Viracta Therapeutics (VIRX) Study Update summary

Unmet need and disease context

• EBV-positive PTCL is an aggressive lymphoma subtype with poor prognosis, limited treatment options, and high unmet medical need, especially after first-line therapy failure.

• EBV infection drives resistance mechanisms, worsening outcomes and increasing immune complications.

• Current therapies yield low response rates and short progression-free survival, with no standard of care for relapsed/refractory PTCL.

• Most patients do not achieve durable remission and often die from disease progression within months.

• EBV is linked to about 2% of the global cancer burden, including lymphomas and nasopharyngeal carcinoma.

Nana-val mechanism and study design

• Nana-val is an all-oral, first-in-class combination of nanatinostat and valganciclovir, targeting EBV-positive cancer cells via a 'kick and kill' mechanism.

• The NAVAL-1 trial is a pivotal, multinational, adaptive, phase 2, open-label, single-arm basket study in relapsed/refractory EBV-positive lymphomas, focusing on PTCL.

• The trial uses a Simon two-stage design, advancing cohorts based on objective response rates (ORR).

• 21 patients with relapsed/refractory EBV+ PTCL were enrolled in the Nana-val arm across Stages 1 and 2; median age was 69, and most had advanced disease.

• Expansion phase of NAVAL-1 will focus on second-line EBV+ PTCL patients, with additional data expected in Q4 2024.

Efficacy results and clinical impact

• In relapsed/refractory EBV+ PTCL, Nana-val showed ORRs of 33%-41% and CRRs of 19%-24% in the intent-to-treat and efficacy-evaluable populations.

• In second-line patients, ORR was 60%-67% and CRR up to 33%, with clinical benefit rates up to 59%.

• Median duration of response has not been reached, with several patients maintaining response beyond 540 days and some proceeding to stem cell transplant without relapse.

• Nana-val compares favorably to other approved R/R PTCL therapies, showing higher ORR and CRR, and oral administration.

• Expansion phase data for the R/R EBV+ PTCL cohort may be shared in future updates.