Electra Therapeutics, Inc.

Listed Primary

Proposed symbol ETRA on Nasdaq Global Select Market · First filed Aug 28, 2026 · CIK 2088082

Effective prospectus: 424B4 Sep 18, 2026 (0001193125-26-395670) · terms available

“We are offering 23,333,334 shares of our common stock. This is our initial public offering, and prior to this offering, there has been no public market for our common stock.”

Now trading as ETRA →

Offer price

$15

Shares offered

23,333,334

Revenue (FY —)

Not available

Net income (FY —)

Not available

What the company does

Electra Therapeutics, Inc. is a late clinical-stage biopharmaceutical company focused on pioneering a new class of precision medicines for the treatment of immune-mediated diseases and cancer. Its novel approach targets signal regulatory proteins (SIRP), a family of cell surface receptors whose expression is restricted to specific immune cell populations, enabling selective depletion of disease-driving cells while preserving normal immune function. The company's lead product candidate is ipsoprubart, a novel pan-SIRP monoclonal antibody currently in a global registrational program for patients with secondary hemophagocytic lymphohistiocytosis (sHLH), and it is also advancing ELA822, a SIRPg-specific monoclonal antibody for chronic T cell-mediated immune and inflammatory diseases.

Use of proceeds

We estimate that the net proceeds to us from the sale of our common stock in this offering will be approximately $319.9 million (or approximately $368.7 million if the underwriters exercise their option to purchase additional shares in full), based on the initial public offering price of $15.00 per share. We currently intend to use the net proceeds, together with our existing cash, cash equivalents and marketable securities, to advance the development of ipsoprubart in sHLH through the ongoing Phase 2/3 global registrational trial topline results and to support BLA submission and commercial readiness activities, to advance the development of ipsoprubart in T/NK cell malignancies through the ongoing Phase 1 clinical trial, to advance the development of ELA822 through the ongoing Phase 1 clinical trial in healthy volunteers and initiation of a planned Phase 1/2 clinical trial in patients with T cell-mediated immune disorders, and for other research and development activities, as well as for capital expenditures, working capital and other general corporate purposes.

Underwriters

Jefferies TD Cowen Evercore ISI Cantor

Extracted from 424B4 0001193125-26-395670, filed Sep 18, 2026 and verified against that filing text.

Key risk factors

Significant operating losses and no revenue

“We have incurred significant operating losses since our inception and have not generated any revenue.”

Financials before the first trade

The completed SEC companyfacts import produced no qualifying full-year financial history for this filer.

Filing history

Filed	Form	Accession
2026-09-18	424B4	0001193125-26-395670	View on EDGAR
2026-09-14	S-1/A	0001193125-26-389755	View on EDGAR
2026-08-28	S-1	0001193125-26-374259	View on EDGAR

Source quotes

Offer price: “The initial public offering price is $15.00 per share of our common stock.”

Shares offered: “23,333,334 Shares Electra Therapeutics, Inc. Common stock We are offering 23,333,334 shares of our common stock.”