecular modeling suggested the importance of adding a hydrophobic aromatic amine side chain in order to improve the potency by a classic kinase H-donor-acceptor binding mode.

PARP inhibitors attenuate chemotherapy-induced painful neuropathy.

Chemotherapy-induced peripheral neuropathy (CIPN) is a major toxicity of chemotherapy treatment for which no therapy is approved. Poly(ADP-ribose) polymerase (PARP)1/2 are nuclear enzymes activated upon DNA damage, and PARP1/2 inhibition provides resistance against DNA damage. A role for PARP inhibition in sensory neurotransmission has also been established.

Discovery and SAR of orally efficacious tetrahydropyridopyridazinone PARP inhibitors for the treatment of cancer.

PARP-1, the most abundant member of the PARP superfamily of nuclear enzymes, has emerged as a promising molecular target in the past decade particularly for the treatment of cancer. A number of PARP-1 inhibitors, including veliparab discovered at Abbott, have advanced into different stages of clinical trials. Herein we describe the development of a new tetrahydropyridopyridazinone series of PARP-1 inhibitors.

Ubiquitin-specific cysteine protease 2a (USP2a) regulates the stability of Aurora-A.

The ubiquitin/proteasome pathway plays critical roles in virtually all aspects of cell biology. Enzymes of the ubiquitin pathway add (ligases) or remove (deubiquitinases) ubiquitin tags to or from their target proteins in a selective fashion. USP2a is a member of a subfamily of deubiquitinases, called ubiquitin-specific cysteine proteases (USPs).

Optimization of phenyl-substituted benzimidazole carboxamide poly(ADP-ribose) polymerase inhibitors: identification of (S)-2-(2-fluoro-4-(pyrrolidin-2-yl)phenyl)-1H-benzimidazole-4-carboxamide (A-966492), a highly potent and efficacious inhibitor.

We have developed a series of phenylpyrrolidine- and phenylpiperidine-substituted benzimidazole carboxamide poly(ADP-ribose) polymerase (PARP) inhibitors with excellent PARP enzyme potency as well as single-digit nanomolar cellular potency. These efforts led to the identification of (S)-2-(2-fluoro-4-(pyrrolidin-2-yl)phenyl)-1H-benzimidazole-4-carboxamide (22b, A-966492). Compound 22b displayed excellent potency against the PARP-1 enzyme with a K(i) of 1 nM and an EC(50) of 1 nM in a whole cell assay.

Discovery and SAR of substituted 3-oxoisoindoline-4-carboxamides as potent inhibitors of poly(ADP-ribose) polymerase (PARP) for the treatment of cancer.

Through conformational restriction of a benzamide by formation of a seven-membered hydrogen-bond with an oxindole carbonyl group, a series of PARP inhibitors was designed for appropriate orientation for binding to the PARP surface. This series of compounds with a 3-oxoisoindoline-4-carboxamide core structure, displayed modest to good activity against PARP-1 in both intrinsic and cellular assays. SAR studies at the lactam nitrogen of the pharmacophore have suggested that a secondary or tertiary amine is important for cellular potency.

ABT-888 confers broad in vivo activity in combination with temozolomide in diverse tumors.

Purpose: ABT-888, currently in phase 2 trials, is a potent oral poly(ADP-ribose) polymerase inhibitor that enhances the activity of multiple DNA-damaging agents, including temozolomide (TMZ). We investigated ABT-888+TMZ combination therapy in multiple xenograft models representing various human tumors having different responses to TMZ.

Experimental Design: ABT-888+TMZ efficacy in xenograft tumors implanted in subcutaneous, orthotopic, and metastatic sites was assessed by tumor burden, expression of poly(ADP-ribose) polymer, and O(6)-methylguanine methyltransferase (MGMT).