Pliant Therapeutics (PLRX) Piper Sandler 37th Annual Healthcare Conference summary

Key clinical results and insights

• Phase 1 study of PLN-101095, an oral dual integrin inhibitor, showed durable responses with a median of 15 months on treatment and four responders (one complete, three partial) in a heavily pretreated, ICI secondary refractory solid tumor population.

• Interferon gamma (IFN-γ) signal distinguished responders from non-responders and was statistically significant after 14 days of monotherapy, suggesting its potential as an early biomarker.

• Safety profile was favorable, with rash as the most common mild or moderate adverse event and only one discontinuation; dose-dependent pharmacokinetics observed.

• 60% of ICI secondary refractory participants experienced disease stabilization or tumor reduction, with a median treatment duration of 10 months.

• Compared to interim data, there is now one additional responder and a previous partial responder converted to a complete responder; new biomarker data, including IFN-γ, were disclosed.

Program advancement and next steps

• The program will advance to Phase 1b, focusing on specific tumor types, starting with non-small cell lung carcinoma (NSCLC) and potentially others, with expansion cohorts planned for 2026.

• The 1,000 mg BID dose will be evaluated, with monotherapy arms retained to further explore biomarker effects.

• Cohort size for Phase 1b is expected to be manageable and easily executed.

• Data from the next phase are anticipated in 2027, depending on cohort size and study design.

• Patient mix will be informed by ongoing data analysis to optimize for responders.

Mechanism and platform potential

• PLN-101095 selectively blocks αvβ8 and αvβ1 integrin-mediated TGF-β activation, modulating the tumor microenvironment and enhancing T cell IFN-γ effector function.

• The mechanism shifts tumors to a high IFN-γ, ICI-responsive state, resensitizing them to anti-PD-(L)1 therapies.

• Integrins are validated targets for both modulation and cell-selective drug delivery, with a 15,000+ compound library supporting broad platform applications.

• The platform includes emerging cell-specific delivery for siRNA payloads, with broad disease applicability.

• Additional early-stage programs, including targeted siRNA delivery to muscle and adipocytes, are expected to be disclosed in 2026.