Biomarkers are increasingly used in drug development to aid scientific and clinical decisions regarding the progress of candidate and marketed therapeutics. Biomarkers can improve the understanding of diseases as well as therapeutic and off-target effects of drugs. Early implementation of biomarker strategies thus promises to reduce costs and time-to-market as drugs proceed through increasingly costly and complex clinical development programs. The 2003 American Association of Pharmaceutical Sciences/Clinical Ligand Assay Society Biomarkers Workshop (Salt Lake City, UT, USA, October 24-25, 2003) addressed key issues in biomarker research, with an emphasis on the validation and implementation of biochemical biomarker assays, covering from preclinical discovery of efficacy and toxicity biomarkers through clinical and postmarketing implementation. This summary report of the workshop focuses on the major issues discussed during presentations and open forums and noted consensus achieved among the participants on topics from nomenclature to best practices. For example, it was agreed that because reliable and accurate data provide the basis for sound decision making, biomarker assays must be validated in a manner that enables the creation of such data. The nature of biomarker measurements often precludes direct application of regulatory guidelines established for clinical diagnostics or drug bioanalysis, and future guidance on biomarker assay validation should therefore be adaptable enough that validation criteria do not stifle creative biomarker solutions.

Purpose The antisense oligonucleotide, LY2275796, blocks expression of eIF-4E, an mRNA translation regulator upregulated in tumors. This Phase I study sought an appropriate LY2275796 dose in patients with advanced tumors. Experimental Design A 3-day loading dose, then weekly maintenance doses, were given to 1–3 patient cohorts, beginning with 100 mg and escalating. Plasma samples were collected to determine LY2275796 concentrations; tumor biopsies, to quantify eIF-4E mRNA/protein. Results Thirty patients with Stage 4 disease received ≥1 LY2275796 dose. A dose-limiting toxicity was observed at 1200 mg, with 1000 mg the maximum-tolerated dose. Across all dose levels, most patients (87%) had only grade 1–2 toxicities. LY2275796 pharmacokinetics supported the dosing regimen. Comparison of pre- and post-dose biopsies showed eIF-4E decreased in most patients. Fifteen patients had progressive disease, and seven patients achieved stable disease (minimum of 6 weeks) as best response, with two patients on therapy >3 months (one with melanoma, one with cystadenocarcinoma of the head/neck). Conclusions LY2275796 was well tolerated up to 1000 mg. Since tumor eIF-4E expression was decreased, but no tumor response observed, LY2275796 should be studied combined with other treatment modalities.

We have cloned and sequenced the rfaL and rfaK genes for lipopolysaccharide synthesis in Salmonella typhimurium LT2 on a 4.28-kb HindIII fragment from the previously described R' factor pKZ3 (S. K. Kadam, A. Rehemtulla, and K. E. Sanderson, J. Bacteriol. 161:277-284, 1985). rfaL is thought to encode a component of the O-antigen ligase, and rfaK is believed to encode the N-acetylglucosamine transferase. The genes were identified by the loss of complementation of prototype rfaL and rfaK mutations after Tn1000 mutagenesis. Translation of the nucleotide sequence predicted sizes of 45.9 and 43.1 kDa for the rfaL and rfaK gene products, respectively. Hydropathy analysis of the rfaL product suggested that it was an integral membrane protein. A third gene, rfaZ, was found to be an 808-bp open reading frame on the pyrE side of rfaK. Insertions into rfaZ reduced rfaK complementation, suggesting cotranscription in the pyrE-cysE direction. The rfaL gene is transcribed in the opposite direction in a separate operon which may also include rfaC. An incomplete open reading frame with homology to an Escherichia coli gene in the same region, rfaY, was found on the pyrE side of rfaZ. Complementation studies with Tn1000 insertions in rfaL showed that rfaL446 and rfaL447 are allelic. With the cloning of the rfaL and -K genes, the order of genes within the rfa cluster at 79 units on the linkage map was found to be cysE-rfaDFCLKZYJIBG-pyrE.

Purpose: Enhanced tumor cell survival through expression of inhibitors of apoptosis (IAP) is a hallmark of cancer. Survivin, an IAP absent from most normal tissues, is overexpressed in many malignancies and associated with a poorer prognosis. We report the first-in-human dose study of LY2181308, a secondgeneration antisense oligonucleotide (ASO) directed against survivin mRNA.Patients and Methods: A dose-escalation study evaluating the safety, pharmacokinetics, and pharmacodynamics of LY2181308 administered intravenously for 3 hours as a loading dose on 3 consecutive days and followed by weekly maintenance doses. Patients were eligible after signing informed consent, had exhausted approved anticancer therapies and agreed to undergo pre-and posttreatment tumor biopsies to evaluate reduction of survivin protein and gene expression.Results: A total of 40 patients were treated with LY2181308 at doses of 100 to 1,000 mg. Twenty-six patients were evaluated at the recommended phase 2 dose of 750 mg, at which level serial tumor sampling and

The ardeemins are a new family of secondary metabolites produced by submerged fermentation of a fungus which was isolated from a soil sample collected in Brazil. Based on taxonomic studies, the producing culture was identified as Aspergillus fischeri var. brasiliensis strain AB 1826M-35. 5-7V-Acetylardeemin potentiated the cytotoxicity of the anticancer agent vinblastine in multidrug resistant humantumorcells.Multidrug resistance (MDR)is characterized by the development of resistance to several structurally unrelated anticancer agents and is a major cause of failure of cancer chemotherapy. The appearance of a specific glycoprotein, P-170, is generally associated with resistant cells1*. P-170 is a membrane associated glycoprotein thought to actively export cytotoxic compoundssuch as anthracyclines and Vinca alkaloids from resistant tumor cells2). Although several compoundsare knownto reverse MDR, none are used clinically because of adverse side effects3*. In the course of screening for modulators of MDR, we discovered a family of novel compounds which we have called ardeemins. 5-JV-Acetylardeemin appears to be the most efficacious of these compoundsin the reversal of MDR. The compoundsare produced in the fermentation broth of Aspergillus fischeri var. brasiliensis strain AB 1826M-35. This paper describes the taxonomy and the fermentation of the producing microorganism and the biological activity of ardeemin and 5-7V-acetylardeemin. The isolation and structural elucidation of these and other congeners are described in an accompanying publication4*. Materials and Methods MicroorganismsStrain AB1826M-35 was isolated from soil collected in Brazil. A subculture of the microorganism was deposited at

HumanRhinoviruses belong to one of the largest family of positive sense RNAviruses; the Picornaviridae, which includes humanpathogens such as enteroviruses (poliovirus, coxsackeivirus, echovirus

Summary Survivin is expressed in tumor cells, including acute myeloid leukemia (AML), regulates mitosis, and prevents tumor cell death. The antisense oligonucleotide sodium LY2181308 (LY2181308) inhibits survivin expression and may cause cell cycle arrest and restore apoptosis in AML. Methods In this study, the safety, pharmacokinetics, and pharmacodynamics/efficacy of LY2181308 was examined in AML patients, first in a cohort with monotherapy (n=8) and then post-amendment in a cohort with the combination of cytarabine and idarubicin treatment (n=16). LY2181308 was administered with a loading dosage of 3 consecutive daily infusions of 750 mg followed by weekly intravenous (IV) maintenance doses of 750 mg. Cytarabine 1.5 g/m2 was administered as a 4-hour IV infusion on Days 3, 4, and 5 of Cycle 1, and idarubicin 12 mg/m2 was administered as a 30-minute IV infusion on Days 3, 4, and 5 of Cycle 1. Cytarabine and idarubicin were administered on Days 1, 2, and 3 of each subsequent 28-day cycle. Reduction of survivin was evaluated in peripheral blasts and bone marrow. Results Single-agent LY2181308 was well tolerated and survivin was reduced only in patients with a high survivin expression. In combination with chemotherapy, 4/16 patients had complete responses, 1/16 patients had incomplete responses, and 4/16 patients had cytoreduction. Nine patients died on study: 6 (monotherapy), 3 (combination). Conclusions LY2181308 alone is well tolerated in patients with AML. In combination with cytarabine and idarubicin, LY2181308 does not appear to cause additional toxicity, and has shown some clinical benefit needing confirmation in future clinical trials.

Dimethylation of adenine 2058 in 23S rRNA renders bacteria resistant to macrolides, lincosamides, and streptogramin B (MLS resistance), because the antibiotic binding site on the altered 50S ribosomal subunit is no longer accessible. We now report that certain 6-O-methyl-11,12-cyclic carbamate derivatives of erythromycin are able to bind to dimethylated MLS-resistant 50S ribosomal subunits, thus inhibiting protein synthesis and cell growth. One of these novel structures, an 11-deoxy-11-(carboxyamino)-6-O-methylerythromycin A 11,12-(cyclic ester) derivative, structure la, was studied in detail. It inhibited in vitro protein synthesis in extracts prepared from both susceptible and MLS-resistant Bacillus subtilis with 50% inhibitory concentrations of 0.4 and 20 ,uM, respectively. The derivative bound specifically to a single site on the 50S subunit of MLS-resistant ribosomes prepared from B. subtilis and Staphylococcus aureus, and no binding to 30S subunits was observed. The association rate constant of derivative la with sensitive and resistant ribosomes was 100-and 500-fold slower, respectively, than that of the parent compound, erythromycin, with sensitive ribosomes. The dissociation rate constant of la from sensitive and resistant ribosomes was 50-to 100-fold slower than the rate of erythromycin dissociation from sensitive ribosomes. Furthermore, la binding to sensitive 50S subunits led to induction of ermC and ermD, while binding to resistant 50S subunits did not, showing that perturbation of sensitive and resistant 50S subunit function by la differs. These data demonstrated that la is unique in its interaction with MLS-resistant ribosomes and that this interaction causes a novel allosteric perturbation of ribosome function.