Vandetanib (ZD6474): an orally available receptor tyrosine kinase inhibitor that selectively targets pathways critical for tumor growth and angiogenesis

Vandetanib (ZD6474; ZACTIMA, AstraZeneca) is a once-daily, orally available agent with potential for use in a number of solid tumor types. Vandetanib targets key signaling pathways in cancer by inhibiting VEGFR-dependent tumor angiogenesis, and EGFR- and RET-dependent tumor cell proliferation and survival. Phase I studies showed vandetanib to be generally well tolerated at doses of < or = 300 mg/day, with a pharmacokinetic profile that supports once-daily oral administration. Phase II evaluation of vandetanib in patients with advanced refractory NSCLC has demonstrated improvements in progression-free survival both as monotherapy (versus gefitinib) and in combination with docetaxel (versus docetaxel alone). These positive outcomes have led to the initiation of Phase III trials of vandetanib in advanced NSCLC. Clinical development is also ongoing in other tumor types and encouraging evidence of antitumor activity has been reported in patients with metastatic hereditary medullary thyroid cancer.     

Phase I trial of aclacinomycin-A

Aclacinomycin-A is a new anthracycline antibiotic with a broad spectrum of antitumor activity in animals. Compared to doxorubicin, it was found to produce less cardiotoxicity and alopecia. A Phase I trial of aclacinomycin-A given as a weekly 15 min IV infusion was conducted in 20 previously treated patients with advanced solid tumors. Four dose levels ranging from 40 to 100 mg/m2 were studied; myelotoxicity was dose-limiting at 85 and 100 mg/m2. Other toxicities were moderate to severe nausea and vomiting in 9 patients, mild phlebitis in 2 patients, and mild abnormality of liver function tests in 3 patients. No cardiac or renal toxicities were seen, but two partial responses were observed. The pharmacokinetic profile of aclacinomycin-A in plasma and urine was studied in 3 patients given 65 mg/m2 using a high performance liquid chromatography assay. The data obtained were consistent with a two compartment model of drug disposition with initial and terminal half-life values of 6.6 min and 13.3 h, respectively. The major fluorescent metabolite was eliminated with a terminal half-life of 25 h. Two metabolites as well as the parent drug were excreted in the urine as less than 10% of the doses given. This pharmacokinetic profile is similar to that of other anthracyclines, although aclacinomycin-A appears to have lower blood levels than doxorubicin given at equivalent doses. On this weekly schedule, the recommended dose is 65 mg/m2 for Phase II trials.     

Preclinical antitumor activity of CI-994

Summary CI-994 [aka: acetyldinaline; PD 123654; 4-acetylamino-N-(2aminophenyl)-benzamide] (Figure 1) is a novel antitumor agent with a unique mechanism of action. It is the acetylated metabolite of dinaline, a compound previously identified as having cytotoxic and cytostatic activity against several murine and human xenograft tumor models. CI-994 had activity against 8/8 solid tumors tested (log cell kills at the highest non-toxic dose): pancreatic ductal adenocarcinoma #02 (4.7); pancreatic adenocarcinoma#03 (3.0; 1/6 cures); colon adenocarcinoma #38 (1.6); colon adenocarcinoma #51/A (1.1); mammary adenocarcinoma #25 (1.7); mammary adenocarcinoma #17/ADR (0.5); Dunning osteogenic sarcoma (4.0); and the human prostate carcinoma LNCaP (1.2). CI-994 had the same spectrum of activity in vivo as dinaline. It also behaved similarly in schedule comparison/toxicity trials. Prolonged administration with lower drug doses was more effective than short-term therapy at higher individual doses. If doses were kept between 40 and 60 mg/kg/injection, prolonged administration (> 50 days) was tolerated with no gross toxicity. Doses 90 mg/kg/injection caused lethality after 4–5 days of administration. The maximum tolerated total dose was also increased with smaller individual doses administered for prolonged intervals. Clinical Phase I trials are ongoing with this agent.     

Safinamide (Newron Pharmaceuticals)

Safinamide (formerly PNU-151774E), a sodium and calcium channel modulator that also inhibits monoamine oxidase B (MAOB), is under development by Newron Pharmaceuticals for the potential treatment of epilepsy, Parkinson's disease (PD), pain and stroke [345222], [348351]. Phase I trials for epilepsy and PD have been completed, and dose-finding studies for both indications had commenced in March 2001 [401685]. The compound was previously developed by Pharmacia & Upjohn (P&U) for the potential treatment of epilepsy, an indication for which it initially reached phase I trials [294891], [345007]. Newron acquired the rights to safinamide from P&U at the end of 1998. Results from two phase I trials of the compound (single ascending dose and steady state at three doses), completed in March 2000, demonstrated that the drug is well tolerated with good bioavailability and linear pharmacokinetics [359652].     

Idarubicin (4-demethoxydaunorubicin)

4-Demethoxydaunorubicin (4-DMDR, IMI 30, Idarubicin, NSC 256439) is a new analog of daunorubicin (DNR) with antileukemic activity in experimental systems that is superior to that of daunorubicin (DNR) or doxorubicin (DX). The drug is more potent than DNR and DX and is active by both the intravenous and the oral routes of administration. After i.v. and oral administration in humans, Idarubicin is rapidly metabolized to its 13-dihydroderivative (Idarubicinol) and the plasma levels of this metabolite are consistently higher than those of the unchanged drug. Idarubicinol has been shown to be an active metabolite in experimental models, being as potent and as active as the parent compound. Phase II clinical trials of Idarubicin have indicated that: By I.V. route Idarubicin is a potent antileukemic agent active in relapsed or refractory, ANLL, ALL (adult and pediatric) either as single agent or in combination with Ara-C at doses of 8-12 mg/m2 by i.v. day 1, 2 and 3 or 7-8 mg/m2 i.v. daily X 5 days (adults). There is evidence of lack of cross-resistance with parent drugs and other antileukemic agents. Phase III studies in previously untreated acute leukemias have been initiated. By oral route Idarubicin has antitumor activity in breast cancer at the doses of 35-45 mg/m2 q 3-4 weeks or 15 mg/m2 daily X 3 days q 3-4 weeks. Idarubicin has activity as a single agent in adult leukemias at the doses of 20-30 mg/m2/day X 3 days. The safety of administration (no risk of extravasation), the good tolerability and the reduced potential for cardiac toxicity, make oral Idarubicin particular attractive for further clinical development. Whether Idarubicin proves to be more effective and/or less cardiotoxic in clinical therapy than DNR or DX remains to be seen through prospective randomized studies which have been already initiated both in leukemias and solid tumors.     

ZD-0473 AstraZeneca

ZD-0473 (formerly JM-473 and AMD-473) is a sterically hindered platinum (II) complex designed and synthesized by Johnson Matthey Technology and the Cancer Research Campaign (CRC) and under development as a potential treatment for cisplatin-resistant cancer. AstraZeneca is developing both an i.v. and an oral formulation of ZD-0473. In December 1999 the i.v. formulation entered phase II clinical trials for the potential treatment of solid tumors; the oral formulation is undergoing preclinical development [351298,349551]. AstraZeneca expects to file for registration of the drug in the fourth quarter of 2002 [377656]. Phase I clinical trials for the potential treatment of a range of solid tumors, including colorectal cancer were carried out jointly by AnorMED (a subsidiary of Johnson Matthey) and the CRC at the Royal Marsden Hospital, UK [301848,315489,337657]. AstraZeneca has licensed ZD-0473 from AnorMED and is responsible for the worldwide development of the drug beyond phase I trials [337540]. Phase I trials to determine the maximum tolerated dose in patients, the nature of the dose-limiting toxicity and the pharmacokinetics of the drug commenced in the US in November 1999 [347964]. In June 2000, Deutsche Bank predicted sales of US $15 million in 2003 [374500]. In March 1999, Lehman Brothers predicted a 15% probability that the drug would reach worldwide markets, and be launched onto the market in 2003 [336599].     

A Phase I trial of spirogermanium administered on a continuous infusion schedule

We have evaluated the toxicity of the antitumor agent spirogermanium on a schedule of continuous intravenous administration for periods up to five days. The doses tested were between 100 mg/m²/day and 500 mg/m²/day. Peripheral vein phlebitis occurred at all dose levels and was not relieved by addition of hydrocortisone or heparin to the infusion. No phlebitis occurred when the drug was administered through a central vein. The dose limiting toxicity of spirogermanium was neurologic, notably tremors and mental confusion. These problems became progressively more severe at doses above 250 mg/m²/day. There was no discernible bone marrow, renal or hepatic toxicity. One patient developed reversible interstitial pneumonitis. The recommended Phase II dose of spirogermanium is 200 mg/m²/day for five days, with the possibility of escalation in selected patients. Because spirogermanium is more toxic to tumor cells with prolonged exposure than with intermittent exposure, this schedule could be considered for Phase II trials, particularly in diseases thought to be especially sensitive such as ovarian and prostatic carcinoma or lymphomas.     

Phase I and pharmacokinetic study of tiazofurin (TCAR,NSC 286193) administered by continuous infusion

Summary Tiazofurin (2--D-ribofuranosylthiazole-4-carboxamide, TCAR) is a synthetic C-nucleoside that demonstrated significant in vivo activity against a variety of animal tumors as well as in vitro activity against human tumor-derived cell lines. Thirteen patients were treated with TCAR administered as a 5-day continuous infusion in this Phase I trial. Seventeen complete cycles were administered in three dose levels ranging from 550 to 1450 mg/M². Dose-limiting toxicities were myelosuppression and neurotoxicity including severe lethargy. Other toxicities including superficial skin peeling, myalgias, and tearing were seen at all doses. One patient had chest pain on day 4 resulting in stopping the drug, however, there was no evidence of cardiac or pericardial disease. Uric acid levels rose within one day in the absence of allopurinol treatment. There were no treatment related deaths. HPLC measurement of drug levels demonstrated steady-state plasma levels during the infusion, and a half-life following the infusion of 7.7 ± 0.6 hours. Minor abnormalities in renal function were associated with dramatic changes in pharmacokinetics and toxicity. No clinical responses were observed in this trial.Abbreviations TCAR Tiazofurin - HPLC High performance liquid chromatography - IMPD Inosine monophosphate dehydrogenase - WBC white blood cell - CPK creatine phosphokinase - C_ss steady-state concentration     

Phase I studies on the safety, tolerability, pharmacokinetics and pharmacodynamics of SB-649868, a novel dual orexin receptor antagonist

The orexin system plays a major role in the integration of metabolic and circadian influences that drive wakefulness. This paper describes initial Phase I trials of a novel dual orexin receptor antagonist SB-649868 that has demonstrated preclinical potential for treatment of sleep disorders. The trial designs included a single ascending dose escalation study (dose range: 10-80?mg in the fed and fasted states) and a multiple repeat dose study (dose range: 5-30?mg in the fed state) enrolling a total of 103 male volunteer subjects. SB-649868 was well tolerated at all doses in this study population, with mechanism-related adverse events (e.g. somnolence and fatigue) observed in a majority of subjects after 60 and 80?mg single doses. Although total drug exposure was similar in the fed and fasted states, the rate, but not the extent, of absorption increased in the fed state, resulting in an increased C(max). The typical estimated half-life of SB-649868 was 3-6?h - comparable with currently used hypnotic agents. Repeated administration of SB-649868 dose-dependently increased exposure to simvastatin (10?mg), suggesting CYP3A4 inhibition ranging from very mild (5?mg) to strong (30?mg). Evening dosing resulted in significant dose-dependent improvement in latency to persistent sleep, total sleep time and wake after sleep onset as measured by polysomnography. Next-morning testing did not detect evidence of residual cognitive effects. Results of these trials support further investigation of SB-649868 and other dual orexin receptor antagonists as potentially effective and well-tolerated treatments for patients with sleep disorders.     

Leflunomide and malononitriloamides

Leflunomide is a new immunomodulatory drug effective in experimental models of autoimmune diseases and allo- or xenotransplantation. In a Phase II clinical trial leflunomide has shown high tolerability and efficacy in patients with advanced rheumatoid arthritis. The immunomodulatory activity of leflunomide is attributed to its primary metabolite, A77 1726, a malononitriloamide. The in vitro and in vivo mechanisms of action of this class of compounds remain to be completely defined. A77 1726 and several malononitriloamide analogues inhibit T- and B-cell proliferation, suppress immunoglobulin production, and interfere with cell adhesion. While no one central molecular mechanism of action has been proposed to explain all the effects of the malononitriloamides, inhibition of de novo pyrimidine biosynthesis and inhibition of cytokine- and growth factor-receptor associated tyrosine kinase activity are leading hypotheses for the effects of A77 1726 on T- and B-cell proliferation and function. Leflunomide is effective when administered at daily doses of 10 and 25 mg to patients with active rheumatoid arthritis. The improved efficacy at the 25 mg dose is associated with a higher incidence of adverse effects (gastrointestinal symptoms, weight loss, allergic reactions, skin rash, and reversible alopecia). Due to the long plasma half-life of A77 1726 (11-16 days), loading doses are required to achieve steady-state concentrations. Phase III randomised, placebo-controlled trials using daily doses of 10 or 20 mg are underway in the US and Europe to confirm and extend the results of the Phase II study. Malononitriloamide analogues of A77 1726 are being evaluated for immunosuppressive efficacy in preclinical models of transplantation, because these compounds have a shorter half-life in animals than A77 1726. If these analogues show efficacies similar to leflunomide in these models and have shorter half-lives than A77 1726 in Phase I trials, the preclinical and Phase I data will be used to select the analogues for Phase II trials in organ transplant recipients.     

Phase I study of mitonafide in 120 hour continuous infusion in non-small cell lung cancer

Summary Mitonafide is the lead compound of a new series of antitumor drugs, the 3-Nitronaphthalimides, which have shown antineoplastic activityin vitro as well asin vivo. This phase I Mitonafide study in non-small cell lung cancer using a 120-hour continuous infusion (120 h. C.I.) schedule of administration was designed to deliver the maximum amount of drug while avoiding the risk of central nervous system (CNS) toxicity, previously observed in studies with daily short (1 hour) administration schedules. Twenty patients were treated at doses ranging from 107–200 mg/m²×120 h. C.I. Dose-limiting toxicity with this schedule of administration was leukopenia. Other toxicities were mild or not relevant. No CNS toxicity was observed. The recommended dose for phase II C.I. Mitonafide studies is 170 mg/m²×120 h. C.I. in previously untreated patients. Plasma level monitoring is recommended.     

Longitudinal FEV1 dose–response model for inhaled PF-00610355 and salmeterol in patients with chronic obstructive pulmonary disease

The objective of this work was to characterize the dose?Cresponse relationship between two inhaled long-acting beta agonists (PF-00610355 and salmeterol) and the forced expiratory volume in one second (FEV1) in order to inform dosing recommendations for future clinical trials in patients with chronic obstructive pulmonary disease (COPD). This meta-analysis of four studies included 8,513 FEV1 measurements from 690 patients with moderate COPD. A longitudinal kinetic-pharmacodynamic (K-PD) model was developed and adequately described changes in FEV1 measurements over time, including circadian patterns within a day, as well as changes in FEV1 measurements elicited from administration of PF-00610355 or salmeterol. The fine-particle dose, the amount of drug present in particles small enough for lung delivery, was used as the exposure measure for PF-00610355. Greater reversibility following administration of a short-acting beta agonist during run-in was associated with increased FEV1 response to long-acting beta agonists (through an increased maximal response, E_max). Simulations were conducted to better understand the response to PF-00610355 relative to placebo and salmeterol. The results of the simulations show that once daily fine-particle doses of 28.1???g versus placebo have a moderate probability of providing an average improvement above 100?mL at trough. The 50???g fine-particle dose, on the other hand, has a greater than 0.78 probability of achieving a 120?mL improvement versus placebo at trough. From an efficacy perspective and assuming a fine-particle fraction of 25?% for the Phase 3 formulation; 100 and 200???g once daily nominal doses would be of interest to investigate in future Phase 3 trials.     

Clinical toxicity associated with tiazofurin

Summary Tiazofurin, an investigational antimetabolite, is undergoing clinical evaluation in leukemia. We analyzed the data base of 198 patients entered in Phase I trials to characterize the incidence and severity of toxicities associated with tiazofurin according to dose and schedule. Severe myelosuppression occurred infrequently, and was not dose-dependent. A five day bolus schedule had a higher incidence of severe or life-threatening neutropenia than other schedules. Tiazofurin produced lymphopenia which was not dose-dependent in the range of 23–36% decrease from baseline, and the effect on lymphocyte count was generally greater than the decline in neutrophil count. Non-hematologic toxicity of a moderate or worse severity ( grade 2) included nausea and vomiting (18% of all courses), serum transaminase elevations (SGOT, 16%; SGPT, 9%), rash (9%), stomatitis (3%), conjunctivitis (3%), headache (10%), other signs of central nervous system toxicity (8%), and cardiac toxicity, primarily pleuropericarditis (4%). Dose-related cutaneous toxicity, headache, and nausea and vomiting were evident in the five day bolus schedule, and myalgia was more frequently reported at higher doses on the single dose schedule. The five day continuous infusion (CI) schedule had a higher incidence of neurotoxicity, cardiac toxicity, SGPT elevations and ocular toxicity than the daily for five days bolus schedule, but none of these differences attained statistical significance. Although the peak plasma concentrations of tiazofurin achieved with the five day bolus schedule were 3-fold higher than the steady-state plasma levels seen with an equal dose given by CI, the area under the concentration-time curve (AUC) was approximately 1.6-fold higher with CI. These observations suggest that both high peak plasma concentrations (above 400 uM) and prolonged exposure to plasma levels exceeding 50 uM may result in a higher incidence of serious non-hematologic toxicity.     

T-3811. Toyama/Bristol-Myers Squibb

Toyama and Bristol-Myers Squibb (BMS) are developing the des-F(6)-quinolone T-3811 (BMS-284756) as a potential treatment for bacterial infections, including respiratory and urinary tract infections, and skin and soft tissue infections. The drug is in phase II trials in the US and Europe, and an injectable formulation began phase I trials in the US in April 2000. Phase I trials commenced in Japan in September 1999. Phase III trials were expected to begin outside Japan in 2000. T-3811 is expected to be administered as an oral or injectable once-a-day formulation. Preclinical studies suggests it has a better side-effect profile than commonly associated with other quinolones on the market. Bristol-Myers Squibb has acquired worldwide development and marketing rights, with the exception of Japan, South Korea, Taiwan and China. In December 2001, Morgan Stanley predicted that T-3811 could have peak sales potential exceeding $500 million if the positive clinical data released at this year's ICAAC continued, and that BMS was on track for filing in 3Q02.     

Recombinant human granulocyte macrophage colony-stimulating factor: current status of clinical trials and potential future applications.

Recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF) was one of the first of the myeloid growth factors to become available for clinical trials. Phase I studies have demonstrated that the optimal administration is by continuous intravenous infusion or subcutaneous injections at doses of 4-5 micrograms/kg/day. Phase II trials in patients with a variety of malignancies who receive rhGM-CSF after standard doses of chemotherapy have demonstrated significant reductions of the duration of leucocytopenia. Use of rhGM-CSF after high-dose chemotherapy (with or without bone marrow rescue) suggest that this agent decreases the time to recovery of a normal blood count and reduces infective complications. Results in myelodysplasia and aplastic anemia have been less encouraging. The potential value of rhGM-CSF in the treatment of a variety of other conditions including AIDS and the leukemias is being tested and the early results are discussed.     

AIT-082, a novel purine derivative with neuroregenerative properties

Introduction: The interaction between the VEGFRs and their ligands plays an important role in tumor angiogenesis. Despite a series of problems encountered during early work on blocking growth factors, current evidence injects further vigor into researching the modulation of VEGFR activity. Emerging preclinical and clinical studies suggest that attenuating receptor activity can synergistically promote antitumor action if utilized concurrently with conventional therapies.

Areas covered: This review presents an up-to-date assessment of the potential role of modulating receptor activities in various cancers. The sentinel work on the proof of principles in various animal models, and the current translational research on these small molecule inhibitors and receptor blocking antibodies, from Phase I to Phase III trials, has been systematically examined with an emphasis on agents in earlier stages of development.

Expert opinion: Many clinical trials are ongoing, but early phase trials show promising results. Recently, there has been a huge explosion of research activity either in the development of new drugs or in the understanding its biology. Many current trials lend support to the rationale behind these therapies, which can function as adjuvants to conventional treatments. It has been argued that normalization of tumor-induced vasculature can promote better drug delivery and prevent resistance to radiotherapy. However, strategies involving the inhibition of the interaction of VEGFRs with ligands and their downstream pathways are not, in general, at a stage where it will be directly useful in clinical cancer treatment. A deeper understanding of these biologic therapies will help to improve the efficacy of conventional treatments and furthermore reduce dose-dependent cytotoxic activity.     

Clinical pharmacology of etoricoxib: a novel selectiveCOX2 inhibitor

The development of COX2 inhibitors with improved biochemical selectivity (such as etoricoxib and valdecoxib) over that of commercially available coxibs has been driven by the potential advantage of safety using higher coxib doses for increased efficacy. Etoricoxib has been approved in the UK as a once-daily medicine for symptomatic relief in the treatment of osteoarthritis (OA), rheumatoid arthritis (RA) and acute gouty arthritis. It is currently approved with additional indications (i.e., for relief of acute pain associated with dental surgery, for primary dysmenorrhoea and for chronic musculo-skeletal pain, including chronic lower-back pain) in Mexico, Brazil and Peru. Etoricoxib has an in vitro COX1/COX2 IC₅₀ ratio of 344, the highest of any coxib. The administration of therapeutic doses of etoricoxib to healthy subjects does not affect COX1 activity in circulating platelets and gastric biopsies. The profound inhibition of monocyte COX2 activity at 24 h after dosing, as predicted by a pharmacological half-life of ~ 22 h, supports a once-daily dosing regimen of etoricoxib. In randomised, well-controlled clinical trials, etoricoxib has been shown to have a comparable clinical efficacy with traditional NSAIDs. Combined analysis of efficacy trials with etoricoxib versus non-selective NSAIDs has shown that the drug halves both investigator-reported upper gastrointestinal perforation, ulcers and bleeds (PUBs) and confirmed PUBs, and reduces the need for gastroprotective agents and gastrointestinal comedications by ~ 40%. The risk of lower extremity oedema and hypertension adverse experiences with etoricoxib was low and generally similar to comparator NSAIDs in a combined analysis of eight Phase III studies in OA, RA, chronic low-back pain and surveillance endoscopy. Large, randomised clinical trials have been planned to confirm the renal, gastrointestinal and cardiovascular safety of etoricoxib.     

Recent development of IMP dehydrogenase inhibitors for the treatment of cancer

Inosine 5'-monophosphate dehydrogenase (IMPDH) represents an attractive target for the development of anticancer agents; however, there are no drugs aimed at this target for the treatment of cancer currently available on the market. Tiazofurin, a potent IMPDH inhibitor, reached clinical trials with Orphan Drug status for the treatment of patients in blast crisis of chronic myelogenous leukemia (CML); however, it was considered too toxic for application against other malignancies and no development has been reported for this drug since 2002. Formulations of mycophenolic acid, another potent inhibitor of IMPDH, are currently used for the prevention of rejection following transplantation, and against autoimmune diseases. More recently, numerous studies have demonstrated the potential of mycophenolic acid as an anticancer agent, with a phase I clinical trial in patients with advanced multiple myeloma ongoing. Furthermore, synergy between imantinib and mycophenolic acid in CML treatments has also been reported. Related compounds such as mycophenolic adenine dinucleotides, along with second-generation analogs, are undergoing preclinical evaluation, while another inhibitor of IMPDH, AVN-944, is currently in phase I clinical trials to investigate the treatment of hematological malignancies. This article reviews recent applications of IMPDH inhibitors as anticancer agents, and highlights the progress that has been made in this field.