ATTO-1091

A pair of biotechs joined the IPO queue on Wednesday, bringing the total number of companies this month who have signalled their intent to go public to four.Cardiology company Braveheart Bio and Attovia Therapeutics, which is developing biologics for immunology and inflammatory (I&I) diseases, are now waiting in the wings alongside in vivo CRISPR tech developer Scribe Therapeutics and sleep apnoea drugmaker Apnimed.The crowded queue comes as public markets are experiencing an explosion in activity compared with 2025. Not only has the pace of biotech IPOs picked up, but the deals are also bringing in more cash. In April, Kailera Therapeutics' $625-million raise set the record for largest-ever biotech IPO, but Parabilis Medicines quickly took the crown with its $670-million offering in June.For an in-depth look at IPO trends this year, see Spotlight On: Investors regain appetite for biotech IPOs.ATTOBODIES for I&IAttovia plans to use the proceeds from its IPO to fund development of a trio of programmes called ATTOBODIES — biparatopic biologics that use spatial positioning technology to attain picomolar binding affinity. Each ATTOBODY comprises two heavy-chain antibody variable region domains that target two different epitopes on a molecule, connected by a peptide-based linker. Lead candidate ATTO-1310 is an ATTOBODY-based IL-31–inhibiting Fc-fusion protein in Phase I testing for chronic pruritus and high-itch atopic dermatitis (AD). Early data suggest ATTO-1310 is well tolerated and can drive rapid, deep itch relief. Attovia is planning to launch a Phase II trial in the first half of 2027 and will also evaluate the asset in several other itching-related diseases, such as cholestatic pruritus in primary biliary cholangitis, primary sclerosing cholangitis and chronic kidney disease-associated pruritus.The company's second programme, ATTO-2306, is an ATTOBODY-based IL-13/IL-31–targeting bispecific; a Phase I trial is slated to start in the first half of 2027. Attovia believes the candidate could become a new standard-of-care treatment for AD and other I&I skin diseases like chronic spontaneous urticaria and prurigo nodularis by improving lesion and itch control with more convenience than currently available medications (see – Spotlight On: I&I marks the next frontier for bispecific antibodies).Also in IND-enabling studies is ATTO-1091, a trispecific ATTOBODY-based Fc-fusion protein designed to block TL1A, IL-23 and integrin a4ß7 — proteins that play vital, but separate roles in inflammatory bowel disease (IBD) pathophysiology. By inhibiting all three pathways simulatneously, and with preserved binding affinity and potency for each arm, the biotech thinks ATTO-1091 can improve upon existing induction and maintenance therapies for IBD. A Phase I trial is expected to kick off in the first half of 2027.Attovia has raised at least $255 million in private funding, including a $90-million series C last year. Cardiac attackBraveheart's run at the IPO window comes less than a year after it debuted with $185 million in series A funding. With its IPO cash, the biotech plans to launch a pair of Phase III trials evaluating its sole programme, BHB-1893, in both obstructive and non-obstructive hypertrophic cardiomyopathy (HCM). The biotech in-licensed ex-China rights to the oral cardiac myosin inhibitor in a deal last year with Jiangsu Hengrui Pharmaceuticals worth up to $1.1 billionThe partners recently presented findings from a Phase II study, run by Hengrui, involving 84 patients with symptomatic non-obstructive HCM. Patients treated with BHB-1893 achieved a placebo-adjusted 5.5-point gain on the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS), while 52% saw at least a 20-point improvement, compared to 21% for placebo. Exercise capacity improved as well, with patients titrated to 60 mg twice daily posting a placebo-adjusted gain of 0.9 mL/kg/min in peak oxygen consumption (pVO2). The small molecule has also posted positive findings in a Phase II trial for obstructive HCM.If approved for obstructive HCM, BHB-1893 will compete with rival cardiac myosin inhibitors Camzyos (mavacamten) from Bristol Myers Squibb. and Cytokinetics' Myqorzo (aficamten). Neither drug is approved for non-obstructive HCM, but recent data from Cytokinetics' ACACIA-HCM study suggest Myqorzo could become the first cardiac myosin inhibitor to reach that patient population (see – Spotlight On: Cytokinetics could double Myqorzo's reach with non-obstructive HCM win).Braveheart plans to launch the LIONHEART-HCM study evaluating BHB-1893 for obstructive HCM in the second half of 2026 and the non-obstructive HCM trial NOBLEHEART-HCM in the first half of 2027. Separately, Hengrui expects data from a Chinese Phase II trial of BHB-1893 in heart failure with preserved ejection fraction in the second half of 2027.