“The immune checkpoint inhibitors anti-PD-1 and anti-PD-L1 have proven efficacy in the treatment of many cancers, but patients may experience immune-related adverse events (irAEs). (Treatment) is usually stopped when a grade 2 or higher irAE occurs,” Dr. Olivier Lambotte of Hopitaux Universitaires Paris Sud AP-HP in France told Reuters Health.
“We were able to study 93 patients with a broad spectrum of cancers in whom a rechallenge was [considered],” he said by email. “Among them, 40 patients [43%] were rechallenged with the same anti-PD-1 or anti-PD-L1.”
“Earlier initial toxicity was associated with more frequent irAE recurrence,” he noted. However, “the second irAEs were not more severe than the first. Thus, the risk-reward ratio for an anti-PD-1 rechallenge appears to be acceptable, but each individual situation has to be taken into account.”
As reported online June 6 in JAMA Oncology, patients’ median age was 62.5, about half were women, and the main cancer types/tumor sites were melanoma (33%), lung (16%), colorectal (9%), and lymphoma (9%). The main outcome was incidence of a second irAE after readministration of an anti-PD-1 or anti-PD-L1 after an initial grade 2 or higher irAE.
Initial irAEs consisted of 43 grade 2 events (46%), 36 grade 3 events (39%), and 14 grade 4 events (15%), presenting primarily as hepatitis (18%), skin toxicity (15%), pneumonitis (14%), colitis (12%), and arthralgia (7.5%).
As Dr. Lambotte noted, 43% of patients were rechallenged with the same anti-PD-1 or anti-PD-L1 agent. The rechallenged and non-rechallenged groups did not differ in terms of median age (61 vs. 63, respectively), time to initial irAE (5 vs. 3 treatment cycles), irAE severity (about half in each group experienced grade 2 and half, grades 3-4), or steroid use (42.5% vs. 60%).
During a median follow-up of 14 months, the same irAE or a different irAE occurred in 22 patients (55%). Shorter time to the initial irAE (9 vs. 15 weeks) was associated with the occurrence of a second irAE, but this was not more severe than the first.
“Rechallenge is a good example of the importance of setting up multidisciplinary boards to assess the management of severe irAEs and to discuss whether or not to rechallenge,” Dr. Lambotte said. “In some patients, the rechallenge is the last possible therapeutic option. In these patients, the rechallenge is important to discuss. On the other hand, in an adjuvant situation, the risk-reward ratio is not for the rechallenge.”