How Legend Biotech Secured FDA Approval for CAR-T Therapy: A China Biotech Case Study

This case study examines how Legend Biotech (传奇生物, Legend Biotech, chuánqí shēngwù) became the first Chinese biotech to secure FDA approval for a CAR-T therapy on February 28, 2022, achieving a landmark milestone in a 7-year journey from its founding in 2014 to regulatory success. The approval of Carvykti (ciltacabtagene autoleucel) for relapsed/refractory multiple myeloma represented a breakthrough valued at over $465,000 per treatment course. For foreign executives evaluating China’s biotech ecosystem, this case demonstrates how Chinese R&D capabilities, strategic partnerships, and global regulatory navigation can produce world-class therapies.

Legend Biotech’s journey is defined by key numbers: 98% overall response rate in its pivotal CARTITUDE-1 trial, $350 million upfront from Janssen (Johnson & Johnson) in December 2017, and a 2-year FDA review window from BLA submission in December 2020 to final approval. The company was spun out from Genscript Biotech (金斯瑞生物科技, Jīn Sī Ruì Shēng Wù Kē Jì), a Nanjing-based contract research organization, and has since become a bellwether for China-originated cell and gene therapies entering Western markets.

1. The Strategic Partnership That Made FDA Approval Possible

Legend Biotech’s partnership with Janssen was not a simple licensing deal—it was a co-development and co-commercialization agreement structured to bridge regulatory and market gaps between China and the United States. Under the terms announced in December 2017, Legend received $350 million upfront, with Janssen retaining 50% of development costs and profits in the US and Europe, while Legend held 70% in China and 50% in the rest of world.

This structure allowed Legend to leverage Janssen’s deep FDA regulatory experience, clinical trial infrastructure across multiple continents, and commercial muscle in oncology. For foreign executives, the lesson is clear: a well-structured partnership can multiply a Chinese biotech’s chances of global approval by providing regulatory expertise that would otherwise take years to build internally. The deal also included milestone payments totaling up to $1.1 billion, contingent on clinical and regulatory achievements, which aligned both parties’ incentives over the long term.

Legend’s choice of partner was critical. Janssen had a strong hematology franchise with Darzalex (daratumumab), a blockbuster multiple myeloma drug, giving the partnership synergies in physician networks, patient access programs, and real-world data generation. Legend retained control of manufacturing in China through a dedicated facility in Nanjing, while Janssen invested in US and European manufacturing capacity at a cost estimated at $200 million+. This dual-manufacturing strategy mitigated supply chain risk and ensured redundancy for a therapy that requires vein-to-vein logistics within days.

2. Navigating the Clinical Trial and Regulatory Pathway

Legend Biotech’s regulatory strategy was built around the CARTITUDE-1 trial, a single-arm, open-label Phase 1b/2 study enrolling 97 patients with relapsed/refractory multiple myeloma who had received at least three prior lines of therapy. The trial’s primary endpoint was overall response rate (ORR), which reached 98%, with 83% achieving a stringent complete response (sCR). Median progression-free survival was not reached at the time of approval, with follow-up extending beyond 12 months for most patients.

These results compared favorably to existing CAR-T therapies like Bristol Myers Squibb’s Breyanzi (lisocabtagene maraleucel) and Johnson & Johnson’s own Tecartus (brexucabtagene autoleucel), which had ORRs in the 60-70% range for similar populations. Legend’s decision to focus on a single-arm design, rather than a randomized trial, was a calculated risk that paid off due to the strength of the efficacy signal. The FDA accepted this design because the patient population had exhausted all standard-of-care options, making a placebo-controlled trial unethical.

One critical regulatory challenge Legend faced was the FDA’s requirement for US-based manufacturing data. The agency requiredLegend to demonstrate that Carvykti manufactured at Janssen’s Raritan, New Jersey facility met the same specifications as the product made in Nanjing. This required extensive comparability studies, analytical data bridging, and process validation, adding 6-9 months to the regulatory timeline. Legend successfully navigated this by conducting head-to-head comparability testing and submitting a comprehensive Chemistry, Manufacturing, and Controls (CMC) package that satisfied FDA reviewers.

The company also invested in a dedicated regulatory affairs team in the US, hiring former FDA reviewers and experienced biotech regulatory professionals. This team managed the rolling BLA submission process, where Legend submitted data modules as they became available, rather than waiting for the complete package. This approach compressed the review timeline from the FDA’s standard 10-12 months for priority review to approximately 14 months total—a rapid timeframe for a first-in-class therapy from a company with no prior US approvals.

3. Key Outcomes and Market Impact

Carvykti’s approval generated immediate market impact across multiple dimensions. First, Legend Biotech’s valuation surged: its Nasdaq-listed shares (LEGN) rose over 200% in the week following FDA approval, reaching a market capitalization of approximately $12 billion. Second, the approval validated China’s cell therapy ecosystem, prompting increased inbound investment from global pharma into Chinese biotech platforms. Total venture capital flowing into China’s CAR-T sector reached $1.8 billion in 2022, up 45% from the previous year.