OP0023 A RANDOMIZED, DOUBLE-BLIND TRIAL COMPARING SECUKINUMAB 300 MG AND 150 MG AT WEEK 52 IN PATIENTS WITH ANKYLOSING SPONDYLITIS WHO DID NOT ACHIEVE INACTIVE DISEASE DURING AN INITIAL 16 WEEKS OF OPEN-LABEL TREATMENT WITH SECUKINUMAB 150 MG

Background

Ankylosing spondylitis (AS) is a chronic, systemic inflammatory condition characterized by inflammatory back pain and is associated with extra-musculoskeletal manifestations and systemic comorbidities. Secukinumab (SEC) doses of 150 mg and 300 mg are approved to treat AS, although no dose escalation studies are available in patients who have inadequate response to SEC 150 mg.

Objectives

The ASLeap study (NCT03350815) estimated the difference in clinical response to SEC 300 mg vs 150 mg at Week (Wk) 52 in patients with AS who failed to achieve Ankylosing Spondylitis Disease Activity Score (ASDAS) inactive disease status on SEC 150 mg at Wk 16.

Methods

In this randomized, double-blind, parallel-group, multicenter, phase 4 study, 322 patients with AS were assigned to receive open-label SEC 150 mg administered per the label for 16 Wks (period 1). At Wk 16, patients who did not achieve inactive disease (ASDAS < 1.3) at Wks 12 and 16 were randomized 1:1 in a double-blind manner to SEC 150 mg or escalated to SEC 300 mg q4w to Wk 52 (period 2). The primary efficacy variable was achievement of ASDAS < 1.3 and the primary analysis time point was Wk 52. Secondary efficacy variables were achievement of ASDAS clinically important improvement ≥ 1.1, 50% improvement in the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI50), Assessment of SpondyloArthritis international Society responses (ASAS20, ASAS40, and ASAS partial remission), and change from baseline in BASDAI, ASAS Health Index (ASAS-HI), and the Functional Assessment of Chronic Illness Therapy – Fatigue Scale (FACIT-F). Safety was evaluated by incidence of treatment-emergent adverse events (TEAEs) through Wk 52. No statistical hypothesis tests for superiority or equivalence were planned in the protocol and none were performed.

Results

Of 279 patients receiving SEC 150 mg who completed the 16-wk open-label period 1, 22 (7.9%) achieved ASDAS < 1.3 at Wks 12 or 16 and continued receiving SEC 150 mg; 207 patients did not attain ASDAS < 1.3 at Wk 12 and Wk 16 and initiated period 2. Demographics and baseline disease characteristics were balanced between patients randomized to SEC 150 mg and SEC 300 mg, including the proportion of patients who were TNFi naive (SEC 150 mg: 73 [72.3%]; SEC 300 mg: 73 [69.5%]) (Table 1). Approximately 60% of patients in either SEC group were HLA-B27 positive. After having an inadequate response to SEC 150 mg through Wk 16, patients receiving either dose of SEC experienced similar improvements at Wk 52 in disease activity as measured by achievement of ASDAS < 1.3, ASDAS clinically important improvement ≥ 1.1, BASDAI50, ASAS20, ASAS40, and ASAS partial remission; and mean changes in BASDAI, quality of life as measured by ASAS HI, and fatigue as measured by FACIT-F (Figure 1). The incidence of TEAEs through Wk 52 was similar between patients receiving SEC 300 mg (63.4%) and 150 mg (68.6%).

Table 1.

Demographics and Baseline Disease Characteristics of Patients in Period 2 (safety set)

CharacteristicSecukinumab 150 mg → 300 mg N = 101Secukinumab 150 mg → 150 mg N = 105Age, mean (SD), years48.5 (14.1)47.0 (13.7)Female, n (%)43 (42.6)52 (49.5)BMI, mean (SD), kg/m232.0 (8.0)32.1 (7.7)HLA-B27 positive, n (%)60 (59.4)65 (61.9)Time since axial symptom onset, mean (SD), years13.9 (11.7)14.0 (12.5)Time since diagnosis of AS, mean (SD), years4.7 (8.6)5.1 (9.7)TNFi naive, n (%)73 (72.3)73 (69.5)History of extra-axial involvement, n (%)Peripheral arthritis34 (33.7)30 (28.6)Enthesitis29 (28.7)31 (29.5)Uveitis13 (12.9)17 (16.2)Psoriasis14 (13.9)14 (13.3)Dactylitis7 (6.9)4 (3.8)Inflammatory bowel disease2 (2.0)1 (1.0)

AS, ankylosing spondylitis; BMI, body mass index; TNFi, tumor necrosis factor inhibitor.

Conclusion

Patients with AS who did not achieve inactive disease by Wk 16 after receiving SEC 150 mg experienced similar clinical response and safety through Wk 52 regardless of dose escalation to SEC 300 mg or continuation on SEC 150 mg.

Acknowledgements

This study was funded by Novartis Pharmaceuticals Corporation. Medical writing support was provided by Richard Karpowicz, PhD, CMPP, of Health Interactions, Inc, and was funded by Novartis Pharmaceuticals Corporation. This abstract was developed in accordance with Good Publication Practice (GPP3) guidelines. Authors had full control of the content and made the final decision on all aspects of this publication.

Disclosure of Interests

Atul Deodhar Consultant of: AbbVie, Amgen, Aurinia, Bristol Myers Squibb, Celgene, Eli Lilly, GSK, Janssen, MoonLake, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, Eli Lilly, GSK, Novartis, Pfizer, and UCB, Alan Kivitz Shareholder of: Amgen, Gilead, GSK, Novartis, Pfizer, and Sanofi, Speakers bureau: AbbVie, Celgene, Flexion, Genzyme, GSK, Eli Lilly, Horizon, Merck, Novartis, Pfizer, Sanofi, and UCB, Consultant of: AbbVie, Boehringer Ingelheim, Flexion, Gilead, Janssen, Pfizer, Regeneron, Sanofi, and Sun Pharma, Marina Magrey Consultant of: Eli Lilly and Novartis, Grant/research support from: AbbVie, Amgen, and UCB, Jessica A. Walsh Consultant of: Amgen, Lilly, Novartis, and UCB, Grant/research support from: AbbVie and Pfizer, Philip J Mease Speakers bureau: AbbVie, Amgen, Janssen, Eli Lilly, Novartis, Pfizer, and UCB, Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Galapagos, Gilead, GlaxoSmithKline, Janssen, Eli Lilly, Novartis, Pfizer, Sun Pharma, and UCB, Grant/research support from: AbbVie, Amgen, Bristol Myers Squibb, Celgene, Gilead, Janssen, Eli Lilly, Novartis, Pfizer, Sun Pharma, and UCB, Maria Greenwald Grant/research support from: AbbVie, Eli Lilly, Novartis, Pfizer, Galapagos, and Janssen, Renato Calheiros Employee of: Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA, Farid Kianifard Employee of: Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA, Chelsea Elam Employee of: Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA, Kriti Nagar Employee of: Novartis Healthcare Pvt Ltd, Hyderabad, India, Adam Winseck Employee of: Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA, Lianne S. Gensler Consultant of: Galapagos, Eli Lilly, Janssen, and Pfizer, Grant/research support from: UCB Pharma, AbbVie, Amgen, and Novartis.

Discovery of novel SERCA inhibitors by virtual screening of a large compound library

Two screening protocols based on recursive partitioning and computational ligand docking methodologies, respectively, were employed for virtual screens of a compound library with 345,000 entries for novel inhibitors of the enzyme sarco/endoplasmic reticulum calcium ATPase (SERCA), a potential target for cancer chemotherapy. A total of 72 compounds that were predicted to be potential inhibitors of SERCA were tested in bioassays and 17 displayed inhibitory potencies at concentrations below 100 μM. The majority of these inhibitors were composed of two phenyl rings tethered to each other by a short link of one to three atoms. Putative interactions between SERCA and the inhibitors were identified by inspection of docking-predicted poses and some of the structural features required for effective SERCA inhibition were determined by analysis of the classification pattern employed by the recursive partitioning models.

Comparison of current docking tools for the simulation of inhibitor binding by the transmembrane domain of the sarco/endoplasmic reticulum calcium ATPase

Inhibitors of the transmembrane protein sarco/endoplasmic reticulum calcium ATPase (SERCA) are invaluable tools for the study of the enzyme's physiological functions and they have been recognized as a promising new class of anticancer agents. For the discovery of novel enzyme inhibitors, small molecule docking for virtual screens of large compound libraries has become increasingly important. Since the performance of various docking routines varies considerably, depending on the target and the chemical nature of the ligand, we critically evaluated the performance of four frequently used programs - GOLD, AutoDock, Surflex-Dock, and FRED - for the docking of SERCA inhibitors based on the structures of thapsigargin, di-tert-butylhydroquinone, and cyclopiazonic acid. Evaluation criteria were docking accuracy using crystal structures as references, docking reproducibility, and correlation between docking scores and known bioactivities. The best overall results were obtained by GOLD and FRED. Docking runs with conformationally flexible binding sites produced no significant improvement of the results.

Design, synthesis, and biological evaluation of hydroquinone derivatives as novel inhibitors of the sarco/endoplasmic reticulum calcium ATPase

Analogues of the compound 2,5-di-tert-butylhydroquinone (BHQ) are capable of inhibiting the enzyme sarco/endoplasmic reticulum ATPase (SERCA) in the low micromolar and submicromolar concentration ranges. Not only are SERCA inhibitors valuable research tools, but they also have potential medicinal value as agents against prostate cancer. This study describes the synthesis of 13 compounds representing several classes of BHQ analogues, such as hydroquinones with a single aromatic substituent, symmetrically and unsymmetrically disubstituted hydroquinones, and hydroquinones with omega-amino acid tethers attached to their hydroxyl groups. Structure-activity relationships were established by measuring the inhibitory potencies of all synthesized compounds in bioassays. The assays were complemented by computational ligand docking for an analysis of the relevant ligand/receptor interactions.

Structure-based virtual screening for novel inhibitors of the sarco/endoplasmic reticulum calcium ATPase and their experimental evaluation

A public compound library with 260,000 compounds was screened virtually by computational docking for novel inhibitors of the transmembrane enzyme sarco/endoplasmic reticulum calcium ATPase (SERCA). Docking was performed with the program GOLD in conjunction with a high resolution X-ray crystal structure of SERCA. Compounds that were predicted to be active were tested in bioassays. Nineteen novel compounds were discovered that were capable of inhibiting the ATP hydrolysis activity of SERCA at concentrations below 50 microM. Crucial enzyme/inhibitor interactions were identified by analyzing the docking-predicted binding poses of active compounds. Like other SERCA inhibitors, the newly discovered compounds are of considerable medicinal interest because of their potential for cancer chemotherapy.

Molecular determinants of sarco/endoplasmic reticulum calcium ATPase inhibition by hydroquinone‐based compounds

The ion transport activity of the sarco/endoplasmic reticulum calcium ATPase (SERCA) is specifically and potently inhibited by the small molecule 2,5-di-tert-butylhydroquinone (BHQ). In this study, we investigated the relative importance of the nature and position of BHQ's four substituents for enzyme inhibition by employing a combination of experimental and computational techniques. The inhibitory potencies of 21 commercially available or synthesized BHQ derivatives were determined in ATPase activity assays, and 11 compounds were found to be active. Maximum inhibitory potency was observed in compounds with two para hydroxyl groups, whereas BHQ analogues with only one hydroxyl group were still active, albeit with a reduced potency. The results also demonstrated that two alkyl groups were an absolute requirement for activity, with the most potent compounds having 2,5-substituents with four or five carbon atoms at each position. Using the program GOLD in conjunction with the ChemScore scoring function, the structures of the BHQ analogues were docked into the crystal structure of SERCA mimicking the enzyme's E(2) conformation. Analysis of the docking results indicated that inhibitor binding to SERCA was primarily mediated by a hydrogen bond between a hydroxyl group and Asp-59 and by hydrophobic interactions involving the bulky inhibitor alkyl groups. Attempts to dock BHQ into crystal structures corresponding to the E(1) conformation of the enzyme failed, because the conformational changes accompanying the E(2)/E(1) transition severely restricted the size of the binding site, suggesting that BHQ stabilizes the enzyme in its E(2) form. The potential role of Glu309 in enzyme inhibition is discussed in the context of the computational results. The docking scores correlated reasonably well with the measured inhibitory potencies and allowed the distinction between active and inactive compounds, which is a key requirement for future virtual screening of large compound databases for novel SERCA inhibitors.

Longitudinal trends in the applicant pool for U.S. medical schools, 1974--1999

PURPOSE

To examine the pool of applicants to U.S. medical schools from 1974--1999 for changes in size and demographics and to identify factors that may be associated with such changes.

METHOD

Data on characteristics of the total applicant pools to U.S. medical schools for 1974--1999 were collected from the Association of American Medical Colleges' Data Warehouse. Data on undergraduates' receiving bachelor's degrees and unemployment rates were obtained from the National Center for Education Statistics and the U.S. Bureau of Labor Statistics, respectively. Variables such as race/ethnicity, gender, age, and first time or reapplicant status were compared across the study period.

RESULTS

The percentage of women applicants increased from 20% of the pool in 1974 to 45% of the pool in 1999, while the percentage of men dropped from 80% to 55%. The number of underrepresented minority (URM) applicants increased 45% during the period, from 2,890 to 4,181, but URM applicants represented only 11% of the total applicant pool in 1999. Between 1974 and 1999, the number of URM men applying to medical school dropped by 18%, from 1,984 to 1,629, while the number of URM women nearly tripled, from 906 to 2,552. The number of Asian/Pacific Islander applicants increased dramatically, from 986 in 1974 to 7,622 in 1999, and they now represent a fifth of all applicants. The proportion of reapplicants grew when the applicant pool grew and it shrank when the applicant pool shrank. No relationship was found between the size of the applicant pool and economic indicators, age, or geographic origin.

CONCLUSION

Changes in the proportions of women and Asian/Pacific Islander applicants were the driving force in the expansion of the applicant pool between 1974 and 1999.

Letters of recommendation: comparing perceptions of premedical advisors and admission committee members

A comparison of admission committee members' and premedical advisors' perceptions of recommendation letters revealed similar ratings of the usefulness of letters and impressions of applicants.

Primary care specialty selection: application of a vocational behavior theory

BACKGROUND AND OBJECTIVES

This study was designed to determine whether medical school graduates who completed undergraduate degrees in particular college majors were more likely to enter primary care residencies. John L. Holland's theory of vocational personalities and work environments was used to cluster undergraduate disciplines sharing distinctive qualities. These clusters were evaluated to determine if graduates from similar fields were more likely to pursue residencies in family practice, general internal medicine, or general pediatrics.

METHODS

Students who graduated from US and Puerto Rican medical schools in 1987 were eligible for the study; college majors of 2,661 graduates entering primary care specialties were analyzed.

RESULTS

Students completing undergraduate studies in the following majors selected primary care residencies by a twofold difference over the expected frequency: agriculture, black studies, civil engineering, general studies, literature, occupational therapy, and speech. Chi-square tests revealed no differences across Holland types in the frequency with which science and nonscience students selected primary care residencies.

CONCLUSIONS

Primary care specialties tend to accommodate students from varied academic backgrounds and appear to be tolerant of individuals who have completed undergraduate course work in either bioscientific or biosocial nonscience disciplines.