Eli Lilly-backed TRex Bio is aiming for a $111.3 million IPO, while hypertension-focused Retension Pharmaceuticals hopes for a more modest $33.8 million and protein degradation biotech Lycia Therapeutics plans its own listing.
Having already unveiled an ambition last month to eventually go public, TRex explained in a Securities and Exchange Commission filing Monday that the company hopes to offer 8.3 million shares priced between $14 and $16 apiece.
Should the final price fall in the middle of this range, TRex estimates the IPO will bring $111.3 million in net proceeds—rising to $128.7 million if underwriters fully take up their option to buy an additional 1.3 million shares at the same price.
Since TRex broke cover in 2021 with a $59 million series A, the South San Francisco-based biotech has attracted attention on the strength of a platform for discovering ways to modulate Tregs, a subset of T cells that play a key role in tissue inflammation. The biotech penned a collaboration with Johnson & Johnson a year later, and in 2023 Lilly paid $55 million to take up its option to license an immune effector cell modulator that has since entered the clinic.
Lilly has already expressed an interest in participating in the IPO, TRex confirmed in Monday's filing.
TRex’s history with the Indianapolis Big Pharma goes way back, with the biotech’s CEO Johnston Erwin being a long-time Lilly veteran. Erwin currently oversees a workforce of 60 full-time employees, with around $91 million sitting in the bank following on from an $84 million series B in 2024 and $50 million financing at the start of this year.
The company expects to spend $90 million on bankrolling phase 2 trials for its tumor necrosis factor receptor 2 (TNFR2) agonist TRB-061 in atopic dermatitis (AD), as well as moving the therapy into other autoimmune and inflammatory diseases, including alopecia areata. Topline data from an ongoing phase 1 trial in AD is due to read out in mid-2027.
A further $10 million will be spent on taking a CD30 agonist dubbed TRB-071 into the clinic in a phase 1 trial of healthy volunteers. By triggering both the activation and expansion of regulatory T cells (Tregs), TRex is hoping that TRB-071 has the potential to address underlying immune dysregulation in immune-mediated diseases such as inflammatory bowel disease.
Retension aims for $33.8 million
Retension first set out its IPO ambitions at the same time as TRex, and the biotech also tacked on some numbers to its plans yesterday. The idea is to offer 3.3 million shares priced between $11 and $13, according to an SEC filing.
The Virginia biotech expects this to bring in $33.8 million—rising to $39.4 million if underwriters snap up 495,000 shares also priced at $12.
A total of $18 million has been earmarked for completing a phase 2b study of RTN-001 in patients with uncontrolled hypertension (uHTN). The biotech has been testing the once-daily, oral, small-molecule phosphodiesterase-5 (PDE-5) inhibitor as a way to reduce blood pressure by potentiating nitric oxide signaling.
A further $10 million will be needed for a phase 3 study in uHTN, according to the company’s filing.
Retension is hoping that RTN-001 will differentiate itself from first-generation PDE-5 inhibitors like Viagra—which never lived up to their early promise to reduce blood pressure—because the next-gen drug has been engineered to have increased bioavailability and an increased distribution to the muscular arteries.
RTN-001 has already demonstrated a clinically meaningful reduction in systolic blood pressure and diastolic blood pressure in pilot phase 2 studies, according to the biotech.
Lycia expresses interest
Lycia also joined the IPO queue yesterday, as the South San Francisco-based biotech seeks funds to advance its pipeline of protein degraders. At the top of the company’s list of priorities is LCA-0061, a catalytic lysosomal targeting chimera (cataLYTAC) degrader designed to deplete immunoglobulin E (IgE) in order to treat food allergy and other allergic diseases.
LCA-0061 is already undergoing a phase 1 trial, and Lycia is also planning to take another cataLYTAC degrader called LCA-0062 into the clinic for food allergy. Then there’s LCA-0321, a LYTAC degrader for Grave’s disease.
Lycia’s workforce of 31 full-time employees is headed up by CEO Aetna Wun Trombley, Ph.D., a former chief operating officer of liver disease-focused NGM Biopharmaceuticals. Having launched with $50 million in 2020 and gone on to raise a $70 million series B in 2021, a $106.6 million series C in 2024 and a $75 million fundraise in June, the company entered the second half of this year with $148.1 million still in the bank.
The interest from Retension, TRex and Lycia in joining the Nasdaq comes during a bumper run of IPOs in 2026 that has included record-breaking listings from the likes of Parabilis Medicines and Kailera Therapeutics. Late September saw ADARx Pharmaceuticals raise $446.3 million from an upsized IPO to fund the likes of its siRNA therapy agazisiran for complement-mediated diseases.
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