Larimar Therapeutics slapped with FDA clinical hold, forced to halt $95M cash raise

Larimar Therapeutics saw its shares nearly halved in after-hours trading last night after it was hit with an FDA trial hold and had to cancel a planned private raise.

The clinical hold is for its leading asset CTI-1601, a recombinant fusion protein intended to deliver human frataxin into the mitochondria of patients with Friedreich’s ataxia (FA), an autosomal-recessive genetic disease that causes difficulty walking, a loss of sensation in the arms and legs, and impaired speech that worsens over time and usually starts in childhood.

The FDA, which previously gave the therapy a fast-track tag, is halting its trial program after the biotech sent off data showing a number of deaths that occurred at the highest dose levels in an ongoing 180-day nonhuman primate (NHP) toxicology study.

This test was designed to support extended dosing of patients with CTI-1601 but now raises new safety questions that need to be addressed.

In the clinical hold letter, the FDA said it needs “a full study report from the ongoing NHP study and Larimar may not initiate additional clinical trials until the company has submitted the report and received notification from the agency that additional clinical trials may commence,” according to the biotech.

This could push back its trial timeline into 2022, the biotech said, which is also about how much runway it has cash-wise.

It has already finished off a phase 1, in which Larimar showed its drug was “generally well tolerated at doses up to 100 mg administered daily for 13 days,” with no serious adverse events, “important medical events, or treatment-related severe adverse events were reported in the trial and the number and severity of adverse events did not increase with increasing exposure to CTI-1601.”

The most common safety issues “were mild and moderate” injection site reactions.

Just five days ago, it announced it was seeking a $95 million in a private placement, which was set to be used toward its clinical work on the drug. But now, given the hold, the biotech said it “will not be closing a previously announced private placement financing.”

“While the notification of a formal clinical hold is disappointing, it does not change our previously stated clinical development strategy for CTI-1601,” said Carole Ben-Maimon, M.D., president and CEO of Larimar.

“Patient safety is our top priority, and we will continue with our plan to complete the NHP toxicology study, assess the data, and discuss that data with FDA to obtain their consent prior to initiating our Jive and pediatric MAD trials. Based on all of the information we have regarding CTI-1601’s safety profile to date, we continue to believe there is a path forward toward the initiation of our Jive and pediatric MAD trials.

“However, due to the additional regulatory requirements that come with responding to a formal clinical hold, we believe there is a possibility that the initiation of these trials may be delayed into 2022. Regarding the termination of the previously announced private placement financing, as of March 31, 2021, we have $81.4 million in cash and investments, which provides cash runway through the first half of 2022.”