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When we founded Vincera Pharma, our vision was to bring together a team with real expertise in targeted oncology to advance potentially paradigm-shifting therapeutics with a strategic focus on opportunities with accelerated approval potential. In October, we were thrilled to announce a licensing agreement with Bayer which delivered a compelling oncology portfolio to Vincera Pharma, which in combination with our experienced leadership team and comprehensive business strategy, lays a strong foundation for both our immediate clinical progress and long-term potential.
As Andrew mentioned, our pipeline includes a selective, clinical-stage PTEFb/CDK9 inhibitor, as well as a preclinical bioconjugation platform that we believe has the potential to overcome the limitations of both small molecule and antibody drug conjugates.
So now let’s dive into our pipeline.
Starting first with our PTEFb/CDK9 program, Vincera Pharma’s immediate clinical opportunity. PTEFb, or positive transcription elongation factor beta, is a protein complex which includes cyclin dependent kinase 9, or CDK9, an important regulator of transcription. Importantly, PTEFb is a key target in oncology, with inhibition leading to the rapid depletion of short-lived mRNA transcripts of known oncogenes, including MCL1 and MYC.
CDK9 is an exciting and clinically validated target, with a number of trials evaluating CDK9 inhibitors, typically in the hematologic malignancy setting. However, we believe these programs had limited success stemming from a lack of specificity for CDK9, either acting as pan-CDK inhibitors or hitting multiple CDKs. And that is where our lead asset, VIP152, is highly differentiated. VIP152 is the most selective CDK9 inhibitor in the clinic, providing highly selective, and ATP independent inhibition of CDK9. In preclinical studies, we also see on-target activity with VIP152, inhibiting the transcription of key targets MYC and MCL1, which translate to reductions in MYC protein levels and induction of apoptosis.
In addition to being a highly specific and differentiated CDK9 inhibitor, VIP152 has shown encouraging signals of clinical activity in prior studies. In a Phase 1 dose-escalation, single-agent setting, we were most excited to see early signs of efficacy in DH-DLBCL, an extremely challenging and aggressive disease with activation of MYC and BCL2 or BCL6 genes. Specifically, a DH-DLBCL patient achieved a PET negative CR, which then led to an expansion cohort in DH-DLBCL for a total of 7 evaluable patients across the cohorts. In total there were two observed complete responses, or a 29% CR rate in these DH-DLBCL patients, which excitingly, have also been durable, with each patient continuing on treatment for over 2 and 3 years, respectively. These data are noteworthy, and we believe the observed response rate, durability of response, and manageable safety profile, even on long term treatment, speaks to the potential of this asset.
In addition to these results, we were also encouraged to see disease control in patients with heavily pretreated solid tumors, including one patient with pancreatic cancer and one patient with salivary gland cancer.
Taken together, these results suggest there is a significant opportunity for VIP152 across a broad range of aggressive, resistant cancers that overexpress MYC and MCL1 in hematological malignancies such as B-cell lymphoma, leukemias and myeloma, as well as solid tumors including ovarian, triple negative breast, and prostate cancers.