The lymphatic system, part of the immune system, is made up of vessels that help to protect the body from infection and foreign substances. It produces and releases lymphocytes (white blood cells) and other immune cells that monitor and then destroy pathogens — such as bacteria, viruses, parasites, and fungi — whenever they enter your body.
Kaposiform lymphangiomatosis (KLA) is a complex lymphatic condition in which the vessels that carry the lymphatic fluid throughout the body expand and interconnect. These abnormal lymphatic vessels invade and cause damage to surrounding tissue, bones, and organs, typically affecting multiple parts of the body, especially the lungs and chest.
Symptoms of KLA usually start during childhood and include shortness of breath and coughing due to the accumulation of fluid around the lungs and heart. Other common symptoms include chest and body pain, abnormal bleeding and bruising, and soft masses under the skin. KLA is diagnosed based on such symptoms, laboratory testing, and a biopsy of the tumor tissue. The cause of this condition is unknown, and it is not thought to be hereditary.
Over the past few years, an activating NRAS mutation was found in the majority of KLA patients. The NRAS gene encodes the N-Ras protein, which is involved primarily in regulating cell division.
A MEK inhibitor is a chemical or drug that blocks proteins called MEK1 and MEK2, which help control cell growth and survival. Recent studies indicated promising treatment results with the MEK inhibitor Trametinib in patients with complex lymphatic anomalies, including the typical NRAS mutation.
Recently, Sheba experts presented the first description of successful Trametinib treatment on a 9-year-old child suffering from KLA and harboring the most characteristic NRAS p.Q61R mutation. Following the administration of a pediatric Trametinib dose, the patient continued follow-ups by a multidisciplinary team and extensive testing.
The young patient has been treated at Sheba for most of his life, with a consistently poor prognosis. Unfortunately, the boy was not qualified for a lung transplant, given his significant systemic illness. However, shortly after starting treatment with Trametinib, he reported increased appetite, reduced nausea, and overall improved wellbeing.
After only two months of treatment, the boy gained 10% of his body weight, and his pulmonary function tests improved significantly, with chest CT imaging showing a marked improvement, as well as other positive indications. Fortunately, the Trametinib therapy was well tolerated with mild dermatological adverse effects.
After years of treatment, these encouraging results have been a game changer in the young patient’s life. Consequently, the results indicate that this treatment can substantially change the prognosis of many patients with NRAS-associated lymphatic anomalies. Sheba is committed to continue leading innovative clinical research with the aim of providing patients with the most advanced treatments available.