Risk of hepatitis B virus reactivation following ruxolitinib treatment in patients with myeloproliferative neoplasms

Biologics Versus JAK Inhibitors. Part II: Risk of Infections. A Narrative Review

INTRODUCTION

The risk of infections associated with biological drugs (BD) and Janus kinase inhibitors (JAKi) has been extensively explored in the literature. However, there is a dearth of studies that evaluate both pharmacological groups together and, furthermore, compare them. Here, we review the risk of infections associated with BD and JAKi used in dermatology.

METHODS

A narrative review was performed. All relevant articles evaluating the risk of infection and opportunistic infections with BD and JAKi between January 2010 and February 2024 were selected.

RESULTS

Overall, the incidence of infections, serious infections, and opportunistic infections associated with BD and JAKi is low, but higher than in the general population. JAKi approved for dermatological disorders (abrocitinib, baricitinib, deucravacitinib, upadacitinib, ritlecitinib, and topical ruxolitinib) have been shown to be safe, and present a low rate of infections. We found an elevated risk, especially with anti-tumor necrosis factor (anti-TNF) agents, rituximab, and JAKi (particularly tofacitinib at high doses). Specific associations with infections include tuberculosis and tuberculosis reactivation with anti-TNF agents and tocilizumab; candidiasis with anti-interleukin (IL) 17 agents; hepatitis B virus reactivation with rituximab, anti-TNF, and JAKi; and herpes simplex and herpes zoster infections with JAKi (especially tofacitinib and upadacitinib at high doses). The incidence of infections with ustekinumab and anti-IL-23 was very low. Anti-IL-1, nemolizumab, tralokinumab, and omalizumab were not associated with an increased risk of infections. Dupilumab could decrease the incidence of cutaneous infections.

CONCLUSIONS

Anti-TNF agents, rituximab, and JAKi (particularly tofacitinib) can increase the risk of infections. Close monitoring of patients undergoing these therapies is recommended. Prospective studies with long-term follow-up are needed to comparatively evaluate the risks of infection deriving from treatment with BD and JAKi.

Understanding and treatment of cutaneous graft-versus-host-disease

The skin is the outermost mechanical barrier where dynamic immune reactions take place and is the most commonly affected site in both acute and chronic graft-versus-host disease (GVHD). If not properly treated, pain and pruritis resulting from cutaneous GVHD can increase the risk of secondary infection due to erosions, ulcerations, and damage of underlying tissues. Furthermore, resulting disfiguration can cause distress and significantly impact patients' quality of life. Thus, a deeper understanding of skin-specific findings of GVHD is needed. This review will highlight some promising results of recent pre-clinical studies on the pathophysiology of skin GVHD and summarize the diagnostic and staging/grading procedures according to the clinical manifestations of skin GVHD. In addition, we will summarize outcomes of various GVHD treatments, including skin-specific response rates.

Risk of hepatitis B reactivation in patients with myeloproliferative neoplasms treated with ruxolitinib

Classical Philadelphia-negative myeloproliferative neoplasms (MPNs), i.e., polycythemia vera, essential thrombocythemia, and primary/secondary myelofibrosis, are clonal disorders of the hematopoietic stem cell in which an uncontrolled proliferation of terminally differentiated myeloid cells occurs. MPNs are characterized by mutations in driver genes, the JAK2V617F point mutation being the most commonly detected genetic alteration in these hematological malignancies. Thus, JAK inhibition has emerged as a potential therapeutic strategy in MPNs, with ruxolitinib being the first JAK inhibitor developed, approved, and prescribed in the management of these blood cancers. However, the use of ruxolitinib has been associated with a potential risk of infection, including opportunistic infections and reactivation of hepatitis B. Here, we briefly describe the association between ruxolitinib treatment in MPNs and hepatitis B reactivation.

Ruxolitinib accelerates influenza A virus adaptation in the Madin-Darby canine kidney (MDCK) cell line

AIM

To investigate the effect of ruxolitinib medium supplement, separately and in combination with trypsin, on influenza A virus (IAV) adaptation and propagation in the Madin-Darby canine kidney (MDCK) cell line.

METHODS AND RESULTS

Two consecutive passages of three egg-based IAV strains were performed in the MDCK cell line with medium (a) without additives; (b) with a combination of ruxolitinib and trypsin; (c) with ruxolitinib; and (d) trypsin. Adaptation without a medium additive failed in both passages. After a single passage, the probability of the IAV adaptation was highly significantly influenced by the type of additive (binomial generalized linear model, χ22 = 23.84, P < 0.00001). The highest probability of adaptation was achieved with the combination of ruxolitinib and trypsin, followed by ruxolitinib alone and trypsin. After the two consecutive passages, the influence of the type of medium additive on the probability of virus adaptation was no longer significant. In two of three IAV MDCK-adapted strains, the type of medium additive had no significant influence on virus yields.

CONCLUSION

Ruxolitinib accelerates the adaptation of IAV in the MDCK cell line both individually and together with trypsin.

Hepatitis B virus reactivation associated with Janus kinase (JAK) inhibitors: a retrospective study of pharmacovigilance databases and review of the literature

BACKGROUND

Recently, there have been clinical reports of hepatitis B virus reactivation (HBVr) related with Janus kinase (JAK) inhibitors. However, there were no studies to investigate the association between HBVr and different JAK inhibitors.

RESEARCH DESIGN AND METHODS

This study was a retrospective review utilizing the FAERS pharmacovigilance database and a systematic literature search for all cases of HBVr reported with JAK inhibitors. Disproportionality analysis and Bayesian analysis were used in data detection to screen the suspected HBVr after the administration of different JAK inhibitors, based on the FDA Adverse Event Reporting System (FAERS) pharmacovigilance database from Q4 2011 to Q1 2022.

RESULTS

There were a total number of 2097 (0.02%) reports of HBVr in FAERS, of which 41 (1.96%) were associated with JAK inhibitors. Baricitinib appeared to have the strongest signal among four JAK inhibitors, based on the highest reporting odds ratio (ROR = 4.45, 95% confidence interval [CI] 1.67-11.89). Ruxolitinib also showed signals, whereas no signals were detected among Tofacitinib and Upadacitinib.

CONCLUSION

While there may be an association between JAK inhibitors and HBVr, it appears to be a numerically uncommon occurrence. Further studies are needed to optimize the safety profiles of JAK inhibitors.

JAK2 in Myeloproliferative Neoplasms: Still a Protagonist

The discovery of the activating V617F mutation in Janus kinase 2 (JAK2) has been decisive for the understanding of myeloproliferative neoplasms (MPN). Activated JAK2 signaling by JAK2, CALR, and MPL mutations has become a focus for the development of targeted therapies for patients with MPN. JAK2 inhibitors now represent a standard of clinical care for certain forms of MPN and offer important benefits for MPN patients. However, several key aspects remain unsolved regarding the targeted therapy of MPN with JAK2 inhibitors, such as reducing the MPN clone and how to avoid or overcome a loss of response. Here, we summarize the current knowledge on the structure and signaling of JAK2 as central elements of MPN pathogenesis and feature benefits and limitations of therapeutic JAK2 targeting in MPN.