Panbela Therapeutics, Inc. announces the publication of clinical data from studies of CPP-1X (also known as a-Difluoromethylornithine (DFMO) or Eflornithine) in neuroblastoma. According to Hogarty et al, children with relapsed refractory neuroblastoma have dismal outcomes and new therapeutic options are needed. Data published in the British Journal of Cancer investigated the tolerability and activity of depleting polyamines by high dose CPP-1X and celecoxib in combination with standard of care chemotherapy in heavily pretreated neuroblastoma patients.

Results showed that DFMO treatment was well tolerated, and the median time-to-progression was 19.8 months. From the Phase 1 dose range finding study of CPP-1X in heavily pretreated neuroblastoma patients, CPP-1X was well tolerated. The best overall response included 2 partial responses (PR), 4 minor responses (MR), 10 Stable disease (SD), 7 progressive disease (PD) and 1 unevaluable.

All patients with an overall response of PR or MR sustained this response until stopping or completing protocol therapy. The overall objective response rate (CR+PR) was 9% and rate of any response (CR+PR+MR) was 26%. At 2 years, PFS (progression free survival) for the entire cohort was 29.5%.

Notably, three patients completed protocol therapy and remain without disease progression or event at >4 years from treatment end in the absence of additional therapy. These results build upon the recent FDA approval of CPP-1X or DFMO to reduce the risk of relapse in adult and pediatric patients with high-risk neuroblastoma (HRNB) who have demonstrated at least a partial response to prior multiagent, multimodality therapy including anti-GD2 immunotherapy. Results from these studies suggest that CPP-1X is a safe, oral treatment option that may improve response rates in heavily pretreated relapsed refractory neuroblastoma patients and are the basis for the ongoing ANBL-1821 Phase 2 trial.