Friday, 23 Aug 2019

You are here

Predictors of Serious Infections with Rituximab

The risk of serious infectious events (SIE) with rituximab (RTX) is similar to that seen in other biologics (e.g., RA: 2% or 4.3/100PY), but with prolonged use the risk may change. Recent research says that low IgG levels, RTX induced neutropenia, prior SIE and comorbidities can significantly augment this risk.

A retrospective longitudinal single center study of 700 rheumatic and musculoskeletal diseases (RMDs) treated monitored serum immunoglobulins (at baseline and 4–6 months after each cycle), clinical outcomes and SIE over time.

The patient population included rheumatoid arthritis (72%), systemic lupus erythematosus (13%),  ANCA‐associated vasculitis (7%) and 8% with other RMDs.

The overall SIE rate was 9.8/100 PY - 281 SIEs in 176 patients. Predictors of SIEs included:

  • non‐RTX‐specific comorbidities: prior history of SIE, cancer, chronic lung disease, diabetes, heart failure
  • higher corticosteroid doses
  • RTX‐specific factors;
    • low IgG(<6g/L) at baseline and subsequently
    • RTX‐associated neutropaenia
    • higher IgM
    • longer time‐to‐RTX retreatment

B‐cell depletion numbers were not predictive.

SIEs rates were even higher in those with low baseline IgG (16.4/100 PY) or acquired it during/post‐RTX (21.3/100 PY) when compared to those with normal IgG (9.7/100 PY). 

Monitoring B cell numbers does not appear to be as effective as monitoring serum IgG levels and neutrophils counts in patients who will receive long term or repeated RTX therapy.

Careful patient selection - those with no prior SIE and without comorbidities - may further limit the risk of SIE in such patients.

Disclosures: 
The author has no conflicts of interest to disclose related to this subject

Add new comment

More Like This

Upadacitinib (RINVOQ) FDA Approved for Rheumatoid Arthritis

The US Food and Drug Administration (FDA) on Friday, August 16, approved AbbVie JAK1 inhibitor, Rinvoq (upadacitinib) for adults with  rheumatoid arthritis with moderately to severely active disease either not responding to, or intolerant of, methotrexate (MTX). 

Are Non-TNF Biologics Superior to TNF inhibitors?

Current ACR and EULAR guidelines list TNF-inhibitors (TNFi) abatacept, rituximab, and tocilizumab as being equally effective after methotrexate or as second line therapies when treating rheumatoid arthritis. An analysis from the Swedish Rheumatology Register shows that the non-TNFi biologic DMARDs (bDMARDs), in particular tocilizumab and rituximab, are more effective than TNFi. 

FINCH2: Filgotinib in Biologic Refractory Rheumatoid Arthritis

The FINCH2 study has shown that filgotinib, an oral once daily JAK 1 inhibitor, is highly effective in rheumatoid arthritis (RA) patients who failed to respond to prior biologic therapy.

Rituximab Safety Concerns when Used in anti-TNF Refractory RA

The SUNSTONE study evaluated the long‐term safety of rituximab in rheumatoid arthritis (RA) previously exposed to ≥1 anti–tumor necrosis factor inhibitors (TNFi) and showed a stable, but high, rate of serious infections, opportunistic infections and an overall higher mortality rate.

No Difference Among Biologics in Arthroplasty Infectious Risk

A large administrative claims analysis of rheumatoid arthritis (RA) patients undergoing arthroplasty has shown no difference among biologics with regard to the risk of infections, but corticosteroid use was associated with a dose dependent risk of infection. 

The Annals of Internal Medicine has published an analysis of peri- and postoperative infectious risk among RA patients receiving biologics or glucocorticoids.