ABBV-176, a PRLR antibody drug conjugate with a potent DNA-damaging PBD cytotoxin and enhanced activity with PARP inhibition.

BACKGROUND: Prolactin receptor (PRLR) is an attractive antibody therapeutic target with expression across a broad population of breast cancers. Antibody efficacy, however, may be limited to subtypes with either PRLR overexpression and/or those where estradiol no longer functions as a mitogen and are, therefore, reliant on PRLR signaling for growth. In contrast a potent PRLR antibody-drug conjugate (ADC) may provide improved therapeutic outcomes extending beyond either PRLR overexpressing or estradiol-insensitive breast cancer populations. METHODS: We derived a novel ADC targeting PRLR, ABBV-176, that delivers a pyrrolobenzodiazepine (PBD) dimer cytotoxin, an emerging class of warheads with enhanced potency and broader anticancer activity than the clinically validated auristatin or maytansine derivatives. This agent was tested in vitro and in vivo cell lines and patient derived xenograft models. RESULTS: In both in vitro and in vivo assays, ABBV-176 exhibits potent cytotoxicity against multiple cell line and patient-derived xenograft breast tumor models, including triple negative and low PRLR expressing models insensitive to monomethyl auristatin (MMAE) based PRLR ADCs. ABBV-176, which cross links DNA and causes DNA breaks by virtue of its PBD warhead, also demonstrates enhanced anti-tumor activity in several breast cancer models when combined with a poly-ADP ribose polymerase (PARP) inhibitor, a potentiator of DNA damage. CONCLUSIONS: Collectively the efficacy and safety profile of ABBV-176 suggest it may be an effective therapy across a broad range of breast cancers and other cancer types where PRLR is expressed with the potential to combine with other therapeutics including PARP inhibitors.

Late embryonic losses in supplemented grazing lactating dairy cows: Risk factors and reproductive performance.

The main objective of this study was to evaluate the risk factors for late embryonic loss (LEL) in supplemented grazing dairy cows. Additional objectives were to assess the incidence of LEL and its association with the reproductive performance of cows. A data set containing productive, reproductive, and health records of 13,551 lactations was used. A retrospective case-control study involving 631 cows with LEL (cases) and 2,524 controls (4 controls per case within each study year) was run. A case of LEL was defined when the embryo had no heartbeat or there was evidence of detached membranes or floating structures including embryo remnants by ultrasonography (US) at 28 to 42 d post-artificial insemination (AI), whereas a non-case was defined as a cow diagnosed with positive pregnancy by US 28 to 42 d post-AI and reconfirmed as pregnant 90 ± 7 d post-AI. Four controls per case were randomly selected from the non-cases with a temporal matching criterion (±3 d around the date of the fecundating AI of the case). Multivariable logistic models were offered with the following predictors: year of LEL (2011 through 2015), season of LEL (summer vs. fall vs. winter vs. spring), parity (1 vs. 2 vs. ≥3), uterine disease (UD), non-uterine disease (NUD), body condition score at parturition, body condition score at 28 to 42 d post-AI (BCS-LEL), days in milk (DIM), and daily milk yield (MY). Statistical significance was set at P < 0.05 and a tendency was set at P ≤ 0.10. We found that 4.7, 22, and 23% of cows had LEL, UD, and NUD, respectively. Cases tended to have higher daily MY than controls (32.5 vs. 31.8 kg); also, cases had much longer calving to pregnancy interval (226 vs. 118 d), lower hazard of pregnancy [hazard ratio = 0.39, 95% confidence interval (CI) = 0.35-0.43], and higher odds for non-pregnancy [odds ratio (OR) = 2.89, 95% CI = 2.37-3.54] than controls. We found that the odds for LEL increased with parity number (OR = 2.48, 95% CI = 1.99-3.08 for parity ≥3) and with BCS-LEL <2.50 (OR = 1.81, 95% CI = 1.33-2.47). Conversely, the odds for LEL decreased with BCS-LEL >3.00 (OR = 0.70, 95% CI = 0.53-0.91). The odds for LEL increased with UD (OR = 1.23, 95% CI = 1.01-1.49), NUD (OR = 1.24, 95% CI = 1.01-1.54), DIM (OR = 1.03, 95% CI = 1.00-1.05), and daily MY (OR = 1.14, 95% CI = 1.04-1.25) in univariable models only. Finally, the odds for LEL were not associated with year, season, DIM, and body condition score at parturition. In conclusion, LEL is associated with extended calving to pregnancy interval, and among its risk factors are parity number and BCS-LEL.

Potential erosive effect of mouthrinses on enamel and dentin.

This in vitro study measured the pH values, titratable acidity (TA), and erosive potential of commercially available mouthrinses. A pH analysis of 6 mouthrinses (Listerine Total Care, Listerine Ultraclean, Listerine Original, Crest Pro-Health, Scope Classic, and ACT Total Care) was performed using a calibrated pH meter, and the neutralizable acidity was measured by titrating the mouthwashes against 0.1 M of sodium hydroxide. A gravimetric analysis was performed by submerging human enamel and dentin specimens in 5 mL of each mouthrinse for a total of 2 weeks. Specimens were weighed on a calibrated analytical balance at baseline, 24 hours, 48 hours, 96 hours, 1 week, and 2 weeks, and finally the loss of mass was calculated. The differences in erosive potential among the 6 mouthrinses were verified using nonparametric tests (Kruskal-Wallis and Mann- Whitney). The level of significance was set at 0.05. The mouthrinses were found to have the following mean pH/ TA values: Crest Pro-Health, 7.05/0.00; ACT Total Care, 6.31/5.44; Scope Classic, 5.18/0.42; Listerine Original, 3.98/9.26; Listerine Total Care, 3.43/5.88; and Listerine Ultraclean, 3.87/10.36. A significant correlation between pH and TA was observed for this dataset (P > 0.0001). No statistically significant difference in enamel loss among the groups was observed (P = 0.0631). However, a significant difference in dentin loss was observed among the 6 mouthrinses (P = 0.0011). Within the limitations of this in vitro study, it can be concluded that some mouthrinses have a pH lower than the critical pH of enamel and dentin. There is a significant association between acidic pH values and higher TA. Some of the tested mouthrinses presented an erosive potential on dentin.

Bcl-XL represents a druggable molecular vulnerability during aurora B inhibitor-mediated polyploidization.

Aurora kinase B inhibitors induce apoptosis secondary to polyploidization and have entered clinical trials as an emerging class of neocytotoxic chemotherapeutics. We demonstrate here that polyploidization neutralizes Mcl-1 function, rendering cancer cells exquisitely dependent on Bcl-XL/-2. This "addiction" can be exploited therapeutically by combining aurora kinase inhibitors and the orally bioavailable BH3 mimetic, ABT-263, which inhibits Bcl-XL, Bcl-2, and Bcl-w. The combination of ABT-263 with aurora B inhibitors produces a synergistic loss of viability in a range of cell lines of divergent tumor origin and exhibits more sustained tumor growth inhibition in vivo compared with aurora B inhibitor monotherapy. These data demonstrate that Bcl-XL/-2 is necessary to support viability during polyploidization in a variety of tumor models and represents a druggable molecular vulnerability with potential therapeutic utility.

ABBV-184: A Novel Survivin-specific TCR/CD3 Bispecific T-cell Engager is Active against Both Solid Tumor and Hematologic Malignancies.

CD3 bispecific T-cell engagers (TCE), comprised of a tumor-targeting domain linked to a CD3 binding domain, function by bridging target-positive tumors and CD3-expressing effector T cells enabling redirected T cell-mediated killing of tumor cells. Although the majority of CD3 bispecific molecules in clinical development incorporate tumor-targeting antibody-based binding domains, many tumor-associated antigens derive from intracellular proteins and are not accessible to targeting via antibody. Intracellular proteins processed into short peptide fragments and presented on the cell surface by MHC proteins are recognized by T-cell receptors (TCR) on the surface of T cells. Here we describe the generation and preclinical evaluation of ABBV-184, a novel TCR/anti-CD3 bispecific composed of a highly selective soluble TCR that binds a peptide derived from the oncogene survivin (BIRC5) bound to the class I MHC allele human leukocyte antigen (HLA)-A*02:01 expressed on tumor cells, linked to a specific binder to the CD3 receptor on T cells. ABBV-184 drives an optimal distance between T cell and target cell thereby enabling sensitive recognition of low-density peptide/MHC targets. Consistent with the expression profile of survivin across a broad range of both hematologic and solid tumors, treatment of acute myeloid leukemia (AML) and non-small cell lung cancer (NSCLC) cell lines with ABBV-184 results in T-cell activation, proliferation, and potent redirected cytotoxicity of HLA-A2-positive target cell lines, both in vitro and in vivo, including patient-derived AML samples. These results indicate that ABBV-184 is an attractive clinical candidate for the treatment of patients with AML and NSCLC.

Neoadjuvant Trastuzumab and Pertuzumab in Combination with Standard Chemotherapy for HER2-Positive Early Breast Cancer: Real-World Practice in Cuba.

PURPOSE: Dual HER2 blockade chemotherapy is the standard of care for localized HER2+ breast cancer (BC). However, despite the efficacy of neoadjuvant therapy, relapses occurring in around 10% of patients highlight the need to improve its clinical approach. Therefore, this study aimed to evaluate the effectiveness/safety of neoadjuvant therapy with subcutaneous (SC) trastuzumab- pertuzumab chemotherapy (real world) to extend the evidence, which comes mainly from clinical trials (selected population; intravenous [IV] trastuzumab). MATERIALS AND METHODS: A prospective, longitudinal, observational study in a Cuban hospital. POPULATION: women aged ≥18 years with histologically confirmed HER2+ early-stage BC (2017-2021) eligible for neoadjuvant treatment (IV pertuzumab, SC trastuzumab, taxane-based chemotherapy). The aim was to determine the pathological complete response (pCR) rate to this scheme, its safety, and the impact of patient's characteristics on the outcomes. RESULTS: Eighty-seven women were included: n=29 (DPT [docetaxel-IV pertuzumab- SC trastuzumab 600 mg; 4 cycles]); n=58 (ddAC-DPT [dose-dense anthracycline-based scheme+DPT]; 8 cycles). The median age was 57 years (range 30-83), ECOG 0: 97%. Time from diagnosis to treatment (median) was 28 days. The overall pCR rate was 62.1% (55.2%, DPT; 66.5%, ddAC-DPT; p =0.351); HR+, 47.7% vs. HR-, 76.7% (p=0.006). There were no statistically significant differences based on nodal status, stage, or Ki-67 levels. Overall, 94.2% of patients experienced ≥1 adverse event related to treatment, all of them grade 1-3 and more common with ddAC-DPT. The main cause of treatment delays (n=19; ddAC-DPT, 16; DPT, 3) was treatment-related toxicities. CONCLUSION: Neoadjuvant trastuzumab (SC) and pertuzumab plus chemotherapy for HER2+ early-stage BC showed benefits in a real-life setting, with an acceptable safety profile.

Association of bovine viral diarrhea virus, bovine herpesvirus 1, and Neospora caninum with late embryonic losses in highly supplemented grazing dairy cows.

The objectives of this study were: 1- to evaluate the association of Bovine Viral Diarrhea Virus (BVDV), Bovine Herpes Virus 1 (BoHV-1), and Neospora caninum (N. caninum) with the risk for Late Embryonic Loss (LEL) in grazing dairy cows, 2- to evaluate blood progesterone concentration at the time of LEL occurrence, and 3- to describe a novel ultrasound-guided technique for conceptus sampling. We run a prospective cohort study involving 92 cows (46 LEL and 46 NLEL). An LEL cow was that having an embryo with no heartbeat, detached membranes, or floating structures, including embryo remnants detected at pregnancy check by ultrasonography (US) 28-42 days post-AI, whereas an NLEL cow was that with embryo heartbeats detectable by US at pregnancy check 28-42 d post-IA. We took two blood samples from every cow at pregnancy check by US (the day of LEL detection) and 28 d later to perform serological diagnosis of BVDV, BoHV-1, and N. caninum; and to measure blood progesterone concentration at pregnancy check (28-42 d post-AI). We also sampled the conceptus from all the LEL cows. We performed PCR to detect BVDV, BoHV-1, and N. caninum in sampled conceptuses from LEL cows. Finally, we evaluated the associations of risk factors (serological titers, seroconversion, and progesterone) with LEL odds with logistic models. The risk for LEL was associated with serological titers to BVDV (P = 0.03) and tended to be associated with seroconversion to BVDV, given that 19.6% (9/46) in LEL and 6.5% (3/46) in NLEL cows seroconverted to BVDV (P = 0.09). In addition, BVDV was detected in conceptuses from LEL cows that seroconverted to BVDV but not in LEL cows that did not seroconvert. Conversely, the risk for LEL was not associated with the titers or seroconversion to BoHV-1 and N. caninum. BoHV-1 and N. caninum were not identified in any of the conceptuses. Finally, blood progesterone concentration was similar in LEL and NLEL cows, and it was not associated with the risk for LEL (P = 0.54). In conclusion, BVDV infection is a risk factor for LEL in dairy cows.

Convolutional Neural Networks for Long Time Dissipative Quantum Dynamics.

Exact numerical simulations of dynamics of open quantum systems often require immense computational resources. We demonstrate that a deep artificial neural network composed of convolutional layers is a powerful tool for predicting long-time dynamics of open quantum systems provided the preceding short-time evolution of a system is known. The neural network model developed in this work simulates long-time dynamics efficiently and accurately across different dynamical regimes from weakly damped coherent motion to incoherent relaxation. The model was trained on a data set relevant to photosynthetic excitation energy transfer and can be deployed to study long-lasting quantum coherence phenomena observed in light-harvesting complexes. Furthermore, our model performs well for the initial conditions different than those used in the training. Our approach reduces the required computational resources for long-time simulations and holds the promise for becoming a valuable tool in the study of open quantum systems.

Use of Tyre-Derived Aggregate as Backfill Material for Wave Barriers to Mitigate Railway-Induced Ground Vibrations.

The use of piles as barriers to mitigate vibrations from rail traffic has been increasing in theoretical and practical engineering during the last years. Tyre-derived aggregate (TDA) is a recycled material with some interesting applications in civil engineering, including those related to railway engineering. As a novelty, this paper combines the concept of pile wave barriers and TDA material and investigates the mitigation effect of pile barriers made of TDA on the vibrations transmitted by rail traffic. This solution has a dual purpose: the reduction of railway vibrations and the recycling of a highly polluting material. The mitigation potential of this material when used as backfill for piles is analysed using a numerical scheme based on a 3D finite-difference numerical model formulated in the space/time domain, which is also experimentally validated in this paper in a real case without pile barriers. The numerical results show insertion loss (IL) values of up to 11 dB for a depth closed to the wavelength of Rayleigh wave. Finally, this solution is compared with more common backfills, such as concrete and steel tubular piles, showing that the TDA pile is a less effective measure although from an environmental and engineering point of view it is a very competitive solution.

Removal and Extraction of Carboxylic Acids and Non-ionic Compounds with Simple Hydroxides and Layered Double Hydroxides.

Carboxylic acids are an important natural component as a final product or intermediates for syntheses. They are produced in plants, animals and also as products from biotechnological processes. This review presents the use of single hydroxide particles and layered double hydroxides as alternative adsorbents to remove carboxylic acids from liquid media. The proposal to use hydroxide particles is based on its affinity to adsorb or intercalate carboxylic acids. Besides, the change in properties of the adsorbate-sorbate product evinces that this intermediate can be used as a vehicle to transport and release carboxylic acids. Additional examples will also be presented to prove that layered hydroxides are capable of removing non-ionic compounds from wine, milk and tomato. The use of layered compounds to remove active ingredients could reduce the number of separations steps, costs and reduce or eliminate solvents, thus encouraging the design of industrial processes of separation using hydroxides particles.

Identification and sub-cellular localization of a NAD transporter in Leishmania braziliensis (LbNDT1).

Nicotinamide adenine dinucleotide (NAD) is one of the central molecules involved in energy homeostasis, cellular signaling and antioxidative defense systems. Consequently, its biosynthetic pathways and transport systems are of vital importance. The nicotinamide/nicotinate mononucleotide adenylyltransferase (NMNAT), a key enzyme in the biosynthesis of NAD, is distributed in all domains of life and exhibits various isoforms in free-living organisms in contrast with intracellular parasites, which displays a single enzyme. In Leishmania braziliensis a unique cytosolic NMNAT has been reported to date and the mechanisms through which adequate levels of NAD are maintained among the different sub-cellular compartments of this parasite are unknown. Experimental evidences have related the transport of NAD to the Nucleotide Transporters (NTTs) family, whose members are located in the cytoplasmic membrane of parasitic life organisms. Additionally, the Mitochondrial Carrier Family (MCF), a group of proteins located in the membrane of internal organelles such as the mitochondria of free life organisms, has been implicated in NAD transport. Applying bioinformatics tools, the main characteristics of the MCF were found in a transporter candidate that we have designated as Nicotinamide Adenine Dinucleotide Transporter 1 of L. braziliensis (LbNDT1). The expression of LbNDT1 was tested both in axenic amastigotes and promastigotes of L. braziliensis, through immunodetection using polyclonal avian antibodies produced in this study. N-glycosylation of LbNDT1 was observed in both stages. Additionally, a possible partial mitochondrial distribution for LbNDT1 in amastigotes and a possible glycosomal location in promastigotes are proposed. Finally, the capability of LbNDT1 to transport NAD was confirmed by complementation assays in Saccharomyces cerevisiae. Our results demonstrate the existence of LbNDT1 in L. braziliensis becoming the first NAD transporter identified in protozoan parasites to date.

Electronic system for step width estimation using programmable system-on-chip technology and time of flight cameras.

This paper proposes a low-cost portable electronic system for estimating step width during the human gait cycle. This device, intended to support the Walking Stance item of the fall risk assessment test Performance Oriented Mobility Assessment (POMA), contains three electronic boards, comprising two sensing nodes and a concentrator. Each sensing node contains a force sensitive resistor (FSR) and time-of-flight camera (TOF). Each FSR is placed inside the subject's shoe, while each TOF camera is located at the back of their foot. The FSR detects contact between heel and ground, and the TOF measures the distance to a barrier located on the right side of the walking path. Step width is calculated as the difference between the TOF measurements. After the walk is complete, the information obtained by the FSRs and TOFs is sent via a 433 MHz wireless communication to the concentrator board, which is connected to the USB port of a personal computer (PC). The proposed step width measurement system was validated with an infrared based motion capture (Vicon Corp.), giving an error equal to 11.4%  ±  5.5%.

Dataset for gait analysis and assessment of fall risk for older adults.

This article presents a five-part dataset for human gait analysis in a healthy older adult population (37 women and seven men; age 69.98 ± 8.57 years, body mass index 27.71 ± 4.57). Part 1 compromises demographic data for the 44 participants, along with the results of the Short Physical Performance Battery (SPPB) motor function test and the Mini-Mental State Examination (MMSE). We used the MMSE to ensure the participants could understand the experimental protocol instructions. Part 2 presents the anthropometric measurements of the participants. Part 3 shows the results for each item of the Gait component of the Performance Oriented Mobility Assessment (POMA-G). Part 4 contains five files per participant, storing motion-capture data for the lower limb in the Coordinate 3D (C3D) format. These files were generated using a Vicon motion analysis system, consisting of 24 reflective markers and seven cameras (Vantage V5) sampled at 100 Hz. Part 5 contains 26 gait parameters for each C3D file obtained using Nexus 2.9.3. The dataset is available in a Mendeley repository (Reserved DOI: 10.17632/xgw6bg3g8h.1).

Potentiation of temozolomide cytotoxicity by poly(ADP)ribose polymerase inhibitor ABT-888 requires a conversion of single-stranded DNA damages to double-stranded DNA breaks.

Poly(ADP-ribose) polymerase (PARP) senses DNA breaks and facilitates DNA repair via the polyADP-ribosylation of various DNA binding and repair proteins. We explored the mechanism of potentiation of temozolomide cytotoxicity by the PARP inhibitor ABT-888. We showed that cells treated with temozolomide need to be exposed to ABT-888 for at least 17 to 24 hours to achieve maximal cytotoxicity. The extent of cytotoxicity correlates with the level of double-stranded DNA breaks as indicated by gammaH2AX levels. In synchronized cells, damaging DNA with temozolomide in the presence of ABT-888 during the S phase generated high levels of double-stranded breaks, presumably because the single-stranded DNA breaks resulting from the cleavage of the methylated nucleotides were converted into double-stranded breaks through DNA replication. As a result, treatment of temozolomide and ABT-888 during the S phase leads to higher levels of cytotoxicity. ABT-888 inhibits poly(ADP-ribose) formation in vivo and enhances tumor growth inhibition by temozolomide in multiple models. ABT-888 is well tolerated in animal models. ABT-888 is currently in clinical trials in combination with temozolomide.

Functional characterization of Mycobacterium tuberculosis Rv2969c membrane protein.

Identifying Mycobacterium tuberculosis membrane proteins involved in binding to and invasion of host cells is important in designing subunit-based anti-tuberculosis vaccines. The Rv2969c gene sequence was identified by PCR in M. tuberculosis complex strains, being transcribed in M. tuberculosis H37Rv, M. tuberculosis H37Ra, and M. bovis BCG. Rabbits immunized with synthetic peptides from highly specific conserved regions of this protein produced antibodies recognizing 27 and 29 kDa bands in M. tuberculosis lysate, which is consistent with the molecular weight of the Rv2969c gene product in M. tuberculosis H37Rv. Immunoelectron microscopy revealed the protein was localized on the bacillus surface. Four and three specific high activity binding peptides (HABPs) to the A549 alveolar epithelial and U937 monocyte cell lines were found, respectively. Two of the HABPs found inhibited M. tuberculosis invasion of A549 cells, suggesting that these peptides might be good candidates to be included in a multiepitopic, subunit-based anti-tuberculosis vaccine.

An enzyme-linked immunosorbent poly(ADP-ribose) polymerase biomarker assay for clinical trials of PARP inhibitors.

Many established cancer therapies involve DNA-damaging chemotherapy or radiotherapy. The DNA repair capacity of the tumor represents a common mechanism used by cancer cells to survive DNA-damaging therapy. Poly(ADP-ribose) polymerase (PARP) is a nuclear enzyme that is activated by DNA damage and has critical roles in DNA repair. Inhibition of PARP potentiates the activity of DNA-damaging agents such as temozolomide, topoisomerase inhibitors and radiation in both in vitro and in vivo preclinical models. Recently, several PARP inhibitors have entered clinical trials either as single agents or in combination with DNA-damaging chemotherapy. Because PARP inhibitors are not cytotoxic, a biomarker assay is useful to guide the selection of an optimal biological dose. We set out to develop an assay that enables us to detect 50% PAR reduction in human tumors with 80% power in a single-plate assay while assuring no more than a 10% false-positive rate. We have developed and optimized an enzyme-linked immunosorbent assay (ELISA) to measure PARP activity that meets the above-mentioned criterion. This robust assay is able to detect PAR levels of 30-2000 pg/ml in both tumor and peripheral blood monocyte samples. In a B16F10 mouse syngeneic tumor model, PARP inhibitor ABT-888 potentiates the effect of temozolomide in suppressing tumor growth, and PARP activity is greatly reduced by ABT-888 at efficacious doses. In summary, the ELISA assay described here is suitable for biomarker studies in clinical trials of PARP inhibitors.

The PARP inhibitor, ABT-888 potentiates temozolomide: correlation with drug levels and reduction in PARP activity in vivo.

ABT-888 is a potent, orally bioavailable PARP-1/2 inhibitor shown to potentiate DNA damaging agents. The ability to potentiate temozolomide (TMZ) and develop a biological marker for PARP inhibition was evaluated in vivo. Doses/schedules that achieve TMZ potentiation in the B16F10 syngeneic melanoma model were utilized to develop an ELISA to detect a pharmacodynamic marker, ADP ribose polymers (pADPr), after ABT 888 treatment. ABT-888 enhanced TMZ antitumor activity, in a dose-proportional manner with no observed toxicity (44-75% tumor growth inhibition vs. TMZ monotherapy), but did not show single agent activity. Extended ABT-888 dosing schedules showed no advantage compared to simultaneous TMZ administration. Efficacy correlated with plasma/tumor drug concentrations. Intratumor drug levels correlated with a dose-proportional/time-dependent reduction in pADPr. Potentiation of TMZ activity by ABT-888 correlated with drug levels and inhibition of PARP activity in vivo. ABT-888 is in Phase 1 trials using a validated ELISA based on the assay developed here to assess pharmacological effect.

ABT-888, an orally active poly(ADP-ribose) polymerase inhibitor that potentiates DNA-damaging agents in preclinical tumor models.

PURPOSE: To evaluate the preclinical pharmacokinetics and antitumor efficacy of a novel orally bioavailable poly(ADP-ribose) polymerase (PARP) inhibitor, ABT-888. EXPERIMENTAL DESIGN: In vitro potency was determined in a PARP-1 and PARP-2 enzyme assay. In vivo efficacy was evaluated in syngeneic and xenograft models in combination with temozolomide, platinums, cyclophosphamide, and ionizing radiation. RESULTS: ABT-888 is a potent inhibitor of both PARP-1 and PARP-2 with K(i)s of 5.2 and 2.9 nmol/L, respectively. The compound has good oral bioavailability and crosses the blood-brain barrier. ABT-888 strongly potentiated temozolomide in the B16F10 s.c. murine melanoma model. PARP inhibition dramatically increased the efficacy of temozolomide at ABT-888 doses as low as 3.1 mg/kg/d and a maximal efficacy achieved at 25 mg/kg/d. In the 9L orthotopic rat glioma model, temozolomide alone exhibited minimal efficacy, whereas ABT-888, when combined with temozolomide, significantly slowed tumor progression. In the MX-1 breast xenograft model (BRCA1 deletion and BRCA2 mutation), ABT-888 potentiated cisplatin, carboplatin, and cyclophosphamide, causing regression of established tumors, whereas with comparable doses of cytotoxic agents alone, only modest tumor inhibition was exhibited. Finally, ABT-888 potentiated radiation (2 Gy/d x 10) in an HCT-116 colon carcinoma model. In each model, ABT-888 did not display single-agent activity. CONCLUSIONS: ABT-888 is a potent inhibitor of PARP, has good oral bioavailability, can cross the blood-brain barrier, and potentiates temozolomide, platinums, cyclophosphamide, and radiation in syngeneic and xenograft tumor models. This broad spectrum of chemopotentiation and radiopotentiation makes this compound an attractive candidate for clinical evaluation.

Potent and conditional redirected T cell killing of tumor cells using Half DVD-Ig.

Novel biologics that redirect cytotoxic T lymphocytes (CTLs) to kill tumor cells bearing a tumor associated antigen hold great promise in the clinic. However, the ability to safely and potently target CD3 on CTL toward tumor associated antigens (TAA) expressed on tumor cells remains a challenge of both technology and biology. Herein we describe the use of a Half DVD-Ig format that can redirect CTL to kill tumor cells. Notably, Half DVD-Ig molecules that are monovalent for each specificity demonstrated reduced non-specific CTL activation and conditional CTL activation upon binding to TAA compared to intact tetravalent DVD-Ig molecules that are bivalent for each specificity, while maintaining good drug like properties and appropriate PK properties.

Innovative assembly strategy contributes to understanding the evolution and conservation genetics of the endangered Solenodon paradoxus from the island of Hispaniola.

Solenodons are insectivores that live in Hispaniola and Cuba. They form an isolated branch in the tree of placental mammals that are highly divergent from other eulipothyplan insectivores The history, unique biology, and adaptations of these enigmatic venomous species could be illuminated by the availability of genome data. However, a whole genome assembly for solenodons has not been previously performed, partially due to the difficulty in obtaining samples from the field. Island isolation and reduced numbers have likely resulted in high homozygosity within the Hispaniolan solenodon (Solenodon paradoxus). Thus, we tested the performance of several assembly strategies on the genome of this genetically impoverished species. The string graph-based assembly strategy seemed a better choice compared to the conventional de Bruijn graph approach due to the high levels of homozygosity, which is often a hallmark of endemic or endangered species. A consensus reference genome was assembled from sequences of 5 individuals from the southern subspecies (S. p. woodi). In addition, we obtained an additional sequence from 1 sample of the northern subspecies (S. p. paradoxus). The resulting genome assemblies were compared to each other and annotated for genes, with an emphasis on venom genes, repeats, variable microsatellite loci, and other genomic variants. Phylogenetic positioning and selection signatures were inferred based on 4,416 single-copy orthologs from 10 other mammals. We estimated that solenodons diverged from other extant mammals 73.6 million years ago. Patterns of single-nucleotide polymorphism variation allowed us to infer population demography, which supported a subspecies split within the Hispaniolan solenodon at least 300 thousand years ago.