Improving the assessment of the probability of success in late stage drug development.

There are several steps to confirming the safety and efficacy of a new medicine. A sequence of trials, each with its own objectives, is usually required. Quantitative risk metrics can be useful for informing decisions about whether a medicine should transition from one stage of development to the next. To obtain an estimate of the probability of regulatory approval, pharmaceutical companies may start with industry-wide success rates and then apply to these subjective adjustments to reflect program-specific information. However, this approach lacks transparency and fails to make full use of data from previous clinical trials. We describe a quantitative Bayesian approach for calculating the probability of success (PoS) at the end of phase II which incorporates internal clinical data from one or more phase IIb studies, industry-wide success rates, and expert opinion or external data if needed. Using an example, we illustrate how PoS can be calculated accounting for differences between the phase II data and future phase III trials, and discuss how the methods can be extended to accommodate accelerated drug development pathways.

A New Comprehensive Approach to Assess the Probability of Success of Development Programs Before Pivotal Trials.

The point at which clinical development programs transition from early phase to pivotal trials is a critical milestone. Substantial uncertainty about the outcome of pivotal trials may remain even after seeing positive early phase data, and companies may need to make difficult prioritization decisions for their portfolio. The probability of success (PoS) of a program, a single number expressed as a percentage reflecting the multitude of risks that may influence the final program outcome, is a key decision-making tool. Despite its importance, companies often rely on crude industry benchmarks that may be "adjusted" by experts based on undocumented criteria and which are typically misaligned with the definition of success used to drive commercial forecasts, leading to overly optimistic expected net present value calculations. We developed a new framework to assess the PoS of a program before pivotal trials begin. Our definition of success encompasses the successful outcome of pivotal trials, regulatory approval and meeting the requirements for market access as outlined in the target product profile. The proposed approach is organized in four steps and uses an innovative Bayesian approach to synthesize all relevant evidence. The new PoS framework is systematic and transparent. It will help organizations to make more informed decisions. In this paper, we outline the rationale and elaborate on the structure of the proposed framework, provide examples, and discuss the benefits and challenges associated with its adoption.

Formoterol delivered via a new multi-dose dry powder inhaler (Certihaler) is as effective and well tolerated as the formoterol dry powder inhaler (Aerolizer) in children with persistent asthma.

The Certihaler is a new multi-dose dry powder inhaler for the delivery of formoterol (Foradil), a long-acting beta(2)-agonist. This dose-ranging study compared the efficacy and safety of formoterol 5, 10, 15 and 30 microg and placebo administered via the Certihaler or formoterol 12 microg via a single-dose dry powder inhaler (Aerolizer) in children with persistent asthma. This was a randomized, placebo-controlled, double-blind, double-dummy, incomplete block crossover, dose-finding and pharmacokinetic study. Children (5-12 years, n = 77) received four of the active treatments twice weekly (BID) for 1 week separated by 1-week single-blind washouts. The primary efficacy variable was 12-h AUC of FEV(1) after 1 week's treatment. Secondary variables included serial 12-h FEV(1). A subset of patients (n = 37) participated in a pharmacokinetic analysis. All formoterol doses resulted in significant increases in 12-h AUC of FEV(1) compared with placebo, and there was no difference between active treatments. The onset of action of formoterol was <3 min for all active treatments. Doses of formoterol > or =10 microg via the Certihaler increased FEV(1) significantly for up to 12 h compared with placebo. The 5 microcg dose via the Certihaler and 12 microg dose via the Aerolizer had a significant effect up to 8 and 7 h post-dose, respectively. Urinary excretion of formoterol via the Certihaler increased in a dose-proportional manner. All formoterol doses were well tolerated, but some patients experienced tremor at the 15 and 30 microg doses. Despite the lack of significant differences between the active doses in the overall bronchodilation, formoterol 10 microg BID via the Certihaler was the dose that provided the best balance between efficacy and tolerability: its duration of action was sustained over 12 h, contrary to that the lower dose (5 microg BID), whereas its tolerability, especially with regard to tremor, was better than the higher doses (15 and 30 microg BID). Overall, Certihaler 10 microg BID was not significantly different from formoterol 12 microg BID via Aerolizer.

Immunogenicity and safety of cell-derived MF59®-adjuvanted A/H1N1 influenza vaccine for children.

Mass immunization of children has the potential to decrease infection rates and prevent the transmission of influenza. We evaluated the immunogenicity, safety, and tolerability of different formulations of cell-derived MF59-adjuvanted and nonadjuvanted A/H1N1 influenza vaccine in children and adolescents. This was a randomized, single-blind, multicenter study with a total of 666 healthy subjects aged 6 months-17 y in one of 3 vaccination groups, each receiving formulations containing different amounts of influenza A/H1N1 antigen with or without MF59. A booster trivalent seasonal MF59 vaccine was administered one year after primary vaccinations. Antibody titers were assessed by hemagglutination inhibition (HI) and microneutralization assays obtained on days 1, 22, 43, 366, and 387 (3 weeks post booster). Safety was monitored throughout the study. One vaccination with 3.75 µg of A/H1N1 antigen formulated with 50% MF59 (3.75_halfMF59) or 7.5 µg of A/H1N1 antigen formulated with 100% MF59 (7.5_fullMF59) induced an HI titer ≥1:40 in >70% of children in the 1-<3, 3-8, and 9-17 y cohorts; however, 2 vaccinations with nonadjuvanted 15 µg A/H1N1 antigen were needed to achieve this response in the 1-<3 and 3-8 y cohorts. Among children aged 6-11 months, 1 dose of 7.5_fullMF59 resulted in an HI titer ≥1:40 in >70% while 2 doses of 3.75_halfMF59 were required to achieve this result. All vaccines were well tolerated. Our findings support the immunogenicity and safety of the 3.75_halfMF59 (2 doses for children <12 months) and 7.5_fullMF59 vaccine formulations for use in children and adolescents aged 6 months to 17 y The use of the 3.75_halfMF59 could have the benefit of antigen and adjuvant sparing, increasing the available vaccine doses allowing vaccination of more people.

Faster onset of bronchodilation with formoterol than with salmeterol in patients with stable, moderate to severe COPD: results of a randomized, double-blind clinical study.

OBJECTIVES: To compare the onset and magnitude of bronchodilation after dry powder inhalations of formoterol fumarate (Foradil Aerolizer) versus salmeterol xinofoate (Serevent Diskus) with respect to normalized (*) forced expiratory volume in 1 s area under the curve 0 to 1 h after inhalation (FEV1 AUC*0-1 h). DESIGN: A double-blind, double-dummy, multicentre, randomized, placebo controlled, single-dose, five-period crossover study. SETTING: Five centres in four countries - one centre each in France, Greece and Italy, and two centres in the Netherlands. PATIENTS: Forty-seven patients aged 42 to 80 years (mean age 63.5 years) with chronic obstructive pulmonary disease (COPD) stage II and III, and mean baseline FEV1 1.17 L (range 0.56 to 1.77 L). INTERVENTIONS: Patients inhaled single doses of formoterol dry powder (12 and 24 mg), single doses of salmeterol (50 and 100 mg) and matching placebo on five separate days. MAIN RESULTS: The estimates of treatment difference in absolute terms (0.086 L) and percentage change from predose baseline (7.8%) for the primary end point, FEV1 AUC*0-1 h, showed that formoterol 12 mg was statistically significantly superior to salmeterol 50 mg (P=0.0044 and P=0.0021, respectively). In addition, both doses of formoterol were statistically superior to placebo for both absolute improvement and percentage change (P=0.0001). The analysis of secondary variables also confirmed the superiority of formoterol over salmeterol. CONCLUSIONS: Formoterol is associated with a faster onset of bronchodilation than salmeterol in patients with COPD.

Enhanced and persistent antibody response against homologous and heterologous strains elicited by a MF59-adjuvanted influenza vaccine in infants and young children.

BACKGROUND: Non-adjuvanted seasonal influenza vaccines show only modest efficacy in young children. This study compared the immunogenicity, reactogenicity and safety of the MF59-adjuvanted trivalent subunit vaccine (aTIV) with two non-adjuvanted trivalent vaccines, TIV-1, the non-adjuvanted version of aTIV, and TIV-2, a split virion vaccine. METHODS: 6078 children received two doses of aTIV (n=3125), TIV-1 (n=1479), or TIV-2 (n=1474) four weeks apart (Days 1 and 29). Children aged 6 to <36 months and 36 to <72 months received 0.25 mL and 0.50 mL doses, respectively. Immunogenicity was assessed by hemagglutination inhibition (HI) assay (n=2435) on Days 1, 29, 50 and 209. Safety was assessed up to Day 394. RESULTS: After the second vaccination (Day 50), the aTIV group showed significantly higher geometric mean HI titers and seroconversion rates than the TIV-1 or TIV-2 groups against all homologous and heterologous strains. The difference was enhanced at HI titers ≥110. aTIV elicited a faster, more persistent antibody response, with significantly higher titers in the aTIV group after one vaccination (Day 29) and after six months (Day 209) than in either TIV group. aTIV was more reactogenic than were TIV-1 and TIV-2 but rates of severe adverse events were very low for all three vaccines. CONCLUSION: In infants and young children, the MF59-adjuvanted vaccine induced substantially faster (after one dose), higher, persistent HI titers than the non-adjuvanted vaccines, with consistently higher seroprotection rates at increased threshold HI titers. This trial is registered at clinicaltrials.gov: NCT01346592.

Safety and immunogenicity of an MF59(®)-adjuvanted A/H5N1 pre-pandemic influenza vaccine in adults and the elderly.

BACKGROUND: The potential consequences of an avian influenza pandemic warrants the development of safe, highly immunogenic pre-pandemic A/H5N1 vaccines with cross-clade protection. In this randomized, controlled study we compared the immunogenicity and safety of an MF59(®)-adjuvanted (Novartis Vaccines, Marburg, Germany) A/H5N1 pre-pandemic vaccine with that of a licensed, MF59-adjuvanted, seasonal influenza vaccine. METHODS: Healthy adult (18-60 years, n=3372) and elderly (≥61 years, n=275) volunteers received either an initial dose of a licensed, non-adjuvanted, trivalent, seasonal influenza vaccine (Agrippal(®)) on Day 1, followed by one dose of MF59-H5N1 study vaccine on Day 22 and a second dose of MF59-H5N1 on Day 43, or alternatively, placebo on Day 1 followed by one dose of MF59-adjuvanted seasonal reference vaccine on Day 22 and a second dose of reference vaccine on Day 43. Homologous and cross-reactive A/H5N1 antibody responses were analysed by haemagglutination inhibition (HI), single radial haemolysis (SRH), and microneutralization (MN) assays three weeks after each vaccination. Vaccine safety was assessed throughout the study. RESULTS: Analysis by HI assay found that two doses of MF59-H5N1 resulted in a seroconversion rate of 56% and a geometric mean ratio (GMR) of 7.1 in adult subjects. Similar results were observed on analysis by SRH (GMR 4.03; seroconversion 78% and seroprotection 91%) and MN (seroconversion 67%) assays. These data met the European licensure criteria for influenza vaccines. No significant difference in immunogenicity was detected between the adult and elderly populations. Anti-A/H5N1 cross-clade antibodies were detected by SRH, 49% of adult and 32% of elderly subjects achieved seroconversion after the second vaccine dose. Overall, MF59-H5N1 containing 7.5µg antigen was less reactogenic than the MF59-adjuvanted trivalent seasonal vaccine which contained 15µg antigen for each component strain. CONCLUSIONS: Two doses of MF59-H5N1 vaccine were well tolerated and induced adequate levels of seroprotection against homologous and cross-clade A/H5N1 virus. These data support the suitability of MF59-adjuvanted A/H5N1 vaccine for pre-pandemic use in adults and the elderly.

A randomised, single-blind, dose-range study to assess the immunogenicity and safety of a cell-culture-derived A/H1N1 influenza vaccine in adult and elderly populations.

BACKGROUND: Modern cell-culture production techniques and the use of adjuvants helps to ensure that the global demand for pandemic influenza vaccine can be met. This study aimed to assess the immunogenicty and safety profiles of various cell-culture-derived A/H1N1 pandemic vaccine formulations in healthy adult and elderly subjects. METHODS: Adult (18-60 years) subjects (n=544) received vaccine either containing 3.75 µg of antigen with half the standard dose of MF59 (Novartis Vaccines and Diagnostics) adjuvant, 7.5 µg antigen with a full dose of MF59, or a non-adjuvanted vaccine containing 15 µg of antigen. Elderly (≥ 61 years) subjects (n=268) received either the 3.75 µg or 7.5 µg adjuvanted formulations. Two priming vaccine doses were administered 3 weeks apart, followed by a single booster dose of seasonal influenza vaccine 1 year later. Immunogenicity was assessed 3 weeks after each vaccination. The safety profile of each formulation was evaluated throughout the study. RESULTS: A single primary dose of each A/H1N1 vaccine formulation was sufficient to meet all three European (CHMP) licensure criteria for pandemic influenza vaccines in adult subjects. Two licensure criteria were met after one vaccine dose in elderly subjects; two primary doses were required to meet all three criteria in this age group. The highest antibody titres were observed in response to the 7.5 µg vaccine containing a full dose of MF59 adjuvant. All subjects rapidly generated seroprotective antibody titres in response to booster vaccination. CONCLUSION: This study identified one 3.75 µg vaccine dose containing half the standard dose of MF59 adjuvant as optimal for adults, two doses were optimal for elderly subjects. The antigen-sparing properties of MF59, and rapid, modern, cell-culture production techniques represent significant steps towards meeting the global demand for influenza vaccine.