Benzinga | Sep 9, 2020 07:37AM EDT

Scholar Rock Announces First Patient Dosed In Part A2 Of DRAGON Phase 1 Proof-Of-Concept Trial Of SRK-181 To Overcome Primary Resistance To Anti-PD-(L)1 Therapy

- Patients with locally advanced or metastatic solid tumors are being enrolled and dosed with SRK-181 in combination with anti-PD-(L)1 therapy in Part A2 of the DRAGON Phase 1 clinical trial

- An update on Part A dose escalation is expected in the fourth quarter of 2020; Part B efficacy and safety data from the trial anticipated starting in 2021

Scholar Rock (NASDAQ:SRRK), a clinical-stage biopharmaceutical company focused on the treatment of serious diseases in which protein growth factors play a fundamental role, today announced that the first patient has been dosed with SRK-181 in combination with anti-PD-(L)1 therapy in Part A2 of the DRAGON Phase 1 proof-of-concept trial. Part A1 of the DRAGON trial has successfully progressed dose escalation of SRK-181 monotherapy through 800 mg and continues to advance dose escalation. Part A1 and Part A2 are being conducted in a parallel but staggered fashion and will each evaluate doses up to 2400 mg. SRK-181 is a potent and highly selective inhibitor of latent TGF?1 activation and is being developed to increase responses to immunotherapy by overcoming primary resistance to anti-PD-1 or anti-PD-L1 antibody therapy.

"We are encouraged by the dose escalation progress-to-date in Part A1 of the DRAGON trial, which has enabled us to begin the evaluation of SRK-181 in combination with anti-PD-(L)1 therapy," said Yung Chyung, M.D., Chief Medical Officer of Scholar Rock. "While checkpoint inhibitor therapies have become standard of care for a large number of cancer patients, there is still significant unmet need as many patients demonstrate resistance to this therapeutic class. It is our belief that SRK-181 could help overcome this immune exclusion and has the potential to increase the therapeutic benefit of this class of drugs."

The DRAGON Phase 1 open-label, dose escalation and dose expansion clinical trial consists of two parts to evaluate the efficacy, safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of SRK-181 in adult patients with locally advanced or metastatic solid tumors enrolled across multiple sites in the U.S. The Part A dose escalation portion of the trial is evaluating SRK-181 as both a single agent (Part A1) and in combination with approved anti-PD-(L)1 therapy (Part A2). The Part B dose expansion portion of the trial is expected to initiate in the first quarter of 2021 and will evaluate SRK-181 in combination with approved anti-PD-(L)1 therapy in multiple tumor-specific cohorts, including urothelial carcinoma, cutaneous melanoma, non-small cell lung cancer, and other solid tumors. As is the case in Part A2, Part B of the trial will enroll patients with locally advanced or metastatic solid tumors who had a lack of response to anti-PD-(L)1 therapy. These patients will be treated with SRK-181 in combination with anti-PD-(L)1 therapy to evaluate if they are able to achieve an anti-tumor response. Intravenous (IV) SRK-181 is administered every 3 weeks (Q3W) and additional dosing regimens may be explored. An update on Part A dose escalation is expected in the fourth quarter of 2020 and efficacy and safety data from Part B of the trial is anticipated starting in 2021.