TORL Targets Hot ADC Space with Oversubscribed $158M Series B-2

Antibody Drug Conjugate with Cytotoxic Payload

Pictured: Antibody-drug conjugate with cytotoxic payload/iStock, Love Employee

Los Angeles-based startup TORL BioTherapeutics on Wednesday closed a $158 million oversubscribed Series B-2 funding round, which will go toward the advancement of its pipeline of novel antibody-drug conjugates for oncology.

TORL’s Series B-2 financing was led by Deep Track Capital with new participation from RA Capital Management, Perceptive Advisors and Avidity Partners. Existing investors Bristol Myers Squibb, Goldman Sachs, Blue Owl Healthcare Opportunities and other big institutional backers also participated in the funding round.

“This investment significantly enhances our opportunity to deliver multiple data-driven milestones from our novel antibody-based discovery platform and clinical-stage oncology drug development pipeline,” Mark Alles, CEO of TORL, said in a statement. 

TORL will use the money to fund the Phase I and pivotal Phase II trials of its lead candidate TORL-1-23, a first- and potentially best-in-class antibody-drug conjugate (ADC) designed to target the claudin 6 (CLDN6) protein. TORL-1-23 is being trialed for CLDN6-positive, platinum-resistant ovarian cancer. The Phase II study is set to begin in the second half of this year.

In June 2023, the biotech posted initial Phase I data for TORL-1-23 showing that the ADC can elicit confirmed treatment responses in 28% of treated patients at all dose levels. Of all platinum-resistant ovarian cancer patients, 32% responded to TORL-1-23 treatment. The investigational therapy was also safe and showed no dose-limiting toxicities across all doses.

President and CFO Dave Licata in a statement on Wednesday said that the Series B-2 financing will not only support the development of TOR-1-23 but will also allow the company to “continue to advance our three other promising clinical stage programs and pipeline.”

The funds will support the Phase I study of TORL-2-307, a monoclonal antibody and ADC being tested for CLDN 18.2-positive solid tumors. The biotech will also use its windfall to advance two other investigational ADCs—TORL-3-600 for CDH17-positive colorectal cancer and TORL-4-500 for DLK1-positive solid tumors.

Wednesday’s haul brings TORL’s fundraising total to $350 million in what is arguably biopharma’s hottest sector. According to a March 2024 report from market intelligence firm Evaluate, the ADC market is expected to reach almost $30 billion by 2028.  

Seeking a slice of the ADC market, several companies have made recent investments in their ADC capacities and portfolios. In March 2023, Pfizer inked one of the industry’s largest acquisition contracts ever when it bought ADC company Seagen for $43 billion. In January 2024, J&J dropped $2 billion to buy Ambrx, while Roche invested $1 billion in a next-generation ADC partnership with China’s MediLink Therapeutics.

Tristan Manalac is an independent science writer based in Metro Manila, Philippines. Reach out to him on LinkedIn or email him at or

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