Efficacy and toxicity of peritumoral delivery of nanoconjugated cisplatin in an in vivo murine model of head and neck squamous cell carcinoma

Importance: Treatment of locally advanced head and neck squamous cell carcinoma (HNSCC) uses a multidisciplinary approach often limited by the toxicity and drug resistance of platinum agents. Objectives: Totest whether a nanocarrier-conjugated cisplatin boosting locoregional drug delivery improves tumor efficacy while decreasing systemic toxicity over systemic cisplatin in a murine model of locally advanced HNSCC. Design: A randomized, controlled, in vivo study compared standard cisplatin with nanocarrier (hyaluronan [HA])-conjugated cisplatin (HA-cisplatin) each at 50% of the maximum tolerated doses in a murine model of locally advanced HNSCC (10 mice/arm, each injected with 1 × 10⁶ MDA-1986 HNSCC cells, with phosphate-buffered saline and HA-only control arms). Mice were treated for 3 weeks and observed for 3 additional weeks. Setting: Academic medical center. Participants: Forty female Nu/Nu mice. Randomization and treatment arms were initiated once tumor volumes reached 30 mm³. Intervention: Injection with MDA-1986 HNSCC cells followed by 3 weeks of treatment with cisplatin, HA-cisplatin, phosphate-buffered saline, or HA only. Main Outcomes and Measures: Animal weights and tumor volumes were measured 3 times each week (modified RECIST [Response Evaluation Criteria in Solid Tumors]). At necropsy, animal kidneys were examined for nephrotoxic effects and cochleae were examined for ototoxic effects. Results: The mice treated with HA-cisplatin showed superior tumor efficacy (1 with complete clinical response, 3 with partial response, 1 with stable disease, and 5 with progressive disease) compared with standard cisplatin (no animals with complete clinical response, 1 with partial response, 1 with stable disease, and 8 with progressive disease), which was statistically significant (P = .003). All control animals developed progressive disease. Weight loss and body score were surrogate measures of treatment toxicity. The HA-cisplatin group had the least weight loss (mean [SD], 10.8% [4.7%]) compared with the cisplatin group (13.6% [5.6%]; P = .25). Body score dropped to 2 or less in all cisplatin-treated mice but not in any HA-cisplatin-treated mice, which also lacked any histologic signs of nephrotoxic or ototoxic effects. Conclusions and Relevance: Nanoconjugated HA-cisplatin significantly improves tumor efficacy with lower toxicity compared with standard cisplatin in locally advanced HNSCC in vivo, justifying additional translational studies.