Can therapeutic efficacy be predicted from phase I data?

Summary— The aim of phase I studies per se is to explore the tolerance of new compounds which have demonstrated a certain level of activity in animals at sufficiently low non-toxic doses. In most cases, these studies are conducted in 2 steps in a limited number of healthy male volunteers: a single rising dose study followed by a repeated dose study in which the pharmacokinetic features of the drug are explored. In such a context, it would be quite presumptuous to ascertain the therapeutic efficacy of a drug from those initial human studies. At best, these trials can provide pharmacological and/or biological indications which are related to some degree to the expected efficacy of the drug: hypnotics, anticancer drugs, antibiotics, platelet antiaggregants, beta-blockers, etc. In these examples it is recommended to design controlled study protocols so as to better investigate these potentially interesting signs of activity. In the majority of cases, however (psychoactive drugs, analgesic, anti-inflammatory drugs, gastro-intestinal compounds), phase I studies will unfortunately not provide much information regarding the expected therapeutic activity.     

Oral cyclophosphamide versus chlorambucil in the treatment of patients with membranous nephropathy and renal insufficiency

We treated patients with idiopathic membranous nephropathy (iMGN) and renal insufficiency, using: (i) (n = 15) monthly cycles of steroids (1 g methyl-prednisolone i.v. on three consecutive days, followed by oral prednisone 0.5 mg/kg/day months 1, 3 and 5) and chlorambucil (0.15 mg/kg/day months 2, 4 and 6); or (ii) (n = 17) oral cyclophosphamide (1.5-2.0 mg/kg/day for 1 year) and steroids in a comparable dose. The groups were comparable in age, renal function and levels of proteinuria. During the 6 months preceding treatment, serum creatinine levels increased from 148 +/- 50 to 219 +/- 73 mumol/l in the chlorambucil group and from 164 +/- 86 to 274 +/- 126 mumol/l in the cyclophosphamide group. Median (range) follow-ups were: chlorambucil 38 months (8-71); cyclophosphamide 26 months (5-68) (NS). Renal function improved in both groups, but the improvement was short-lived in the chlorambucil group; 12 months after starting treatment, mean serum creatinine was 6.3 mumol/l lower in the chlorambucil group and 121 mumol/l lower in the cyclophosphamide group (p < 0.01). Four chlorambucil-treated patients developed ESRD, and five needed a second course of therapy, whereas only one cyclophosphamide-treated patient developed ESRD (p < 0.05). Remissions of proteinuria occurred more frequently after cyclophosphamide treatment (15/17 vs. 5/15; p < 0.01). Side-effects necessitated interruption of treatment in six patients on cyclophosphamide and in 11 on chlorambucil (p < 0.05). In our patients, oral cyclophosphamide was better tolerated than oral chlorambucil. The suggested greater efficacy of the oral cyclophosphamide regimen needs to be ascertained by longer follow-up.      

Lymphome non hodgkinien Ki-1 positif révélé par des ulcérations cutanéomuqueuses et une glomérulonéphrite

Malignant lymphoma particularly of T phenotype can be associated with specific or non specific cutaneous lesions. These cutaneous manifestations can occur at the onset of the disease being sometimes the revealing sign or they can appear during the course of the lymphoreticular malignancies. Glomerulonephritis was also described in lymphoma. Ki- positive large cell lymphoma was recently identified. A new case is reported with lymphadenopathy and intestinal localisation revealed by cutaneous and mucosal ulcerations principally in the mouth and a focal segmental glomerulonephritis with endo- and extracapillary proliferation. The absence of lymphoma in cutaneous and renal lesions and the clinical presentation support the hypothesis of paraneoplastic manifestations, may be related to a vasculitis.     

Review of the Lynch syndrome: history, molecular genetics, screening, differential diagnosis, and medicolegal ramifications

Platelets have a central role in the development of arterial thrombosis and subsequent cardiovascular events. An appreciation of this complex process has made antiplatelet therapy the cornerstone of cardiovascular disease management. However, numerous patients will experience a recurrent atherothrombotic vascular event despite adequate antiplatelet therapy. Individual differences in the rate of platelet activation and reactivity markedly influence normal hemostasis and the pathological outcome of thrombosis. Such an individual variability is largely determined by environmental and genetic factors. These are known to either hamper platelets' response to agonists, and thereby mimic the pharmacological modulation of platelet function or mask therapy effect and sensitize platelets. In this article, we reviewed the antiplatelet mechanisms of aspirin and clopidogrel and the possible role of different polymorphisms, which may affect the efficacy of antiplatelet therapy. Heterogeneity in the way patients respond to aspirin and clopidogrel may in part reflect variation in cyclooxygenase (COX)-1, COX-2, glycoprotein (GP) Ib alpha, GP Ia/IIa, GP IIb/IIIa, UGT1A6*2, P2Y₁, P2Y₁₂, CYP2C9, CYP3A4 and CYP3A5 genotypes.     

Clinical features of chromosome 22q11.2 microdeletion syndrome in 208 Chilean patients

Patients with chromosome 22q11 deletion syndrome exhibit significant phenotypic variability. Epidemiologic data suggest a higher incidence in Hispanics, but limited clinical information is available from Latin-American patients. We describe the clinical features of Chilean patients with 22q11 deletion syndrome and compare their findings with those reported in large European, Japanese and US series. Data were obtained from 208 patients from five medical centers. Mean age at diagnosis was 5.2 years, with a median of 2.3 years. Congenital heart defects were present in 59.6%, lower than other large series that averaged 75.8%. Palate abnormalities were present in 79%, higher than previous reports averaging 56%. Patients with congenital heart disease were diagnosed earlier (median 0.3 years of age) than those without heart defects (median 5.6 years) and had greater mortality attributable to the syndrome (9.8% vs 2.4%, respectively). The differences in frequencies of major anomalies may be due to growing awareness of more subtle manifestations of the syndrome, differences in clinical ascertainment or the presence of modifier factors. These observations provide additional data useful for patient counseling and for the proposal of health care guidelines.     

The nuclear concentration of kin17, a mouse protein that binds to curved DNA, increases during cell proliferation and after UV irradiation

UV-irradiation induces, in mammalian cells, the expression of a set of genes known as the 'UV-response', which may be reminiscent of the bacterial response, called SOS system. The multifunctional protein RecA controls the expression of the SOS genes. We report the expression profile of a mouse gene conserved among mammals, called Kin17, that codes a DNA-binding protein of undetermined biochemical activity and which shares epitopes with the bacterial RecA protein. We demonstrate that the level of Kin17 RNA was 5-fold higher in mid-S phase of serum- stimulated BALB/c 3T3 fibroblasts than in quiescent cells. Cells in S- phase displayed a high level of kin17 protein with a marked nuclear localisation. The maximal level of Kin17 RNA was observed 18 h after serum stimulation, indicating that Kin17 gene is a new member of the late growth-related genes. The accumulation of kin17 protein during cell proliferation follows the increase in Kin17 RNA and correlates with DNA synthesis, which suggests a possible role of kin17 protein in a transaction related to DNA-replication. In quiescent fibroblasts, a 3- fold increase in Kin17 RNA was seen 13 h after UV irradiation. In parallel, kin17 protein accumulated in the nucleus, which suggests that it might be required after the stress produced by UV irradiation.