ICI safety
In patients with NSCLC and preexisting ILD, the incidence of immune-related adverse events (irAes) of any grade was 56.7%, whereas the incidence of irAEs grade 3 and higher was 27.7%. “Among the 179 patients included in the studies, 45 developed any grade of CIP, corresponding to a crude incidence of 25.1%,” the authors noted – very similar to the pooled incidence of 27% on meta-analysis.
The pooled incidence of grade 3 and higher CIP in the same group of patients was 15%. The median time from initiation of ICIs to the development of CIP ranged from 31 to 74 days, but 88% of patients who developed CIP improved with appropriate treatment. In patients with NSCLC who did not have ILD, the pooled incidence of CIP was 10% (95% CI, 6%-13%), again with significant heterogeneity between studies (I2 = 78.8%). “Generally, CIP can be managed through ICI discontinuation with or without steroid administration,” the authors noted.
However, even if most CIP can be easily managed, “the incidence of severe CIP is higher [in NSCLC patients with preexisting ILD] than in other populations,” Dr. Chen observed. “So patients with preexisting ILD should be closely monitored during ICI therapy,” she added.
Indeed, compared with patients without preexisting ILD, grade 3 or higher CIP in patients with the dual diagnosis was significantly higher at an OR of 3.23 (95%, 2.06-5.06), the investigators emphasized.
A limitation to the review and systematic meta-analysis included the fact that none of the studies analyzed were randomized clinical trials and most of the studies were retrospective and had several other shortcomings.
Umbrella diagnosis
Asked to comment on the review, Karthik Suresh, MD, associate professor of medicine, Johns Hopkins University, Baltimore, pointed out that ILD is really an “umbrella” diagnosis that a few hundred diseases fit under, so the first question he and members of his multidisciplinary team ask is: What is the nature of the ILD in this patient? What is the actual underlying etiology?
It could, for example, be that the patient has undergone prior chemotherapy or radiation therapy and has developed ILD as a result, as Dr. Suresh and his coauthor, Jarushka Naidoo, MD, Sidney Kimmel Comprehensive Cancer Center, Baltimore, pointed out in their paper on how to approach patients with preexisting lung disease to avoid ICI toxicities. “We’ll go back to their prior CT scans and can see the ILD has been there for years – it’s stable and the patient’s lung function is not changing,” Dr. Suresh related to this news organization.
“That’s a very different story from a [patients] whom there are new interstitial changes, who are progressing and who are symptomatic,” he noted. Essentially, what Dr. Suresh and his team members want to know is: What is the specific subdiagnosis of this disease, how severe is it, and is it progressing? Then they need to take the tumor itself into consideration.
“Some tumors have high PD-L1 expression, others have low PD-L1 expression so response to immunotherapy is usually very different based on tumor histology,” Dr. Suresh pointed out. Thus, the next question that needs to be addressed is: What is the expected response of the tumor to ICI therapy? If a tumor is exquisitely sensitive to immunotherapy, “that changes the game,” Dr. Suresh said, “whereas with other tumors, the oncologist might say there may be some benefit but it won’t be dramatic.”
The third risk factor for ICI toxicity that needs to be evaluated is the patient’s general cardiopulmonary status – for example, if a patient has mild, even moderate, ILD but is still walking 3 miles a day, has no heart problems, and is doing fine. Another patient with the same severity of disease in turn may have mild heart failure, be relatively debilitated, and sedentary: “Performance status also plays a big role in determining treatment,” Dr. Suresh emphasized.
The presence of other pulmonary conditions such as chronic obstructive pulmonary disease – common in patients with NSCLC – has to be taken into account, too. Lastly, clinicians need to ask themselves if there are any alternative therapies that might work just as well if not better than ICI therapy for this particular patient. If the patient has had genomic testing, results might indicate that the tumor has a mutation that may respond well to targeted therapies. “We put all these factors out on the table,” Dr. Suresh said.
“And you obviously have to involve the patient, too, so they understand the risks of ICI therapy and together we decide, ‘Yes, this patient with ILD should get immunotherapy or no, they should not,’ “ he said.
The study had no specific funding. The study authors and Dr. Suresh have disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
