Integrated pharmacokinetic, pharmacodynamic and immunogenicity profiling of an anti-CCL21 monoclonal antibody in cynomolgus monkeys

QBP359 is an IgG1 human monoclonal antibody that binds with high affinity to human CCL21, a chemokine hypothesized to play a role in inflammatory disease conditions through activation of resident CCR7-expressing fibroblasts/myofibroblasts. The pharmacokinetics (PK) and pharmacodynamics (PD) of QBP359 in non-human primates were characterized through an integrated approach, combining PK, PD, immunogenicity, immunohistochemistry (IHC) and tissue profiling data from single- and multiple-dose experiments in cynomolgus monkeys. When compared with regular immunoglobulin typical kinetics, faster drug clearance was observed in serum following intravenous administration of 10 mg/kg and 50 mg/kg of QBP359. We have shown by means of PK/PD modeling that clearance of mAb-ligand complex is the most likely explanation for the rapid clearance of QBP359 in cynomolgus monkey. IHC and liquid chromatography mass spectrometry data suggested a high turnover and synthesis rate of CCL21 in tissues. Although lymphoid tissue was expected to accumulate drug due to the high levels of CCL21 present, bioavailability following subcutaneous administration in monkeys was 52%. In human disease states, where CCL21 expression is believed to be expressed at 10-fold higher concentrations compared with cynomolgus monkeys, the PK/PD model of QBP359 and its binding to CCL21 suggested that very large doses requiring frequent administration of mAb would be required to maintain suppression of CCL21 in the clinical setting. This highlights the difficulty in targeting soluble proteins with high synthesis rates.

Abstract P6-07-01: Multigene profiling to identify clinically relevant actionable mutations in breast cancer: An Indian study

Background: Numerous chemotherapeutic agents are available against breast cancer (BC), but a vast majority of patients diagnosed with this disease still develop treatment resistance and eventually succumb to disease. It remains an unmet need to identify specific molecular defects against which targeted therapy are available for improving clinical outcomes in BC. Our study aims to identify frequent hotspot mutations in BCs and determine their clinical impact.

Methods: 200 women with BC(early diagnosed and/or metastatic) aged 26-75 yrs (median age 50.5yrs) diagnosed at HCG from April 2013-15 were consented to be profiled by targeted deep sequencing for hotspot mutations in 48 cancer-related genes using Illumina's TSCAP panel and MiSeq technology in an IRB-approved prospective study in a CLIA compliant laboratory. All the cases had pathology review for stage, histological type, hormonal status and Ki67. The average coverage across 220 hot spots was greater than 1000X. Data was processed using Strand Avadis NGS™. Mutations identified in the tumor were assessed for 'actionability' i.e. response to therapy and impact on prognosis. Results: Somatic variants were detected in 75% of cases with direct impact on therapy or prognosis. Genetic aberrations were identified in PI3K/AKT/ mTOR signalling pathway in substantial fraction (27%) of breast cancer cases, out of which 17% had PIK3CA activating mutations,13 and 5 cases had PTEN and AKT deletions or truncating mutations respectively. Aberration in this pathway was more prevalent in HR+ve (53%) and HER2-ve including TNBC (61%) than in HR+/HER2+ve tumors (10.6%) of IDC histology. However, no correlation was found with stage and Ki67 index of the tumor. Notably 80% of BC cases presented with liver metastasis at the time of diagnosis were detected with PIK3CA mutation indicating its role as a surrogate marker of organ specific metastasis. PIK3CA was found to be co mutated with p53 in 16 cases (9%) of which 4 cases showed npCR post NACT. Also disruptive and non-disruptive mutations in TP53 alone were found in 25% of BC, varying widely among different histologies. A follow up of few cases showed shorter PFS and poor outcome in resected BC treated with NACT indicating its robust prognostic value in NACT setting. Furthermore, two patients were detected with cKIT mutations indicating sensitivity to imatinib and therefore enrolled on a clinical trial. The other variants were found in RB1(n=8),Her2 (n=2),FGFR amplification(n=1), KRAS(n=2),NRAS(n=3)CDH1(n=1),FBXW7(n=2) and EGFR(n=1).All these variants detected indicated resistance to conventional therapy and suggested sensitivity to available targeted therapy, either approved or in clinical trials. The response and outcome are being monitored in about 20 (10%) patients who have been enrolled in clinical trials and receiving mutation specific targeted therapy. Conclusions: This study confirms the utility of multigene profiling in early diagnosed and advanced BC patients, to stratify them on their molecular profile who could potentially benefit from targeted therapy. Prospective studies and randomized clinical trials are ongoing to confirm the independent prognostic and therapeutic value of the mutations in a larger cohort of Indian population.

Citation Format: Ghosh M, Sheela ML, Choudhury S, Bahadur U, Patil S, Satheesh CT, Murugan K, Nayak R, Sridhar PS, Rao N, Mahesh B, Shashidhara HP, Krishnamoorthy N, Gupta V, Sankaran S, Subramanian K, Ajaikumar BS. Multigene profiling to identify clinically relevant actionable mutations in breast cancer: An Indian study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-07-01.

Abstract P6-06-06: Comprehensive analysis of BRCA (BRCAm) and other germline mutations (GRm) with a clinicopathological association in breast cancer: An Indian study

Background: BRCAm and other GRm testing using next generation sequencing (NGS) in early diagnosed and/or metastatic breast cancer (BC) helps in the identification of both unambiguously defined deleterious mutations and sequence variants of unknown clinical significance (VUS). The early detection of these mutations in the proband and the family members help in risk stratification and instituting effective monitoring, surveillance and disease management strategies.

Methods: Out of total 200 patients diagnosed with BC (April 2013-15) 77 unrelated individuals were consented to be profiled by NGS on MiSeq platform using TruSight Cancer panel (consisting of 94 genes including 13 genes highly associated with risk of inherited breast and/or ovarian cancer) in an IRB-approved prospective study in a CLIA compliant laboratory. Paired end sequencing was done with an average coverage of > 450X. Data was processed using STRAND software and interpreted using "Strand Omics" platform. The paired tumor samples were analysed for pathological stage, histological type and hormonal status.

Results: GRm were detected in 61 cases (79%). Among all mutations detected, BRCA1/2 were found in 51% (31% in BRCA1, 20% in BRCA2) of cases. BRCA1 was found to be co-mutated with BRCA2 in 2 cases. Out of 37 deleterious mutations in BRCA1/2 genes only 10 were reported to be pathogenic (6 in BRCA1 and 4 in BRCA2) and rest were VUS. Mutation frequencies were higher among high grade IDC with HER2-ve tumors including TNBC (53%, p<0.05) with an early onset of the disease. TNBC with BRCAm were found to have no/incomplete pCR on conventional TAC regimen , subsequently started with platinum therapy and the outcome being monitored. Interestingly, 4 BRCA1 mutations including 3 non-sense and 1 frameshift mutation were found in two unrelated individuals suggesting them to be founder mutations in Indian population. The other GRm frequency (alone/ co-mutated with BRCA) was also found to be significantly high (49%) and include BRIP1, CHEK2, ERCC2, CDH1, SDHB, APC, MSH6, TP53, PALB2 and RAD51C. Stratification based on age of diagnosis(dx) showed a detection rate significantly higher in the age group of 25-50 yrs (74%) as compared to the 50-75 yrs (26%). Also a strong association of GRm status with the family history(Hx) of BC in 1st or 2nd degree relatives was indicated.

Table 1: Correlation of GRm with Dx and HxGenen%Age at dx(yrs)Family Hx (Yes=Y, No=N,Unknown=UK)BRCA1193125-50 (n=23) 50-75(n=8)Y(n=13) N(n=3) UK(n=3)BRCA2122025-50(n=21) 50-75(n=9)Y(n=8) N(n=2) UK(n=2)PALB211.7>50YCHEK258.825-50 (n=4) 50-75(n=1)YATM610.525-50 (n=4) 50-75(n=2)Y(n=5) N(n=1)RAD5111.7<50Y

Conclusions: Our study in a small cohort clearly highlighted the significance of germline testing and classifying the variant in larger cohort of BC patients with a strong family Hx of cancer particularly in BRCA1/2 positive families , and in women <50yrs for early detection and risk assessment. The study also indicates BRCAm to be an important contributor to the etiology of high grade HER2-/ TNBC in Indian patients. Expanded testing of this subtype is warranted to impact management of the disease with PARP inhibitors and/or platinum therapy.

Citation Format: Ghosh M, ML S, Upasana M, Chodhury S, Mannan AU, Southekal S, Manjima C, Patil S, Murugan K, Mahesh B, Nayak R, Sridhar PSS, Rao N, Krishnamoorthy N, Gupta V, Satheesh CT, Subramanian K, Ajaikumar BS. Comprehensive analysis of BRCA (BRCAm) and other germline mutations (GRm) with a clinicopathological association in breast cancer: An Indian study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-06-06.

Tunable anchoring groups@acridone-linked triphenylamine based pendant chromophores and their effects on the photovoltaic performance as sensitizers for dye-sensitized solar cells

In this study, a series of pendant chromophores bearing methacrylate polymers with different anchoring/acceptor groups were synthesized for use as sensitizers in the dye-sensitized solar cells.

Conjugated donor–acceptor copolymers derived from phenylenevinylene and trisubstituted pyridine units

Copolymers having intramolecular donor–acceptor systems encompassing trisubstituted pyridine derivatives as acceptor and phenylenevinylene (PPV) unit as a donor segment were synthesized. In addition, thiophene-containing random terpolymer PPVPYT via palladium-catalyzing Heck coupling reaction is reported. The novel-substituted pyridine monomers (PYBr) are synthesized by adopting a one-pot synthesis method using p-toluenesulfonic acid as catalyst in ethanol medium, which results in an excellent yield of about 95%. All the copolymers Poly phenylenevinylene-co-Pyridine derivatives (PPVPY) and terpolymers of Polyphenylenevinylene-co-Pyridine and Thiophene (PPVPYT) are found to be soluble in organic solvents, such as tetrahydrofuran, chloroform, and N, N-dimethylformamide. The molecular weights of the synthesized polymers were characterized by gel permeation chromatography (GPC), and their chemical structures were confirmed by infra red and nuclear magnetic resonance spectroscopies. The electrochemical band gaps of PPVPY-1, PPVPY-2, and PPVPY-3 copolymers are estimated to be 2.55, 2.48, and 2.0, respectively. Similarly, the band gap of PPVPY75T25, PPVPY50T50, and PPVPY25T75 random copolymers are estimated as 2.31, 1.95, and 2.23, respectively. These polymers also show excellent optical and thermal properties.

Insulin receptor-insulin interaction kinetics using multiplex surface plasmon resonance

Type 2 diabetes affects millions of people worldwide, and measuring the kinetics of insulin receptor-insulin interactions is critical to improving our understanding of this disease. In this paper, we describe, for the first time, a rapid, real-time, multiplex surface plasmon resonance (SPR) assay for studying the interaction between insulin and the insulin receptor ectodomain, isoform A (eIR-A). We used a scaffold approach in which anti-insulin receptor monoclonal antibody 83-7 (Abcam, Cambridge, UK) was first immobilized on the SPR sensorchip by amine coupling, followed by eIR-A capture. The multiplex SPR system (ProteOn XPR36™, Bio-Rad Laboratories, Hercules, CA) enabled measurement of replicate interactions with a single, parallel set of analyte injections, whereas repeated regeneration of the scaffold between measurements caused variable loss of antibody activity. Interactions between recombinant human insulin followed a two-site binding pattern, consistent with the literature, with a high-affinity site (dissociation constant K(D1)  = 38.1 ± 0.9 nM) and a low-affinity site (K(D2)  = 166.3 ± 7.3 nM). The predominantly monomeric insulin analogue Lispro had corresponding dissociation constants K(D1)  = 73.2 ± 1.8 nM and K(D2)  = 148.9 ± 6.1 nM, but the fit to kinetic data was improved when we included a conformational change factor in which the high-affinity site was converted to the low-affinity site. The new SPR assay enables insulin-eIR-A interactions to be followed in real time and could potentially be extended to study the effects of humoral factors on the interaction, without the need for insulin labeling.

Sensitive detection of C. parvum using near infrared emitting Ag2S@silica core–shell nanospheres

Optical detection ofC. parvumin environmental samples using anti-oocysts McAb immobilized NIR emitting Ag₂S@silica core–shell nanospheres as immunosensors is reported.

Correlation of myocardial perfusion SPECT with invasive and computed tomography coronary angiogram

BACKGROUND

The consequences of atherosclerosis can be detected by multislice computed tomography (MSCT), invasive coronary angiogram (CAG) and the resultant myocardial ischaemia by myocardial perfusion single photon emission computed tomography (MPS). In this study an attempt is made to compare MSCT with MPS and also to compare the MSCT findings with that of invasive CAG in patients suspected to have coronary artery disease (CAD).

MATERIALS AND METHODS

A total of 99 patients suspected to have CAD underwent both MSCT and MPS with (99m)Tc sestamibi. The MSCT studies were classified as having no CAD, significant CAD (>50% diameter stenosis), and insignificant CAD (<50% diameter stenosis). Myocardial perfusion single photon emission computed tomography was reported as normal and reversible ischaemia. In a subgroup of 33 patient invasive CAG was done.

RESULTS

In 99 patients, 396 coronaries were evaluated with MSCT and MPS. Coronary artery calcium scoring (CACS) in these patient ranged from 0 to 2200. No CAD was noted in 128 (32%) coronaries but MPS was found abnormal in 9 (7%) coronaries. Insignificant CAD was noted in 169 (43%) coronaries amongst which reversible ischaemia was noted in 23 (14%). Significant CAD was noted in 99 (25%) coronaries of which only 54 (55%) were MPS positive for reversible ischaemia. The MSCT has a negative predictive value (NPV) of 97%. When MSCT was normal, MPS was almost normal, but the reverse was not true. That is when MPS was normal MSCT was not always normal but showed lesion of insignificant obstruction. In the subset of 33 patients, who underwent invasive angiogram, 132 coronaries were evaluated. Coronary angiogram showed 48 coronaries (36%) to have significant CAD (>50% diameter stenosis). Multislice computed tomography correlated well in 46 (84%) with P value of <0.001 (χ(2)-test) but for 9 (16%) showing overestimation due to increased CACS (>800). Myocardial perfusion single photon emission computed tomography was normal in 15 (27%) coronaries.

CONCLUSION

Myocardial perfusion single photon emission computed tomography provides functional information of the anatomical lesions and MSCT provides anatomical information. Both are two different diagnostic modalities. The MSCT has high NPV in patients with less likelihood for CAD. When compared with CAG, the correlation with MSCT was good and is useful where the calcium score is low.