The pharmacological and clinical aspects behind dose loading of biological disease modifying anti-rheumatic drugs (bDMARDs) in auto-immune rheumatic diseases (AIRDs): rationale and systematic narrative review of clinical evidence

Moving Beyond Boundaries: Utilization of Longitudinal Exposure-Response Model for Bounded Outcome Score to Inform Decision Making in the Accelerated Drug Development Paradigm

BACKGROUND AND OBJECTIVES

As drug development scientists strive to accelerate availability of therapies for patients, model-informed drug development (MIDD) plays an important role in contextualizing existing information and facilitating decision making. This paper describes an example of MIDD, where modeling and simulation informed decision making in the circumstance of a combined phase 2b and single pivotal study for ritlecitinib (JAK3/TEC family kinases inhibitor).

METHODS

Longitudinal exposure-response (ER) modeling was conducted to describe ritlecitinib efficacy in alopecia areata patients. The Severity of Alopecia Tool (SALT) score (a continuous bounded outcome [CBO] score [0-100]) was used as the efficacy response. The average concentration during the time interval between two adjacent SALT scores was used as the exposure metric driving efficacy.

RESULTS

The developed model well described the longitudinal SALT profile of ritlecitinib as well as the frequency of boundary data. The CBO model indicated tested doses in the phase 2b/3 clinical trial are in the ascending region of ER and contextualized a loading dose effect that impacted onset of efficacy without long-term benefit. It also identified disease severity as the only covariate impacting efficacy. The model-based simulation further informed impact of treatment interruption on the loss of efficacy in the absence of a dedicated treatment withdrawal study. Results indicated temporary treatment interruption ≤ 6 weeks is not expected to result in significant loss of efficacy.

CONCLUSION

The CBO modeling approach and simulation supported the single pivotal trial strategy and guided dose selection in the accelerated drug development program of ritlecitinib, which can be applied to many indications where efficacy is measured on a bounded scale.

Systematic literature review and network meta-analysis of therapies for psoriatic arthritis on patient-reported outcomes

OBJECTIVES

Head-to-head clinical trials are common in psoriasis, but scarce in psoriatic arthritis (PsA), making treatment comparisons between therapeutic classes difficult. This study describes the relative effectiveness of targeted synthetic (ts) and biologic (b) disease-modifying antirheumatic drugs (DMARDs) on patient-reported outcomes (PROs) through network meta-analysis (NMA).

DESIGN

A systematic literature review (SLR) was conducted in January 2020. Bayesian NMAs were conducted to compare treatments on Health Assessment Questionnaire Disability Index (HAQ-DI) and 36-item Short Form (SF-36) Health Survey including Mental Component Summary (MCS) and Physical Component Summary (PCS) scores.

DATA SOURCES

Ovid MEDLINE (including Epub Ahead of Print, In-Process & Other Non-Indexed Citations and Daily),Embase and Cochrane Central Register of Controlled Trials.

ELIGIBILITY CRITERIA

Phase III randomised controlled trials (RCTs) evaluating patients with PsA receiving tsDMARDS, bDMARDs or placebo were included in the SLR; there was no restriction on outcomes.

DATA EXTRACTION AND SYNTHESIS

Two independent researchers reviewed all citations. Data for studies meeting all inclusion criteria were extracted into a standardised Excel-based form by one reviewer and validated by a second reviewer. A third reviewer was consulted to resolve any discrepancies, as necessary. Risk of bias was assessed using the The National Institute for Health and Care Excellence clinical effectiveness quality assessment checklist.

RESULTS

In total, 26 RCTs were included. For HAQ-DI, SF-36 PCS and SF-36 MCS scores, intravenous tumour necrosis factor (TNF) alpha inhibitors generally ranked higher than most other classes of therapies available to treat patients with PsA. For almost all outcomes, several interleukin (IL)-23, IL-17A, subcutaneous TNF and IL-12/23 agents offered comparable improvement, while cytotoxic T-lymphocyte-associated antigen 4, phosphodiesterase-4 and Janus kinase inhibitors often had the lowest efficacy.

CONCLUSIONS

While intravenous TNFs may provide some improvements in PROs relative to several other tsDMARDs and bDMARDs for the treatment of patients with PsA, differences between classes of therapies across outcomes were small.

Points to consider for cost-effective use of biological and targeted synthetic DMARDs in inflammatory rheumatic diseases: results from an umbrella review and international Delphi study

OBJECTIVES

To develop evidence-based points to consider for cost-effective use of biological and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) in the treatment of inflammatory rheumatic diseases, specifically rheumatoid arthritis, psoriatic arthritis and axial spondyloarthritis.

METHODS

Following EULAR procedures, an international task force was formed, consisting of 13 experts in rheumatology, epidemiology and pharmacology from seven European countries. Twelve strategies for cost-effective use of b/tsDMARDs were identified through individual and group discussion. For each strategy, PubMed and Embase were systematically searched for relevant English-language systematic reviews and, for six strategies, additionally for randomised controlled trials (RCTs). Thirty systematic reviews and 21 RCTs were included. Based on the evidence, a set of overarching principles and points to consider was formulated by the task force using a Delphi procedure. Level of evidence (1a-5) and grade (A-D) were determined for each point to consider. Individual voting on the level of agreement (LoA; between 0 (completely disagree) and 10 (completely agree)) was performed anonymously.

RESULTS

The task force agreed on five overarching principles. For 10 of 12 strategies, the evidence was sufficient to formulate one or more points to consider, leading to 20 in total, regarding response prediction, drug formulary use, biosimilars, loading doses, low-dose initial therapy, concomitant conventional synthetic DMARD use, route of administration, medication adherence, disease activity-guided dose optimisation and non-medical drug switching. Ten points to consider (50%) were supported by level 1 or 2 evidence. The mean LoA (SD) varied between 7.9 (1.2) and 9.8 (0.4).

CONCLUSION

These points to consider can be used in rheumatology practices and complement inflammatory rheumatic disease treatment guidelines to incorporate cost-effectiveness in b/tsDMARD treatment.