PD-1–blocking antibodies may trigger neurologic effect

August 4, 2016

Letter to editor excerpts

Pembrolizumab and nivolumab, two humanized antibodies against programmed cell death 1 (PD-1) receptor, were recently approved for the treatment of unresectable or metastatic melanoma and for other cancers. 

We report two cases of severe demyelinating polyradiculoneuropathy that occurred after treatment with pembrolizumab for advanced melanoma.

These cases of an acute Guillain–Barré–like syndrome (in Patient 1) and chronic inflammatory demyelinating polyradiculoneuropathy2 (in Patient 2) appeared 8 and 20 weeks, respectively, after the initiation of pembrolizumab. 

We conclude that the two conditions may be associated with pembrolizumab, since neither patient had evidence of infectious causes or a documented paraneoplastic syndrome.  

Since demyelinating polyradiculoneuropathies are believed to be a result of autoimmunization, we speculate that PD-1–blocking antibodies may trigger one or more of the complex immune mechanisms involved in this disease.

Source and full text availability:

de Maleissye, M-F et al.  Pembrolizumab-Induced Demyelinating Polyradiculoneuropathy.  N Engl J Med 2016; 375:296-297July 21, 2016  DOI: 10.1056/NEJMc1515584  
http://www.nejm.org/doi/full/1...