Acute myeloid leukemia (AML) is part of a market of blood malignancies that commercial cell therapies have not managed to penetrate yet. While allogeneic hematopoietic stem cell transplants (HSCT) provide long-term benefit to a subset of AML patients, other cell therapy modalities such as natural killer (NK) cells or chimeric antigen receptor (CAR)-T cells have failed to show conclusive benefit in late-stage clinical trials. A lack of good antigens to target in AML is widely believed to have caused this dearth of effective cell therapies. Antigens such as CD123 and CD33, despite being markers of myeloid cells, are shared with their healthy counterparts, and myeloablation following their depletion often leads to detrimental clinical outcomes. However, it is possible to target CD33 in the clinic, as evidenced by the FDA approval of Pfizer’s anti-CD33 antibody-drug conjugate Mylotarg (gemtuzumab ozogamicin) in 2000.
The first clinical attempt at managing AML with CAR-T cells was reported in 2013 with a small Phase I study that did not demonstrate activity. Despite this, CAR-T approaches in the pipeline became numerous, and now include the targeting of CLL-1, CD123, and CD33, among others. GlobalData’s Pharma Intelligence Center shows 19 autologous CAR-T cell products in Phase I, and nine products in Phase II, globally. None of these products are in a registrational trial, and as such, GlobalData does not anticipate their entry into the AML market earlier than 2028.
Despite the challenges faced by gene-modified cell therapies such as CAR-T cells, significant promise remains for allogeneic cell therapies that have not been gene edited. For example, Marker Therapeutics’s zelenoleucel, a multi-tumor-associated antigen-specific T cell aimed to be used after an HSCT for newly diagnosed and relapsed/refractory (R/R) AML patients. Zelenoleucel is being evaluated in the Phase II ARTEMIS trial, and if it demonstrates a benefit over the standard of care arm, it could reach the US market as early as 2025. Furthermore, tremendous promise exists for products that supplement or even replace HSCTs. The HSCT procedure carries a high risk of graft-versus-host disease, resulting in substantial HSCT-related mortality. As such, numerous cell therapies in the pipeline aim to ameliorate this process.
The most advanced candidate is Gamida Cell’s NiCord (omidubicel), which consists of cord blood-derived stem cells that aim to offer a solution to patients who do not have an allogeneic HSCT donor. NiCord’s biologics license application is currently being investigated by the FDA with a review date set by May 2023. If approved, it could reach sales of $158 million in the 8MM (US, France, Germany, Italy, Spain, the UK, Japan, and China) by 2031. Orca Biosystems’s Orca-T is another modified allogeneic HSCT product. Orca-T is being evaluated in the Phase III Precision-T trial compared to unmodified allogeneic HSCT and could reach the market as early as 2025. GlobalData forecasts Orca-T to reach peak sales of $78 million in the 8MM by 2031. The success of these allogenic cell therapies will undoubtedly prompt further R&D investment into different cell therapy modalities for AML.