Phase I and biomarker study of OPB-51602, a novel signal transducer and activator of transcription (STAT) 3 inhibitor, in patients with refractory solid malignancies

BACKGROUND

The aim of this study was to determine the maximum-tolerated dose (MTD), safety, pharmacokinetics, and pharmacodynamics of OPB-51602, an oral, direct signal transduction activator of transcription 3 (STAT3) inhibitor, in patients with refractory solid tumors.

PATIENTS AND METHODS

Three cohorts were studied: cohort A, a sequential dose escalation of OPB-51602 administered intermittently (days 1-14 every 21 days); cohort B, an expansion cohort evaluating the dose lower than the MTD; cohort C, evaluating continuous daily dosing.

RESULTS

Fifty-one patients were studied at 2, 4, and 5 mg per day dosing. The MTD was 5 mg; first-cycle dose-limiting toxicities (DLTs) were grade 3 hyponatremia in one patient, and grade 3 dehydration in another. Intermittent dosing of both 2 and 4 mg doses were tolerable, and the recommended phase II dose was 4 mg. Cohort B investigated 4 mg intermittently, whereas cohort C investigated 4 mg continuously. Common toxicities included fatigue, nausea/vomiting, diarrhea, anorexia, and early-onset peripheral neuropathy. Drug-induced pneumonitis occurred in two patients in cohort C. Continuous dosing was associated with a higher incidence of peripheral neuropathy and a lower mean relative dose intensity, compared with intermittent dosing. Steady-state pharmacokinetics was characterized by high oral clearance, mean elimination half-life ranging from 44 to 61 h, and a large terminal-phase volume of distribution. An active metabolite, OPB-51822, accumulated to a greater extent than OPB-51602. Flow cytometry of peripheral blood mononuclear cells demonstrated pSTAT3 (Tyr(705)) inhibition following exposure. Two patients achieved partial responses at 5 mg intermittently and 4 mg continuously; both had epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC) with prior EGFR tyrosine kinase inhibitor exposure.

CONCLUSION

OPB-51602 demonstrates promising antitumor activity, particularly in NSCLC. Its long half-life and poorer tolerability of continuous dosing, compared with intermittent dosing, suggest that less frequent dosing should be explored.

CLINICALTRIALSGOV IDENTIFIER

NCT01184807.

Disease control with a second epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) after failure of a first TKI in Asian patients with non-small cell lung cancer (NSCLC)

18104

Background: Asian NSCLC patients are known to have higher response rates to the EGFR TKI gefitinib (G) and erlotinib (E). Anecdotal reports suggest some activity for a second EGFR TKI after failure of the first. Methods: A retrospective review of the electronic pharmacy records, clinical and radiographic records of patients with advanced NSCLC at the National University Hospital who received both G and E in the previous 2 years was conducted. Objectives were to assess the disease control (response/stable disease) of the second TKI after failure of the first and characterize the clinical, pathological and molecular features of patients benefiting from a 2nd TKI. Results: 14 patients with advanced NSCLC who received a 2nd EGFR TKI after progression on the 1st TKI were identified. Patient characteristics: Chinese 12, female 10, and non-smokers 13. Histologic subtype: adenocarcinoma 7, bronchioloalveolar carcinoma (BAC) 3, squamous-cell carcinoma 1, NSCLC unspecified 3. 12 patients received cytotoxic chemotherapy with a median of 2 lines, (range 1–5). G and E was used as 1st/2nd/3rd/=4th line treatment in 8/2/2/2 and 0/4/2/8 patients respectively. G was used before E in 13 cases and disease control was seen in 8/14 (57%) patients. With a 2nd TKI after disease progression, disease control was seen 4/14 (28%) patients. Patient characteristics were: adenocarcinoma 3, BAC 1, all were never smokers and all received and responded to prior G. Median duration of control in these 4 patients for G was 8 (range 7–12) months, and subsequently to E was 2.5 (range 2–8) months. Disease control was associated with symptomatic improvement. Conclusion: This study documents disease control in 28% of Asian NSCLC patients treated with a second EGFR TKI after failure of a first. The molecular basis for these observations is currently being investigated.

No significant financial relationships to disclose.

A case of penicillamine-induced dermopathy

INTRODUCTION

We describe an interesting patient with penicillamine-induced dermopathy.

CLINICAL PICTURE

A 49-year-old woman presented with a 1-year history of recurrent haemorrhagic blisters, milia and purpura over both her elbows, while on long-term penicillamine therapy (1.5 g daily) for Wilson's disease. Histologically, dermal elastin fibres were markedly reduced in the affected areas, consistent with penicillamine-induced elastolysis.

TREATMENT AND OUTCOME

The patient's lesions improved significantly after reduction of her penicillamine dose to 500 mg daily.

CONCLUSIONS

The cutaneous side effects of long-term penicillamine therapy are important to recognise as they may be associated with significant morbidity and may be markers of more ominous underlying systemic elastic fibre damage.

Formation of DNA triple helix containing N(4)-(6-aminopyridin-2-yl)-2'-deoxycytidine

A cytidinyl derivative, N(4)-(6-aminopyridin-2-yl)- 2'-deoxycytidine ((p)C), could interact with a CG base pair to support the triple-helix (triplex) formation of oligodeoxyribonucleotides. Characteristics of (p)C in the formation of both intramolecular triplex, i.e., a "paper clip type" triplex ((P)CT) and intermolecular triplex, i.e., a "linear type" triplex (LT) was monitored by optical methods and isothermal titration calorimetric measurements. Experimental results revealed that the LT with (p)C*CG internally was independent of the solution pH. Only single substitution of (p)C, situated internally but not terminally, facilitated the (P)CT formation by the UV thermal melting study at the neutral pH. However, the best stabilization of the PCT in acidic conditions occurred when (p)C at the end of the triplex rather than internally. In addition, an LT, but not a (P)CT, containing an alternating (p)CT(p)CT(p)C sequence, could be formed in the conditions of 20 mM MgCl(2) and/or 5 mM spermine. Thus, the presence of several nucleotides of (p)C in proximity along the Hoogsteen strand may lead to structural distortion such that the more flexible LT with multiple substitutions is formed in favor of the more rigid PCT.

"Paper-clip" type triple helix formation by 5'-d-(TC)3Ta(CT)3Cb(AG)3 (a and b = 0-4) as a function of loop size with and without the pseudoisocytosine base in the Hoogsteen strand

The formation of a DNA "paper-clip" type triple helix (triplex) with a common sequence 5'-d-(TC)(3)T(a)()(CT)(3)C(b)()(AG)(3) (a and b = 0-4) was studied by UV thermal melting experiments and CD spectra. These DNA oligomers form triplexes and duplexes under slightly acidic and neutral conditions, respectively. The stability of the formed triplexes (at pH 4.5) or duplexes (at pH 7.0 or 8.0) does not vary significantly with the size of the loops (a and b = 1-4). At pH 6.0, the triplex stability is, however, a function of a and b. It is also interesting to note that the oligomer 5'-d-(TC)(3)(CT)(3)(AG)(3) (a and b = 0) forms a stable triplex at pH 4.5 with a slightly lower T(m) value, due to dissociation of a base triad at one end and a distorted base triad at the other, observed by (1)H NMR. Thus, we have here a model system, 5'-d-(TC)(3)T(a)(CT)(3)C(b)(AG)(3), that could form a triplex effectively with (a and b = 1-4) and without (a and b = 0) loops under acidic conditions. In addition, the triplex formation of oligomers with replacement of one, two, or three 2'-deoxycytidine in the Hoogsteen strand by either 2'-deoxypseudoisocytidine (D) or 2'-O-methylpseudoisocytidine (M) was also studied in the sequence 5'-d-(TX)(3)T(2)(CT)(3)C(2)(AG)(3) (where X is C, D, or M). Both CD spectra and UV melting results showed that only D3 [(TX)(3) = (TD)(3)] and M3 [(TX)(3) = (TM)(3)] were able to form the paper-clip structure under both neutral and acidic conditions. This is because the N(3)H of a pseudoisocytosine base can serve as a proton donor without protonation. We hereby proved that the 2'-deoxypseudoisocytidine, similar to 2'-O-methylpseudoisocytidine, could replace 2'-deoxycytidine in the Hoogsteen strand to provide triplex formation at neutral pH.

The processes of case management: a review of the evaluation of a pilot study for elderly people in Hong Kong

AIM

This paper is based on research into case management that aimed to evaluate the processes of the introduction of case management for elderly people into the community nursing services in Hong Kong.

BACKGROUND

The Hospital Authority in Hong Kong introduced a pilot Case Management scheme into the Community Nursing Services. A research project was therefore developed to evaluate this case management model.

METHOD

The processes were measured through information gained from group interviews, daily diaries and weekly activity sheets.

FINDINGS

The roles and work practices of the Care Coordinators and Case Managers are described and the benefits of case management to patients, carers and nurses are highlighted. Difficulties are also discussed and good practices are identified.

CONCLUSION

Staff in the hospital and community need time to get used to the model of case management and to the accompanying documentation. The role of the case manager needs to be clearly dilineated.

Case management: a review of the definitions and practices

Case management has been suggested as an innovative strategy which facilitates the linking of quality and cost-effective care. However, there is little consensus about what is actually being introduced under the name of case management. It is suggested that this absence of a clear understanding of case management has been an obstacle in moving forward case management practice and research. This paper presents a critical review of the confusion surrounding case management with an attempt to unravel issues relevant to the implementation of case management into community nursing practice in Hong Kong. It is concluded that there is a need for different definitions of case management as a result of the differences in the cultural and health care context in which it is being practised. Also, if case management programmes are to be advanced, there needs to be more co-ordinated effort in researching not only the expected outcomes but also the structures and processes of these programmes so that findings of similar case management programmes can be compared for ways of future improvement.

A novel, multilayer structure of a helical peptide

X-ray diffraction analysis at 1.5 A resolution has confirmed the helical conformation of a de novo designed 18-residue peptide. However, the crystal structure reveals the formation of continuous molecular layers of parallel-packed amphiphilic helices as a result of much more extensive helix-helix interactions than predicted. The crystal packing arrangement, by virtue of distinct antiparallel packing interactions, segregates the polar and apolar surfaces of the helices into discrete and well-defined interfacial regions. An extensive "ridges-into-grooves" interdigitation characterizes the hydrophobic interface, whereas an extensive network of salt bridges and hydrogen bonds dominates the corresponding hydrophilic interface.

The amplification refractory mutation system (ARMS): a rapid and direct prenatal diagnostic technique for beta-thalassaemia in Singapore

beta-Thalassaemia major patients have chronic anaemia and since 3-4 per cent of Singaporeans carry the beta-gene, prenatal diagnosis is essential. We evaluated the amplification refractory mutation system (ARMS) technique as a routine test for prenatal diagnosis of beta-major. Six mutations along the beta-gene were studied--41-42 (-TCTT), IVSII #654 (C-T), 17 beta (A-T), -28 TATA (A-G), IVSI #5 (G-C), and IVSI #1 (G-T). Our results indicate that prenatal diagnosis using these mutations can be offered to 90 per cent (35/39) of our Chinese couples and 54.6 per cent (12/22) of our Malay couples at risk. Confirmation of ARMS results was carried out using allele-specific oligonucleotide hybridization. Prenatal diagnosis using ARMS was successfully carried out in nine cases which included a set of triplets and twins. The triplets were diagnosed with the beta-trait carrying the 41-42 mutation. The couple with twins possessed the #654 mutation and one twin was diagnosed with the beta-trait and the other with #654 homozygosity. Genomic sequencing of the undefined mutations in the Chinese couples revealed rarer mutations at -29 and an ATG-AGG base substitution at the initiation codon for translation. In the Malay couples, genomic sequencing detected mutations at codon 15 (TGG-TAG) and codon 26 (GAG-AAG). We conclude that ARMS with its direct detection of amplified products by gel electrophoresis provides an accurate, rapid, and simpler method for our beta-thalassaemia prenatal diagnosis programme in Singapore.

Probabilistic and sequential computation of optical flow using temporal coherence

In the computation of dense optical flow fields, spatial coherence constraints are commonly used to regularize otherwise ill-posed problem formulations, providing spatial integration of data. We present a temporal, multiframe extension of the dense optical flow estimation formulation proposed by Horn and Schunck (1981) in which we use a temporal coherence constraint to yield the optimal fusing of data from multiple frames of measurements. Conceptually, standard Kalman filtering algorithms are applicable to the resulting multiframe optical flow estimation problem, providing a solution that is sequential and recursive in time. Experiments are presented to demonstrate that the resulting multiframe estimates are more robust to noise than those provided by the original, single-frame formulation. In addition, we demonstrate cases where the aperture problem of motion vision cannot be resolved satisfactorily without the temporal integration of data enabled by the proposed formulation. Practically, the large matrix dimensions involved in the problem prohibit exact implementation of the optimal Kalman filter. To overcome this limitation, we present a computationally efficient, yet near-optimal approximation of the exact filtering algorithm. This approximation has a precise interpretation as the sequential estimation of a reduced-order spatial model for the optical flow estimation error process at each time step and arises from an estimation-theoretic treatment of the filtering problem. Experiments also demonstrate the efficacy of this near-optimal filter.

Molecular characterization of beta-thalassaemia in Singaporean Chinese: application to prenatal diagnosis

Sixty-five beta-thalassaemia genes from 14 unrelated Chinese beta-thalassaemia major patients and 37 Chinese beta-carriers were analysed by allele-specific oligonucleotide (ASO) hybridization after DNA amplification by the polymerase chain reaction (PCR). Six mutations were studied and are represented by 49.2% of codon 41-42, 30.8% of IVSII #654, 6.2% of 17 beta, 3.1% of IVSI #5 (G-->C) and 1.5% of -28 TATA box. The complete mutations responsible for beta-thalassaemia major in 13 of our 14 affected families were identified. For these families prenatal diagnosis at 10 weeks gestation using DNA amplification and ASO hybridization will replace the globin chain biosynthesis technique at 19 weeks gestation. Using ASO analysis, our results indicate that 5 oligo-probes (41-42, II-#654, 17 beta, IVSI-#5 and -28) allow determination of beta-thalassaemia mutations in 59/65 (90.8%) of the Singaporean Chinese studied.

Modeling of cardiac rhythms. A signal-processing perspective

The authors describe their perspective on the modeling of cardiac rhythms as a component of cardiac arrhythmia signal-processing algorithms. They emphasize that these models are for a specific end purpose and that the aspects of cardiac behavior that are captured by the models are only those relevant for the development of the signal-processing algorithms. The approach is to use statistics to describe ranges of cardiac behavior that share some common feature with respect to the purpose of the signal processing. The statistical approach has the advantage that, coupled with a statistical performance criterion, it specifies an optimal signal-processing algorithm. These optimal algorithms are often computationally intractable, however, especially for real-time use in instruments. Approximations are therefore crucial. The mathematical form of the model is then important since, even if two forms generate identical statistics, the approximations that are natural in different forms can be quite different. Two different mathematical formulations are described--stochastic Petri nets and interacting Markov chains--and the different types of approximately optimal signal-processing algorithms that are natural in these two frameworks are discussed.

Stochastic Petri net modeling of wave sequences in cardiac arrhythmias

We describe a methodology for modeling heart rhythms observed in electrocardiograms. In particular, we present a procedure to derive simple dynamic models that capture the cardiac mechanisms which control the particular timing sequences of P and R waves characteristic of different arrhythmias. By treating the cardiac electrophysiology at an aggregate level, simple network models of the wave generating system under a variety of diseased conditions can be developed. These network models are then systematically converted to stochastic Petri nets which offer a compact mathematical framework to express the dynamics and statistical variability of the wave generating mechanisms. Models of several arrhythmias are included in order to illustrate the methodology.

Allergic hypersensitivity to lidocaine hydrochloride

A 39-year-old man developed allergic hypersensitivity to lidocaine hydrochloride and showed urticarial dermographism. Although hypersensitivity reactions to local anesthetics are rare and are usually due to esters of procaine, reaction to the amides of lidocaine can occur. A review of the literature for the past decade revealed only four reported cases of allergic hypersensitivity to lidocaine hydrochloride.