FDA Grants Orphan Drug Designation to MT-601 for Pancreatic Cancer

The FDA’s Office of Orphan Products Development has granted an orphan drug designation to the multitumor-associated antigen-specific T-cell therapy (MultiTAA), MT-601, for the treatment of patients with pancreatic cancer.¹

MT-601 was designed to target the following 6 tumor-associated antigens that are highly expressed in this disease: PRAME, NY-ESO-1, Survivin, MAGE-A4, SSX2, and WT1. The MultiTAA technology uses a non-genetically modified cell therapy approach that selectively expands tumor-specific T cells in the blood that can identify a wide range of tumor antigens.²

According to Marker Therapeutics, Inc., this technology differs from other cell therapies that are genetically engineered to identify a single portion of a sing tumor-associated antigen; these T cells can recognize up to 5 antigens to produce a strong, durable antitumor response. These therapies have demonstrated consistent epitope spreading, which induces the T cells within a patient to expand, resulting in a durable effect.

Moreover, the MultiTAA-specific T-cell therapies are based on the selective expansion of a the natural T cells in a patient and are not genetically engineered, thus, they do not carry the risk of mutagenesis and they have been hypothesized to have reduced toxicity vs other CAR T-cell therapies and T-cell receptor–based therapies in the field.

Data from early clinical trials have indicated that the multi-antigen approach is well tolerated and results in enhanced tumor-killing capability.

“The FDA’s orphan drug designation underscores MT-601’s potential has a treatment for pancreatic cancer, a cancer typically diagnosed at an incurable advanced stage with a total overall 5-year survival rate of 10%,” Peter L. Hoang, president and chief executive officer of Marker Therapeutics, stated in a press release. “Our novel therapy has shown encouraging results in an ongoing phase 1 trial sponsored by Marker’s partners at the Baylor College of Medicine…our therapy has demonstrated the potential to safely produce durable responses in combination with chemotherapy as a first-line treatment option for patients with advanced or metastatic pancreatic adenocarcinoma.”

Data from the phase 1 trial (NCT03192462) were reported during the 2020 ASCO Virtual Scientific Program.² Thirteen patients received up to 6 monthly infusions of 1 x 10⁷ multiTAA-T cells/m² in conjunction with ongoing frontline chemotherapy, and without prior protocol-associated lymphodepletion. For 12 of these patients, sufficient cells were generated for all 6 planned doses and 2 doses were available for the remaining patient.

Results showed that while on study treatment, 10 patients had ongoing radiographic stable disease or tumor responses that lasted for 6 months to 19 months; this included 1 radiographic complete response. One patient experienced a mixed response to treatment and 2 experience

progressive disease. Moreover, 9 of the 13 patients had disease control that lasted for longer than the expected duration vs historical controls.

Five additional patients underwent procurement for T-cell product creation but did not receive cells and thus, were not included in the response evaluation. Two of these patients had an unacceptable number of doses of T cells created, 1 had disease progression and initiated a second line of chemotherapy before study enrollment, and 2 had disease progression and died from their disease before enrollment.

“These results also revealed that epitope spreading was consistent in responders to Multi-TAA–specific T cells,” Hoang added in the release.

The initiation of a multicenter phase 1 study that will further examine MT-601 in combination with chemotherapy in the frontline treatment of patients with locally advanced, unresectable or metastatic pancreatic cancer is planned. The study was designed to comprise an initial antigen escalation period that will be followed by a dose-escalation period. The trial is slated to enroll 20 to 25 participants.

Additionally, Marker Therapeutics shared plans to file an investigational new drug application for MT-601 for the treatment of pancreatic cancer later this year.

References

1. Marker Therapeutics receives FDA orphan drug designation for its multi-antigen targeted T cell therapy for pancreatic cancer. News release. Marker Therapeutics, Inc.; January 19, 2022. Accessed January 20, 2022. https://bit.ly/33SNmh5
2. Smaglo BG, Musher BL, Vasileiou S, et al. A phase I trial targeting advanced or metastatic pancreatic cancer using a combination of standard chemotherapy and adoptively transferred nonengineered, multiantigen specific T cells in the first-line setting (TACTOPS). J Clin Oncol. 2020;38(suppl 15):4622. doi:10.1200/JCO.2020.38.15_suppl.4622