FDA Awards Orphan Drug Designation to NXC-201 for Multiple Myeloma

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The FDA has granted orphan drug designation to NXC-201 for use as a potential therapeutic option in patients with multiple myeloma.

The FDA has granted orphan drug designation to NXC-201 (formerly HBI0101) for use as a potential therapeutic option in patients with multiple myeloma, according to an announcement from Nexcella, Inc.¹

The safety and efficacy of the BCMA-targeted CAR T-cell therapy is under evaluation in adult patients with BCMA-expressing, relapsed/refractory multiple myeloma and AL amyloidosis, as part of the ongoing phase 1b/2a NEXICART-1 study (NCT04720313).²

“We are pleased to receive FDA’s orphan drug designation in multiple myeloma for NXC-201, the only clinical-stage BCMA-targeted CAR T-cell therapy with no neurotoxicity observed in over 50 patients dosed to date,” Ilya Rachman, MD, PhD, executive chairman of Nexcella, stated in a press release.¹ “We are thrilled to potentially expand therapeutic options for [patients with] multiple myeloma, while eliminating the most feared adverse effect of this therapeutic class, neurotoxicity.”

The phase 1 trial is enrolling patients with relapsed/refractory multiple myeloma who have previously received at least 3 different lines of therapy, including a proteasome inhibitor, an immunomodulatory agent, and at least 1 antibody therapy.² Patients needed to be at least 18 years of age and have an ECOG performance status of 0 to 2.

They also needed to have measurable disease, including at least 1 of the following: serum M-protein level of at least 0.5 g/dL, urine M-protein of at least 200 mg/24h, serum free light chain (FLC) level of at least 5 mg/dL provided serum FLC ratio is abnormal, an evaluable plasmacytoma, and bone marrow plasma cells greater than 20% of total bone marrow cells. Patients also needed to have had any non-hematologic toxicities from previous treatments recover to grade 2 or less in severity with the exception of alopecia and grade 3 neuropathy.

In the dose-escalation portion of the trial, investigators are evaluating the CAR T-cell therapy at doses of 150 x 106 CAR-positive T cells, 450 x 106 CAR-positive T cells, 800 x 106 CAR-positive T cells, and 1200 x 106CAR-positive T cells. In the dose-expansion phase of the research, a dose between 450 x 106 and 800 x 106CAR-positive T cells will be examined.

The primary objective of the trial is to identify the maximum tolerated dose of NXC-201 in part A and confirmed selected dose tested for part B. Secondary objectives include 2-year overall survival and progression-free survival.

Nexcella, Inc. recently announced that clinical data on NXC-201 will be shared at the 2023 International Myeloma Society (IMS) Annual Meeting as part of a poster presentation.³

“We are delighted to continue to see US and international recognition of the progress we are making,” Polina Stepensky, MD, principal study investigator and director of the Department of Bone Marrow Transplantation and Immunotherapy for Adults and Children at the Hadassah Medical Organization, stated in the press release.³ “We are pleased to present clinical data in relapsed multiple myeloma at the upcoming IMS Annual Meeting, an important international forum for discussion of novel treatments for multiple myeloma.”

Previously, data on 8 patients enrolled to NEXICART-1 were shared at the 2023 Annual Meeting of The American Society of Gene and Cell Therapy.⁴In patients with AL amyloidosis who were relapsed or refractory to daratumumab (Darzalex) and received NXC-201 at doses ranging from 150 x 106 to 800 x 106 CAR-positive T cells, the overall response rate was 100%, with a complete response rate of 63%.

Notably, one responder experienced a duration of response of 16.5 months at the time of the data cutoff date of May 11, 2023; their response was still ongoing. Moreover, the organ response rate was 75%, and rapid organ response is believed to be associated with fast reduction of free light chain toxicity.

The CAR T-cell therapy was determined to be well tolerated, with no grade 4 cytokine release syndrome observed.

The phase 1b portion of the trial was able to identify the recommended phase 2 dose of the agent to be 800 x 106 CAR-positive T cells. Nexcella, Inc., shared that they will submit findings from this population to the FDA once 30 to 40 patients receive treatment with the CAR T-cell therapy. Data for this population will also be shared at the 2023 IMS Annual Meeting.⁵