Peficitinib Hydrobromide: A Strategic JAK Inhibitor for Drug Discovery and Generic Development
Abstract
Peficitinib hydrobromide, a potent pan-Janus kinase (JAK) inhibitor, has emerged as a valuable compound for pharmaceutical research and generic drug development. Initially approved in Japan for the treatment of rheumatoid arthritis, Peficitinib demonstrates strong clinical efficacy and a well-defined pharmacological profile. Its broad activity across JAK1, JAK2, JAK3, and Tyk2, along with excellent oral bioavailability and predictable pharmacokinetics, makes it highly suitable for use in drug screening assays, bioequivalence studies, and formulation development. Supported by robust clinical data from multiple Phase II and III trials, Peficitinib serves as a trusted reference compound for both early discovery and late-stage generics work. The hydrobromide salt form offers superior chemical stability, making it ideal for storage, testing, and quality control. For pharmaceutical companies aiming to expand their immunology pipelines or launch generic versions of targeted therapies, Peficitinib hydrobromide represents a strategic and scientifically validated development tool.
Peficitinib Hydrobromide: A High-Value Asset for Modern Drug Development
As the landscape of autoimmune and inflammatory disease treatment continues to evolve, Janus kinase (JAK) inhibitors have emerged as powerful tools in targeted immunotherapy. Among these, Peficitinib hydrobromide stands out for its broad-spectrum activity and excellent oral bioavailability, making it an increasingly valuable molecule for pharmaceutical research and development.
Approved in Japan in 2019 under the brand name Smyraf®, Peficitinib is indicated for the treatment of rheumatoid arthritis, particularly in patients who show inadequate response to conventional therapies. Its ability to inhibit multiple JAK isoforms—JAK1, JAK2, JAK3, and Tyk2—positions it as a potent modulator of cytokine-driven inflammation and joint damage.
Beyond its clinical application, Peficitinib hydrobromide offers significant potential in drug discovery, efficacy testing, and generic drug development. It serves as a robust reference compound for mechanistic studies, a valuable tool in high-throughput screening platforms, and a strategic choice for bioequivalence and formulation research.
For pharmaceutical companies engaged in R&D or generics, Peficitinib hydrobromide is not just a compound—it’s an opportunity to advance innovation and accelerate development pipelines.
Inside the Molecule: Pharmacological Advantages of Peficitinib Hydrobromide
Peficitinib hydrobromide is a small molecule inhibitor belonging to the adamantane-based pyrrolo[2,3-b]pyridine class, designed for oral administration. Its mechanism of action centers on broad inhibition of the Janus kinase (JAK) family, targeting JAK1, JAK2, JAK3, and Tyk2, with IC₅₀ values of 3.9, 5.0, 0.71, and 4.8 nmol/L, respectively. This pan-JAK inhibition results in the suppression of key cytokine signaling pathways involved in chronic inflammation and autoimmune tissue damage.
Pharmacodynamically, Peficitinib demonstrates robust inhibition of STAT5 phosphorylation in both human and rat whole blood, a validated marker of JAK activity. It also exhibits dose-dependent efficacy in vivo, significantly reducing paw swelling and bone destruction in preclinical arthritis models.
On the pharmacokinetic front, Peficitinib is rapidly absorbed with a median time to peak plasma concentration (Tmax) ranging from 1 to 2.1 hours, and a half-life (t½) of 9.9 to 16.2 hours depending on dosage. Steady-state levels are achieved by day 3 of administration, with predictable dose-proportional increases in Cmax and AUC.
The hydrobromide salt form offers enhanced stability and solubility, making it especially suitable for formulation development, dissolution profiling, and analytical method validation. For pharmaceutical developers, these properties enable streamlined integration into in vitro assays, pharmacokinetic modeling, and preclinical formulation studies.
With its well-characterized pharmacological behavior and chemical consistency, Peficitinib hydrobromide is ideally positioned as a versatile tool compound for both mechanistic research and applied drug development workflows.
Backed by Evidence: Clinical Data Validating Peficitinib’s Therapeutic Power
The clinical development of Peficitinib hydrobromide is backed by a robust series of multinational, phase II and III trials, which consistently demonstrate its efficacy in patients with moderate-to-severe rheumatoid arthritis (RA)—particularly those who have shown inadequate response to conventional DMARDs, including methotrexate.
In the pivotal RAJ4 Phase III trial conducted in Japan, Peficitinib at 100 mg and 150 mg/day, in combination with methotrexate, significantly outperformed placebo across key endpoints. After 12 weeks, ACR20 response rates reached 58.6% and 64.4%, respectively, compared to just 21.8% in the placebo group. Higher response rates were also observed for ACR50 and ACR70, with meaningful reductions in DAS28-CRP and modified total Sharp score (mTSS) by week 28, indicating both symptomatic relief and structural joint protection.
Complementary data from the RAJ3 trial (Japan, Korea, Taiwan) reinforced these findings, showing significant clinical improvement even when Peficitinib was used as monotherapy. Similarly, earlier Phase II studies (RAJ1, RA21, RA22) confirmed dose-dependent reductions in inflammatory markers, such as C-reactive protein, and strong ACR response rates across a range of dosages.
Importantly, these results demonstrate that Peficitinib is not only clinically effective but also supported by a reproducible, well-documented data set, making it a trusted candidate for further development, bioequivalence testing, and reference formulation in generic drug pipelines.
For companies seeking compounds with both therapeutic credibility and regulatory visibility, Peficitinib hydrobromide stands as a high-value option.
From Bench to Bioequivalence: Practical Uses in Screening, Formulation, and Generics
Beyond its clinical use, Peficitinib hydrobromide offers wide-ranging applications in pharmaceutical research, preclinical development, and generic drug programs. Its well-characterized mode of action and favorable pharmacokinetics make it a powerful and reliable reference compound across multiple stages of the drug development pipeline.
In early-stage discovery, Peficitinib serves as an ideal benchmark molecule for Janus kinase pathway assays. Its inhibition profile across JAK1, JAK2, JAK3, and Tyk2 allows researchers to validate assay sensitivity, calibrate screening platforms, and test new candidates for comparative efficacy. This is particularly useful in target validation studies or when building structure–activity relationship (SAR) models for kinase inhibitors.
In high-throughput screening (HTS), Peficitinib can be incorporated into small-molecule libraries to identify synergistic or antagonistic interactions with novel compounds. It also plays a key role in disease modeling studies, especially for autoimmune and inflammatory diseases such as rheumatoid arthritis, inflammatory bowel disease, and psoriasis.
For generic drug development, Peficitinib hydrobromide is a prime candidate for bioequivalence trials, stability testing, and formulation development. Its known clinical profile and availability of a reference product (Smyraf®) support its use in analytical method development, dissolution comparison studies, and ICH-compliant quality assessments. The hydrobromide form’s physicochemical stability further simplifies formulation efforts.
Additionally, there is potential to explore fixed-dose combinations (FDCs) or repurposing strategies, leveraging its multi-targeted activity in new therapeutic contexts or adjacent disease areas.
Whether you are screening novel immunomodulators or optimizing a generic RA therapy, Peficitinib hydrobromide delivers the flexibility and reliability pharma teams need to accelerate R&D progress and reduce regulatory risk.
Quality You Can Trust: Why Sourcing Matters for Peficitinib-Based Projects
For pharmaceutical companies engaged in efficacy testing, formulation development, or generic registration, the quality of the compound used is as critical as the science behind it. With Peficitinib hydrobromide, sourcing from a reputable supplier ensures the consistency, reproducibility, and regulatory compliance that today’s drug development demands.
High-purity Peficitinib hydrobromide—validated by full COA (Certificate of Analysis), MSDS, NMR, and HPLC documentation—enables confident integration into analytical method development, bioanalytical validation, and preclinical assay systems. When used as a reference standard or test article, it supports GLP-compliant data generation and aligns with the documentation needs of regulatory submissions and comparative studies.
Furthermore, the hydrobromide form provides excellent chemical stability under controlled storage, ensuring batch-to-batch reproducibility and minimal degradation. This is especially important when conducting longitudinal stability studies, conducting stress tests, or preparing clinical-grade formulations.
In short, working with research-grade Peficitinib hydrobromide is not just about accessing a molecule—it’s about unlocking consistent, high-integrity data that drives smart development decisions and accelerates time-to-market.
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