Preliminary top-line data from a phase 2, 4-week, placebo-controlled, dose exploration trial demonstrated increased frataxin levels and good tolerability for CTI-1601 in patients with Friedreich ataxia (FA), Larimar Therapeutics announced.

The trial enrolled 13 patients with FA. Nine were administered 25 mg of CTI-1601 as a daily subcutaneous injection for 14 days and then every other day thereafter until day 28, while 4 participants received placebo.

“Our preliminary phase 2 data provide the first clinical indication that a 25 mg dose of CTI-1601 can increase frataxin levels in peripheral tissues, building upon our proof-of-concept phase 1 results,” stated Carole Ben-Maimon, MD, president and chief executive officer of Larimar. “Importantly, the frataxin increases achieved with a relatively low 25 mg dose in our Phase 2 trial suggest a continuous daily dosing regimen is preferred for maintaining increases achieved with 25 mg CTI-1601.”

On day 14, analysis of skin cells showed a median 3.5 pg/µg placebo-adjusted frataxin level increase from baseline. Seven CTI-1601-treated patients with quantifiable levels of frataxin in the skin at both baseline and day 14 had increases in skin frataxin concentrations, while the skin frataxin concentrations of those receiving placebo remained the same.

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The researchers also found a median 0.9 pg/µg placebo-adjusted frataxin level increase from baseline in buccal cells on day 14. Five of the 7 CTI-1601-treated participants with quantifiable levels of frataxin in buccal cells at both baseline and day 14 had increased buccal cell frataxin concentrations, while the buccal cell frataxin concentrations of those receiving placebo remained the same.

“Our phase 2 results add to our safety database indicating that CTI-1601 is generally well tolerated. Thirty-seven adults with FA have been dosed with CTI-1601 across our phase 1 and 2 trials, with 35 completing treatment, one withdrawing due to an allergic reaction, and another withdrawing after a single 50 mg dose in the multiple ascending dose trial due to mild to moderate nausea and vomiting,” Dr. Ben-Maimon added.

No serious adverse events were reported throughout the study. Among the other adverse events reported, some patients experienced mild and moderate injection site reactions.

The clinical-stage biotechnology company has submitted the data from the trial’s 25 mg cohort to the US Food and Drug Administration (FDA) and will discuss the initiation of a 50 mg cohort in the phase 2 trial at a meeting scheduled later this quarter.


Larimar Therapeutics reports preliminary top-line data from phase 2 trial’s 25 mg cohort showing increases in frataxin levels in patients with Friedreich’s ataxia and first quarter 2023 financial results. News release. Larimar Therapeutics; May 15, 2023.