Mythic Therapeutics Shares Early Dose Escalation Data from Phase 1 KisMET-01 Study on MYTX-011 at ASCO Annual Meeting

Mythic Therapeutics, a biotechnology company in the clinical stages, has announced promising results from its Phase 1 KisMET-01 study. This study evaluates MYTX-011, an investigational antibody-drug conjugate (ADC) targeting cMET for patients with previously treated, locally advanced, or metastatic non-small cell lung cancer (NSCLC). The results were presented at the American Society of Clinical Oncology (ASCO) Annual Meeting.

According to Gilles Gallant, BPharm, Ph.D., FOPQ, the Chief Development Officer at Mythic Therapeutics, the initial dose escalation results, supported by preclinical data, highlight the potential of MYTX-011 to benefit patients with varying levels of cMET expression. Dr. Gallant emphasized the transformative nature of ADCs for cancer treatment and noted that the initial data shows promise for patients who previously had limited treatment options due to their level of target expression or tumor type. The company plans to continue with the dose escalation and expansion study.

MYTX-011 is described as a novel cMET-targeted DAR 2 vcMMAE ADC. It features an antibody engineered for pH-dependent binding, which improves internalization and payload delivery to tumor cells with different cMET expression levels.

The KisMET-01 study (NCT05652868) is a multicenter, first-in-human trial focusing on MYTX-011 for patients with previously treated, locally advanced, or metastatic NSCLC. The study consists of two parts: Part 1 involves dose escalation regardless of cMET expression levels, and Part 2 involves dose expansion in cohorts defined by cMET expression and histology. The primary goals of Part 1 include evaluating safety, tolerability, and determining the recommended Phase 2 dose. Secondary goals focus on pharmacokinetics (PK) and preliminary anti-tumor activity.

As of April 30, 2024, 42 patients had been enrolled and received at least one dose of MYTX-011. Data from 41 patients was available by the cutoff date, with a median follow-up of 15 weeks. Patients were administered doses ranging from 1.0 to 6.7 mg/kg every three weeks. The treated patients had a median of three prior therapy lines. PK data up to a 5.0 mg/kg dose showed nearly dose-proportional exposure, with little separation between ADC and total mAb concentration, indicating good stability and supporting a three-week dosing schedule. MYTX-011 was well tolerated, with a low incidence of common adverse events associated with MMAE or cMET-targeted therapeutics. No dose-limiting toxicities were observed, and dose escalation is ongoing. Efficacy data will be shared at a future conference or publication.

Dr. Melissa Johnson, Director of Lung Cancer Research at Sarah Cannon Research Institute, highlighted the urgent need for new treatments for patients with locally advanced or metastatic NSCLC who have not responded to previous therapies. She expressed optimism about the favorable safety, tolerability, and PK of MYTX-011 across a diverse range of cMET-expressing patients and looked forward to additional data from the Phase 1 study.

MYTX-011 leverages Mythic’s FateControl™ technology, designed to enhance ADC efficacy by improving their navigation within cells and delivery of anti-cancer agents to tumor cells while minimizing impact on healthy cells. This innovative approach aims to improve ADC efficacy against a broader set of molecular targets and patient profiles. MYTX-011 is currently being evaluated in the Phase 1 KisMET-01 clinical trial (NCT05652868) for patients with locally advanced, recurrent, or metastatic NSCLC.

Mythic Therapeutics continues to develop its pipeline of ADCs with the goal of expanding the range of treatable diseases and patient profiles. The company's major investors include Venrock, Viking Global Investors, and First Round Capital.