T-DXd for HER2+ MBC and Interstitial Lung Disease

Volkmar Müller, MD, PhD: Coming back to ILD [interstitial lung disease]. There’s a potential adverse effect of the drug that must be watched, but can we manage? What’s your approach and your experience with that?

Carmen Criscitiello, MD, PhD: Trastuzumab deruxtecan is extremely effective, so I’m not afraid to use it with a potential ILD. When we think of trastuzumab deruxtecan and ILD, we’re influenced by the DESTINY-Breast01 trial data, where there was 2.2% of grade 5 ILD. Whereas in the DESTINY-Breast03 trial, there are no grade 5 and 4 ILD and just 0.8% of grade 3 ILD. This suggests that toxicity decreases with experience in managing it right. We must be aware of the potential adverse events so we can recognize it promptly and start early management in case of toxicity. I’ve seen 2 women with ILD occurring during trastuzumab deruxtecan treatment. We monitor for ILD in clinical trials, so most of ILD has been detected in symptomatic patients with regular CT scans performed every 3 cycles. Most of the ILD events occur within the first 12 months of treatment, and there’s decrease after that period…. In the first year, patients should perform regular CT scans…and bring the…identification and effective management of ILD treatment. We must remember how to manage the toxicity in terms of treatment. Patients with ILD should stop therapy. In the case of grade 2 or more ILD, treatment must be withheld; in the case of grade 1 ILD, treatment may be resumed upon resolution. Steroids may also be used to manage ILD.

Volkmar Müller, MD, PhD: Not all patients must come off treatment. If they develop a mild, low-grade ILD, we will learn to manage it. We must be careful, but the patient…will contribute to that. Thank you for your thoughts.

Transcript edited for clarity.