# CytomX Therapeutics CytomX Therapeutics is an Asset Manager based in South San Francisco, United States. ## Overview - **Organization type:** Asset Manager - **Headquarters:** South San Francisco, United States - **Region:** North America - **Address:** South San Francisco, CA, United States - **Founded:** 2010 - **Assets under management:** Undisclosed - **Website:** cytomx.com ## Regulatory record - **Reports private funds:** No ## About CytomX Therapeutics launched in 2010, founded by Nancy Stagliano and Henry Lowman with scientific roots in the laboratory of Patrick Daugherty at UC Santa Barbara. The firm's core technology — Probody® — uses peptides to mask antibody binding sites, activating only in the tumor microenvironment. This approach targeted a central oncology problem: on-target, off-tumor toxicity that constrains dosing for otherwise potent antibodies. Sean McCarthy, a veteran of Millennium Pharmaceuticals, was brought in as CEO early to translate the academic work into a drug pipeline. The firm's strategy channels capital into proprietary masked immunotherapies, spanning immuno-oncology, antibody-drug conjugates, and T-cell engagers. Its lead asset, CX-2009, a CD166-directed ADC, showed monotherapy responses in hormone receptor-positive breast cancer during Phase I, leading to a partnership with AbbVie on CD71-targeted conjugates. A marquee collaboration with Bristol Myers Squibb, signed in 2014 and significantly expanded in 2017, focused on CTLA-4-targeted probody ipilimumab (BMS-986249) — demonstrating preclinical tumor-selective activation. Additional partnerships materialized with Amgen on a CytomX-derived bispecific T-cell engager and with Astellas on T-cell engaging bispecifics, deploying the Probody platform across North America and Asia-Pacific territories. CytomX filed its IPO in 2015 on NASDAQ under ticker CTMX, raising $80M after a decade of private financing totaling over $400M from backers including Canaan Partners, Venrock, and Fidelity. In May 2024, the firm announced a corporate restructuring that reduced its workforce by approximately 40% and narrowed its pipeline focus entirely to its clinical-stage assets — most notably CX-2051, an EpCAM-directed ADC in Phase I for advanced solid tumors, and CX-904, a conditionally activated EGFRxCD3 bispecific partnered with Amgen. The company also terminated its internal CX-2028 program and eliminated discovery research to extend cash runway into late 2026. The firm's structural differentiator is its clinical-stage masking technology, which attempts to convert systemic immunotherapy into a localized event. Unlike conventional oncology platforms that rely on tumor-specific antigens, CytomX's approach harnesses dysregulated protease activity in the tumor microenvironment to unmask antibody function. This architecture allows the company to target validated, broadly expressed antigens — such as EpCAM or CD71 — that are otherwise pharmacologically inaccessible due to normal-tissue toxicity, creating a pipeline built on validated biology rather than novel targets. ## Sectors - Biotechnology - Oncology ## People - Sean McCarthy — Chief Executive Officer ## Questions ### Which pharmaceutical partners has CytomX worked with? CytomX has entered partnerships with Bristol Myers Squibb on a Probody version of ipilimumab (BMS-986249), with AbbVie on CD71-directed antibody-drug conjugates, with Amgen on CX-904 and a broader bispecific collaboration, and with Astellas on T-cell engaging bispecifics. The BMS collaboration was initially signed in 2014 and expanded in 2017 with $200 million in upfront payments. ### Is CytomX structured as an investment fund or an operating company? CytomX Therapeutics is a publicly traded operating company listed on NASDAQ under ticker CTMX. It develops drug candidates internally and through pharma partnerships. Though the name was input with a family-office classification, CytomX is a clinical-stage biotechnology company that raised venture capital from 2010 to 2015 before its IPO. ### How does CytomX source capital for its operations? Since its 2015 IPO, CytomX has funded operations through a combination of equity financings, partnership upfront payments, milestone payments, and royalties. Pre-IPO investors include Canaan Partners, Venrock, and Fidelity. The company has not disclosed private-market fundraising since becoming a public entity, relying instead on partnership economics and occasional public offerings. ## Related profiles - [Netlist](https://altss.com/profile/netlist-inc) - [BlackRock MuniYield Quality Fund](https://altss.com/profile/blackrock-muniyield-quality-fund-inc) --- Last updated: 2026-06-03T20:00:00.000Z Canonical page: https://altss.com/profile/cytomx-therapeutics-inc Maintained by Altss — https://altss.com — methodology: https://altss.com/methodology