Syncona investment Achilles upbeat on safety review of trials

Healthcare investor Syncona said on Friday that its portfolio company Achilles Therapeutics, which is developing precision T-cell therapies to treat solid tumours, had announced that an independent data and safety monitoring committee had completed the first review of the ongoing, first-in-human phase 1 and 2 ‘CHIRON’ and ‘THETIS’ trials.

The FTSE 250 company said the committee had recommended that both clinical trials continued as planned.

In the review of the first six patients dosed with the company's clonal neoantigen targeting T-cell therapy (cNeTs), the overall tolerability profile was similar to that of standard tumour-infiltrating lymphocyte (TIL) products that had not been enriched for cNeT reactivities, with the lymphodepletion regimen accounting for most higher-grade adverse events.

Additionally, it said initial data from the first six patients provided “encouraging” evidence of cNeT engraftment.

Based on those observations, Achilles planned to increase the administered cNeT doses in the next series of monotherapy patients.

“This independent safety review along with the initial data from our CHIRON and THETIS trials are promising and are based on patients that have been dosed with cNeTs at the lower end of our prospectively targeted therapeutic dose range,” said Achilles chief executive officer Dr Iraj Ali.

“We now plan to move to higher cNeT doses and also open a combination cohort in the THETIS trial evaluating the addition of nivolumab, a PD-1 inhibitor, following cNeT infusion, subject to further safety review.”

Following the first disease evaluation by scan six-weeks post cNeT infusion, stable disease was observed in four out of the six patients and progressive disease in two.

One patient had a reduction in the size of two of their four tumour lesions by approximately 55% and 90%.

Engraftment data for the cNeTs were currently available from four patients, with evidence of engraftment in two.

The highest engraftment was in the patient who received the highest cell dose.

At the same time, Syncona also noted that Achilles Therapeutics had announced that it expected to consider additional capital raising options in the current year, which could include an initial public offering in the United States.

The timing and the terms of any such offering had not yet been determined, the board said, and would be subject to market conditions and other factors.

At 0901 GMT, shares in Syncona were up 1.17% at 255.95p.