Alzheimer's biotech Korsana to go public via reverse merger

Korsana Biosciences only emerged onto the scene a few weeks ago, but is already planning to go public to raise funds for its Alzheimer's disease candidate.

The start-up will achieve that through a reverse merger with Cyclerion Therapeutics, a Nasdaq-listed company that suffered a string of setbacks and was forced to reduce its workforce to a skeleton staff before re-launching last September with an early-stage drug/device combination for treatment-resistant depression.

For Korsana, merging with Cyclerion gives it a fast track to a Nasdaq listing without the complexities of going down the IPO route. The deal comes with $380 million in private financing – led by Fairmount and Venrock Healthcare Capital Partners – that adds to the $175 million it raised in seed and first-round financing.

The cash injection will fund the operations of the combined company – which will still be called Korsana Biosciences and trade under the KRSA symbol – into 2029.

Korsana will use the funding for clinical development of its preclinical-stage Alzheimer's candidate KRSA-028, an amyloid-targeting 'brain-shuttled' antibody that uses technology designed to transfer it into the central nervous system more effectively than current amyloid-directed drugs.

The approach is similar to that deployed by Roche in its development of trontinemab, which has already progressed into phase 3 trials and is also hoping to improve on the current generation of anti-amyloid antibodies, Eisai/Biogen's Leqembi (lecanemab) and Eli Lilly's Kisunla (donanemab).

It has been estimated that less than 1% of current anti-amyloid antibodies end up in the CNS, where they can exert their activity. If drugs like KRSA-028 or trontinemab can achieve improved brain penetration using a lower dose, they may also reduce side effects that have held back uptake of the first-generation amyloid therapies.

Korsana said its timeline for the clinical development of KRSA-028 is to start phase 1 trials in mid-2027, with interim proof of concept data measuring amyloid plaque clearance in Alzheimer's patients expected by the end of that year.

Under the terms of the merger agreement, Cyclerion shareholders will hold around 1.5% of the merged company's stock on closing, with some variation depending on the amount of cash held by Cyclerion on that date. Korsana's chief executive, Jonathan Violin, will continue to lead the merged company.

"Patients deserve better options than what is currently available, and we believe…KRSA-028 can deliver a best-in-class product to treat Alzheimer's," said Violin.

According to the company. The drug is expected to match intravenously-administered trontinemab in brain penetration with a low-volume, subcutaneous dose that could be compatible with self-injection devices.

Photo by Marc Sendra Martorell on Unsplash