Pharmacodynamic monitoring of (immuno)proteasome inhibition during bortezomib treatment of a critically ill patient with lupus nephritis and myocarditis

Discovery and Early Clinical Development of Selective Immunoproteasome Inhibitors

Inhibitors of the proteolytic activity of the 20S proteasome have transformed the treatment of multiple B-cell malignancies. These agents have also been employed with success in the treatment of patients with autoimmune diseases and immune-mediated disorders. However, new agents are needed to fully unlock the potential of proteasome inhibitors as immunomodulatory drugs. The discovery that selective inhibitors of the immunoproteasome possess broad anti-inflammatory activity in preclinical models has led to the progression of multiple compounds to clinical trials. This review focuses on the anti-inflammatory potential of immunoproteasome inhibition and the early development of KZR-616, the first selective inhibitor of the immunoproteasome to reach clinical testing.

The spectrum of lupus myocarditis: from asymptomatic forms to cardiogenic shock

Lupus myocarditis is a serious, potentially deadly disease. When it presents as an acute or fulminant myocarditis in a patient without an established diagnosis of lupus, lupus as an etiology of the condition is not commonly suspected. Meanwhile, it has a distinct treatment which may be lifesaving. Review of the literature can shed more light as current management is mostly based on clinical experience and case reports rather than randomized control trials. In this review we are discussing this diagnostic entity, focusing on cardiogenic shock as a manifestation of lupus myocarditis, and discussing management including aggressive immunosuppression, mechanical circulatory support, and cardiac transplantation.

Case of severe acute lupus myocarditis and multiple-organ failure

We report a case of severe lupus myocarditis with rapid, acute deterioration to cardiogenic shock and multiorgan failure, highlighting the importance of early identification and treatment of acute presentations in patients with systemic lupus erythematosus. A 31-year-old woman with previously diagnosed subacute cutaneous lupus erythematosus initially presented with abdominal pain and frank per-rectal bleeding. She deteriorated rapidly with type 1 respiratory failure and acute kidney injury requiring dialysis secondary to acute cardiac failure with a prolonged intensive care unit admission, over a month. A significantly elevated troponin, global hypokinesia on echocardiogram and normal coronary artery angiogram and cardiac MRI lead to the diagnosis of acute lupus myocarditis as the cause for the cardiogenic shock. She was treated with high-dose corticosteroids and eventually made a full recovery, with cardiac function returning to normal.

(Immuno)proteasomes as therapeutic target in acute leukemia

The clinical efficacy of proteasome inhibitors in the treatment of multiple myeloma has encouraged application of proteasome inhibitor containing therapeutic interventions in (pediatric) acute leukemia. Here, we summarize the positioning of bortezomib, as first-generation proteasome inhibitor, and second-generation proteasome inhibitors in leukemia treatment from a preclinical and clinical perspective. Potential markers for proteasome inhibitor sensitivity and/or resistance emerging from leukemia cell line models and clinical sample studies will be discussed focusing on the role of immunoproteasome and constitutive proteasome (subunit) expression, PSMB5 mutations, and alternative mechanisms of overcoming proteolytic stress.

Multicenter double-blind randomized controlled trial to evaluate the effectiveness and safety of bortezomib as a treatment for refractory systemic lupus erythematosus

OBJECTIVES

The objective of this study is to evaluate the efficacy and safety of bortezomib for treating systemic lupus erythematosus (SLE), in patients whose disease activity could not be controlled.

METHODS

Fourteen SLE patients with persistent disease activity were selected, who required prednisolone doses of >10 mg/d despite concomitant immunosuppressive therapy. Patients were randomly administered either bortezomib or a placebo, eight times. The primary and secondary end-points were a change in anti-dsDNA antibody titer at week 24 and the SLE Responder Index (SRI), respectively.

RESULTS

In the bortezomib group, four out of eight patients discontinued the trial; three others failed to complete the minimum protocol treatment due to adverse reactions. The changes in anti-dsDNA antibody titers at week 24 were 4.24% and -1.96%, for the bortezomib and placebo groups, respectively, disconfirming bortezomib's efficacy. In contrast, the corresponding SRI at week 12 was 75% and 40%.

CONCLUSIONS

As bortezomib therapy for SLE is associated with many adverse reactions, treatment indications should be selected carefully, and protocols should aim to prevent these occurrences. Although the change in anti-dsDNA antibody titer did not support the efficacy of bortezomib as a treatment for SLE, high SRI in the treatment group suggests bortezomib may utilize mechanisms other than inhibition of anti-dsDNA antibody production.