Ateeq Ahmad

Phase I study of liposome-encapsulated c-raf antisense oligodeoxyribonucleotide infusion in combination with radiation therapy in patients with advanced malignancies.

PURPOSE: Raf proteins are key elements of growth-related cellular signaling pathways and are a component of cancer cell resistance to radiation therapy. Antisense oligonucleotides to c-raf-1 permit highly selective inhibition of the gene product and offer a strategy for sensitizing cancer cells to radiation therapy. In this dose escalation study, we evaluated the safety of combined liposomal formulation of raf antisense oligonucleotide (LErafAON) and radiation therapy in patients with advanced malignancies. EXPERIMENTAL DESIGN: Patients with advanced solid tumors were treated with LErafAON in a phase I dose escalation study while receiving palliative radiation therapy. Drug-related and radiation-related toxicities were monitored. Pharmacokinetics and expression of c-raf-1 mRNA and Raf-1 protein were determined in peripheral blood mononuclear cells. RESULTS: Seventeen patients with palliative indications for radiation therapy were entered into this study. Thirteen patients received daily infusions of LErafAON and four received twice-weekly infusions. Radiation therapy was delivered in daily 300-cGy fractions over 2 weeks. Patients tolerated radiation, and no unexpected radiation-related side effects were observed. Drug-related reactions (grade > or =2), such as back pain, chills, dyspnea, fatigue, fever, flushing, and hypertension, were observed in most patients and were managed by premedication with corticosteroids and antihistamines. Serious adverse events occurred in five patients, including acute infusion-related symptoms, abnormal liver function tests, hypoxia, dehydration, diarrhea, esophagitis, fever, hypokalemia, pharyngitis, and tachypnea. Twelve of 17 patients were evaluable for tumor response at completion of treatment; four showed partial response, four showed stable disease, and four experienced progressive disease. The intact rafAON was detected in plasma for 30 minutes to several hours. Six patients with partial response or stable disease were evaluable for c-raf-1 mRNA and/or Raf-1 protein expression. Inhibition of c-raf-1 mRNA was observed in three of five patients. Raf-1 protein was inhibited in four of five patients. CONCLUSION: This is the first report of the combined modality treatment using antisense oligonucleotides with radiation therapy in patients with advanced cancer. A dose of 2.0 mg/kg of LErafAON administered twice weekly is tolerated with premedication and does not enhance radiation toxicity in patients. The observation of dose-dependent, infusion-related reactions has led to further modification of the liposomal composition for use in future clinical trials.

Use of surface plasmon resonance biosensor technology as a possible alternative to detect differences in binding of enantiomeric drug compounds to immobilized albumins

The use of biosensors for monitoring real time interactions between biomolecules and drug compounds has a lot of advantages over presently existing detection methods, the major ones being the elimination of radio labels and rapid screening. We can also obtain information about the kinetic parameters and these values may serve as useful indicators towards subtle differences in the binding strength and characteristics of closely related drug compounds and enantiomers. The Biacore 3000 biosensor based on the Surface Plasmon Resonance (SPR) technology was used to assess the albumin protein binding differences between two enantiomers of a drug compound. Normalized responses (NRU) and affinity constants (K(D)) were readily calculated. Statistical parameters like mean normalized responses, %CV values were determined to make the technique robust. The %CV values obtained were within the preset limits of < or = 25% (FDA limits for drug development and method validation protocols) for the binding interactions for majority of the concentrations studied. For example, the %CV values for the normalized responses for the binding of the control drug warfarin to human albumin ranged from 7.9 to 24.3%. The method gave reproducible results, and the results indicated slight differences in binding patterns of the enantiomers to human and rat albumin.

Nanosomal Amphotericin B is an efficacious alternative to Ambisome® for fungal therapy.

Amphotericin B was formulated in lipids (Nanosomal Amphotericin B) without using any detergent or toxic organic solvents during the preparation. Electron microscopy and particle size determination of Nanosomal Amphotericin B showed a homogeneous population of nanosized particles below 100 nm. Hemolysis assay indicated that Nanosomal Amphotericin B causes significantly less lysis of red blood cells than Amphotericin B deoxycholate and was comparable to Ambisome. A maximum daily dose of Nanosomal Amphotericin B at 5 mg/kg in rabbits and 10 mg/kg in mice for 28 days showed no symptoms of toxicity, mortality or significant body weight reduction. Hematological and gross pathological analysis of tissues revealed no abnormalities attributable to the drug treatment. Nanosomal Amphotericin B and Ambisome were injected (iv) at 2 mg/kg consecutively for 5 days into mice infected with Aspergillus fumigatus. The treatment resulted in 90% survival with Nanosomal Amphotericin B and only 30% survival with Ambisome after 10 days of fungal infection. However, all of the 10 control mice which were not treated with Amphotericin B died within 5 days of fungal infection. Nanosomal Amphotericin B is safe, cost effective and provides an alternative option for treatment of fungal disease.

Endoxifen is a new potent inhibitor of PKC: A potential therapeutic agent for bipolar disorder

Protein kinase C (PKC) plays a major role in regulation of both pre and postsynaptic neurotransmission. Excessive activation of PKC results in symptoms related to bipolar disorder. Tamoxifen, a widely used breast cancer drug is known to inhibit PKC and demonstrate antimanic properties in human. We describe herein the synthesis of endoxifen, a tamoxifen active metabolite and compared its PKC inhibitory activity with that of tamoxifen. Endoxifen exhibited fourfold higher potency compared to tamoxifen.

Separation of Liposome-Entrapped Mitoxantrone from Nonliposomal Mitoxantrone in Plasma: Pharmacokinetics in Mice

A method is described for quantification of the liposomal and nonliposomal forms of mitoxantrone (MTO) in mouse plasma after intravenous administration of liposome-entrapped MTO Easy-to-Use (LEM-ETU) formulation. This is based on the property of liposome-entrapped MTO (LEM) to pass through reversed-phase C(18) silica gel cartridges, while nonliposomal MTO or free MTO is retained with strong hydrophobicity and later is eluted with acidic methanol. Extraction of LEM and free MTO from plasma is performed in two steps. This technique is rapid and sensitive and can be used for a large series of sample preparation. The plasma samples are found stable after one freeze-thaw cycle. The recovery of MTO, as well as the precision, linearity, and accuracy of the method for both free and liposomal MTO, appears satisfactory for pharmacokinetic studies. The pharmacokinetic results in mice show a sustained release of MTO from LEM-ETU.

Polyoxyl 60 hydrogenated castor oil free nanosomal formulation of immunosuppressant Tacrolimus: Pharmacokinetics, safety, and tolerability in rodents and humans

OBJECTIVE Develop Nanosomal formulation of Tacrolimus to provide safer alternative treatment for organ transplantation patients. Investigate safety, tolerability and pharmacokinetics of Nanosomal Tacrolimus formulation versus marketed Tacrolimus containing polyoxyl 60 hydrogenated castor oil (HCO-60) that causes side effects. METHODS Nanosomal Tacrolimus was prepared in an aqueous system. The particle size was measured by Particle Sizing Systems and structure morphology was determined by freeze-fracture electron microscopy. Investigational safety studies were conducted in mice and rats. Safety and pharmacokinetics of Nanosomal Tacrolimus were also evaluated in healthy human subjects. RESULTS The morphology of Nanosomal Tacrolimus showed a homogeneous population of nanosized particles with mean particle size of less than 100 nm. A 14 day consecutive administration of Nanosomal Tacrolimus up to 5 and 10mg/kg dose in rats and mice respectively, resulted in no mortality. Nanosomal Tacrolimus in human studies showed that it is safe and the pharmacokinetics profile is similar to the marketed HCO-60 based Tacrolimus. No significant change in peripheral blood lymphocyte percentage was noted in either mice or healthy human male subjects. CONCLUSIONS Nanosomal Tacrolimus is well characterized product which provides a new treatment option. It contains no alcohol or surfactants like HCO-60. Thus, Nanosomal Tacrolimus presents a new and improved therapeutic approach for organ transplant patients compared to the marketed HCO-60 based Tacrolimus product.

Guggullipid derivatives: synthesis and applications

Two guggullipid derivatives, Z-guggulsulfate [4,17(20)-pregnadiene-3-one-16beta-sulfate] sodium salt and Z-guggullaurate [4,17(20)-pregnadiene-3-one-16beta-laurate], have been synthesized and evaluated for liposomal drug delivery system. Its precursor, Z-guggulsterol [4,17(20)-pregnadiene-3-one-16beta-ol], is also synthesized in gram scale starting from guggulsterone using the novel combination of known reactions in fewer steps and with higher yield than previously reported synthesis. These new synthetic guggullipid derivatives were also used in the preparation of liposomes. This new class of lipid molecules will be a useful tool in the development of nanosomal or liposomal drug delivery system.

Bioequivalence Study of Pegylated Doxorubicin Hydrochloride Liposome(PEGADRIA) and DOXILî in Ovarian Cancer Patients: PhysicochemicalCharacterization and Pre-clinical Studies

Objective:To develop Pegylated Doxorubicin Hydrochloride Liposome (PEGADRIA) and compare its physicochemical properties, preclinical safety and efficacy, clinical pharmacokinetic and safety profiles with those of the reference product, Doxil®. Methods: PEGADRIA was prepared and the structure morphology, lamellarity, size, shape, drug loading, lipid bilayer and Peg layer thickness were determined. Safety studies were conducted in mice and rats and efficacy study was conducted in a P-388 leukemia mouse model. To evaluate the pharmacokinetic profile of PEGADRIA, a multicenter, open label, balanced, randomized, two-treatment, two-period, two-sequence, single dose cross-over bioequivalence study was conducted with Doxil® in ovarian cancer patients whose disease had progressed or reoccurred after platinum based chemotherapy under fasting conditions. The pharmacokinetic parameters were determined based on the concentration-time profiles of doxorubicin, whereas the concentration was determines using LC-MS/MS methods. Results: PEGADRIA was similar to Doxil® in terms of general morphology, lamellarity, size, shape, drug loading, lipid bilayer and Peg layer thickness. PEGADRIA and Doxil® showed comparable survival benefit in leukemic mice. The toxicity profiles of PEGADRIA in both mice and rats were comparable to those of Doxil®. Plasma concentrations of doxorubicin from cancer patients were measured to determine the pharmacokinetics profile. The geometric mean ratios (90% confidence intervals) of PEGADRIA /Doxil® for free doxorubicin and encapsulated doxorubicin were similar. Conclusion: PEGADRIA was found to have similar physicochemical profile compared to Doxil®. In addition, it was safe and bioequivalent to Doxil® in ovarian cancer patients.

Nanosomal Paclitaxel Lipid Suspension Demonstrates Higher Response Rates Compared to Paclitaxel in Patients with Metastatic Breast Cancer

Lung cancer is one of the most common causes of cancer-related death in men and women throughout the world. An appropriate statistical model for survival analysis on lung cancer can provide precise prognosis for treatment planning. Usually the traditional prognostic decisions are made purely based on pathologists’ subjective evaluations. It has been proven that accuracy and objectivity of diagnosis and prognosis, when assisted with computational algorithm, will dramatically increase. In this paper, we have developed a novel prediction model called LC-Morph. The prediction model includes cell detection, segmentation, and statistical model for survival analysis. 122 lung cancer patients’ images extracted from the cancer genome atlas (TCGA) data set has been used in this study. A robust seed detection-based cell segmentation algorithm is proposed to accurately segment each individual cell in the image. Based on the cell segmentation results, a set of comprehensive cellular features are extracted using some efficient image feature descriptors. To build a prognostic image signature for patient overall survival, the study data set is randomly split into a training data set (82 patients) and a testing data set (40 patients). Based on the training data, univariate Cox models are used to identify informative image features. A lasso-penalized Cox model is used to derive an image feature-based prognostic model and calculate the corresponding risk score (LC-Morph score) which is used to evaluate the patient’s survival. This prediction score is externally validated using the testing data set. We also stratify patients into high- and low-risk groups based on the LC-Morph score and find significantly longer survival time in the low-risk group than the high-risk group (log-rank P=0.013), which indicates the efficacy of the LC-Morph score in estimating the survival rates of lung cancer patients.

A New Topical Formulation of Minoxidil and Finasteride Improves Hair Growthin Men with Androgenetic Alopecia

Objectives: To compare the safety and efficacy of MorrF (combination of Minoxidil [5%]+Finasteride [0.1%] lipid solution) with Minoxidil (5%) solution in adult male patients suffering from Androgenetic Alopecia (AGA). Background: AGA is one of the three most common forms of non-scarring alopecia with approximately 95% of hair loss cases in men and women. Fifty percent of men by age 50 years exhibit some degree of AGA. Currently there are two effective treatments available for the treatment of AGA in men: topical Minoxidil and oral Finasteride. Clinical studies have demonstrated that both Minoxidil and Finasteride have well established therapeutic effect in the management of AGA. Materials and methods: Safety study in rats was carried out for 28 days with topical application of MorrF twice a day for 28 days. Human Pharmacokinetics (PK) and efficacy study was conducted in male patients suffering from Androgenetic Alopecia. PK parameters were determined after 2 weeks of MorrF administration. For efficacy study patients were randomized to receive either MorrF or Minoxidil (5%) alone for 24 weeks. Patients administered 1 mL of the either solution twice day on the effected part of the scalp. Results: Topical treatment of MorrF was found to be well-tolerated in rats and humans. Pharmacokinetics study in human showed the steady state Cmax,ss and exposure (AUC0-τ,ss) for Minoxidil to be 2.7 ng/mL and 19.3 ng.h/mL respectively whereas the steady state maximum Finasteride concentration (Cmax,ss) was 0.6 ng/mL and exposure (AUC0-τ,ss) of Finasteride was found to be 6.3 ng.h/mL. Significantly more patients treated with MorrF showed greater improvement in Investigator score (65% vs. 26%), global photographic assessment (89% vs. 60%) and patient’s self-assessed questionnaire as compared to Minoxidil alone. Conclusion: Topical formulation of MorrF was shown to have clinically significant improvement in terms of hair growth as compared to Minoxidil (5%) alone.