A phase 1 study to assess the safety, tolerability and effectiveness of PV-10 (Rose Bengal Sodium) in neuroendocrine tumours metastatic to the liver.

Background: Metastatic neuroendocrine neoplasms (mNEN) require new treatment options. Intralesional (IL) PV-10 is an autolytic chemotherapy that may elicit an adaptive immune response.

Methods: This phase 1 study evaluated IL PV-10 administered percutaneously to hepatic lesions in patients with progressive mNEN. IL PV-10 was injected in a single lesion per treatment cycle. A treatment cycle could be repeated after ≥ 6 weeks if multiple targetable lesions were present. The primary endpoint was safety.

Results: Twelve patients were enrolled with a median age of 66 years (range 47-79). All patients had progressive disease at enrolment and received prior somatostatin analogues; 10 patients had peptide receptor radionuclide therapy (PRRT) treatment. One lesion was injected per cycle for all 12 patients. Reported grade 3 side effects were photosensitivity (1 patient), face oedema (1 patient), elevated transaminases (1 patient), hypertension (2 patients). Response rate was 42% of injected lesions with patient-level disease control of 84%, PFS 9.4 months and median OS 24.0 months.

Conclusions: IL PV-10 elicited no safety concerns. Encouraging evidence of local and systemic disease control was seen in a heavily pre-treated, progressing mNEN population.

Clinical trial registration number: NCT02693067.