Khartis Lands $50M Series B for Thyroid Eye Disease Drug

San Diego biotech Khartis Therapeutics raised a $50 million Series B led by backers including Forge Life Science Partners, Longwood Fund and Lilly Asia Ventures to fund development of its thyroid eye disease candidate.

Khartis Therapeutics, a privately held San Diego biotech, has closed a $50 million Series B financing to push forward a drug candidate for thyroid eye disease, or TED — an autoimmune condition in which inflammation and tissue expansion behind the eye push the eyeball forward, causing bulging, double vision, pain and, in severe cases, sight loss.

The round drew Forge Life Science Partners, Longwood Fund and Lilly Asia Ventures alongside other unnamed investors, according to Endpoints News, which reported the financing as part of a wider round-up that also flagged a royalty transaction at Zealand. The Series B lifted Khartis's cumulative funding since inception, though the company did not put a figure on the total.

Why a $50 million cheque for one eye indication

Thyroid eye disease is a small population by the standards of chronic disease, but it has become one of the more closely watched niches in immunology-adjacent drug development. The reason is straightforward: the condition was, until recently, managed largely with steroids, radiation and orbital decompression surgery — interventions that treat the consequences rather than the biology. The arrival of targeted therapy showed that patients and payers would pay for a drug that reduces proptosis, the forward displacement of the eye, and resolves double vision.

That commercial proof point is what a $50 million Series B is buying into. For a private biotech, a round of this size typically funds a clinical program through a meaningful readout rather than a full development cycle. Khartis has not disclosed the mechanism, the molecule format or the stage of its TED candidate in the material available, so the round should be read as an investor vote on the target and the team rather than on data already in hand.

The investor list carries information of its own. Longwood Fund is a specialist life-science firm with a history of company creation rather than late-stage crossover investing. Lilly Asia Ventures brings a strategic dimension — corporate-affiliated venture arms often signal where a large pharmaceutical organisation is watching, without committing it to anything. Forge Life Science Partners rounds out a syndicate built for a multi-year clinical slog rather than a quick flip.

What Khartis has to beat in the clinic

Any new entrant in thyroid eye disease is measured against a standard of care that already delivers visible, patient-reported improvement. The bar is not whether a candidate works, but whether it works with fewer trade-offs. Existing targeted treatment is delivered by intravenous infusion over a course of months, which means chair time, infusion-centre logistics and a reimbursement conversation for each patient. Tolerability has been the other pressure point, with hearing-related side effects a recognised concern in the class.

That leaves several routes to differentiation, and investors in TED assets are generally underwriting one of them:

Route of administration. A subcutaneous injection or an oral drug that matches infusion-level efficacy would change the treatment setting entirely.
Safety profile. Preserving efficacy while avoiding the tolerability issues associated with the current mechanism would open the door to earlier and broader use.
Disease stage. Most attention has gone to active, moderate-to-severe disease. Chronic or inactive TED, where fibrosis rather than inflammation drives symptoms, remains poorly served.
Duration of response. Relapse after treatment has been documented in the field; a durable answer would be commercially valuable.

Khartis has not stated which of these it is targeting. Until it does, the $50 million is best understood as capital to generate the evidence, not evidence itself.

Private money keeps flowing while public biotech grinds sideways

Until it does, the $50 million is best understood as capital to generate the evidence, not evidence itself.

The financing lands in a market where private capital has been noticeably more willing than public equity to underwrite single-asset clinical stories. Broad benchmarks were firm on the day the news circulated: as of the last trade at 16:32 GMT on 13 August 2026, the S&P 500 tracker SPY stood at $776.55, up 0.53%, with the Nasdaq 100 proxy QQQ at $732.03, up 1.15%, and the Dow tracker DIA at $536.65, down 0.09%. Broad-index strength led by large-cap technology, as the QQQ–DIA spread on the day suggests, has not historically translated into enthusiasm for pre-commercial biotech, which is one reason private syndicates rather than public markets have been funding rounds like this one.

The practical consequence for a company such as Khartis is that the exit route matters as much as the science. With a strategic venture arm in the syndicate and a target class that big pharmaceutical buyers already understand and have paid for, an acquisition or licensing deal at the point of proof-of-concept is at least as plausible an outcome as an initial public offering. Rare-disease and specialty-ophthalmology assets have been reliable acquisition targets precisely because the commercial model — a defined prescriber base, high per-patient revenue, no primary-care sales force — is easy for an acquirer to model.

The royalty half of the story

The same Endpoints round-up paired the Khartis financing with a royalty deal at Zealand. Terms were not disclosed in the material available here, so the specifics — counterparty, size, the asset whose future sales are being pledged — remain to be confirmed. The structural point is worth making anyway, because royalty monetisation and venture financing are two answers to the same question.

A royalty deal lets a company sell a slice of future product revenue for cash today without issuing equity or taking on conventional debt. For a mid-cap developer with an approved or near-approved product, it is often the cheapest capital available, measured in dilution avoided. For a preclinical or early-clinical company such as Khartis, that option does not exist — there is no revenue stream to sell — which is why the Series B route is the only one on the table. Seeing both instruments in the same news cycle is a fair snapshot of how sector financing has bifurcated: those with products sell royalties; those with programs sell shares.

What to watch from here

Three disclosures would turn this round from a funding headline into an investable thesis. First, the mechanism and format of the TED candidate, which determines whether it competes head-on with the incumbent target or opens a new one. Second, a stated clinical milestone the $50 million is meant to reach — first-in-human data, or a controlled proptosis endpoint. Third, any indication that Lilly Asia Ventures' participation comes with an option or a right of first negotiation, which would reframe the round as a partnership in waiting.

Until then, the verifiable facts are narrow but not trivial: $50 million, three named investors, one San Diego company, and an indication where the market has already demonstrated that patients will use a targeted drug and payers will cover it.

Key facts

Round size: $50 million Series B
Named investors: Forge Life Science Partners, Longwood Fund, Lilly Asia Ventures
Company and location: Khartis Therapeutics, San Diego (private, no ticker)
Market backdrop: SPY $776.55 (+0.53%), QQQ $732.03 (+1.15%) as of 16:32 GMT, 13 Aug 2026

Frequently asked questions

How much did Khartis Therapeutics raise?

Khartis Therapeutics raised a $50 million Series B. Named participants include Forge Life Science Partners, Longwood Fund and Lilly Asia Ventures, alongside other investors that were not identified. The company said the round increased its cumulative funding since inception, but did not disclose a total-funding figure.

What is thyroid eye disease?

Thyroid eye disease, often abbreviated TED, is an autoimmune condition usually associated with thyroid dysfunction. Inflammation and tissue expansion in the orbit push the eyeball forward, a symptom called proptosis, and can cause double vision, pain, eyelid retraction and in severe cases vision loss. It has historically been managed with steroids, radiation and surgery.

Is Khartis Therapeutics publicly traded?

No. Khartis Therapeutics is a private San Diego biotech and does not have a listed stock or exchange ticker. Investors gain exposure only through the venture syndicate, which in this round includes Forge Life Science Partners, Longwood Fund and Lilly Asia Ventures. Any public listing would require a future IPO.

What stage is the Khartis TED drug at?

The disclosed material does not specify the molecule, its mechanism or its clinical stage. A Series B of this size typically funds a program toward a defined clinical milestone rather than through full development, but without company disclosure the stage of the candidate cannot be stated as fact.

What was Zealand's royalty deal?

The Endpoints News round-up that reported the Khartis financing also referenced a royalty transaction involving Zealand. The terms, counterparty and underlying asset were not detailed in the available material. Royalty deals let companies sell a share of future product revenue for immediate cash without issuing new equity or taking conventional debt.

Why does Lilly Asia Ventures' participation matter?

Lilly Asia Ventures is a corporate-affiliated venture investor. Participation by such a firm is often read as a signal that a large pharmaceutical organisation is monitoring a therapeutic area, though it commits the parent company to nothing. It can also make a future licensing deal or acquisition a more visible path than an initial public offering.

Sources

Zealand's royalty deal; Khartis raises money for TED drug — Endpoints News

Photo: Pavel Danilyuk · Pexels Licence — source