TScan Therapeutics (TCRX) TD Cowen 45th Annual Healthcare Conference summary

Key program updates and clinical progress

• Two main clinical programs: heme malignancies (post-allogeneic transplant) and solid tumors, both advancing with internal TCR discovery and manufacturing.

• Phase I ALLOHA study in heme malignancies showed promising results, with a pivotal trial launching in H2 2024 and top-line data expected H2 2027.

• Solid tumor program focuses on multiplex TCR therapy to address tumor heterogeneity, with seven TCRs in a single trial and first multiplex dosing targeted for H1 2024.

• Multiple clinical catalysts in 2024: pivotal trial initiation, long-term heme data, and solid tumor safety/efficacy updates, including multiplex therapy.

• $290 million in cash provides runway into Q1 2027.

Heme malignancies program details

• Addressable market estimated at over $1 billion in US and Europe, with 1,000–5,000 eligible patients annually depending on clinical practice changes.

• Phase I data: 26 treated vs. 13 control, high-risk patients, with significant reduction in relapse and improved donor chimerism and MRD negativity.

• Safety profile favorable; minimal product-related adverse events, no ICANS, and only two mild CRS cases.

• Pivotal trial will use TSC-101 only, leveraging an external control arm from the CIBMTR database, with relapse-free survival as the primary endpoint.

• Targeting a 50% reduction in two-year relapse rates, aiming for transformative impact in transplant therapy.

Solid tumor program strategy and milestones

• Multiplex TCR approach customizes therapy based on tumor antigen profile, aiming for deeper and more durable responses.

• Enhanced TCR-T cells include CD8 co-receptor and dominant negative TGF-beta receptor to overcome tumor microenvironment suppression.

• Seven TCRs cleared INDs; dose escalation ongoing, with multiplex (T-Plex) therapy to be tested at higher dose levels.

• Focused on HPV-positive (head and neck, cervical, anal, genital) and HPV-negative (lung, sarcoma, head and neck) cancers in second/third-line settings.

• By year-end, goal is to treat ~12 patients with multiplex therapy and provide comparative data on single-plex vs. multiplex efficacy.