Update 27/09/2022
In May 2021, the US Food and Drug Administration (FDA) put a full clinical hold on Larimar Therapeutics programme for Friedreich’s ataxia (FA) drug CTI-1601. CTI-1601 is a treatment which delivers frataxin protein to cells of people with FA. Frataxin is the protein which is reduced in FA. The hold meant that Larimar could not start any additional clinical trials of the drug. This was due to a question around safety of the higher dose of the drug in a preclinical animal study (in non-human primates) that was designed to support the longer-term dosing of people with FA. On 11 August 2022, Larimar announced that that it had recently had a meeting with the FDA to receive feedback on what information would be needed to resolve the clinical hold.
On 14 September 2022, Larimar announced that the FDA had lifted a full clinical hold and imposed a partial hold on the programme. This was following Larimar submitting a detailed analysis of its non-human primate and Phase 1 studies. Their previous Phase 1 studies in people with FA looked at doses of CTI-1601 of up to 100 mg daily for up to 13 days. These reported no serious adverse events, important medical events, or treatment-related severe adverse events. The most common adverse event was mild and moderate injection site reactions which all resolved. The injection site reaction was the only adverse event to increase with increasing exposure to the drug.
This partial hold will allow Larimar to begin a Phase II trial looking at two doses of CTI-1601, with the FDA reviewing the data from the first dosing cohort (25 mg of CTI-1601) before the second cohort is given a 50 mg dose of the drug. The new Phase II trial will include approximately 24 to 30 people with FA. In their Phase 1 trial, Larimar saw that 50 mg dose of CT-1601 increased frataxin levels in cells of people with FA (frataxin levels are lower in people with FA). By looking at a 25 mg dose in their new trial, they aim to understand if lower dosing for longer periods of time will also increase frataxin. The initial results of this trial are expected in the second half of 2023.
Read the press releases here and here.
Original post 28/05/2021
Larimar Therapeutics is a clinical-stage biotechnology company focused on developing treatments for complex rare diseases, such as Friedreich’s ataxia (FA). Previously, we reported that Larimar Therapeutics were evaluating the FA drug CTI-1601 in a Phase 1 multiple ascending dose clinical trial (https://www.ataxia.org.uk/research-news/larimar-therapeutics/). FA is caused by a fault in the frataxin gene, which means that lower levels of frataxin are produced. CTI-1601 is a drug intended to deliver frataxin to the mitochondria of people with FA.
Larimar Therapeutics have now announced positive topline data from their Phase 1 trial that included 27 people with FA. In the trial, people with FA were given injections of either CTI-1601 or a placebo at increasing doses and frequencies over 13 days. Treatment with CTI-1601 showed a dose-dependent increase in frataxin levels compared with placebo in all tissues tested [buccal cells (cells from the inside of a person’s cheek), skin biopsies, and platelets]. Interestingly, daily injection of CTI-1601 led to frataxin levels in buccal cells being either the same or higher than what would be expected in an FA carrier (a person with one copy of the faulty frataxin gene but does not have FA symptoms). Safety data from the trial also showed that CTI-1601 was generally well tolerated at doses of up to 100mg daily for 13 days.
Due to the positive data from the non-clinical studies and the Phase 1 trial, the European Medicines Agency (EMA) has granted CTI-1601 Priority Medicines (PRIME) designation. PRIME is a scheme which is designed to support the development of medicines for unmet medical needs, such as supporting the generation of robust data on the medicine and accelerated assessment of medicine applications.
People who took part in the Phase 1 trial in the US are eligible to screen for an open-label extension clinical trial, and Larimar Therapeutics are also planning a multiple ascending dose clinical trial in people with FA who are under 18 years of age.
More recently (25 May) Larimar Therapeutics however announced that there had been an issue with safety of the higher dose of the drug in their preclinical animal studies (in non-human primates) so the FDA has put a clinical hold on the CTI-1601 clinical program and it needs the full report of the study. We will provide an update as soon as it is known, although it is likely any new trial start date will be delayed
Read the full press releases here, here, and here.
Updated: 28/05/2021
