Esanex has started dosing patients in a Phase I clinical trial of its drug candidate SNX-5422 combined with ibrutinib to target residual disease in patients with chronic lymphocytic leukaemia (CLL).
SNX-5422 is an orally active inhibitor of the heat shock protein 90 (Hsp90), with durable clinical responses demonstrated in non-small cell lung cancer (NSCLC) and neuroendocrine tumours (NET) trials.
The open-label Phase I trial will evaluate the safety and efficacy of the SNX-5422 and ibrutinib combination, along with clinical benefit of adding SNX-5422 to an established ibrutinib dose.
Set to be performed in patients with stable residual disease on ibrutinib alone, the trial will include administration of 56mg/m2 SNX-5422 in the morning once every day for a duration of 21 days.
The trial will include a seven-day period without SNX-5422, while oral ibrutinib will be given daily in the afternoon at determined dose level.
Esanex president and CEO Steve Hall said: “The new mechanistic understanding of SNX-5422 that Esanex has uncovered, which differentiates our compound from other Hsp90 inhibitors, has enabled us to rationally approach monotherapy and select combination therapies for distinct indications.
“We believe we are only beginning to see the potential of SNX-5422 and Hsp90 inhibition as a treatment for cancer and possibly other diseases.”
Estimated to be complete in July next year, the primary outcome measure of the trial is the proportion of patients achieving a complete response at the end of six SNX-5422 treatment cycles.
The trial’s secondary outcome measures include number of participants experiencing adverse events, complete response at 12 months, improved clinical status and progression free survival up to 52 weeks.