First-in-human randomized clinical trials of the safety and efficacy of tanezumab for treatment of chronic knee osteoarthritis pain or acute bunionectomy pain.

INTRODUCTION: The neurotrophin nerve growth factor has a demonstrated role in pain transduction and pathophysiology. OBJECTIVES: Two randomized, double-blind, placebo-controlled, phase 1 studies were conducted to evaluate safety, tolerability, and analgesic efficacy of single doses of tanezumab, a humanized anti-nerve growth factor monoclonal antibody, in chronic or acute pain. METHODS: In the first study (CL001), patients with moderate to severe pain from osteoarthritis (OA) of the knee received a single intravenous infusion of tanezumab (3-1000 µg/kg) or placebo in a dose-escalation (part 1; N = 42) or parallel-arm (part 2; N = 79) study design. The second study (CL002) was a placebo-controlled dose-escalation (tanezumab 10-1000 µg/kg; N = 50) study in patients undergoing bunionectomy surgery. RESULTS: Adverse event rates were generally similar across treatments. Most adverse events were generally mild to moderate in severity and no patients discontinued as a result of adverse events. Adverse events of abnormal peripheral sensation were more common with higher doses of tanezumab (≥100 µg/kg) than with placebo. These were generally mild to moderate in severity. Tanezumab provided up to 12 weeks of effective analgesia for OA knee pain, with statistically significant improvements at doses ≥100 µg/kg (P < 0.05). By contrast, no trend for analgesic activity was found when tanezumab was administered 8 to 16 hours before bunionectomy. CONCLUSIONS: The demonstration of a favorable safety profile and clinical efficacy in OA pain supports clinical development of tanezumab as a potential treatment for chronic pain conditions.

Launching Effectiveness Research to Guide Practice in Neurosurgery: A National Institute Neurological Disorders and Stroke Workshop Report.

This workshop addressed challenges of clinical research in neurosurgery. Randomized controlled clinical trials (RCTs) have high internal validity, but often insufficiently generalize to real-world practice. Observational studies are inclusive but often lack sufficient rigor. The workshop considered possible solutions, such as (1) statistical methods for demonstrating causality using observational data; (2) characteristics required of a registry supporting effectiveness research; (3) trial designs combining advantages of observational studies and RCTs; and (4) equipoise, an identified challenge for RCTs. In the future, advances in information technology potentially could lead to creation of a massive database where clinical data from all neurosurgeons are integrated and analyzed, ending the separation of clinical research and practice and leading to a new "science of practice."

The case for soluble Aß oligomers as a drug target in Alzheimer's disease.

Soluble Aß oligomers are now widely recognized as key pathogenic structures in Alzheimer's disease. They inhibit synaptic function, leading to early memory deficits and synaptic degeneration, and they trigger the downstream neuronal signaling responsible for phospho-tau Alzheimer's pathology. The marginal effects observed in recent clinical studies of solanezumab, targeting monomeric Aß, and bapineuzumab, targeting amyloid plaques, prompted expert comments that drug discovery efforts in Alzheimer's disease should focus on soluble forms of Aß rather than fibrillar Aß deposits found in amyloid plaques. Accumulating scientific data suggest that soluble Aß oligomers represent the optimal intervention target within the amyloid manifold. Active drug discovery approaches include antibodies that selectively capture soluble Aß oligomers, selective modifiers of oligomer assembly, and receptor antagonists. The onset of symptomatic clinical benefit is expected to be rapid for such agents, because neuronal memory signaling should normalize on blockage of soluble Aß oligomers. This key feature is not shared by amyloid-lowering therapeutics, and it should translate into streamlined clinical development for oligomer-targeting drugs. Oligomer-targeting drugs should also confer long-term disease modification and slowing of disease progression, because they prevent the downstream signaling responsible for phospho-tau mediated cytoskeletal degeneration.

A review and update of the current status of the vasculature-disabling agent combretastatin-A4 phosphate (CA4P).

Vascular-disrupting strategies impair a tumor's blood vessel network, which is essential for tumor progression and metastasis. Vascular-disrupting agents (VDAs) cause a rapid and selective vascular shutdown in tumors to produce extensive secondary neoplastic cell death due to ischemia. A lead agent in this therapeutic strategy is the tubulin depolymerizing agent combretastatin-A4 phosphate (CA4P). Used alone, CA4P induces extensive necrosis in a wide variety of preclinical cancer models and significant blood flow reductions in the patient tumors. Preclinical and clinical data further indicate that CA4P can effectively be combined with chemotherapy or radiotherapy. Finally, the potential of combining VDAs with antiangiogenic therapies has shown considerable promise in preclinical models and such combinations are now beginning to be evaluated in patients.

Safety of efalizumab in adults with chronic moderate to severe plaque psoriasis: a phase IIIb, randomized, controlled trial.

BACKGROUND: To provide safety data for efalizumab, a recombinant humanized monoclonal IgG(1) antibody, in adults with chronic plaque psoriasis. METHODS: A 12-week, Phase IIIb, randomized, double-blind, parallel-group, placebo-controlled trial. At 58 study sites in the USA and Canada, 686 patients with moderate to severe chronic plaque psoriasis received an initial conditioning dose of efalizumab 0.7 mg/kg subcutaneously (SC) followed by either 11 weekly doses of efalizumab 1 mg/kg SC or matching placebo. Main outcome measures were safety and tolerability outcomes (primary) and efficacy outcomes (secondary). RESULTS: During 12 weeks of therapy with efalizumab or placebo, the incidence of clinical adverse events was 82.2% and 72.9%, respectively; the incidence of serious adverse events was 1.8% and 3.4%, respectively; and the incidence of nonserious adverse events leading to withdrawal was 1.8% and 1.7%, respectively. In the efalizumab group, there were no clinically significant changes in vital signs or laboratory parameters and no evidence of end-organ toxicities. A significantly higher proportion of patients receiving efalizumab than those receiving placebo achieved > or = 75% improvement in the Psoriasis Area and Severity Index (PASI) (P < 0.001), > or = 50% improvement in PASI (P < 0.001), and a static Physician's Global Assessment rating of Minimal or Clear (P < 0.001). The mean improvement in the Psoriasis Symptom Assessment was significantly greater in the efalizumab group (P < 0.001). CONCLUSIONS: Efalizumab treatment SC for 12 weeks was safe, well tolerated, and effective in patients with moderate to severe chronic plaque psoriasis.

An overview of the pharmacokinetics and pharmacodynamics of efalizumab: a monoclonal antibody approved for use in psoriasis.

Efalizumab is a recombinant humanized monoclonal IgG(1) antibody shown to be efficacious for the treatment of moderate to severe chronic plaque psoriasis. Efalizumab, a targeted inhibitor of T cell interactions, binds to the CD11a subunit of lymphocyte function-associated antigen 1 (LFA-1), thereby preventing LFA-1 binding to intercellular adhesion molecule 1 (ICAM-1). The authors review the pharmacokinetic and pharmacodynamic data from the efalizumab clinical development program and discuss how these data led to selection of the optimal weekly subcutaneous (SC) dose of efalizumab (1.0 mg/kg) in adults. Efalizumab SC dosages of 1.0 mg/kg/wk or greater exerted maximal pharmacodynamic effects for CD11a expression and available CD11a binding sites on T lymphocytes. Dosages greater than 1.0 mg/kg/wk SC did not provide additional benefits; moreover, higher doses did not alter the safety profile. During long-term administration of efalizumab, serum levels were generally stable and pharmacodynamic markers remained maximally affected.

Novel class of pain drugs based on antagonism of NGF.

Nerve growth factor (NGF) was identified originally as a survival factor for sensory and sympathetic neurons in the developing nervous system. In adults, NGF is not required for survival but it has a crucial role in the generation of pain and hyperalgesia in several acute and chronic pain states. The expression of NGF is high in injured and inflamed tissues, and activation of the NGF receptor tyrosine kinase trkA on nociceptive neurons triggers and potentiates pain signalling by multiple mechanisms. Inhibition of NGF function and signalling blocks pain sensation as effectively as cyclooxygenase inhibitors and opiates in rodent models of pain. Several pharmaceutical companies have active drug-discovery and development programs that are based on a variety of approaches to antagonise NGF, including NGF 'capture', blocking the binding of NGF to trkA and inhibiting trkA signalling. NGF antagonism is expected to be a highly effective therapeutic approach in many pain states, and to be free of the adverse effects of traditional analgesic drugs.

Extended efalizumab therapy improves chronic plaque psoriasis: results from a randomized phase III trial.

BACKGROUND: Efalizumab inhibits multiple T-cell-mediated processes. OBJECTIVE: To evaluate 12- and 24-week efalizumab therapy for psoriasis. METHODS: In this phase III, randomized, double-blind trial, 498 patients received subcutaneous 1 or 2 mg/kg/wk efalizumab or placebo for 12 weeks. Efalizumab-treated patients who achieved <75% Psoriasis Area and Severity Index improvement (PASI-75) were re-randomized to a second 12-week course of treatment. Results At week 12, 39% and 27% of efalizumab-treated patients (1 and 2 mg/kg, respectively) achieved PASI-75 (vs 2% placebo; P < .001, both dose groups). At week 24, an additional 20% of efalizumab-treated patients achieved PASI-75 (vs placebo 7%, P = .018). Efalizumab was well tolerated. CONCLUSION: Twelve-week efalizumab treatment resulted in significant improvement; extension of therapy to 24 weeks resulted in additional improvement in patients who initially had not achieved PASI-75. There were no significant changes in safety profile during weeks 13-24.

Pharmacokinetics and pharmacodynamics of multiple weekly subcutaneous efalizumab doses in patients with plaque psoriasis.

Efalizumab pharmacokinetics, pharmacodynamics, and efficacy were assessed after subcutaneous administration of 1.0 or 2.0 mg/kg/wk for 12 weeks with 12 weeks of follow-up in subjects with psoriasis. Steady-state serum concentrations were achieved by 4 and 8 weeks, respectively. C(max) was 12 and 31 microg/mL, occurring approximately 2 days after a SC dose. Serum trough levels were 9 and 24 microg/mL, and CL/F(ss) was 24 and 16 mL/kg/d. At both doses, CD11a expression on T lymphocytes was maximally down-modulated to approximately 20% of baseline, and CD11a binding sites were >95% saturated. The extent of this PD effect was less for other leukocytes. Leukocyte counts increased by approximately 40%, with the majority of this increase related to a significant but reversible increase in the lymphocyte population. Maximal pharmacodynamic effects were sustained at both dose levels through the course of treatment and were commensurate with improvements in psoriasis.

Safety of efalizumab in patients with moderate to severe chronic plaque psoriasis: review of clinical data. part II.

BACKGROUND: The efficacy and safety of efalizumab have been evaluated in multiple clinical trials. OBJECTIVE: The purpose of this review is to provide an overview of the safety profile of efalizumab during the clinical trials. METHODS: Twelve-week data from four placebo-controlled trials were pooled and analyzed. Data from patients receiving 13-60 weeks of efalizumab therapy were pooled to evaluate longer-term safety. RESULTS: The most common adverse events were mild to moderate, self-limiting, flu-like symptoms that were most frequent following the first two efalizumab doses; by the third dose the incidence was comparable to placebo. Serious adverse events were observed in 2.2% and 1.7% of efalizumab- and placebo-treated patients, respectively. Nonserious adverse events leading to withdrawal were infrequent and similar to placebo (2.8% vs 1.8%). There does not appear to be increased risk of end-organ toxicity, infection, or malignancy in efalizumab-treated patients. CONCLUSION: Efalizumab was well tolerated, with a favorable safety profile.

Clinical efficacy of efalizumab in patients with chronic plaque psoriasis: results from three randomized placebo-controlled Phase III trials: part I.

BACKGROUND: Effective psoriasis therapies are needed for long-term symptom control. OBJECTIVE: Assess efalizumab (Raptiva) efficacy in a large cohort of psoriasis patients. METHODS: Data from three Phase III, randomized, double-blind, parallel-group, placebo-controlled, multicenter studies were pooled. Patients (n = 1,651) with moderate to severe plaque psoriasis received 12 weeks of subcutaneous efalizumab 1 or 2 mg/kg/wk or placebo. RESULTS: All efficacy measures reached statistical significance within each of the individual studies (p < 0.001) and overall. More efalizumab-treated patients achieved > or = 75% and > or = 50% Psoriasis Area and Severity Index (PASI) improvement at week 12 than did placebo-treated patients (27.8% vs 3.8% [p < 0.001] and 56.1% vs 14.6% [p < 0.001], respectively). Significant PASI improvements occurred as early as week 2 (12.5% vs 7.9%, p =0.0001). Adverse events were generally mild to moderate. CONCLUSION: Efalizumab resulted in early and significant improvement for all efficacy endpoints and was well tolerated in patients with moderate to severe chronic plaque psoriasis.

Extended efalizumab therapy sustains efficacy without increasing toxicity in patients with moderate to severe chronic plaque psoriasis.

Agents that safely provide long-term control of psoriasis are needed. To determine the safety and efficacy of extended efalizumab therapy, 339 patients with moderate to severe chronic plaque psoriasis received 2 mg/kg subcutaneous (SC) efalizumab weekly for 12 weeks. At Week 12, 290 patients who achieved > or =50% Psoriasis Area and Severity Index (PASI-50) improvement or a static Physician's Global Assessment grading of "mild," "minimal," or "clear" entered maintenance treatment with weekly SC efalizumab. At Week 12, 82%, 41%, and 13% of 339 patients achieved a PASI-50, PASI-75, and PASI-90 response, respectively. At 15 months, 65%, 50%, and 25% of patients achieved a PASI-50, PASI-75, and PASI-90 response, respectively (intent-to-treat, n = 339). The incidence of adverse events did not increase over time, and no new common adverse events were reported. The majority of patients experienced sustained efficacy with no increase in toxicity. This study is planned to continue; patients will receive up to 36 months of continuous efalizumab.

Efalizumab for patients with moderate to severe plaque psoriasis: a randomized controlled trial.

CONTEXT: Because T-cell interactions are involved in the pathophysiology of psoriasis, therapy with a T-cell modulator may have beneficial effects on psoriasis severity and health-related quality of life (HRQL). OBJECTIVE: To assess the efficacy and safety of efalizumab, a T-cell modulator, in patients with plaque psoriasis. DESIGN, SETTING, AND PATIENTS: Phase 3 randomized, double-blind, parallel-group, placebo-controlled trial involving 556 adult patients with stable, moderate to severe plaque psoriasis and conducted at 30 study centers in the United States and Canada between January and July 2002. INTERVENTIONS: Patients were randomly assigned in a 2:1 ratio to receive 12 weekly doses of subcutaneous efalizumab, 1 mg/kg (n = 369), or placebo equivalent (n = 187). MAIN OUTCOME MEASURES: At least 75% improvement on the Psoriasis Area and Severity Index (PASI-75); improvement on the overall Dermatology Life Quality Index (DLQI), Itching Visual Analog Scale (VAS), and Psoriasis Symptom Assessment (PSA) at week 12 vs baseline. RESULTS: Efalizumab-treated patients experienced significantly greater improvement on all end points than placebo-treated patients. Twenty-seven percent of efalizumab-treated patients achieved PASI-75 vs 4% of the placebo group ( P<.001). Efalizumab-treated patients exhibited significantly greater mean percentage improvement than placebo-treated patients on the overall DLQI (47% vs 14%; P<.001), Itching VAS (38% vs -0.2%; P<.001), and PSA frequency and severity subscales (48% vs 18% and 47% vs 17%, respectively; P<.001 for both) at the first assessment point. Efalizumab was safe and well tolerated, with primarily mild to moderate adverse events. CONCLUSION: In this 12-week study, efalizumab resulted in significant improvements in clinical end points, including physician-assessed and dermatology-specific patient-reported HRQL measures, in patients with moderate to severe plaque psoriasis.

A novel targeted T-cell modulator, efalizumab, for plaque psoriasis.

BACKGROUND: Interactions between leukocyte-function-associated antigen type 1 (LFA-1) and intercellular adhesion molecules are important in the pathogenesis of psoriasis. Efalizumab, a humanized monoclonal antibody, binds to the alpha subunit (CD11a) of LFA-1 and inhibits the activation of T cells. METHODS: In a phase 3, multicenter, randomized, placebo-controlled, double-blind study, we assign 597 subjects with psoriasis to receive subcutaneous efalizumab (1 or 2 mg per kilogram of body weight per week) or placebo for 12 weeks. Depending on the response after 12 weeks, subjects received an additional 12 weeks of treatment with efalizumab or placebo. Study treatments were discontinued at week 24, and subjects were followed for an additional 12 weeks. RESULTS: At week 12, there was an improvement of 75 percent or more in the psoriasis area-and-severity index in 22 percent of the subjects who had received 1 mg of efalizumab per kilogram per week and 28 percent of those who had received 2 mg of efalizumab per kilogram per week, as compared with 5 percent of the subjects in the placebo group (P<0.001 for both comparisons). Efalizumab-treated subjects had greater improvement than those in the placebo group as early as week 4 (P<0.001). Among the efalizumab-treated subjects who had an improvement of 75 percent or more at week 12, improvement was maintained through week 24 in 77 percent of those who continued to receive efalizumab, as compared with 20 percent of those who were switched to placebo (P<0.001 for both comparisons). After the discontinuation of efalizumab at week 24, an improvement of 50 percent or more in the psoriasis area-and-severity index was maintained in approximately 30 percent of subjects during the 12 weeks of follow-up. Efalizumab was well tolerated, and adverse events were generally mild to moderate. CONCLUSIONS: Efalizumab therapy resulted in significant improvements in plaque psoriasis in subjects with moderate-to-severe disease. Extending treatment from 12 to 24 weeks resulted in both maintenance and improvement of responses.

Subcutaneously administered efalizumab (anti-CD11a) improves signs and symptoms of moderate to severe plaque psoriasis.

BACKGROUND: Phase I and Phase II studies in patients with moderate to severe plaque psoriasis demonstrated that intravenous (IV) efalizumab improved clinical signs and symptoms and was well tolerated. OBJECTIVE: To determine if subcutaneous (SC) delivery of efalizumab improves chronic plaque psoriasis and demonstrates an acceptable safety profile. METHODS: This was a Phase I, open-label, single- and multiple-dose, escalating-dose study. Subjects received a single dose of efalizumab (0.3 mg/kg/wk SC) or escalating multiple doses of efalizumab (0.50-2.0 mg/kg/wk SC). Effectiveness was assessed using the Psoriasis Area and Severity Index (PASI), target lesion assessment, and Physician's Global Assessment (PGA). Safety was assessed by evaluating adverse events, clinical laboratory test results, physical examination results, immunologic responses, and vital signs. RESULTS: PASI score, target lesion assessment, and PGA showed improvement of approximately 40%-60% in signs and symptoms of plaque psoriasis by day 56. Mean PASI scores were still declining at the end of the eight-week dosing period, suggesting that longer duration of treatment would be more effective. By day 91, mean PASI scores were 16.2 vs. 14.6 at day 56 in the 0.5-1.0-mg/kg/wk group and 11.7 vs. 10.1 in the 1.0-2.0-mg/kg/wk group. This demonstrates that, on average, patients maintained their treatment benefit during the 42-day followup period. Overall, there were considerably fewer adverse events than in previous IV studies. These consisted principally of mild to moderate headache, pain, and rhinitis. No allergic reactions were observed. Antibodies to efalizumab were observed in only one subject (2%) and did not have any clinical relevance. CONCLUSION: The SC administration of eight weekly doses of efalizumab improves signs and symptoms of psoriasis. The treatment was safe and very well tolerated. In comparison to previously published results with IV efalizumab, SC administration of efalizumab improves overall safety and tolerability, with the additional advantage of greater convenience.

Anti-adhesion antibodies efalizumab, a humanized anti-CD11a monoclonal antibody.

The acquired immune response that leads to graft rejection depends on regulated adhesive interactions between T lymphocytes, endothelial cells, dendritic cells, graft tissue and the extracellular matrix to coordinate cellular trafficking and activation of antigen-reactive T lymphocytes. Inhibiting the function of molecules involved in the adhesion processes offers the potential for interfering with the allograft response. The leukocyte function associated antigen-1 molecule (LFA-1), a heterodimer of CD11a (alphaL) and CD18 (beta2) integrin subunits, is an attractive therapeutic target because it plays an important role in key steps of inflammation and tissue rejection. These include: (1) binding of leukocytes to endothelium; (2) trafficking through activated endothelium; and (3) costimulatory interactions between T lymphocytes and antigen presenting cells. Clinical experience with efalizumab, a humanized anti-CD11a monoclonal antibody (mAb), in patients with chronic plaque psoriasis has shown that anti-CD11a therapy is well tolerated and effective at reducing the severity of the disease without depleting lymphocytes. Initial results in renal transplant patients are also promising.

Psoriasis as a model for T-cell-mediated disease: immunobiologic and clinical effects of treatment with multiple doses of efalizumab, an anti-CD11a antibody.

BACKGROUND: Leukocyte function-associated antigen 1 (LFA-1), consisting of CD11a and CD18 subunits, plays an important role in T-cell activation and leukocyte extravasation. OBJECTIVE: To test whether blocking CD11a decreases immunobiologic and clinical activity in psoriatic plaques. DESIGN: Open-label, multicenter, dose escalation study. PATIENTS: Thirty-nine patients with moderate-to-severe psoriasis. INTERVENTION: Intravenous infusions of efalizumab, a humanized anti-CD11a monoclonal antibody, for 7 weeks at doses of 0.1 mg/kg every other week or 0.1 mg/kg weekly (category 1), 0.3 mg/kg weekly (category 2), and 0.3 increasing to 0.6 or 1.0 mg/kg weekly (category 3). Skin biopsies were performed on days 0, 28, and 56. MAIN OUTCOME MEASURES: Serum efalizumab levels, levels of total and unoccupied T-cell CD11a, T cell counts, epidermal thickness, cutaneous intercellular adhesion molecule 1 (ICAM-1) and keratin 16 (K16) expression, Psoriasis Area and Severity Index (PASI) scores. RESULTS: Dose-response relationships were observed for pharmacokinetics and pharmacodynamic measures. Category 1 failed to maintain detectable serum efalizumab or T cell CD11a down-modulation between doses. Category 2 achieved both. Category 3 achieved both and additionally maintained sustained T-cell CD11a saturation between doses. A dose-response relationship was also observed clinically and histologically. The mean decrease in the PASI score was 47% in category 3, 45% in category 2, and 10% in category 1 (P<.001). Epidermal and dermal T-cell counts, epidermal thickness, and ICAM-1 and K16 expression decreased in categories 2 and 3 but not in category 1. Circulating lymphocyte counts increased in categories 2 and 3. CONCLUSIONS: At doses of 0.3 mg/kg or more per week, intravenous efalizumab produced significant clinical and histologic improvement in psoriasis, which correlated with sustained serum efalizumab levels and T-cell CD11a saturation and down-modulation.