HCPCS Code J2323: Injection, Natalizumab, 1 mg

## **What is the HCPCS code J2323 for?** The HCPCS code J2323 is a J code, which means it's part of a massive cluster of codes that are mostly used to designate injected medication. For this code in particular, what is being injected is a 1 mg dose of natalizumab, which is commonly referred to as a Tysabri or Tyruko injection. Please note that this isn't an injection for chemotherapy administration. Natalizumab is an immunotherapy injection administered intravenously, and it is the first non-tumor necrosis factor alpha antagonist approved for the treatment of (severely active) Crohn's disease. According to the National Multiple Sclerosis Society, it's also used to treat a relapsing-remitting disease, specifically relapsing-remitting multiple sclerosis (RRMS), clinically isolated syndrome (CIS), and secondary progressive multiple sclerosis. If any of these are confirmed to be an aggressive initial disease, natalizumab treatment is sometimes used as an initial therapy. What this medicine does is reduce inflammation and prevent immune cells (T and B cells) from attacking and damaging myelin, which protects the nerves of our spinal cords and brains . This injected medication has undergone controlled clinical trials and has been confirmed to induce and maintain clinical responses as well as remission in natalizumab-treated patients who have moderate or severe active Crohn's disease with inflammation. It can prevent RRMS or Crohn's disease severity from getting worse, and reduce clinical exacerbations and the clinical relapse rate of those diseases (Polman et al., 2006). However, it was withdrawn from the Crohn's disease market in 2009 due to safety concerns and then re-launched with stricter prescribing guidelines (Shirani & Stüve, 2018).