Redx cleared to start Wnt cancer trial again after safety scare

Redx was hit hard last year when it was forced to suspend a phase 1/2a trial of its porcupine inhibitor for solid tumors, but it’s now been given the OK to restart testing.

The U.K. biotech says the Medicines and Healthcare products Regulatory Agency has given “formal approval” to continue the trial of RXC004, which targets the Wnt embryonic signaling pathway and is thought to disrupt tumor processes including tumorigenesis, metastasis and resistance.

Redx paused its trial last March after the first patient to receive the drug suffered a serious adverse event caused by a higher-than-expected systemic exposure to the drug. That forced the company to come up with a new protocol based on a significantly lower starting dose, with the amount of the drug given stepped up slowly to balance safety and efficacy, as well as a new formulation and “enhanced safety monitoring.”

The trial in patients with advanced solid tumors will get underway again in the first half of this year, according to Redx CEO Lisa Anson, who thinks the drug “has the potential to offer clinical benefit both as a monotherapy and in combination with standard of care treatments.”

Redx thinks RXC004 works by inhibiting cancer cell growth directly as well as engaging the immune system to attack the tumor. If the trial proceeds as hoped, Redx intends to start testing the drug in tandem with checkpoint inhibitors.

“We have learnt a significant amount from the first patient treated with RXC004, and this provides the basis for an optimized RXC004 development plan as well as the confidence to evaluate the clinical potential of RXC004 in cancer patients,” said Natalie Cook, consultant oncologist and principal investigator from the Christie Hospital in Manchester, U.K.

Following RXC004 is a porcupine inhibitor for fibrosis called RXC006, which is due to enter the clinic next year and is being developed for idiopathic pulmonary fibrosis, and two programs based on drugs that target an enzyme called ROCK with potential in nonalcoholic steatohepatitis and fibrosis associated with Crohn’s disease.

Shares in the company had gained around 7% to £7.50 in mid-morning trading on the London Stock Exchange, still well down on its 52-week high of more than £18.

The suspension of the RXC004 study followed a torrid period for the company which included a temporary slip into administration owing to unpaid debt, which was resolved when it sold a preclinical program to Loxo Oncology.