Health-related quality of life of adult and adolescent patients living with alopecia areata in Australia

INTRODUCTION

To understand the experiences of adolescent and adult patients living with alopecia areata (AA) in Australia regarding symptom severity and the impact on psychosocial well-being and work/classroom productivity.

MATERIALS AND METHODS

A cross-sectional online patient survey among adolescent and adult patients diagnosed with AA was recruited via the Australia Alopecia Areata Foundation. Patient-reported outcomes were also assessed.

RESULTS

A total of 337 patients (49 adolescents; 288 adults), with a mean ± standard deviation age of 14.7 ± 1.55 and 38.9 ± 13.31 years for adolescents and adults, respectively, were included. In the group with extensive hair loss (Scalp Hair Assessment Patient-Reported Outcome, categories 3 + 4, n = 172), we observed higher emotional symptom and activity limitation scores (Alopecia Areata Patient Priority Outcomes, emotional symptoms: adults 2.5 ± 1.03, adolescents 2.2 ± 1.15; activity limitations: adults 1.4 ± 1.15, adolescents 1.2 ± 0.99). Additionally, in adults, the Alopecia Areata Symptom Impact Scale global score was 4.0 ± 2.10 (symptoms subscale score 4.1 ± 1.91; interference subscale scores 3.8 ± 2.73). Hospital Anxiety and Depression Scale scores were high across participants, irrespective of hair loss extent (adults: anxiety 9.2 ± 3.85, depression 6.6 ± 3.95; adolescents: anxiety 9.7 ± 4.65, depression 5.2 ± 3.59). Work and classroom productivity were substantially impaired due to AA, with 70.5% of adults and 57.1% of adolescents reporting activity impairment, and overall work/classroom impairment reported at 39.2% and 44.9%, respectively.

CONCLUSIONS

AA impacts the physical, emotional and psychosocial well-being of both adult and adolescent patients. More extensive hair loss more profoundly impacts those living with AA. Patients may benefit from patient-centred care approaches addressing the impact of hair loss on mental and emotional well-being, daily activities and work productivity.

Real-world evaluation of persistence, effectiveness and usage patterns of tofacitinib in treatment of psoriatic arthritis in Australia

OBJECTIVES

To describe treatment patterns and persistence of tofacitinib, interleukin 17 inhibitors (IL-17Ai) and tumour necrosis factor inhibitors (TNFi), in patients with psoriatic arthritis (PsA).

METHODS

Data from adult patients with PsA and who had received at least one prescription of tofacitinib, IL-17Ai or TNFi between May 2019 and September 2021 were sourced from the Australian OPAL dataset. Persistence, analysed via Kaplan-Meier methods, and propensity score matching between tofacitinib and bDMARD (IL-17Ai and TNFi) groups were conducted.

RESULTS

Of 16,692 patients with PsA, 1486 (n = 406 tofacitinib, n = 416 IL-17Ai and n = 664 TNFi) were included. More females were in the tofacitinib group (75.4%) than in the IL-17Ai (61.1%) and TNFi (64.8%) groups. Overall, 19.2% of tofacitinib patients were first line, compared with 41.8% of IL-17Ai and 62.8% of TNFi patients. In the overall population, the median persistence was 16.5 months (95% CI 13.8 to 19.5 months), 17.7 months (95% CI 15.8 to 19.6 months) and 17.2 months (95% CI 14.9 to 20.5 months) in the tofacitinib, IL-17Ai and TNFi groups, respectively. Persistence was similar in the tofacitinib/IL-17Ai matched population; however, in the tofacitinib/TNFi matched population, persistence was longer in the tofacitinib group (18.7 months, 95% CI 15.6 to 21.4 months) compared with the TNFi group (12.2 months, 95% CI 19.9 to 14.9 months).

CONCLUSIONS

In this Australian real-world dataset, tofacitinib was more frequently used in later lines and among a slightly higher proportion of female patients than IL-17Ai or TNFi. Overall, treatment persistence was similar for tofacitinib, IL-17Ai and TNFi, but tofacitinib exhibited longer persistence than TNFi in a matched population. Key Points • This is the first, large real-world study from Australia investigating the demographics, treatment patterns and comparative treatment persistence of patients with psoriatic arthritis (PsA) treated with tofacitinib and biologic disease-modifying drugs (bDMARDs). • The study suggests that tofacitinib is an effective intervention in PsA with at least comparable persistence to bDMARDs: tumour necrosis factor inhibitors (TNFi) and interleukin-17 A inhibitors (IL-17Ai).

Incidence and prevalence of alopecia areata in the Australian primary care setting: A retrospective analysis of electronic health record data

BACKGROUND

Alopecia areata (AA) is a common immune-mediated non-scarring hair loss, with a worldwide incidence between 0.57% and 3.8%. The incidence and prevalence of AA in the Australian general population have not been previously reported.

OBJECTIVE

To describe the incidence and prevalence of AA in Australia using primary care data. A secondary objective was to identify common demographic characteristics, comorbidities and treatment patterns among Australians living with AA.

METHODS

We analysed electronic health record data captured from a national clinical practice management software over a 10-year index period between 2011 and 2020 calendar years, inclusive. The incidence of new-onset AA and the prevalence of active records with AA were estimated. Differences in incidence by sociodemographic groups, and patterns of treatment were also evaluated.

RESULTS

There were 976 incident AA records. The incidence of new-onset AA in the total study cohort was 0.278 per 1000 person-years (95% CI 0.26-0.295). By age, the incidence was highest in the 19- to 34-year-old age bracket (0.503 per 1000 person-years: 95% CI 0.453-0.554). AA incidence was lower among females than males (IRR 0.763, p < 0.001, 95% CI 0.673-0.865). Among active records, 520 were prevalent AA records. AA point prevalence at 31/12/2020 was 0.13% (1.26 per 1000 persons; 95% CI 1.15-1.37).

CONCLUSION

This is the first study to describe the epidemiology (incidence and point prevalence) and management of AA in the Australian primary health-care population through large-scale database analysis. Incidence and prevalence findings were consistent with earlier estimates from other regions.

POS1019 REAL-WORLD EVALUATION OF TREATMENT PATTERNS AND PERSISTENCE OF TOFACITINIB IN TREATMENT OF PSORIATIC ARTHRITIS IN AUSTRALIA: AN ANALYSIS OF THE OPAL DATASET

Background

Tofacitinib (TOF), a potent selective inhibitor of Janus kinase (JAK), is an approved treatment of psoriatic arthritis (PsA). In Australia, patients with active PsA despite six months of therapy with a pre-specified combination of csDMARDs are eligible to receive subsidised b/tsDMARDs. The clinician can prescribe the b/tsDMARD they deem to be the most clinically appropriate for the patient. Limited data exist to describe the real-world treatment patterns, characteristics and clinical outcomes of patients with PsA who receive TOF in the real-world setting.

Objectives

To describe real-world treatment patterns and treatment persistence among patients with PsA treated with TOF in the Australian post-approval setting using the OPAL dataset.

Methods

The OPAL dataset is a collection of deidentified clinical data derived from the electronic medical records of 112 rheumatologists at 43 sites around Australia. Adult patients with a diagnosis of PsA who received at least one prescription of TOF, a tumour necrosis factor inhibitor (TNFi) or an interleukin 17 inhibitor (IL-17Ai) between May 2019 and Sept 2020 were eligible, with data up to Sept 2021 included in the analysis. Results were summarised descriptively. Treatment persistence was summarised using Kaplan-Meier methods.

Results

Of 16,692 patients with PsA identified in the OPAL dataset, 1,486 (TOF n=406, IL-17Ai n=416, and TNFi n=664) were eligible for inclusion in this study. At the time of treatment initiation, the mean (SD) age of TOF, IL-17Ai and TNFi treated patients was 55.56 (12.68), 52.65 (12.72) and 50.32 (14.57) years, respectively. 19.2% of patients receiving TOF were first line compared with 41.8% of IL-17Ai and 62.8% of TNFi treated patients. The mean (SD) time from symptom onset to treatment initiation was longest for patients receiving TOF in first line (153.29 (127.50) months) compared to first line IL-17Ai (116.83 (113.97) months) and TNFi treated patients (92.37 (89.01) months). Overall, 34.2% of TOF, 32.9% of IL-17Ai and 26.4% of TNFi treated patients initiated therapy without concomitant cDMARDs being recorded.

Overall median persistence was 16.54 months (95% CI 13.84, 19.53) for TOF treated patients, 17.65 months (95% CI, 15.75, 19.56) for IL-17Ai treated patients and 17.16 months (95% CI 14.86, 20.48) for TNFi treated patients. As expected, persistence was generally longer in patients treated as first line (Figure 1) with patients receiving TOF observed to have slightly higher persistence in the first 15 months of treatment.

Figure 1.

Treatment persistence of patients receiving TOF, IL-17Ai and TNFi as first line therapy. Plot curtailed at 15 months as relatively few patients have information past this point. Where no stop date was recorded, censoring occurs at last recorded visit

Conclusion

In this analysis of a large Australian real-world dataset, TOF was more commonly utilised as a later line therapy for patients with PsA. Patients receiving TOF were observed to have slightly higher persistence within the first 15 months of starting first line therapy in this preliminary analysis.

Acknowledgements

The authors acknowledge the members of OPAL Rheumatology Ltd and their patients for providing clinical data for this study, and Software4Specialists Pty Ltd for providing the Audit4 platform. Financial support was provided by Pfizer Australia

Disclosure of Interests

Geoff Littlejohn Consultant of: Abbvie, Janssen, Bristol Myers Squibb, Gilead, Eli Lilly, and MSD, Jo Leadbetter: None declared, Belinda Butcher: None declared, Marie Feletar: None declared, Catherine OSullivan: None declared, Tegan Smith: None declared, David Witcombe Employee of: Pfizer Australia, Ho Yin Employee of: Pfizer Australia, Peter Youssef Speakers bureau: AbbVie, Novartis, Janssen and Eli Lilly

Ulcerative Colitis Narrative findings: Australian survey data comparing patient and physician disease management views

Background and Aim

The Global Ulcerative Colitis (UC) Narrative Survey aimed to evaluate the impact of UC, perceptions of UC burden, and management approaches. Here, we present data from patients and physicians in Australia.

Methods

Surveys, fielded by The Harris Poll, were completed by 215 patients with UC and 90 physicians, between August 2017 and February 2018. Surveys included questions on disease characteristics, impact on life, communication with physicians, and patient knowledge of UC. Results are presented descriptively from all respondents (with no imputation for missing data).

Results

Based on medication history, 84% of patients had moderate to severe UC. Diagnostic delay was on average 1.9 (SD 5.0) years and 48% of patients had waited ≥1 year for diagnosis. Nearly two‐thirds (65%) of patients considered themselves to be in remission, with 97% also reporting a flare in the past year. The majority (92%) of patients were satisfied with their UC medication and, if their treatment made them feel “good enough,” many (75%) would not consider an alternative. Most (90%) patients were satisfied with communication with their physician; however, only 48% felt comfortable raising emotional concerns. Both patients and physicians desired more time during routine appointments. Patients had gaps in their knowledge of UC, which physicians mostly recognized.

Conclusions

The Australian survey results highlighted the diagnostic delay and burden of UC patients' experience, gaps in patients' knowledge of UC, and challenges in patient–physician communication. Compared with the overall Global UC Narrative Survey, patients in Australia reported a high burden of disease.

Real-world evaluation of effectiveness, persistence, and usage patterns of monotherapy and combination therapy tofacitinib in treatment of rheumatoid arthritis in Australia

Objective

This study aimed to describe the real-world effectiveness and treatment persistence among patients with rheumatoid arthritis treated with monotherapy and combination therapy tofacitinib and biologic disease-modifying antirheumatic drugs (bDMARDs).

Methods

This was a post hoc analysis of a retrospective, non-interventional study that extracted data for patients treated with tofacitinib or bDMARDs from the Australian OPAL dataset between March 2015 and September 2018. Monotherapy tofacitinib and bDMARDs and combination therapy tofactinib and bDMARDs were propensity score matched and treatment effectiveness and persistence of the groups were evaluated.

Results

In the bDMARD and tofacitinib monotherapy and combination therapy matched populations there were 1300 bDMARD initiators (n = 564 monotherapy) and 650 tofacitinib initiators (n = 282 monotherapy). In the bDMARD and tofacitinib monotherapy matched groups, 62.9% and 66.7% were in DAS-28 CRP disease remission after 18 months of treatment, respectively. In the combination therapy bDMARD and tofacitinib groups, 50% and 58.9% were in DAS-28 CRP disease remission after 18 months, respectively. The median treatment persistence was similar between the monotherapy bDMARD and tofacitinib treatment groups (36.7 months (95% CI 27.4 to “not reached’) and 34.2 months (95%CI 30.3 to “not reached”) respectively) as well as the combination therapy bDMARD and tofacitinib groups (32.2 months (95% CI 25.7 to 34.4) and 32.7 months (95%CI 28.7 to “not reached”, respectively).

Conclusions

Patients receiving combination therapy with tofacitinib or bDMARDs had higher disease activity scores at index than patients receiving monotherapy. Monotherapy with tofacitinib or bDMARDs, and combination therapy with tofacitinib or bDMARDs demonstrated similar treatment effectiveness and persistence, respectively.

Key Points • This study provides real-world evidence regarding effectiveness, treatment persistence, and treatment patterns, among patients with rheumatoid arthritis (RA) treated with monotherapy or combination therapy tofacitinib. • The study suggests that monotherapy and combination therapy tofacitinib is an effective intervention in RA with persistence and effectiveness comparable to bDMARDs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10067-021-05853-x.

Patient Perceptions of Psoriatic Arthritis Management and Communication with Physicians in Australia: Results from a Patient Survey

Introduction

The objective of this report was to evaluate perceptions of psoriatic arthritis (PsA) treatment and satisfaction with healthcare professional (HCP) communication among patients with PsA in Australia, compared with overall global perceptions.

Methods

Data were collected via a global and country-specific survey (The Harris Poll; November 2, 2017–March 12, 2018). Eligible patients were ≥ 18 years old, had been diagnosed with PsA > 1 year prior, had seen a rheumatologist or dermatologist within the past 12 months, and had previously received ≥ 1 conventional synthetic or biologic disease-modifying antirheumatic drug. Data reported by patients included baseline demographics, overall health, time since PsA diagnosis, PsA severity, satisfaction with current PsA medication and management, and experiences regarding communication with their HCP. Descriptive statistics were obtained.

Results

Most patients in Australia were very or somewhat satisfied with their PsA medication, and reported always or often taking their medication exactly as directed by their HCP. However, the majority still experienced symptoms, reported their overall health as poor or fair, and would change something about their PsA medication. While the majority of patients in Australia were satisfied with the communication with their HCP, most would prefer increased communication but some felt that asking too many questions would affect the quality of their care. Perceptions in Australia were similar to global perceptions.

Conclusions

Although most patients with PsA in Australia were satisfied with their disease management and communication with their HCP, many still experienced symptoms, would change something about their PsA medication, and would prefer increased communication with their HCP.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-021-00297-w.

Psoriatic arthritis (PsA) can cause tender and swollen joints. If not treated properly, the joint damage can get worse, until patients struggle to cope with everyday tasks. Patients and their doctors need to communicate well to successfully manage PsA. We used an online survey to ask patients in Australia how they feel about their PsA medication and the way they communicate with their doctor. These patients were adults who had had PsA for more than 1 year, had seen a specialist doctor in the past year, and had taken one or more prescription PsA medications. A total of 152 patients in Australia completed the survey. Most patients were very or somewhat satisfied with the PsA medication they were taking, and most always or often took it exactly as their doctor told them to. However, almost all patients still had symptoms, most said their overall health was poor or fair, and most would like to change something about their medication. While most patients were satisfied with the communication with their doctor about PsA, most wished they talked more with their doctor about their PsA and treatment goals, but some felt that asking too many questions would harm their quality of care. Patients in Australia had similar answers to patients who answered the survey in other countries. Although the survey was limited by the number of patients who responded, and whether patients answered questions properly, it suggests that patients and doctors need to communicate more closely to improve PsA management.

Real-world evaluation of effectiveness, persistence, and usage patterns of tofacitinib in treatment of rheumatoid arthritis in Australia

INTRODUCTION

The aim of this study was to describe the real-world evidence for effectiveness, treatment persistence, and treatment patterns among patients in the community with rheumatoid arthritis treated with the JAK inhibitor tofacitinib.

METHODS

This was a retrospective, non-interventional cohort study that extracted data for new users of tofacitinib or biologic disease-modifying antirheumatic drugs (bDMARDs) from the Australian Optimizing Patient outcomes in Australian RheumatoLogy (OPAL) dataset between March 2015 and September 2018. Patients were propensity score matched at a 1:2 tofacitinib to bDMARD ratio based on age, sex, and selected baseline treatment combinations. Treatment effectiveness was evaluated using disease status measures. Treatment persistence was calculated and the percentage of patients receiving monotherapy or combination therapy at treatment initiation was evaluated.

RESULTS

Data from 2810 patients were extracted and 1950 patients were included in the matched population (1300 bDMARD initiators and 650 tofacitinib initiators). Patients were predominantly aged 55 to 74 years (57.8%) and female (81.2%). After 18 months of treatment, 52.4% and 57.8% of patients had achieved disease activity score (DAS) remission in the bDMARD and tofacitinib groups, respectively. The median treatment persistence for tofacitinib was similar to that for bDMARDs: 34.2 months (95% CI 32.2 to not reached) and 33.8 months (95% CI 28.8 to 40.4), respectively. In the overall population, more patients were prescribed tofacitinib as monotherapy (43.4%) compared with bDMARD monotherapy (33.4%).

CONCLUSIONS

Tofacitinib demonstrated treatment effectiveness and persistence similar to bDMARDs. Overall, there was a trend for more use of tofacitinib as monotherapy than bDMARDs. Key Points • This study provides real-world evidence regarding effectiveness, treatment persistence, and treatment patterns, among patients with rheumatoid arthritis (RA) in the community being treated with tofacitinib. • The study suggests that tofacitinib is an effective and enduring intervention in RA with tofacitinib persistence and effectiveness comparable to bDMARDs.

Tofacitinib 5 mg Twice Daily in Patients with Rheumatoid Arthritis and Inadequate Response to Disease-Modifying Antirheumatic Drugs: A Comprehensive Review of Phase 3 Efficacy and Safety

BACKGROUND

Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). We performed a comprehensive review of phase 3 studies of tofacitinib 5 mg twice daily (BID) (approved dose in many countries) in patients with moderate to severe RA and inadequate response to prior disease-modifying antirheumatic drugs.

METHODS

A search of PubMed and ClinicalTrials.gov identified 5 studies: ORAL Solo (NCT00814307), ORAL Sync (NCT00856544), ORAL Standard (included adalimumab 40 mg once every 2 weeks; NCT00853385), ORAL Scan (NCT00847613), and ORAL Step (NCT00960440). Efficacy and safety data for tofacitinib 5 mg BID, placebo, and adalimumab were analyzed.

RESULTS

Across the 5 studies, 1216 patients received tofacitinib 5 mg BID, 681 received placebo, and 204 received adalimumab. At month 3, tofacitinib demonstrated significantly higher 20%, 50%, and 70% improvement in American College of Rheumatology response criteria (ACR20, ACR50, and ACR70, respectively) response rates, greater improvement in Health Assessment Questionnaire-Disability Index, and a higher proportion of Disease Activity Score-defined remission than placebo. Frequencies of adverse events (AEs), serious AEs, and discontinuations due to AEs were similar for tofacitinib and placebo at month 3; serious infection events were more frequent for tofacitinib. In ORAL Standard, although not powered for formal comparisons, tofacitinib and adalimumab had numerically similar efficacy and AEs; serious AEs and serious infection events were more frequent with tofacitinib.

CONCLUSIONS

Tofacitinib 5 mg BID reduced RA signs and symptoms and improved physical function versus placebo in patients with inadequate response to prior disease-modifying antirheumatic drugs. Tofacitinib 5 mg BID had a consistent, manageable safety profile across studies, with no new safety signals identified.

Treatment outcomes in patients with seropositive versus seronegative rheumatoid arthritis in Phase III randomised clinical trials of tofacitinib

Objectives

Tofacitinib is an oral JAK inhibitor for the treatment of rheumatoid arthritis (RA). We examined response to tofacitinib 5 or 10 mg two times a day in patients with seropositive vs seronegative RA.

Methods

Data were pooled from five Phase III studies of conventional synthetic disease-modifying antirheumatic drug (csDMARD)- or biological DMARD-inadequate responders (ORAL Step [NCT00960440]; ORAL Scan [NCT00847613]; ORAL Solo [NCT00814307]; ORAL Sync [NCT00856544]; ORAL Standard [NCT00853385]). ‘Serotype’ subgroups were: anticyclic citrullinated peptide (CCP) and rheumatoid factor (RF) positive (anti-CCP+/RF+); anti-CCP+/RF negative (-); anti-CCP-/RF+; anti-CCP-/RF-. At month 3, ACR20/50/70 response rates, Disease Activity Score (DAS28-4[ESR])-defined remission (DAS28-4[ESR]<2.6) and low disease activity (LDA; DAS28-4[ESR]≤3.2), changes from baseline (CFB) in Health Assessment Questionnaire-Disability Index (HAQ-DI), Short Form-36 Health Survey (SF-36) physical functioning and Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) were evaluated. Safety endpoints were compared.

Results

Baseline demographics/characteristics were similar across subgroups. Tofacitinib significantly improved ACR20/50/70 response rates, DAS28-4(ESR) LDA rates and CFB in HAQ-DI and FACIT-F vs placebo across subgroups. More anti-CCP+/RF+ than anti-CCP-/RF- patients had ACR20/50/70 responses (ACR20/50: both tofacitinib doses; ACR70: 10 mg two times a day). SF-36 physical functioning improved in anti-CCP+/RF+, anti-CCP+/RF- and anti-CCP-/RF+ patients (both tofacitinib doses) and anti-CCP-/RF- patients (10 mg two times a day) vs placebo. More anti-CCP+/RF+ and anti-CCP+/RF- than anti-CCP-/RF- patients achieved DAS28-4(ESR) remission and LDA with tofacitinib 10 mg two times a day. Frequency of adverse events (AEs), serious AEs and discontinuations due to AEs were similar across subgroups.

Conclusion

Generally, tofacitinib efficacy (ACR20/50/70 responses) and safety were similar across subgroups. DAS28-4(ESR) remission rates and SF-36 physical functioning appeared lower in anti-CCP- patients.

A systematic review of conversion from calcineurin inhibitor to mammalian target of rapamycin inhibitors for maintenance immunosuppression in kidney transplant recipients

This was a systematic review of randomized controlled trials comparing delayed conversion of mammalian target of rapamycin inhibitors (mTORi) for calcineurin inhibitors (CNIs) versus CNI continuation in kidney transplantation. Databases (2000-2012) and conference abstracts (2009-2012) were searched giving a total of 29 trials. Outcomes analyzed included GFR, graft loss, rejection and adverse events and were expressed as weighted mean differences (WMDs) or as risk ratios (RRs). Patients converted to mTORi up to 1 year posttransplant in intention-to-treat analysis had higher GFR compared with those remaining on CNI (WMD 0.28 mL/min/1.73 m(2) , 95% confidence interval [CI] 0.21-0.36; I(2)  = 68%, p < 0.001). Stratifying trials by time posttransplant or type of mTORi did not change the overall heterogeneity. For on-treatment population, mTORi was associated with higher GFR (14.21 mL/min/1.73 m(2) , 10.34-18.08; I(2)  = 0%, p = 0.970) 2-5 years posttransplant. The risk of rejection at 1 year was higher in mTORi trials (RR 1.72, 1.34-2.22; I(2)  = 12%, p = 0.330). Discontinuation secondary to adverse events was more common in patients on mTORi, whereas the incidence of skin cancers and cytomegalovirus infection was lower in patients on mTORi. Conversion from CNI to mTORi is associated with short-term improvements in GFR in a number of studies but longer-term follow-up data of graft and patient survival are required.

Functional genomics of gam56: characterisation of the role of a 56 kilodalton sexual stage antigen in oocyst wall formation in Eimeria maxima

Gam56 (M(r) 56,000) is an antigen found in the sexual (macrogametocyte) stage of the intestinal parasite Eimeria maxima that is implicated in protective immunity. The gene (gam56) encoding this protein was cloned and sequenced. It is a single-copy, intronless gene, that localises to a 1,754 bp transcript, and is first detected at 120 h p.i. The gene predicts two distinct protein domains; a tyrosine-serine rich region, composed of amino acids implicated in oocyst wall formation in Eimeria spp., and a proline-methionine rich region often detected in extensins, protein components of plant cell walls. The tyrosine-serine rich region predicts a secondary structure commonly seen in the structural protein fibroin, a component of the cocoon of the caterpillar Bombyx mori. The inference that gam56 is a structural component of the oocyst wall was confirmed when a specific antibody to gam56 recognised the wall forming bodies in macrogametocytes, and the walls of oocysts and sporocysts. Together, these data identify a developmentally regulated, sexual stage gene in E. maxima that shares primary and secondary structure features in common with intrinsic structural proteins in other parasites such as Schistosoma mansoni and Fasciola hepatica, and other organisms across different phyla, including the caterpillar Bombyx mori. In addition, these findings provide evidence for the molecular mechanisms underlying oocyst wall formation in Eimeria and the role of gametocyte antigens in this process.