Boundless Bio eyes $88M offering as spring biotech IPO market blooms

Boundless Bio’s announcement earlier this month of plans to go public was a sign that the biotech IPO window hadn’t slammed shut after a flurry of offerings at the start of the year.

Now, the company has set out its IPO pricing ambitions at the more modest end of the year’s offerings. Boundless is expecting to sell 6,250,000 shares priced between $15 and $17 per share, according to a March 21 Securities and Exchange Commission filing. Boundless expects "net proceeds to us from this offering will be approximately $88.4 million" assuming the final share price falls in the middle of that range, the company said in the filing.

However, this could rise to $102.3 million if underwriters take up their option to buy an additional 937,000 shares, the biotech said.

At $88.4 million, Boundless has set expectations closer to the likes of preclinical gene editing company Metagenomi, which brought in $93.7 million in a February IPO, and far below CG Oncology and its whopping $380 million IPO in January, which remains 2024’s largest to date.

Boundless may end up bringing in less from the IPO than from its most recent funding round, including a $100 million haul in in May 2023 that had the backing of big beasts like Arch, Bayer and RA Capital Management. The sizable cash infusion helped fuel the biotech’s clinical ambitions, with two programs now in phase 1 studies.

The precision oncology company, which describes itself as “the world’s leading ecDNA company,” is focused on extrachromosomal DNA, which are double-stranded molecules that can be the source of cancer-driving genes.

The first program, BBI-335, looks to inhibit checkpoint kinase 1 in the hopes of cooling down ecDNA replication. Boundless said in its original IPO filing earlier this month that proof-of-concept and anti-tumor activity data on up to 90 patients are expected in the second half of the year. That asset is followed up by BBI-825, which was launched into its first trial last month. An investigational new drug application for a third program isn't expected to be filed until the first half of 2026.

Boundless isn’t the only biotech IPO set for spring. Contineum Therapeutics also filed paperwork this month to raise money for phase 2 trials of its lead prospect and a Johnson & Johnson-partnered molecule.

Editor's Note: This story was updated at 3:37 p.m. ET on Thursday, March 21, 2024, to clarify the number of shares being sold in the offering.