PTC Therapeutics Present Interim Data from FIREFISH Clinical Trial

21 June 2018

PTC Therapeutics recently presented preliminary data from the FIREFISH Phase II clinical trial of their splice-modifying drug, RG7916, at the 2018 Cure SMA conference in Dallas, USA.

RG7916, which has been renamed risdiplam, is a small molecule, oral drug that targets and encourages the SMN2 backup gene to produce more functional SMN protein, which is lacking in people with SMA.

Principally designed to test the safety, tolerability, and properties of risdiplam in babies with SMA Type 1, FIREFISH has been divided into two parts: Part 1 was designed to find a safe and tolerable dose of the drug to be tested over a 24 month period in Part 2.

The presented interim data from Part 1 of the trial, indicate that risdiplam appears to be well tolerated at all doses tested and to date has not caused any drug-related adverse events causing patient withdrawal from the trial.

In addition, risdiplam treatment appears to have a preliminary positive effect on motor milestone development as assessed by the Children’s Hospital of Philadelphia Infant Test of Neuromscular Disroders (CHOP-INTEND).

Compared to baseline scores at the start of the trial, patients receiving risdiplam showed median increases in CHOP-INTEND scores of 5.5 points at Day 56 after initial treatment (20 patients), 12.5 points at Day 119 (16 patients), and 14 points at Day 182 (11 patients).

The longer term testing of risdiplam in Part 2 of FIREFISH, which is ongoing, will provide additional evidence over the coming years as to the effectiveness of the drug for the treatment of SMA. As will the additional clinical trials of risdiplam called SUNFISH, and JEWELFISH (for further information click here).

Unfortunately, trials of risdiplam are not currently being conducted in the UK.

Further Information

PTC press release

FIREFISH trial Page