prodchem
Aug 21, 2026
The legacy of XinThera is increasingly visible in a new generation of immunology-focused biotechnology companies. Although the San Diego-based drug discovery company was acquired by Gilead Sciences in 2023, members of its scientific and executive team have continued to build new ventures around small-molecule drug discovery.
One of the clearest examples is Khartis Therapeutics, founded in 2024 by Robert Hoffman, Craig Murphy and Chris LeMasters. The company recently emerged from stealth with $95 million in total financing, including a $50 million Series B, to advance an oral small-molecule pipeline targeting immunological and chronic diseases.
The development highlights a broader feature of biotech innovation: successful drug-discovery teams can carry scientific expertise, development experience and investor relationships from one company into the next, creating a repeatable ecosystem for new therapeutic ventures.
XinThera was founded in 2021 by Stephen Kaldor, Qing Dong and Gene Hung, with Foresite Capital as its founding investor. The company focused on small-molecule programs involving targets such as PARP1 and MK2, spanning oncology and immunology.
The company's development strategy was built around experienced medicinal chemistry and translational biology capabilities. That combination is particularly valuable in small-molecule discovery, where identifying a biologically relevant target is only the beginning. Drug developers must also establish selectivity, pharmacokinetics, safety margins and a practical path toward clinical development.
XinThera was acquired by Gilead Sciences in 2023, providing an important validation point for the team's scientific and company-building capabilities.
The most direct continuation of the XinThera network can be seen at Khartis Therapeutics.
Robert Hoffman previously served as XinThera's vice president of chemistry after spending more than three decades at Pfizer. Craig Murphy previously led immunology at XinThera, while Chris LeMasters became its chief executive and later joined Khartis as executive chairman.
Khartis is therefore not simply another newly formed biotech. Its foundation includes a team that has already worked together on drug discovery and company development.
That experience can reduce some of the risks associated with early biotech formation. Instead of assembling a management team, scientific organization and development strategy independently, experienced founders can begin with established working relationships and a shared understanding of how to move programs from discovery toward the clinic.
Khartis's lead program illustrates how the team's experience is being applied to a new therapeutic opportunity.
The company's lead candidate is described as an oral, selective inhibitor of insulin-like growth factor 1 receptor (IGF-1R) designed specifically for thyroid eye disease (TED). The program remains preclinical and is being advanced toward clinical development.
The strategy is notable because IGF-1R has already been clinically validated as a therapeutic target in TED. Existing treatment approaches include teprotumumab, an intravenously administered antibody. Khartis is attempting to develop an oral small-molecule alternative, potentially addressing administration convenience and other treatment considerations.
However, the commercial and clinical opportunity remains unproven. Khartis has not yet disclosed human clinical efficacy or safety data for its lead program. The key test will be whether selective oral IGF-1R inhibition can translate into meaningful clinical benefits while maintaining an acceptable safety profile.
Khartis is not the only example of former XinThera executives continuing to build immunology companies.
Qing Dong and Gene Hung, who co-founded XinThera, later founded RayThera in 2023. RayThera subsequently became part of Biogen in a transaction announced in 2026, further demonstrating how experienced biotech teams can repeatedly form companies around new therapeutic programs.
Foresite Capital has described this progression as a longer-running relationship with the team, beginning with FronThera, followed by XinThera and then RayThera. This illustrates how venture investors can remain involved across multiple generations of companies and founders.
The pattern is important because biotech ecosystems are not built only around individual assets. They are also built around people, institutional knowledge and repeatable drug-discovery capabilities.
The continuation of the XinThera network demonstrates why experienced scientific teams can attract significant venture backing even before a new company's lead drug enters clinical trials.
Khartis's $50 million Series B was led by Forge Life Science Partners, with Longwood Fund and Alexandria Venture Investments joining existing investors Foresite Capital, Lilly Asia Ventures and Nextech Invest. The financing brought the company's total capital raised to $95 million.
For investors, the team's previous experience provides an additional layer of confidence around execution. It does not eliminate scientific or clinical risk, but it can increase confidence that the company understands how to select programs, build research capabilities and manage development milestones.
This is particularly relevant in small-molecule drug development, where years of medicinal chemistry and optimization can determine whether an initially promising biological hypothesis becomes a viable medicine.
The XinThera alumni network also reflects a broader investment trend toward differentiated immunology programs.
Rather than relying exclusively on established biologic approaches, newer companies are increasingly exploring orally available small molecules against clinically validated or genetically supported targets.
For Khartis, the opportunity is to combine an established biological target with a different drug modality. The company is pursuing IGF-1R selectively and orally while also maintaining a broader pipeline of small molecules against immunology pathways.
This approach could create multiple potential development opportunities if the underlying discovery platform proves capable of repeatedly generating differentiated compounds.
At the same time, investors will need evidence that the approach produces advantages beyond convenience. Selectivity, pharmacokinetics, tolerability, durability of response and clinical efficacy will ultimately determine whether these programs can compete with existing and emerging therapies.
The XinThera story illustrates a model that may become increasingly common in biotechnology: experienced teams repeatedly forming new companies around validated scientific expertise and emerging therapeutic opportunities.
The model can create a cycle:
Experienced scientific team → new therapeutic hypothesis → venture-backed biotech → clinical development → acquisition or exit → new company formation
Such cycles can accelerate knowledge transfer across companies. Scientists and executives carry lessons from previous programs into subsequent ventures, while investors can use their understanding of the team to evaluate new opportunities more efficiently.
For the broader biotech ecosystem, this can contribute to regional clusters of specialized expertise, particularly in areas such as medicinal chemistry, immunology, translational biology and drug development.
The next phase for Khartis and other XinThera-linked ventures will be measured less by their founders' previous achievements and more by clinical execution.
Key milestones include:
Advancement of Khartis's IGF-1R program toward human trials.
Disclosure of preclinical efficacy, selectivity and safety data.
Regulatory progress and clinical-trial initiation.
Evidence that oral IGF-1R inhibition can differentiate itself from existing therapies.
Progress of additional small-molecule immunology programs.
Further acquisitions, partnerships or financing involving companies founded by former XinThera personnel.
These milestones will determine whether the XinThera legacy represents simply a successful group of repeat entrepreneurs or the foundation of a durable drug-discovery ecosystem.
XinThera's acquisition by Gilead Sciences did not end the story of the team behind the company. Instead, its former executives and scientists have continued to establish new ventures focused on small-molecule drug discovery and immunology.
Khartis Therapeutics is the latest prominent example, combining former XinThera leadership with a new oral IGF-1R strategy for thyroid eye disease and a broader immunology pipeline.
The broader lesson is that biotech value can extend beyond individual drug candidates. Scientific expertise, founder networks, medicinal chemistry capabilities and investor relationships can become reusable assets that support multiple generations of companies.
As Khartis and other XinThera-linked ventures advance, their clinical outcomes will show whether this accumulated experience can continue translating into differentiated medicines and successful new biotechnology businesses.
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