IPO Week Preview

Four names sit on this week’s U.S. IPO calendar, split into two conversations.

Pine Tree Acquisition has priced. AfterNext Acquisition I, the other blank-check company, is expected to list today. Then Friday belongs, at least for now, to two clinical-stage biotechnology companies: TRex Bio and Retension Pharmaceuticals.

INFORMATION GATHERED BY STAFF

Pine Tree Acquisition is the settled piece of the week. Its final SEC prospectus is dated October 6. The company sold 10 million units at $10 each, a $100 million offering, and the prospectus says delivery is expected on or about October 7. Each unit contains one Class A ordinary share and a right that can ultimately deliver three-fourths of a share after a business combination. Maxim Group is the underwriter. Pine Tree has not identified an acquisition target.

AfterNext Acquisition I is also a SPAC, but its public-market process has taken longer. It filed its initial registration statement in December 2025 and amended it repeatedly through September. The company is based in Singapore, is sponsored by AfterNext Sponsor I LLC and is led by CEO Anna Zhou. Its filing calls for 10 million units at $10 each. Each unit contains one Class A ordinary share, one right and one redeemable warrant. ARC Group Securities is the underwriter.

AfterNext says it intends to concentrate on financial technology and technology-enabled financial services in Asia-Pacific, including businesses using artificial intelligence, big-data analytics, cloud computing, digital payments, embedded finance and blockchain. It says it will not combine with a business based in, or principally operating in, mainland China, Hong Kong or Macau. It has not selected a target. Nasdaq approved the securities for listing upon official notice of issuance in August. Calendars show October 7, but a final primary-source pricing prospectus was not located, so this edition does not call the deal finally priced.

TRex Bio is a different story entirely. It was founded and seed-funded by SV Health Investors in 2018 and is headquartered in South San Francisco. CEO Johnston Erwin joined in 2021 after 36 years at Eli Lilly, where his work included clinical, regulatory, corporate-development and venture-investment responsibilities.

TRex is trying to turn regulatory T-cell biology into medicines for autoimmune and inflammatory disease. Its lead wholly owned program is TRB-061, a TNFR2 agonist now in a Phase 1b study in moderate-to-severe atopic dermatitis. The first patient in that part of the trial was dosed in April. In August, TRex reported Phase 1a topline results from healthy participants and said Phase 1b topline data are expected in mid-2027.

The company first filed its public S-1 on September 18 and amended it October 5 with the numbers investors can finally put on a calculator: 8,333,334 shares at $14 to $16. At the $15 midpoint, gross proceeds would be about $125 million before underwriting discounts and offering expenses.

Management specifies where much of that capital goes. About $90 million is earmarked for TRB-061, including Phase 2 trials in atopic dermatitis and alopecia areata through topline data. About $10 million is intended to move TRB-071 into and through a Phase 1 healthy-volunteer trial. The remainder is for working capital and general corporate purposes. TRex says the IPO proceeds plus existing cash and marketable securities should fund its operating plan into the second half of 2029.

Retension Pharmaceuticals was founded in 2023 and is headquartered in Falls Church, Virginia. CEO and co-founder Eric Keller has nearly 30 years of life-sciences business and legal experience. Co-founder and chief scientific officer Paul Sweetnam led the discovery and early development of the company’s lead drug, RTN-001, at Surface Logix.

That history matters because Retension is a young company carrying an older scientific program. RTN-001 is a once-daily oral PDE-5 inhibitor for hypertension. Retension says nine trials have enrolled 265 people, with 243 receiving the drug. The current program is in Phase 2b.

Retension first filed its S-1 on September 18 and amended it October 5. It proposes 3.3 million shares at $11 to $13. At the $12 midpoint, that is $39.6 million gross. The filing says approximately $18 million would complete the Phase 2b trial, approximately $10 million would prepare for and advance a planned Phase 3 trial, and the remainder would support general corporate purposes and operating expenses. Management says existing cash plus estimated IPO proceeds should fund operations for at least the next 21 months.

NOTES FROM FRANK

TRex is the one where the money started telling the story for me.

One hundred twenty-five million dollars sounds like a very large pile until you put road signs next to it. Ninety million toward TRB-061. Ten million toward TRB-071. Then the rest keeps the lights on and the work moving.

Now I can ask a question I understand: what do we know when they get to the next exit?

They are not selling a medicine today. They are financing the trip toward finding out whether these programs can become medicines. There is quite a bit of highway between those two places.

Retension fooled me for about thirty seconds.

Founded in 2023? My first reaction was that this thing had barely gotten its shoes tied. Then I found the history of RTN-001 and had to change the picture in my head. The company is young. The drug program is not. Nine completed trials is a very different starting point from nine slides in a presentation.

With Retension, I want to know whether this smaller offering gets the company through the Phase 2b answer it needs and far enough into the Phase 3 preparation that the next financing decision comes from a stronger position.

Then we have Pine Tree and AfterNext.

Those are shopping carts with money in them. Pine Tree has $100 million from the public offering. AfterNext tells us the aisle — fintech and technology-enabled financial services in Asia-Pacific — but not what it is buying.

At least we know the neighborhood. We do not know the house.

NOTES FROM STAN ROSENBERG

The easy thing would be to put TRex and Retension next to each other and call them comparable biotech IPOs.

I’m not doing that.

TRex is raising roughly $125 million at the midpoint. Retension is raising $39.6 million. TRex has a broader pipeline and pharmaceutical collaborations. Retension is much more concentrated around RTN-001. TRex’s lead wholly owned program entered human testing in 2025. Retension’s molecule carries clinical history from Surface Logix.

Same Friday. Different financial problem.

That is where bad comparisons start: two biotech companies suddenly become apples, oranges and whatever was left in the fruit stand.

I went looking for a historical IPO I could put in the empty chair and call a genuine match. I found companies with pieces of the resemblance, but not enough of it. Clinical stage changed. Revenue changed. Lead-asset concentration changed. Market conditions changed. Offering size changed.

So the chair stays empty.

TRex gives me another number I like better than a giant market-size slide: runway. Management says the IPO money plus existing resources should carry the operating plan into the second half of 2029. That is not a promise that the science works. It tells me how long the company believes it can keep paying to find out.

Retension says at least 21 months.

Now we’re talking.

My grandfather’s version of investing was less elegant. If I gave up the ice cream today, what was I supposed to get for waiting? At ten, I thought it was ridiculous because I knew what I got from the ice cream. The public-market version is harder.

TRex is asking investors to fund several more pieces of clinical work. Retension is asking them to push one main program through a particularly important stretch. Pine Tree and AfterNext are asking investors to back the people who will eventually choose the business.

That last category always makes me put my wallet back in my pocket for another minute and keep reading. Before there is a target, I cannot analyze customers, margins, cash flow or market share because there is no operating company yet.

I can analyze the SPAC structure, sponsor, unit economics, rights, warrants, redemption provisions and the people shopping. Useful — but not the same as knowing what I own.

WHAT WE KNOW

Pine Tree’s $100 million IPO is priced and covered by a final prospectus. AfterNext’s 10-million-unit offering is on today’s calendar and its securities have Nasdaq listing approval upon official notice of issuance, but a final primary-source pricing prospectus was not located in this research pass. TRex is proposing 8,333,334 shares at $14 to $16. Retension is proposing 3.3 million shares at $11 to $13. Both biotechnology prospectuses reviewed remain preliminary.

WHAT WE DON’T KNOW YET

TRex and Retension still need final pricing, and expected dates can move. AfterNext needs a final primary-source pricing confirmation before this publication will describe the deal as priced. Neither SPAC has disclosed an acquisition target. And for both biotechnology companies, the most important unknown cannot be solved by an IPO document: the clinical programs still have to produce the data that determine what comes next.