Updated Analysis Confirms Vitrakvi’s High Response Rate and Durable Responses Over Three Years in TRK Fusion Cancer Patients

September 30, 2019 / BIOON -- The 2019 European Society for Medical Oncology (ESMO) Annual Meeting was held in Barcelona, Spain, from September 27 to October 1. At this meeting, German pharmaceutical giant Bayer announced updated clinical data on the precision oncology drug Vitrakvi (larotrectinib) for the treatment of adult and pediatric patients with TRK fusion cancers. The results showed that, as of the data cutoff date of February 19, 2019, Vitrakvi demonstrated a high response rate among 153 evaluable patients, with an overall response rate (ORR) of 79% (95% CI: 72-85), a complete response rate of 16% (n=24), and a partial response rate of 63% (n=97).

It is worth noting that Vitrakvi is the TRK inhibitor with the largest dataset and the longest follow-up data. Among patients with confirmed responses (n=108), the response was durable, with a median duration of response of nearly 3 years (35.2 months; 95% CI: 22.8–NE). In the pooled dataset (n=159), the median progression-free survival was 28.3 months (95% CI: 22.1–NE), and the median overall survival was 44.4 months (95% CI: 36.5–NE), with 88% (95% CI: 83–94) of patients still alive one year after initiating treatment.

In a subgroup analysis of the pooled dataset (n=12), Vitrakvi demonstrated a high response rate in solid tumors with brain metastases, with an objective response rate (ORR) of 75%. The activity of Vitrakvi in primary central nervous system (CNS) tumors was previously presented at the 2019 ASCO Annual Meeting. Given the aggressive nature of CNS tumors, Vitrakvi has achieved disease control in this patient population over an extended period.

The safety data presented at the ESMO 2019 Congress encompassed the entire safety dataset of Vitrakvi in cancer patients (n=260), demonstrating a favorable safety profile despite the increase in patient numbers. The majority of reported adverse events were Grade 1 or 2. No Grade 3/4 treatment-related adverse events with an incidence >3% were reported, and no treatment-related deaths were reported.

Dr. Ulrik Lassen, Head of the Department of Oncology at Copenhagen University Hospital (Rigshospitalet), stated: “Vitrakvi has demonstrated that precision oncology treatments can deliver meaningful long-term efficacy and safety. It is exciting to see that, as we expand treatment to a broader patient population across a wide range of tumor types and ages, we are observing consistent durability and response rates with Vitrakvi. This underscores the value of testing our patients for genomic alterations, such as NTRK gene fusions.”

Scott Fields, M.D., Senior Vice President and Head of Oncology Development at Bayer’s Pharmaceuticals Division, stated, “The current patient population is three times larger than in our initial analysis, and Vitrakvi continues to demonstrate impressive efficacy. We remain committed to bringing Vitrakvi to patients worldwide, as evidenced by its recent approvals in multiple global markets.”

NTRK gene fusions are aberrant genetic alterations present in a wide range of tumor types, leading to uncontrolled tropomyosin receptor kinase (TRK) signaling and tumor growth. Accumulating evidence indicates that the NTRK genes, which encode TRK proteins, may undergo abnormal fusion with other genes, generating signals that can drive cancer growth at multiple sites throughout the body. TRK fusion cancers are overall rare, affecting no more than a few thousand patients annually in Europe. TRK fusions can occur in both children and adults and arise with varying frequencies across different tumor types.

The active pharmaceutical ingredient of Vitrakvi is larotrectinib, a potent, oral, selective tropomyosin receptor kinase (TRK) inhibitor designed to directly target TRKs (including TRKA, TRKB, and TRKC), thereby shutting down the signaling pathways that drive tumor growth in TRK fusion cancers. TRK fusion cancers are generally rare, affecting no more than a few thousand patients annually in Europe. The disease can affect both children and adults and occurs with varying frequency across different tumor types. In clinical studies, Vitrakvi was investigated for the treatment of 29 different histological subtypes of solid tumors. Results demonstrated that Vitrakvi exhibits significant and durable antitumor activity against TRK fusion tumors, including primary central nervous system (CNS) tumors and brain metastases, regardless of patient age or tumor histology.

Vitrakvi is a first-in-class oral TRK inhibitor specifically developed for the treatment of tumors harboring NTRK gene fusions. The drug demonstrates high response rates and durable responses in pediatric and adult patients with TRK fusion cancers, including primary central nervous system (CNS) tumors and brain metastases.

In late November 2018, Vitrakvi received approval from the U.S. FDA for the treatment of pediatric and adult patients with advanced solid tumors harboring NTRK gene fusions. This approval established Vitrakvi as the first oral TRK inhibitor in history, as well as the first “broad-spectrum” anticancer drug independent of tumor type (tumor-agnostic), ushering in a new era of “tumor-agnostic” therapy.

In September this year, Vitrakvi received approval from the European Union, becoming the first drug approved in Europe for a "tumor-agnostic" indication. Additionally, Vitrakvi has been approved in Brazil and Canada. Regulatory applications in other regions are either ongoing or planned. Following Eli Lilly's acquisition of Loxo Oncology in February 2019, Bayer obtained exclusive global rights, including the U.S. market, to develop and commercialize Vitrakvi and the investigational TRK inhibitor selitrectinib (BAY 2731954, formerly known as LOXO-195). (Bioon.com)

Original Source: Updated analysis for larotrectinib confirms high response rate and durable responses over three years in children and adults with TRK fusion cancer

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