Exelixis, a California-based oncology company, will close its King of Prussia, Pennsylvania facility and lay off 130 employees, the company confirmed this week. The move eliminates the firm's entire presence in the Philadelphia region, less than three years after it first expanded eastward to tap into one of the country's richest biotech talent pools.
The layoffs represent an 11% workforce reduction for Exelixis, which reported 1,174 employees at the end of 2024. It is the company's second round of cuts in less than two years, following the elimination of 175 positions in January 2024.
Strategic Consolidation to California
"As our business has continued to evolve, we have made the difficult decision to reorganize the company's structure to focus largely on our operations in Alameda," the company said in a statement. Exelixis is looking at the possibility of relocating some of these terminated roles to its California office, with the spokesperson adding that focusing operations in Alameda "reflects our continued belief that working together as a single, cohesive team puts us in the best position" to maximize the potential of its assets.
When Exelixis arrived in King of Prussia in 2022, executives highlighted the region's robust biotech ecosystem, its proximity to major universities, and its pool of skilled researchers. The company initially leased 64,000 square feet of laboratory space, but in its 2024 annual filing, it disclosed plans to reduce that footprint by more than half. Now, the company is vacating the site entirely.
Pipeline Focus Amid Patent Pressures
The layoffs come at a critical time for Exelixis as it advances its investigational drug zanzalintinib, a tyrosine kinase inhibitor positioned as the successor to its cabozantinib brands. In June, the company reported positive results from its STELLAR-303 Phase III trial, showing that zanzalintinib when combined with Roche's PD-L1 inhibitor Tecentriq (atezolizumab) significantly improved overall survival in previously treated patients with microsatellite instability-high metastatic colorectal cancer.
The win was hailed as a potential lifeline for Exelixis, which faces looming patent expirations for its top-selling cancer drug Cabometyx (cabozantinib). Approved in 2012 and expanded to multiple cancer indications including hepatocellular carcinoma, neuroendocrine tumors and thyroid cancer, Cabometyx generated $1.81 billion of the company's $2.17 billion revenue in 2024. Analysts warn that revenue will come under pressure when generic competition arrives after 2030.
Beyond colorectal cancer, Exelixis is also testing zanzalintinib for non-clear cell renal cell carcinoma, with enrollment in a Phase III trial completed in May and early data expected in the first half of 2026. The drug is also being assessed for neuroendocrine tumors.
Industry-Wide Restructuring Trend
Like many in the industry, Exelixis aggressively expanded during the pandemic, hiring in-person and remote staff to meet research and commercial needs. A spokesperson confirmed that the company "hired a significant number of employees—including many in fully remote positions—during the pandemic and post-pandemic period" to help meet business needs.
The pandemic hiring boom has now given way to a wave of restructuring across biopharma, with companies that once pursued geographic diversification now centralizing operations to cut costs and streamline decision-making.
Regional Impact on Philadelphia Biotech
Exelixis' exit is another setback for the Philadelphia biotech corridor, which has been hit hard by job losses in 2025. Spark Therapeutics, Carisma Therapeutics, and Century Therapeutics are among the companies that have trimmed headcount this year, reflecting broader financial pressures across the sector.
The company's stock (NASDAQ:EXEL) jumped 12% in June after zanzalintinib's successful Phase III readout, demonstrating that investor sentiment often hinges more on clinical milestones than geographic footprint. However, the layoffs also signal the pressure Exelixis faces to extend its growth trajectory and avoid the fate of mid-cap biotechs that stumble post-patent cliff.
Analysts at Leerink Partners noted that the late-stage win for zanzalintinib could help Exelixis maintain its revenue stream beyond 2030, when cabozantinib loses key patent protections and becomes open to generic competition.
