Introduction

We aimed to determine the ability to escalate drug doses in a 15-week CHOP protocol. We hypothesized that at least 50% of dogs would be successfully escalated in at least one drug. Secondary endpoints included objective response rate (ORR), progression-free interval (PFI), and overall survival time (OST).

Methods

30 dogs with newly diagnosed lymphoma were prospectively treated with a 15-week CHOP protocol. The first cycle was administered at standard doses. Drug doses that did not cause dose-limiting adverse effects (AEs) were increased using a standardized dose escalation protocol. AEs and response to therapy were assessed using VCOG criteria.

Results

Of 30 patients, 23 had the opportunity to dose escalate. Of those, 78% were successfully escalated (18/23). Vincristine was successfully escalated to a minimum of 0.8 mg/m² in 11 patients, cyclophosphamide was successfully escalated to a minimum of 300 mg/m² in 16 patients, and doxorubicin was successfully escalated to a minimum of 35 m/m² or 1.4 mg/kg in 9 patients. 7 patients (23%) were hospitalized at least once. Neutropenia was the most common dose-limiting toxicity for all drugs. 13/30 patients had T cell lymphoma. 19 patients achieved a CR, and 11 patients experienced a PR. The median PFI was 171 days (203.5 for B cell, 83 for T cell). The median OST was 254 days (260 for B cell, 222 for T cell).

Conclusion

Drugs in the CHOP protocol can often be escalated safely, with manageable AEs.

Funding Information

This study was funded by the Eldred Foundation.