Drug Permeability - Best Practices for Biopharmaceutics Classification System (BCS)-Based Biowaivers: A workshop Summary Report

The workshop "Drug Permeability - Best Practices for Biopharmaceutics Classification System (BCS) Based Biowaivers" was held virtually on December 6, 2021, organized by the University of Maryland Center of Excellence in Regulatory Science and Innovation (M-CERSI), and the Food and Drug Administration (FDA). The workshop focused on the industrial, academic, and regulatory experiences in generating and evaluating permeability data, with the aim to further facilitate implementation of the BCS and efficient development of high-quality drug products globally. As the first international permeability workshop since the BCS based biowaivers was finalized as the ICH M9 guideline, the workshop included lectures, panel discussions, and breakout sessions. Lecture and panel discussion topics covered case studies at IND, NDA, and ANDA stages, typical deficiencies relating to permeability assessment supporting BCS biowaiver, types of evidence that are available to demonstrate high permeability, method suitability of a permeability assay, impact of excipients, importance of global acceptance of permeability methods, opportunities to expand the use of biowaivers (e.g. non-Caco-2 cell lines, totality-of-evidence approach to demonstrate high permeability) and future of permeability testing. Breakout sessions focused on 1) in vitro and in silico intestinal permeability methods; 2) potential excipient effects on permeability and; 3) use of label and literature data to designate permeability class.

POS0244 ASSOCIATION OF PROTEINASE 3 GENE (PRTN3) Val119Ile POLYMORPHISM (SNP rs351111) WITH RISK OF RELAPSE AMONG HOMOZYGOUS PATIENTS WITH PR3 ANCA-ASSOCIATED VASCULITIS

Background

The frequency of the proteinase 3 gene (PRTN3) polymorphisms in patients with ANCA-associated vasculitis (AAV) is not well characterized. We hypothesize that PRTN3 gene polymorphisms induce allosteric changes in PR3 conformation which may alter its interaction with ligands and PR3-ANCA during inflammation with potential implications for disease presentation and clinical outcomes.

Objectives

To analyze the association of PRTN3 Val119Ile polymorphism (SNP rs351111) with risk of relapse risk among homozygous patients with PR3 ANCA-associated vasculitis.

Methods

DNA variant calling for SNP rs351111 (chr.19:844020, c.355G>A) in PRTN3 gene assessed the allelic frequency in patients with PR3-AAV included in the Rituximab versus Cyclophosphamide (RAVE) trial. This was followed by RNA-seq variant calling to characterize the mRNA expression. We compared clinical presentation and outcomes between patients homozygous for PR3-Ile119 or PR3-Val119.

Results

Serum samples for DNA calling were available in 188 of the 197 patients with AAV in the RAVE cohort. 75 PR3-AAV patients had the allelic variant: 13 patients were homozygous for PR3-Ile119 and 62 patients were heterozygous PR3-Val119Ile with an allele frequency threshold of 29.3 – 55.1% of reads (Figure 1A and 1B). RNA-seq was available for 89 patients and the mRNA corresponding to the allelic variant was found in 35 PR3-AAV patients: 13 patients were homozygous for PR3-Ile119 and 22 patients were heterozygous PR3-Val119Ile with an allele frequency threshold of 11.1 – 62.8% of reads (Figure 1A and 1C). The agreement between the DNA calling results and the mRNA expression of the 86 patients that overlapped was 100%. We found an additional homozygous patient for PR3-Val119 in which blood was not available for DNA calling. We compared the clinical presentation and outcomes of 74 patients with PR3-AAV: 13 homozygous for PR3-Ile119 and 51 homozygous for PR3-Val119 (Table 1). The frequency of severe flares at 18 months in homozygous PR3-Ile119 was ≥ 2x higher when compared with homozygous PR3-Val119 (46.2% vs. 19.6%, p=0.048). We found no differences in clinical presentation.

Figure 1.

RAVE trial population distribution according to the zygosity status for PRTN3 gene (PR3 and MPO-ANCA patients) and DNA or RNA variant calling (panel A). Allelic frequency for rs351111, chr.19:844020 (c.355G>A) in PRTN3 among patients with AAV (PR3 and MPO-ANCA) in the DNA (panel B) and RNA (panel C) variant calling.

Table 1.

Outcomes of patients with PR3-ANCA according with PRTN3 zygosity.

PR3-ANCA (n=64)Homozygous PR3-Val119(n=51)HomozygousPR3-Ile119(n=13)p-value Remission, n (%)45 (88.2)13 (100)0.194 Complete remission, n (%)36 (70.6)10 (76.9)0.650 Any flare 18 months, n (%)30 (58.8)7 (53.8)0.746 Severe Relapse* 18 months, n (%)10 (19.6)6 (46.2)0.048

* Relapse was considered “Severe” if Birmingham Vasculitis Activity Score for Wegener’s Granulomatosis (BVAS/WG) > 3 or one major item as per the RAVE trial definition.

Abbreviations: ANCA - anti-neutrophil cytoplasmic antibody; Ile – isoleucine; n- number; PR3 - proteinase 3; Val - valine.

Conclusion

In patients with PR3-AAV the presence of PRTN3 Val119Ile polymorphism was associated with higher frequency of severe relapse. Further studies are necessary to understand the association of this observation with the risk of severe relapse.

References

[1]Stone JH et al N Engl J Med 2010; 363:221-232

Disclosure of Interests

None declared

Efficacy of leflunomide in the treatment of vasculitis

OBJECTIVES

Only a few small case series, case reports, and one small clinical trial suggested some benefit of leflunomide (LEF) in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis and other vasculitides. We analysed the clinical efficacy and tolerability of LEF in a large cohort of patients with various vasculitides.

METHODS

This was a retrospective analysis of patients who received LEF for treatment of their vasculitis enrolled in the Vasculitis Clinical Research Consortium (VCRC) Longitudinal Study and in 3 additional centres from the Canadian vasculitis research network (CanVasc).

RESULTS

Data for 93 patients were analysed: 45 had granulomatosis with polyangiitis (GPA), 8 microscopic polyangiitis (MPA), 12 eosinophilic granulomatosis with polyangiitis (EGPA), 14 giant-cell arteritis (GCA), 9 Takayasu's arteritis (TAK), and 5 polyarteritis nodosa (PAN). The main reason for initiation of LEF was active disease (89%). LEF was efficacious for remission induction or maintenance at 6 months for 62 (67%) patients (64% with GCA, 89% with TAK, 80% with PAN, 69% with GPA, 75% with MPA, 33% with EGPA); 20% discontinued LEF before achieving remission because of persistent disease activity. Overall, 22 adverse events (gastrointestinal symptoms being the most common) led to drug discontinuation in 18 (19%) patients, of which 12 stopped LEF before month 6, before showing any benefit in 8/12 of these patients.

CONCLUSIONS

Leflunomide can be an effective therapeutic option for various vasculitides, especially for non-severe refractory or relapsing ANCA-associated vasculitis or large-vessel vasculitis. No new safety signals for LEF were identified in this population.

THU0040 PROTEINASE 3-REACTIVE B CELL RECONSTITUTION AFTER TREATMENT WITH RITUXIMAB FOR ANCA-ASSOCIATED VASCULITIS

Background:

Proteinase 3 (PR3)-reactive B cells are present in PR3-ANCA-associated vasculitis (AAV) at levels higher than healthy controls.

Objectives:

To evaluate the dynamics of the PR3-reactive B cell repopulation in patients with PR3-AAV after treatment with rituximab, and to analyze possible associations between these immunological changes and long-lasting remissions.

Methods:

We analyzed all available frozen peripheral blood mononuclear cells (n=148) from 23 randomly-selected PR3-AAV patients who participated in the RAVE trial and achieved complete remission (BVAS=0, prednisone=0) after treatment with rituximab.

We measured PR3-reactive B cells and the relative subsets by a multi-color flow cytometry panel including CD19, IgD, CD27, CD38, CD24, and a biotinylated PR3 revealed by fluorescent streptavidin. The clinical data of the trial were correlated with flow-cytometry data.

Results:

10/23 (43%) patients relapsed during the follow up, 8/10 relapses were severe. At baseline, clinical features, PR3-ANCA levels, % of total PR3-reactive B cells and PR3-reactive B cell subsets were similar between relapsers and non-relapsers. All patients were followed until the end of the trial, for a mean of 44 months (25-75%IQR 31-54), without difference in follow-up time between relapsers and non-relapsers (p=0.98).

The majority of patients had B cell repopulation at 12 (range 12-24) months after rituximab. At the time of B cell repopulation, transitional (CD19+CD24+CD38+) and naïve (CD19+CD27+IgD-) B cells were higher compared to baseline, while total plasmablasts (PB) were unchanged, and mature B cells significantly decreased in both relapsers and non relapsers. PR3-reactive B cells reappeared in all the patients, and the % of PR3-reactive of B cells were higher at the B cell repopulation visit compared to baseline (5.82% vs 4.25%, p<0.05), while total B cells were lower (66/μL vs 151/μL, p<0.01), regardless of future relapse.

Within PR3-reactive B cells, only the % of PB (CD19+CD27+CD38+PR3+) were higher in relapsers vs. non-relapsers (median [25-75%IQR]; 1.95% [1.315-3.845] vs 0.84% [0.05-1.66], p=0.022) and severe relapsers vs non-severe relapsers (2.165% [1.66-4.315] vs 0.84% [0.1-1.74], p=0.015). Time-to-relapse and time-to severe-relapse were significantly shorter in patients with circulating PR3-PB higher than the median value of the cohort (1.6%) during B cell reconstitution (Figure 1A-B).

Conclusion:

In PR3-AAV, during B cell reconstitution after rituximab, the total fraction of PR3-B cells increases, due to the expansion of the transitional and naïve B cell compartments. Circulating PR3-PB within PR3-B cells are enriched in the peripheral blood of relapsing and severely relapsing patients compared to non-relapsing patients. Higher levels of PR3-PB after rituximab during B cell reappearance significantly increased the risk of subsequent relapse and severe relapse.

References:

[1]Cornec D, Berti A, Hummel A, et al. J Autoimmun. 2017

Disclosure of Interests:

Alvise Berti: None declared, Sophie Hillion: None declared, Amber Hummel: None declared, Eva Carmona: None declared, Tobias Peikert: None declared, Carol Langford: None declared, Peter A. Merkel: None declared, Paul Monach: None declared, Philip Seo: None declared, Robert Spiera Grant/research support from: Roche-Genetech, GSK, Boehringer Ingelheim, Chemocentryx, Corbus, Forbius, Sanofi, Inflarx, Consultant of: Roche-Genetech, GSK, CSL Behring, Sanofi, Janssen, Chemocentryx, Forbius, Mistubishi Tanabe, E. William St. Clair: None declared, Fernando Fervenza: None declared, Kristina Harris: None declared, John H. Stone Grant/research support from: Roche, Consultant of: Roche, Jacques-Olivier Pers: None declared, Ulrich Specks: None declared, Divi Cornec: None declared

THU0318 PATTERNS OF CLINICAL PRESENTATION IN TAKAYASU’S ARTERITIS

Background:

Takayasu’s arteritis (TAK) is a clinically heterogenous disease. Patterns of clinical presentation in TAK at diagnosis have not been well described, and a “triphasic pattern” of constitutional symptoms evolving into vascular inflammation and fibrosis has been reported but never systematically evaluated.

Objectives:

To describe patterns of clinical presentation in TAK at diagnosis and evaluate the presence of an antecedent triphasic disease pattern in patients with TAK who presented with a major ischemic event at diagnosis.

Methods:

Patients with TAK were prospectively recruited from the National Institutes of Health (NIH) and the Vasculitis Clinical Research Consortium (VCRC). All patients fulfilled the 1990 American College of Rheumatology (ACR) Classification Criteria for TAK. Based on clinical presentation at diagnosis, patients were divided into five groups from the different stages of the triphasic pattern of disease as follows: 1) constitutional symptoms (phase I), 2) carotidynia (phase II), 3) other vascular-associated symptoms (phase II), 4) major ischemic event (phase III) defined as CVA or TIA, retinal ischemia, MI, renovascular hypertension, or mesenteric ischemia, or 5) asymptomatic. Phase II was divided into two separate groups because patients with carotidynia reportedly have a higher rate of relapsing disease.

Associated clinical characteristics were evaluated in each group and differences among groups were assessed by chi square test and Kruskal-Wallis test, as appropriate. Preceding symptoms were also assessed to determine the presence of a triphasic disease pattern.

Results:

A total of 275 patients with TAK were included (VCRC=208; NIH=67). Similar heterogeneity of clinical presentation was identified in each cohort: constitutional symptoms (8%), carotidynia (13-15%), other vascular symptoms (43-47%), major ischemic event (28-30%), and asymptomatic (2-6%). Frequency of male gender was more common in patients who presented with constitutional symptoms or were asymptomatic at diagnosis (p<0.01). Patients who presented with constitutional symptoms and major ischemic events were youngest at diagnosis. Patients in the asymptomatic group were oldest at diagnosis and often were not treated (p<0.01). Involvement of the abdominal vasculature was associated with major ischemic events and asymptomatic presentations. Major ischemic events after diagnosis were infrequent in the groups who did not present with a major ischemic event, occurring in 10-20% cases. Relapse (p<0.01) and recurrent pharyngitis preceding diagnosis (p<0.01) was most frequent in patients who presented with carotidynia.

A total of 79 patients [VCRC=59 patients, NIH=20 patients] presented with a major ischemic event. The majority of these patients (53%) reported symptoms of active disease prior to the major ischemic event. Few patients (19%) who presented with a major ischemic event reported a triphasic pattern of disease.

Conclusion:

There is heterogeneity in clinical presentation at the time of diagnosis in TAK and this heterogeneity can be used to group patients according to pattern of disease presentation. Patients do not necessarily progress sequentially through phases of disease, but the majority of patients presenting with a major ischemic event report some preceding symptoms. Data from this study demonstrate distinct subgroups within TAK and supports the concept that TAK is possibly a heterogenous collection of multiple diseases.

References:

N/A

Disclosure of Interests:

None declared

THU0310 CASE–CONTROL SEROPREVALENCE STUDY ON THE ASSOCIATION BETWEEN BARTONELLA INFECTION AND ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODY-ASSOCIATED VASCULITIS

Background:

Bartonellosis is an emerging anthropozoonosis caused by infection with intracellular Gram-negativeBartonellaspecies. It leads to necrotizing granulomas and endothelial damage and causes acute and chronic human diseases, such as cat scratch disease, bacillary angiomatosis and endocarditis. Endocarditis due toBartonella henselaeandB. quintanais reported to produce anti-neutrophil cytoplasmic antibodies (ANCAs) that disappear with effective antimicrobial treatment.

Objectives:

Hypothesizing a role forBartonellainfection in ANCA-associated vasculitis (AAV), which also includes granulomatous and vascular inflammation, we studied the seroprevalence of 5Bartonellaspecies in patients with AAV.

Methods:

The study used plasma samples from patients with granulomatosis with polyangiitis and microscopic polyangiitis that were enrolled in the Rituximab for AAV (RAVE) trial and from healthy controls living in the United States. Western blot assays were used for serological testing of infection withB. quintana,B. henselaeHouston-1,B. elizabethae,B. vinsoniisubsp.berkhoffiiandB. alsatica. The associations of positive serology results and AAV were expressed as odds ratios (OR). Clinical characteristics of seropositive and seronegative patients, assessed by the BVAS/WG instrument, were compared. These comparisons were done for 9 organ systems; in case they showed differences withP<0.10, the corresponding organ system-specific clinical features were also analyzed. Statistical analysis was performed using Fisher’s exact test or Student’s t-test, as appropriate.

Results:

We analyzed blood samples of 187 patients with AAV (collected at start of the trial) and of 127 controls. There were no significant differences between the cases and controls for mean age (P=0.148) and proportion of males (P=0.36).Bartonellaspp. serological testing was positive for 112 (60%) cases and 40 (31%) controls (OR 3.25 [95% CI 2.02–5.22],P<0.001). Significant associations were also found within subsets of PR3-AAV (OR 4.00 [95% CI 2.37–6.76],P<0.001), MPO-AAV (OR 2.18 [95% CI 1.17–4.06],P=0.017), newly-diagnosed (OR 3.89 [95% CI 2.21–6.86],P<0.001) and relapsing disease (OR 2.86 [95% CI 1.65–4.98],P<0.001). Species-specific positive serological testing was found in particular againstB. henselae(cases: 27%, controls: 0.8%; OR 39.93 [95% CI 5.42–293.90];P<0.001). Compared to AAV patients without seropositivity forBartonellaspp., AAV patients testing seropositive forBartonellaspp. had significantly more bloody nasal discharge (P=0.046), sinus involvement (P=0.035) and conjunctivitis/episcleritis (P=0.016).

Conclusion:

This study reveals higher seroprevalence ofBartonella, especiallyB. henselae, in patients with AAV than in healthy controls. Although cross-reactivity ofBartonellawith other microorganisms cannot be excluded, these results may support an etiopathogenic role ofBartonellainfection in AAV that deserves further investigation.

Disclosure of Interests:

Alfred Mahr Consultant of: Celgene, Speakers bureau: Roche, Chugai, Sophie Edouard: None declared, Divi Cornec: None declared, Solange GONZALEZ-CHIAPPE: None declared, Jörg Goronzy: None declared, Philippe Guilpain: None declared, Carol Langford: None declared, Pierre-Yves Lévy: None declared, Peter A. Merkel: None declared, Paul Monach: None declared, E. William St. Clair: None declared, Philip Seo: None declared, Robert Spiera Grant/research support from: Roche-Genetech, GSK, Boehringer Ingelheim, Chemocentryx, Corbus, Forbius, Sanofi, Inflarx, Consultant of: Roche-Genetech, GSK, CSL Behring, Sanofi, Janssen, Chemocentryx, Forbius, Mistubishi Tanabe, Cornelia Weyand: None declared, John H. Stone Grant/research support from: Roche, Consultant of: Roche, Didier Rauolt: None declared, Ulrich Specks: None declared

Immunoglobulin (Ig)M antibodies to proteinase 3 in granulomatosis with polyangiitis and microscopic polyangiitis

Anti-neutrophil cytoplasmic antibodies (ANCA) appear to play an important role in the pathogenesis of ANCA-associated vasculitis (AAV). However, ANCA alone are not sufficient to generate disease, and some evidence suggests that infectious triggers may serve as inciting events for AAV disease activity. Antibodies of the immunoglobulin (Ig)M isotype often serve as markers of recent infection, and IgM ANCA have been identified previously in patients with AAV, although the frequency and clinical relevance of IgM ANCA is not well established. We sought to characterize IgM ANCA more clearly by creating a novel enzyme-linked immunosorbent assay (ELISA) for IgM antibodies to proteinase 3 [IgM proteinase 3 (PR3)-ANCA], which we applied to two large, clinically well-characterized trial cohorts of patients with granulomatosis with polyangiitis and microscopic polyangiitis. In the first cohort, IgM PR3-ANCA occurred with a frequency of 15·0%, and were associated with a higher degree of disease severity and a trend towards a higher rate of alveolar haemorrhage (29·6 versus 15·7%, P = 0·10). Analysis of follow-up samples in this cohort showed that the presence of IgM PR3-ANCA was transient, but could recur. In the second cohort, IgM PR3-ANCA occurred with a frequency of 41·1%, and were also associated with a higher degree of disease severity. A higher rate of alveolar haemorrhage was observed among those with IgM PR3-ANCA (45·3 versus 15·8%; P < 0·001). The association of transient IgM PR3-ANCA with an acute respiratory manifestation of AAV suggests a possible link between an infectious trigger and AAV disease activity.

Outcomes of nonsevere relapses in antineutrophil cytoplasmic antibody-associated vasculitis treated with glucocorticoids

OBJECTIVE

Nonsevere relapses are more common than severe relapses in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), but their clinical course and treatment outcomes remain largely unexamined. We undertook this study to analyze the outcomes of patients with nonsevere relapses in the Rituximab in ANCA-Associated Vasculitis (RAVE) trial who were treated with prednisone according to a prespecified protocol.

METHODS

RAVE was a randomized, double-blind, placebo-controlled trial comparing rituximab (RTX) to cyclophosphamide (CYC) followed by azathioprine (AZA) for induction of remission. Patients who experienced nonsevere relapses between months 1 and 18 were treated with a prednisone increase without a concomitant change in their nonglucocorticoid immunosuppressants, followed by a taper.

RESULTS

Forty-four patients with a first nonsevere relapse were analyzed. In comparison to the 71 patients who maintained relapse-free remission over 18 months, these patients were more likely to have proteinase 3-ANCAs, diagnoses of granulomatosis with polyangiitis (Wegener's), and a history of relapsing disease at baseline. A prednisone increase led to remission in 35 patients (80%). However, only 13 patients (30%) were able to maintain second remissions through the followup period (mean 12.5 months); 31 patients (70%) had a second disease relapse, 14 of them with severe disease. The mean time to second relapse was 9.4 months (4.7 months in the group treated with RTX versus 13.7 months in the group treated with CYC/AZA; P < 0.01). Patients who experienced nonsevere relapses received more glucocorticoids than those who maintained remission (6.7 grams versus 3.8 grams; P < 0.01).

CONCLUSION

Treatment of nonsevere relapses in AAV with an increase in glucocorticoids is effective in restoring temporary remission in the majority of patients, but recurrent relapses within a relatively short interval remain common. Alternative treatment approaches are needed for this important subset of patients.

Rituximab for the treatment of relapses in antineutrophil cytoplasmic antibody-associated vasculitis

OBJECTIVE

Disease relapses are frequent in antineutrophil cytoplasmic antibody-associated vasculitis (AAV). This study was undertaken to evaluate outcomes in patients with AAV who are re-treated with rituximab (RTX) and prednisone for severe disease relapses.

METHODS

The Rituximab in AAV trial was a randomized, double-blind, placebo-controlled trial comparing the rates of remission induction among patients treated with RTX (n = 99) and patients treated with cyclophosphamide (CYC) followed by azathioprine (AZA) (n = 98). Prednisone was tapered to discontinuation after 5.5 months. After remission was achieved, patients who experienced a severe disease relapse between months 6 and 18 were eligible to receive RTX and prednisone on an open-label basis according to a prespecified protocol. Investigators remained blinded with regard to the original treatment assignment.

RESULTS

Twenty-six patients received RTX for disease relapse after remission had initially been achieved with their originally assigned treatment. Fifteen of these patients were initially randomized to receive RTX and 11 to receive CYC/AZA. Thirteen (87%) of the patients originally assigned to receive RTX and 10 (91%) originally assigned to receive CYC/AZA achieved remission again with open-label RTX (an overall percentage of 88%). In half of the patients treated with open-label RTX, prednisone could be discontinued entirely. Patients in this cohort experienced fewer adverse events compared to the overall study population (4.7 adverse events per patient-year versus 11.8 adverse events per patient-year).

CONCLUSION

Re-treatment of AAV relapses with RTX and glucocorticoids appears to be a safe and effective strategy, regardless of previous treatment.

BK virus replication in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis

BACKGROUND

BK virus (BKV) is an important cause of renal dysfunction in kidney transplant (KTX) recipients. Immunosuppression intensity is a major risk factor for BKV replication in these patients. The prevalence of BKV replication in immunosuppressed patients with granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) without transplant is not known.

METHODS

Consecutive patients (n = 37) with a diagnosis of GPA (n = 25) or MPA (n = 12) without history of KTX were evaluated for plasma BKV replication by quantitative PCR (group A). Descriptive data were collected. BKV replication in this nontransplant immunosuppressed vasculitis cohort was compared with a historical cohort of vasculitis KTX recipients (group B).

RESULTS

Group A patients had mean disease duration of 75 months. Mean age was 57 years and 54% were female. Mean time from vasculitis onset to BKV testing was 36 months, and 19/37 patients were tested within 24 months of induction therapy. At the time of BKV testing, 73% were on prednisone (P) with azathioprine, mycophenolate mofetil (MMF), methotrexate or leflunomide. None of the nontransplanted vasculitis patients had detectable plasma BKV. Among 35 patients in group B, 16 were tested for BKV; 5/16 (31%) had detectable virus in plasma at a mean of 6 months after TX (p = 0.002). Most (94%) were on maintenance therapy with MMF, P and tacrolimus.

CONCLUSION

Immunosuppressed patients with GPA/MPA without KTX had no evidence of plasma BKV. However, BKV was common in GPA/MPA patients after KTX, suggesting that replication may be related to differences in immunosuppression, alloimmune activation or differences in host defense mechanisms.

Clinical outcomes of remission induction therapy for severe antineutrophil cytoplasmic antibody-associated vasculitis

OBJECTIVE

To evaluate the reasons that complete remission is not achieved or maintained with original treatment in some patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) treated with rituximab (RTX) or with cyclophosphamide/azathioprine (CYC/AZA).

METHODS

The Rituximab in AAV trial was a randomized, double-blind, placebo-controlled trial comparing the rate of remission induction among patients treated with RTX (n = 99) and patients treated with CYC followed by AZA (n = 98). Glucocorticoids were tapered over a period of 5 months. The primary outcome measure was lack of disease activity without glucocorticoid treatment at 6 months. To determine the most important reason for failure to achieve the primary outcome, 7 hierarchical categories of reasons were defined retrospectively (uncontrolled disease, adverse event leading to therapy discontinuation, severe flare, limited flare, Birmingham Vasculitis Activity Score for Wegener's Granulomatosis >0, prednisone treatment at any dosage, and other).

RESULTS

Although remission (lack of disease activity) was achieved in 170 of the 197 patients (86%) in the first 6 months, the primary outcome measure was not achieved in 42%. There were 3 deaths. Twenty-four percent of the patients failed to achieve the primary end point due to active disease: 10 (5%) experienced uncontrolled disease in the first month and 37 (19%) experienced flares after initial improvement. In the majority of such patients, treatment with blinded crossover or according to best medical judgment led to disease control. Ninety-one percent of patients who had uncontrolled disease or experienced a severe flare had proteinase 3 (PR3)-ANCA. When patients with uncontrolled disease were excluded from analysis, those who were PR3-ANCA positive were found to experience fewer flares when treated with RTX compared to CYC/AZA (8 of 59 [14%] versus 20 of 62 [32%]; P = 0.02). Neither ANCA titers nor B cell counts predicted disease flare.

CONCLUSION

Current treatment regimens are largely successful in controlling AAV, but in approximately one-fourth of patients, active disease persists or recurs in the first 6 months despite treatment. PR3-ANCA positivity is a risk factor for recurrence or persistence of severe disease. ANCA titers and B cell detectability are poor predictors of both disease relapse and disease quiescence in the first 6 months.

Characteristics of cross-hybridization and cross-alignment of expression in pseudo-xenograft samples by RNA-Seq and microarrays

Background

Exploring stromal changes associated with tumor growth and development is a growing area of oncologic research. In order to study molecular changes in the stroma it is recommended to separate tumor tissue from stromal tissue. This is relevant to xenograft models where tumors can be small and difficult to separate from host tissue. We introduce a novel definition of cross-alignment/cross-hybridization to compare qualitatively the ability of high-throughput mRNA sequencing, RNA-Seq, and microarrays to detect tumor and stromal expression from mixed ‘pseudo-xenograft’ samples vis-à-vis genes and pathways in cross-alignment (RNA-Seq) and cross-hybridization (microarrays). Samples consisted of normal mouse lung and human breast cancer cells; these were combined in fixed proportions to create a titration series of 25% steps. Our definition identifies genes in a given species (human or mouse) with undetectable expression in same-species RNA but detectable expression in cross-species RNA. We demonstrate the comparative value of this method and discuss its potential contribution in cancer research.

Results

Our method can identify genes from either species that demonstrate cross-hybridization and/or cross-alignment properties. Surprisingly, the set of genes identified using a simpler and more common approach (using a ‘pure’ cross-species sample and calling all detected genes as ‘crossers’) is not a superset of the genes identified using our technique. The observed levels of cross-hybridization are relatively low: 5.3% of human genes detected in mouse, and 3.5% of mouse genes detected in human. Observed levels of cross-alignment are practically comparable to the levels of cross-hybridization: 6.5% of human genes detected in mouse, and 2.3% of mouse genes detected in human. We also observed a relatively high percentage of orthologs: 40.3% of cross-hybridizing genes, and 32.2% of cross-aligning genes.

Normalizing the gene catalog to use Consensus Coding Sequence (CCDS) IDs (Genome Res 19:1316–1323, 2009), our results show that the observed levels of cross-hybridization are low: 2.7% of human CCDS IDs are detected in mouse, and 2.4% of mouse CCDS IDs are detected in human. Levels of cross-alignment using the RNA-Seq data are comparable for the mouse, 2.2% of mouse CCDS IDs detected in human, and 9.9% of human CCDS IDs detected in mouse. However, the lists of cross-aligning/cross-hybridizing genes contain many that are of specific interest to oncologic researchers.

Conclusions

The conservative definition that we propose identifies genes in mouse whose expression can be attributed to human RNA, and vice versa, as well as revealing genes with cross-alignment/cross-hybridization properties which could not be identified using a simpler but more established approach. The overall percentage of genes affected by cross-hybridization/cross-alignment is small, but includes genes that are of interest to oncologic researchers. Which platform to use with mixed xenograft samples, microarrays or RNA-Seq, appears to be primarily a question of cost and whether the detection and measurement of expression of specific genes of interest are likely to be affected by cross-hybridization or cross-alignment.

Abstract 2994: Characteristics of cross-hybridization/cross-alignment of expression in xenograft samples by RNAseq and microarrays

Stromal changes have been the focus of numerous research publications and have led to insights in both tumor development and promising new avenues for treatment. In order to study molecular changes in stroma from tissue samples it is recommended to separate tumor tissue from stromal tissue. One such context is mouse tumor xenograft models where tumors, particularly metastatic tumors, can be small and difficult to separate from the host tissue. In our research we compared qualitatively the ability of RNA-seq and microarray data to detect tumor (human) and stromal (mouse) expression from mixed samples in terms of cross-alignment and cross-hybridization. Samples were analyzed using HumanWG-6_V3_0_R1 and MouseWG-6_V2_0_R0 Expression BeadChips and the GenomeAnalyzer IIe (Illumina, Inc.). Samples consisted of total RNA from normal mouse lung from NOD/SCID gamma mice and total RNA from MDA-MB-231 breast cancer cells combined in fixed proportions in triplicate. We define a gene which cross-hybridizes from mouse to human as one which exists in the set defined by (B U C U D) - A, where A, B, C, and D are defined as follows. A is the set of all genes detected when pure mouse RNA was hybridized onto mouse chips (or aligned to the mouse genome); B is the set of all genes detected when 25% human/75% mouse RNA was hybridized onto mouse chips (or aligned to the mouse genome); C is the set of all genes detected when 50% human/50% mouse RNA was hybridized onto mouse chips (or aligned to the mouse genome); D is the set of all genes detected when 75% human/25% mouse RNA was hybridized onto mouse chips (or aligned to the mouse genome). A gene that cross-hybridizes from human to mouse is defined analogously. Our results show that observed levels of cross-hybridization are quite low (5.32% of human probes detected in mouse, 3.48% of mouse probes detected in human). The observed levels of cross-alignment are practically comparable to the levels of cross-hybridization (6.50% of human genes detected in mouse, 2.27% of mouse genes detected in human). However, there are genes and pathways of considerable interest to oncology researchers which show significant cross-hybridization/cross-alignment and, as such, their presence/absence or level of expression in tumor tissue versus stromal tissue cannot be determined using the platforms from this study. Cross-hybridizing/cross-aligning genes in our studies include PDGF, b-Raf, Beta-catenin, erbB2, NF-kB, MDM2, Claudin, VEGF-R, Notch2, Cyclin B, HSP90 and Ubiquitin. Biological pathways significantly enriched for genes which show cross-hybridization/cross-alignment include TGF-mediated regulation of cell proliferation, TGF/WNT and cytoskeletal remodeling, regulation of EMT, hedgehod signaling, and the FGFR signaling pathway. Which platform to use with mixed tissues from xenografts - microarrays or NGS - appears to be primarily a question of cost and specific genes of interest.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2994. doi:1538-7445.AM2012-2994

Will periodic intravenous injections of conditioned bone marrow cells effectively reduce atherosclerosis?

Maintenance of healthy arteries requires a balance between injuries to the arterial wall and processes of intrinsic arterial repair. Such repair requires the availability of progenitor cells that are local to the wall itself. Progenitor cells from distant reservoirs like the bone marrow may also contribute to repair. Arterial repair seems to degrade over a lifetime, particularly with risk factors such as smoking and diabetes. Hence, a potential preventive/therapeutic strategy for atherosclerosis could be transfusion of competent bone marrow cells (BMCs) to restore effective repair in the face of arterial injury and depleted endogenous repair reservoirs. The challenge with this strategy has been the reliable collection and/or generation of BMCs that support arterial repair. In this study, we describe a set of experiments to elucidate a method of culturing BMCs that robustly retards atherosclerosis development in apolipoprotein E knockout mice. Identifying such a method would represent an important step in developing cell-based treatments for patients with proclivity for developing atherosclerosis.

Phase 2 study of neoadjuvant treatment with NOV-002 in combination with doxorubicin and cyclophosphamide followed by docetaxel in patients with HER-2 negative clinical stage II-IIIc breast cancer

NOV-002 (a formulation of disodium glutathione disulfide) modulates signaling pathways involved in tumor cell proliferation and metastasis and enhances anti-tumor immune responsiveness in tumor models. The addition of NOV-002 to chemotherapy has been shown to increase anti-tumor efficacy in animal models and some early phase oncology trials. We evaluated the clinical effects of NOV-002 in primary breast cancer, whether adding NOV-002 to standard preoperative chemotherapy increased pathologic complete response rates (pCR) at surgery, and determined whether NOV-002 mitigated hematologic toxicities of chemotherapy and whether levels of myeloid derived suppressor cells (MDSC) were predictive of response. Forty-one women with newly diagnosed stages II-IIIc HER-2 negative breast cancer received doxorubicin-cyclophosphamide followed by docetaxel (AC → T) every 3 weeks and concurrent daily NOV-002 injections. The trial was powered to detect a doubling of pCR rate from 16 to 32% with NOV-002 plus AC → T (α = 0.05, β = 80%). Weekly complete blood counts were obtained as well as circulating MDSC levels on day 1 of each cycle were quantified. Of 39 patients with 40 evaluable tumors, 15 achieved a pCR (38%), meeting the primary endpoint of the trial. Concurrent NOV-002 resulted in pCR rates for AC → T chemotherapy higher than previously reported. Patients with lower levels of circulating MDSCs at baseline and on the last cycle of chemotherapy had significantly higher probability of a pCR (P = 0.02). Further evaluation of NOV-002 in a randomized study is warranted.

Abstract P1-11-05: Phase 2 Study of Neoadjuvant Treatment with Cellular Redox Modulator NOV-002 in Combination with Doxorubicin and Cyclophosphamide Followed by Docetaxel (AC→T) in Patients with Stage II-III HER-2 (-) Breast Cancer

Background: NOV-002 (a formulation of disodium glutathione disulfide) modulates signaling pathways involved in tumor cell proliferation and metastasis and enhances anti-tumor immune responsiveness in tumor models. The addition of NOV-002 to a range of cytotoxic chemotherapeutic regimens has been shown to increase their anti-tumor efficacy in several early phase oncology trials and in animal models. Pathological complete response (pCR) has been demonstrated to be associated with favorable overall survival in primary breast cancer, and neoadjuvant treatment of early breast cancer aims at achieving high rates of pCR. In patients with HER-2 (-) breast cancer pCR rates with anthracycline and taxane combinations have been reported to be approximately 10-20% depending on hormone receptor status. We conducted a clinical trial in HER-2 negative patients (pts) combining daily N0V-002 with AC→T. Methods: Women with newly diagnosed stages II-III HER-2 (-) breast cancer received AC x 4 [60/600 mg/m2] followed by T [100 mg/m2] x 4 every 3 weeks in conjunction with daily N0V-002 [60mg IV day 1 and subcutaneously days 2-21 of each cycle]. The primary endpoint is pCR, defined as: (i) ypN0, and (ii) ypT0 or presence of invasive tumor &lt;10mm.

Sample size (n=46 total patients) was calculated using a Simon 2-stage optimal design assuming a doubling of the historical pCR rate with the addition of NOV-002 to AC→T from a p0 of 0.16 to a p1 of 0.32. If a total of 12 or more patients experience a pCR by the end of the trial, then the treatment regimen will be declared active. The calculation assumes an alpha of 0.05 and 80% power.

Results: A total of 39 pts have been enrolled to date across three study sites, with 31 patients having completed chemotherapy and undergone surgery. One patient dropped out during cycle 1 and was not assessable for response; 5 are currently receiving chemotherapy; and 2 patients have completed all chemotherapy, but have not yet undergone surgery. A total of 292 chemotherapy cycles have been administered, with 92% of all patients being able to complete all 8 cycles of planned chemotherapy. Of the 31 evaluable patients, 12 achieved a pCR (39%), meeting the primary endpoint of the trial. In patients with residual invasive primary breast tumor &lt;10mm and ypN0 (19%) mean residual tumor size was 4.4 mm. Interestingly, of the 17 patients with biopsy-proven axillary involvement, 4 (23%) had no residual invasive tumor in axillary nodes at time of surgery. In 26 patients with estrogen positive breast cancer, which is least sensitive to chemotherapy, 42% achieved a pCR. The most common toxicities included: nausea, sensory neuropathy, emesis, fatigue, and hand-foot syndrome. Conclusions: The addition of NOV-002 has to date resulted in a doubling of previously published pCR rates with AC→T in HER-2 (-) breast cancer patients. Subsequent investigation of NOV-002 in conjunction with neoadjuvant chemotherapy in breast cancer is warranted. Updated clinical data on all 39 patients as well as immunologic correlative markers will be presented.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-11-05.

The role of SATB1 in breast cancer pathogenesis

BACKGROUND

SATB1 has been previously proposed as a key protein that controls the development and progression of breast cancer. We explored the potential of the SATB1 protein as a therapeutic target and prognostic marker for human breast cancer.

METHODS

We used aggressive (MDA-MB-231 and BT549) and nonaggressive (SKBR3 and MCF7) breast cancer cell lines to investigate the potential of SATB1 as a therapeutic target. SATB1 mRNA expression was silenced in aggressive cells by use of short hairpin RNAs against SATB1. SATB1 was overexpressed in nonaggressive cells by use of SATB1 expression vectors. We assessed the effect of modifying SATB1 expression on the transformed phenotype by examining anchorage-independent cell proliferation, acinar morphology on matrigel, and migration by wound healing in cultured cells. We examined tumor formation and metastasis, respectively, by use of orthotopic mammary fat pad and tail vein xenograft mouse models (mice were used in groups of six, and in total, 96 mice were used). SATB1 mRNA expression was compared with outcome for patients with primary breast cancer from six previous microarray studies that included a total of 1170 patients. All statistical tests were two-sided.

RESULTS

The transformed phenotype was not suppressed by SATB1 silencing in aggressive cells and was not enhanced by ectopic expression of SATB1 in nonaggressive cells. Modifying SATB1 expression did not alter anchorage-independent cell proliferation, invasive acinar morphology, or cell migration in cultured cells and did not affect tumor formation or metastasis in xenograft mouse models. In addition, SATB1 expression was not associated with decreased overall survival of patients with primary breast cancer in six previous independent microarray studies (overall odds ratio = 0.80, 95% confidence interval = 0.62 to 1.03, P = .10).

CONCLUSION

In contrast to previous studies, we found that SATB1 expression did not promote breast cancer progression and was not associated with breast cancer outcome.

Statistical expression deconvolution from mixed tissue samples

MOTIVATION

Global expression patterns within cells are used for purposes ranging from the identification of disease biomarkers to basic understanding of cellular processes. Unfortunately, tissue samples used in cancer studies are usually composed of multiple cell types and the non-cancerous portions can significantly affect expression profiles. This severely limits the conclusions that can be made about the specificity of gene expression in the cell-type of interest. However, statistical analysis can be used to identify differentially expressed genes that are related to the biological question being studied.

RESULTS

We propose a statistical approach to expression deconvolution from mixed tissue samples in which the proportion of each component cell type is unknown. Our method estimates the proportion of each component in a mixed tissue sample; this estimate can be used to provide estimates of gene expression from each component. We demonstrate our technique on xenograft samples from breast cancer research and publicly available experimental datasets found in the National Center for Biotechnology Information Gene Expression Omnibus repository.

AVAILABILITY

R code (http://www.r-project.org/) for estimating sample proportions is freely available to non-commercial users and available at http://www.med.miami.edu/medicine/x2691.xml.

Successful induction of remission with rituximab for relapse of ANCA-associated vasculitis post-kidney transplant: report of two cases

Kidney transplantation should be considered the treatment of choice for patients with end-stage renal disease due to antineutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV). However, relapses of AAV have been reported to occur in 9-40% of cases following kidney transplantation and may adversely affect allograft outcome. These relapses are usually treated with cyclophosphamide (CYC) and glucocorticoids, but the repeated use of CYC carries a risk of substantial toxicity that may limit or prohibit its use in some patients. B lymphocytes have been implicated in the pathogenesis of AAV, and their depletion has been effective as salvage therapy for refractory disease in the nontransplant setting. We report the successful induction of remission using rituximab in two patients who suffered relapse of AAV post-kidney transplant. Given the substantial morbidity and adverse effects of CYC, rituximab appears to be a suitable alternative agent to treat relapses of AAV posttransplantation.

Renal transplantation in the ANCA-associated vasculitides

Despite advances in the diagnosis and treatment of the antineutrophil cytoplasmic autoantibodies (ANCA)-associated vasculitides, renal morbidity is common. End-stage renal disease occurs in up to 20% of patients with these diagnoses, which include Wegener's granulomatosis and microscopic polyangiitis. As the mortality of patients with ANCA-associated vasculitis continues to improve, our ability to address the consequences of renal failure in this patient population becomes paramount. Renal transplantation is an important therapeutic option for these patients. Graft and patient survival rates among patients with ANCA-associated vasculitis are comparable to those observed in nondiabetic patients. This review summarizes our current knowledge of indications and contraindications for renal transplantation in these patients, the recurrence of vasculitis after transplantation and the impact of posttransplant immunosuppression on the clinical course of these patients.

Retinoic Acid Receptor- 2 Promoter Methylation in Random Periareolar Fine Needle Aspiration

Methylation of the retinoic acid receptor-beta2 (RARbeta2) P2 promoter is hypothesized to be an important mechanism for loss of RARbeta2 function during early mammary carcinogenesis. The frequency of RARbeta2 P2 methylation was tested in (a) 16 early stage breast cancers and (b) 67 random periareolar fine needle aspiration (RPFNA) samples obtained from 38 asymptomatic women who were at increased risk for breast cancer. Risk was defined as either (a) 5-year Gail risk calculation > or = 1.7%; (b) prior biopsy exhibiting atypical hyperplasia, lobular carcinoma in situ, or ductal carcinoma in situ; or (c) known BRCA1/2 mutation carrier. RARbeta2 P2 promoter methylation was assessed at two regions, M3 (-51 to 162 bp) and M4 (104-251 bp). In early stage cancers, M4 methylation was observed in 11 of 16 (69%) cases; in RPFNA samples, methylation was present at M3 and M4 in 28 of 56 (50%) and 19 of 56 (38%) cases, respectively. RPFNAs were stratified for cytologic atypia using the Masood cytology index. The distribution of RARbeta2 P2 promoter methylation was reported as a function of increased cytologic abnormality. Methylation at both M3 and M4 was observed in (a) 0 of 10 (0%) of RPFNAs with Masood scores of < or = 10 (nonproliferative), (b) 3 of 20 (15%) with Masood scores of 11 to 12 (low-grade proliferative), (c) 3 of 10 (30%) with Masood scores of 13 (high-grade proliferative), and (d) 7 of 14 (50%) with Masood scores of 14 of 15 (atypia). Results from this study indicate that the RARbeta2 P2 promoter is frequently methylated (69%) in primary breast cancers and shows a positive association with increasing cytologic abnormality in RPFNA.

Function in elderly cancer survivors depends on comorbidities

BACKGROUND

Factors associated with functional status in elderly cancer survivors, in particular, comorbidity, have been inadequately studied.

METHODS

Of 4162 participants aged 65 and older enrolled in the Duke Established Populations for Epidemiologic Studies of the Elderly study in 1986, 376 of the participants self-reported a diagnosis of cancer. Participants were divided into 2 comorbidity groups and 4 cancer groups. Cancer groups included 132 participants diagnosed 0-4 years ago, 117 diagnosed 5-15 years ago, 127 diagnosed >15 years ago, and 3784 participants who had never been diagnosed with cancer. Comorbidity (self-reported stroke, diabetes, hypertension, and myocardial infarction) was classified as presence of 1 or no comorbidities (n = 3089) or 2 or more comorbidities (n = 1073). Function was assessed by Katz Activities of Daily Living, Rosow-Breslau, Nagi, and Instrumental Activities of Daily Living scales at the time of interview.

RESULTS

In a two-way analysis of covariance model of comorbidity and cancer group controlling for age, race, sex, education, marital status, depression, and cognitive status, duration of cancer survivorship does not influence most measures of function. In the subset of 376 cancer survivors, comorbidity significantly correlates with the functional status of these older cancer survivors (<0.02, for all 4 measures of function).

CONCLUSIONS

In the older cancer survivor, regardless of duration following diagnosis, the presence of comorbidity rather than the history of cancer per se correlates with impaired functional status.

Current and potential uses of low molecular weight heparin: a review and an economic analysis

AUDIENCE

This article is intended for primary care providers who care for patients requiring anticoagulation therapy.

GOAL

To provide the reader with a basic understanding of the pharmacology and uses of low molecular weight heparin, including its potential to reduce the length of hospitalization for a variety of indications.

OBJECTIVES

1. To describe the pharmacology of low molecular weight heparin. 2. To outline studies examining the use of low molecular weight heparin for the treatment of deep venous thrombosis and acute coronary syndromes. 3. To discuss the cost-effectiveness of low molecular weight heparins, as well as therapeutic considerations associated with their use. 4. To discuss the possible use of low molecular weight heparin in patients with mechanical prosthetic valves.

Expression of the sea urchin MyoD homologue, SUM1, is not restricted to the myogenic lineage during embryogenesis

SUM1 (sea urchin myogenic factor 1) is a sea urchin homologue of the myogenic basic helix-loop-helix transcription factors of the MyoD family. SUM1 was initially cloned from Lytechinus variegatus where immunocytochemistry demonstrated restricted expression in precursors of the circumesophageal muscles, the only identified muscle cells in the early embryo. Subsequent in situ hybridization analysis indicates that SUM1 embryonic expression is not restricted to the myogenic lineage; a distinct population of nonmyogenic cells also expresses SUM1. For comparative purposes, we cloned the SUM1 orthologue in the distantly related sea urchin, Strongylocentrotus purpuratus, where we found SpSUM1 transcripts in the same population of nonmyogenic cells.

Discovery of amphibian Tc1-like transposon families

We have discovered transposase sequences in the bull frog (Rana catesbeiana) and in the clawed frog (Xenopus laevis), which demonstrates that there are DNA-mediated transposons in Amphibia. The DNA sequences of 11 new Xenopus elements describe two new vertebrate transposon families. Phylogenetic analysis, using these sequences along with previously defined vertebrate and invertebrate elements, reveals at least five families of Tc1-like elements in Vertebrata. Some of these families co-exist in the same genome. Furthermore, the grouping of one of the amphibian transposon families with a branch of the teleost transposons raises the possibility of horizontal transfer.