Exact Therapeutics’ attempt to get its solid tumor clinical trial back on track has hit a snag, with the U.K. Medicines and Healthcare products Regulatory Agency (MHRA) asking for information on the ultrasound system used to activate the therapy.
Oslo-based Exact Therapeutics sees the technology as a way to increase the concentration of the drug at the target site without causing systemic side effects. Patients receive microscopic clusters of gas bubbles and liquid droplets with the therapeutic agent. When ultrasound hits the clusters, larger bubbles form. If Exact Therapeutics is right, the larger bubbles will act as micropumps that get the drug to its target.
A phase 1 clinical trial of the technology started in the U.K. in 2019. However, the study has been beset by problems, most recently a request from the MHRA for additional information to support a protocol amendment.
The MHRA request is the latest in a series of delays. In May, Exact Therapeutics said enrollment in the trial had been “adversely impacted” by the pandemic. The situation prompted the company to target the filing of a protocol amendment “with a consequent impact on patient enrollment”. At that time, the plan was to restart enrollment in the fourth quarter.
Exact Therapeutics provided an update in November, revealing it still planned to file an amendment with a view to completing recruitment in the part one cohort of its study by mid-2022. The MHRA request may put that target in jeopardy.
“The Company expects that meeting this requirement, which is specifically focused on the Ultrasound system used in combination with PS101, from the regulator will impact the timing of additional patient recruitment,” Exact Therapeutics wrote in a statement.