Recovery with residual disparities: Real-world patterns of platinum chemotherapy use after the 2023 drug shortage.

1562 Background: The 2023 national shortages of cisplatin and carboplatin disrupted standard cancer treatment across multiple malignancies. Although the acute effects have been described, patient-level evidence of recovery in platinum chemotherapy access after supply stabilization is limited. We evaluated real-world recovery in platinum initiation across platinum-dependent cancers. Methods: We conducted a retrospective cohort study using the TriNetX U.S. Collaborative Network. Adults with platinum-sensitive malignancies, including lung, ovarian, bladder, uterine, testicular, and head and neck cancers, were identified using ICD-10-CM and ICD-O codes and assigned according to the national platinum chemotherapy shortage timeline: shortage (February 10, 2023-January 31, 2024) and post-shortage (July 1, 2024-June 30, 2025) eras. The primary endpoint was time from cancer diagnosis to first receipt of any platinum chemotherapy (cisplatin or carboplatin), analyzed using Kaplan–Meier methods and multivariable Cox proportional hazards models, adjusted for demographic characteristics, NCI Comorbidity Index, risk factors, BMI, and cancer type. Secondary analyses evaluated agent-specific initiation (cisplatin vs carboplatin) and heterogeneity of recovery across cancer sites. Prespecified subgroup analyses assessed differences in recovery by sex and race/ethnicity within matched cohorts. Results: The analysis included 33,856 patients diagnosed during the shortage and 30,256 diagnosed post-shortage. Platinum initiation improved post-shortage compared with the shortage period (adjusted hazard ratio [aHR], 1.11; 95% CI, 1.09–1.14; p<.001), with median time to initiation decreasing from 206 to 128 days. This improvement was driven primarily by increased carboplatin initiation, while cisplatin initiation continues to stall. Recovery patterns varied by cancer type, with greater improvement observed in ovarian and head/neck cancers and incomplete recovery in bladder cancer. Across eras, slower platinum initiation was observed among older patients (aHR per year increase, 0.99), male patients (aHR 0.92), and racial/ethnic minority groups, including Black (aHR 0.92) and Hispanic patients (aHR 0.90). Comorbidities associated with platinum toxicity, such as CKD (aHR, 0.79), neuropathy (aHR, 0.63), heart failure (aHR, 0.93), and liver disease (aHR, 0.84), were also associated with delayed initiation. Conclusions: After resolution of the 2023 platinum shortage, platinum chemotherapy initiation improved across multiple cancers, providing patient-level evidence of recovery in access. However, recovery was heterogeneous, driven largely by carboplatin, and modified by patient clinical and demographic factors, suggesting that restoration of drug supply does not uniformly translate into timely or equitable recovery of standard-of-care treatment.