Tocilizumab looks promising for corticosteroid refractory anti-PD-1-related adverse events

CHICAGO – Tocilizumab may be a therapeutic option for steroid-refractory immune-related adverse events that are secondary to PD-1 blockade, according to findings from a review of patients treated with nivolumab for various malignancies.

Of 87 patients who were treated with the PD-1 inhibitor between April 2015 and October 2016, 34 received tocilizumab for high-grade immune-related adverse events (irAEs) that were refractory to corticosteroids. Of those, 27 experienced clinical improvement, which was defined as documentation of symptom resolution or hospital discharge within 7 days, Aparna Hegde, MD, of East Carolina University, Greenville, N.C., reported at the Chicago Multidisciplinary Symposium in Thoracic Oncology.

The median time to discharge was 4 days, and no adverse effect on median overall survival was seen between those who received tocilizumab and those who did not (6.1 vs, 6.7 months, respectively), Dr. Hegde said.

There was, however, a trend toward inferior overall survival in patients who required more than one dose of tocilizumab, but the difference was not statistically significant (hazard ratio, 1.72), she noted.

“Immune checkpoint inhibitors are associated with an unprecedented clinical benefit in patients with lung cancer. However, they are also associated with a unique spectrum of immune-mediated adverse events. While the standard of care for initial management of these adverse events is corticosteroids, the management of steroid-refractory events is poorly defined,” she said, adding that data from randomized trials on which consensus guidelines could be based are lacking.

At East Carolina University, a significant proportion of patients treated with PD-1 inhibitors were presenting with systemic inflammatory response syndrome (SIRS)-like symptoms and immune-related organ toxicities similar to what has been described in cytokine release syndrome, Dr. Hegde said.

Such symptoms have also been reported with other types of immune therapy, such as CAR T-cell therapy and bispecific T-cell receptor–engaging antibodies in hematologic malignancies, she noted.

“In our experience, when we treated these patients with tocilizumab, which is an [anti-interleukin-6] receptor monoclonal antibody, we saw dramatic and rapid responses, not only in the SIRS symptoms, but also in other immune-related organ toxicities. Therefore, we adopted the use of tocilizumab as our standard treatment for high-grade immune-related adverse events,” she said, explaining that it has been well documented that interleukin (IL)-6 levels increase during cytokine release syndrome and are mediators of inflammation, suggesting that blocking IL-6 may treat irAEs without compromising the efficacy of immune therapy.

The current study was undertaken to look more closely at the responses to tocilizumab and to assess overall survival in those who received tocilizumab.

Study participants were being prospectively followed as part of another ongoing study looking at the relationship between systemic inflammation and cancer-related symptom burden. Most (77) were being treated for lung cancer and 10 had other types of malignancy. They received nivolumab at a dose of 3 mg/kg (or a flat dose of 240 mg after September 2016) every 2 weeks, and received tocilizumab at a dose of 4 mg/kg given over 1 hour. Those with grade 3 or 4 irAEs also received supportive care and corticosteroids. Median follow-up was 10.6 months.

C-reactive protein (CRP), a reliable surrogate marker of IL-6, was drawn at the first nivolumab infusion and before each subsequent infusion as part of the study in which the patients were enrolled, and for the current analysis was measured in relation to irAEs.

Significant reductions were seen in CRP levels after tocilizumab treatment; similar responses have been described in cytokine release syndrome, Dr. Hegde noted.

“Tocilizumab is a therapeutic option for management of immune-related adverse events in patients who are already on corticosteroids. CRP may be of clinical utility in detecting immune-related adverse events as well as monitoring the response to tocilizumab,” she said, adding that the current analysis is limited by the small patient number, single-center setting, use of tocilizumab outside of a clinical trial setting, and short follow-up.

Therefore, the findings require confirmation in multicenter randomized trials to determine “the definitive utility of tocilizumab, as well as CRP as an accompanying biomarker in the management of high-grade steroid refractory immune-related adverse events.”

Heather Wakelee, MD, an invited discussant at the symposium, commended Dr. Hegde and her colleagues for “coming up with a novel idea about how to treat [irAEs],” but also stressed the need for further study.

“This is a novel agent that has the potential ability to manage toxicity, and that’s important, because when you get beyond the steroids that we use as a first-line approach ... there’s not a whole lot else. We definitely have a clear unmet need,” said Dr. Wakelee of Stanford (Calif.) University.

However, she stressed that the approach must be evaluated in multicenter randomized trials “before we can be widely discussing this as a good thing to be doing.”

Dr. Hegde reported having no disclosures. Dr. Wakelee has been the institutional principal investigator for studies of nivolumab, tocilizumab, and other agents. She has consulted for Peregrine, ACEA, Pfizer, Helsinn, Genentech/Roche, Clovis, and Lilly, and received research/grant support from Clovis, Exelixis, AstraZeneca/Medimmune, Genentech/Roche, BMS, Gilead, Novartis, Xcovery, Pfizer, Celgene, Gilead, Pharmacyclics, and Lilly.