IMX-110 Granted Rare Pediatric Disease Designation by FDA for Rhabdomyosarcoma

IMX-110, which was granted a rare pediatric disease designation for patients with rhabdomyosarcoma, is currently being assessed as part of a phase 1b/2a study.

The FDA has granted a rare pediatric disease designation to IMX-110, qualifying the treatment to receive priority review and a fast track designation voucher, for pediatric patients with life threatening rhabdomyosarcoma.1

The therapy is currently being assessed as part of an ongoing phase 1b/2a study (NCT03382340). If the new drug application is accepted, IMX-110 will be eligible for priority review designation.

“We are pleased by FDA’s acknowledgment of the urgent need for a safe and effective treatment for children with this devastating disease,” Ilya Rachman, MD, PhD, chief executive officer at ImmixBio, said in the press release. “We are encouraged by our phase 1b/2a clinical data in soft tissue sarcoma. IMX-110 is a tissue-specific therapeutic that simultaneously attacks all 3 components of the tumor micro-environment, severing the critical lifelines between the tumor and its metabolic and structural support. We believe our SMARxT platform generating Tissue-Specific Therapeutics represents a distinct alternative to the traditional ‘single target, single mutation’ development model.”

It was noted that IMX-110 is the first clinical-stage product within the SMARxT Tissue-Specific Platform that generates tissue-specific therapeutics at intended therapeutic sites 3 to 5 times faster than the rate of other medications. Thus far, the treatment has been granted an orphan drug designation for patients with soft tissue sarcoma. The therapeutic consists of a 5:1 ratio of a polykinase inhibitor and apoptosis inducer delivered into the tumor microenvironment.

Phase 1b/2a data indicated that in a population of 8 heavily pretreated patients with soft tissue sarcoma, 75% experienced tumor shrinkage.2 Investigators also noted a median progression-free survival of 4 months across the population of patients with heavily pretreated soft tissue sarcoma with a 100% disease control rate at 2 months. Additionally, no drug-related toxicities were observed. Patients had a median of 7 prior lines of treatment (range, 4-14).

The treatment is also being examined in several other disease types, including nasopharyngeal, colorectal, and breast cancer. Notably, treatment with IMX-110 resulted in a PFS of 4 months for 1 patient who received the treatment as their fourteenth line of therapy.

IMX-110 is currently being developed as a monotherapy, with a total of 14 patients having been treated to-date. The phase 2a study will examine the therapy as a first-line treatment for patients with soft tissue sarcoma based on findings from precedent trials in the United States and Europe. Additionally, IMX-110 will be examined as part of a combination regimen with PD-L1 inhibitor tislelizumab (BGB-A317), with 1 trial planned.


  1. U.S. Food and Drug Administration approves Immix Biopharma rare pediatric disease designation for IMX-110 as a treatment for life-threatening pediatric cancer in children. News release. Immix Biopharma. January 3, 2022. Accessed January 4, 2022.
  2. Immix Biopharma. Novel Tissue-Specific Therapeutics (TSTx) targeting oncology & immuno-dysregulated diseases. Accessed January 4, 2021.