On December 13, 2021 Viracta Therapeutics, Inc. (Nasdaq: VIRX), a precision oncology company targeting virus-associated malignancies, reported that final data from its Phase 1b/2 trial of Nana-val in relapsed/refractory (R/R) EBV+ lymphoma (VT3996-201) were presented in an oral presentation at the 2021 American Society of Hematology (ASH) (Free ASH Whitepaper) Annual Meeting by Bradley Haverkos, M.D., Associate Professor at the University of Colorado School of Medicine (Press release, Viracta Therapeutics, DEC 13, 2021, View Source [SID1234596948]). Nana-val was well tolerated and continues to demonstrate promising activity with complete responses observed across multiple EBV+ lymphoma subtypes and a median duration of response of 10.4 months.

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Key data and conclusions from the ASH (Free ASH Whitepaper) presentation:

As of the October 28, 2021, data cutoff, 55 patients were enrolled. Patients had a median age of 60 (range 19-84) and had a median of two prior therapies. 75% (41/55) were refractory to their last therapy, and 96% (53/55) had exhausted all standard therapies (per Investigator).

Nana-val was generally well tolerated with reversible low-grade toxicities. The most commonly observed treatment emergent adverse events were reversible cytopenias, low grade creatinine elevations, and gastrointestinal symptoms.

Efficacy in evaluable patient (n=43):

Across all lymphoma subtypes: ORR = 40% (17/43); CR = 19% (8/43); Clinical Benefit Rate (CBR) [(CR+ partial response (PR) + stable disease (SD) ≥6 months] = 56% (24/43)
T/NK-NHL: ORR = 60% (9/15); CR = 27% (4/15); CBR = 67% (10/15)
Extranodal NK/T-Cell Lymphoma (ENKTL): ORR = 63% (5/8); CR = 13% (1/8); CBR = 63% (5/8)
Peripheral T-cell lymphoma (PTCL)/ Angioimmunoblastic T-cell lymphoma (AITL): ORR = 67% (4/6); CR = 50% (3/6); CBR = 83% (5/6)
DLBCL: ORR = 67% (4/6); CR = 33% (2/6); CBR = 83% (5/6)
Both DLBCL complete responses were in patients refractory to first line R-CHOP
IA-LPD: ORR = 50% (3/6); CR = 33% (2/6); CBR = 50% (3/6)
Durable responses:

Median DoR was 10.4 months
Three patients achieved responses with durations >2 years
"EBV is easily detectable and can be associated with a number of lymphoma subtypes, having a negative impact on clinical outcomes such as survival," said Dr. Haverkos, lead investigator of the VT3996-201 study. "The clinical safety and efficacy profile demonstrated thus far in this refractory patient population is very encouraging and underscores the utility of this unique EBV-targeted approach."

"Clinicians and key opinion leaders have shown a high level of enthusiasm for our potentially registration-enabling NAVAL-1 study, which we believe underscores the strength of the clinical dataset supporting the trial and the urgency of the unmet need in EBV-associated cancers. We expect this enthusiasm to be further bolstered following this oral presentation at ASH (Free ASH Whitepaper), which has provided us with the opportunity to broadly discuss the final Phase 1b/2 results with the clinical community," said Ivor Royston, M.D., President and Chief Executive Officer of Viracta. "We are encouraged by the final Phase 1b/2 data, as the response rates and median durations observed in the B- and T-cell lymphoma subtypes compare favorably to those seen in other single arm R/R lymphoma studies that have led to accelerated approvals and demonstrate Nana-val’s potential to provide meaningful clinical benefit to patients who currently lack effective treatment options. We look forward to the continued evaluation of this promising combination therapy in NAVAL-1 and anticipate providing further clinical program updates in 2022."

A copy of the ASH (Free ASH Whitepaper) presentation will be available by visiting the Events and Webcasts page of the Viracta website following the conference’s conclusion.

About Nana-Val (Nanatinostat and Valganciclovir)

Nanatinostat (VRx-3996) is an orally available histone deacetylase (HDAC) inhibitor being developed by Viracta. Nanatinostat is selective for specific isoforms of Class I HDACs, which is key to inducing viral genes that are epigenetically silenced in EBV-associated malignancies. Nanatinostat is currently being investigated in combination with the antiviral agent valganciclovir as an all-oral combination therapy, Nana-Val, in various subtypes of EBV-associated malignancies. Ongoing trials include a registration-enabling global, multicenter, open-label Phase 2 basket trial in multiple subtypes of relapsed/refractory EBV+ lymphoma (NAVAL-1) as well as a multinational Phase 1b/2 trial in patients with EBV+ recurrent or metastatic nasopharyngeal carcinoma and other EBV+ solid tumors.

About EBV-Associated Cancers

Approximately 95% of the world’s adult population is infected with Epstein-Barr virus (EBV). Infections are commonly asymptomatic or associated with mononucleosis. Following infection, the virus remains latent in a small subset of lymphatic cells for the duration of the patient’s life. Cells containing latent virus are increasingly susceptible to malignant transformation. Patients who are immunocompromised are at an increased risk of developing EBV+ lymphomas. EBV is estimated to be associated with approximately 2% of the global cancer burden and is also associated with a variety of solid tumors, including nasopharyngeal carcinoma and gastric cancer.