Scalp cooling outcomes in patients receiving trastuzumab deruxtecan for metastatic breast cancer

BACKGROUND: Trastuzumab deruxtecan (T-DXd) has improved outcomes for many patients with metastatic breast cancer (MBC). T-DXd is associated with alopecia, yet limited data exist describing the efficacy of scalp cooling (SC) in preventing alopecia among patients receiving T-DXd. PATIENTS AND METHODS: This prospective, phase II trial evaluated the efficacy of SC among patients with MBC receiving T-DXd. Conducted at Dana-Farber Cancer Institute, the trial enrolled patients with MBC without alopecia at baseline, initiating treatment with T-DXd. Participants elected either the SC arm, using the Paxman Scalp Cooling System, or the non-SC arm. The primary endpoint was hair loss rate, defined as locally assessed Common Terminology Criteria for Adverse Events (version 5.0) grade ≥1 alopecia occurring at cycle 3, day 1; cycle 5, day 1; or end of treatment, whichever occurred first. RESULTS: Among 40 enrolled evaluable patients, 33 (82.5%) patients 18 (90%) in the SC arm and 15 (75%) in the non-SC arm experienced grade ≥1 alopecia. The difference in rates between arms was not statistically significant (P = 0.41). Grade 2 alopecia rates were the same in both arms (55%). Centralized image review revealed no significant differences in grade ≥1 (P = 1.00) or grade 2 alopecia (P = 0.33) between treatment arms. Grade 2 alopecia was the primary reason for SC discontinuation (45%). The median time to grade 2 alopecia was 2.76 months 95% confidence interval (CI), 1.64-NA in the SC arm; 4.60 months (95% CI, 2.53-NA) in the non-SC arm (P = 0.7). CONCLUSIONS: SC with T-DXd did not reduce alopecia rates. Small sample size and lack of randomization may have limited the interpretation. Further studies are crucial to improve SC's efficacy with antibody-drug conjugate therapy.