Y-mAbs Updates on Omburtamab

Y-mAbs Therapeutics (NASDAQ:YMAB) has announced a clinical update on its omburtamab treatment for desmoplastic small round cell tumor (DSRCT).

As quoted in the press release:

DSRCT is an aggressive malignancy that typically presents as intraabdominal sarcomatosis in young males. Less than 100 patients are diagnosed each year in the US, and given this incidence, optimal treatment has not yet been defined. Patients with DSRCT have a very poor prognosis with limited five year survival. Even for those patients where Gross Total Resection (“GTR”) is possible, five year Overall Survival (“OS”) appears to be approximately 20%. Based on observations from MSK, Whole Abdominalpelvic Intensity-Modulated RadioTherapy (“WA-IMRT”) may be advisable for all patients whose tumor can be resected.

Data reported by Dr. Modak was based on evaluation of 33 GTR patients treated at MSK from 2009 to 2017. A total of 24 patients from a Phase I study at MSK received WA-IMRT in combination with omburtamab Interperitoneal Radio Immunotherapy (“IP-RIT”) and nine patients received WA-IMRT without omburtamab IP-RIT. The study showed a median OS of 41 months for the DSRCT patients who did not receive omburtamab IP-RIT and 59 months for those receiving omburtamab IP-RIT. The data presented at CTOS indicates that adding IP-RIT with iodinated omburtamab to the standard WA-IMRT treatment appears to be well tolerated. Furthermore, adding omburtamab IP-RIT to GTR improved the five year Kapplan Meier estimated OS from a historical rate of approximately 20% to approximately 40%. While this approach may not help patients who do not achieve GTR of DSRCT, we believe that it may help patients with microscopic disease and help prevent relapse. Lack of evaluable disease means that survival is the only relevant endpoint for these patients.

Click here to read the full press release.