Immunotherapy-focused biotech Immatics recently announced encouraging interim clinical data from one of the three cohorts of its Phase Ib trial evaluating its leading T-cell receptor-based T-cell (TCR-T) therapy candidate, IMA203. The positive data represents considerable progress in the development of adoptive cell therapies (ACTs) for the treatment of solid cancers, says GlobalData, a leading data and analytics company.

GlobalData’s latest report, ‘Immuno-oncology (IO) – Thematic Intelligence’, reveals that 89% of high prescribers have adopted cell therapies as part of their regular practice or as part of clinical trials, a noticeable increase from 78% in 2021. The increased familiarity with cell therapies in general, including a greater familiarity regarding delivery and side-effect management, should mean that ACTs are becoming more readily adopted, facilitating future market growth for the modality.

Draco Tai , Oncology & Hematology Analyst at GlobalData, comments: “TCR-T therapies in solid tumors have a competitive advantage, which may trump current immuno-oncology therapies. By offering the possibility of responses akin to chimeric antigen receptor T-cell therapies in efficacy and durability but with a superior safety profile, the entry of TCR-T therapies into the solid tumour space could potentially threaten the sales of blockbuster immune checkpoint inhibitors and bispecific antibodies where these are indicated in the same line of therapy.”

IMA203 demonstrated a confirmed objective response rate of 67% as a monotherapy in the relapsed/refractory (R/R) setting across multiple solid tumor types, including platinum-resistant ovarian cancer, cutaneous/uveal melanoma, and synovial sarcoma. The median duration of response was not reached at a median follow-up time of 8.5 months. The therapy appeared to be well tolerated by patients, with no occurrences of immune effector cell-associated neurotoxicity syndrome or cytokine release syndrome above Grade 3.

Tai continues: “Nonetheless, time is of top priority for Immatics as the US-based biotech Adaptimmune is slightly ahead in the race to commercialization of its MAGE-A4-targeted TCR-T programs, afami-cel and ADP-A2M4CD8. Adaptimmune anticipates its biologics license application for afami-cel in synovial sarcoma will be completed by mid-2023. The Phase II trial (SURPASS-3) evaluating ADP-A2M4CD8 in treating recurrent ovarian cancer is scheduled to begin this year. Conversely, data readout on IMA203’s Phase I trial can be expected from Immatics by the end of this year. In addition, a registrational Phase II trial on IMA203 as a treatment for late-line cancers is likely to be initiated in the first quarter of 2024.”

It is still early to determine which candidate is superior, as further clinical data on IMA203 is required from a larger pool of patients. There are similarities in both companies’ clinical strategies though, both in terms of the indications they are investigating, as well as their evaluation of these candidates in combination with a PD-1 inhibitor. Immatics prioritized its go-to-market strategy on gaining approvals for only one or two indications with high PRAME prevalence to deliver best-in-class efficacy, which helps the company in securing market share and earlier cash flow for pipeline development.

Tai concludes: “It is unclear if Adaptimmune’s and Immatics’ TCR-T therapies will be head-to-head competitors eventually, since the only indication they are covering in the coming stage is R/R ovarian cancer. This means there is great growth potential for both biotechs. Should they be head-to-head competitors in the future, Immatics has the competitive edge of a significantly shorter vein-to-vein time driven by a manufacturing process of seven days compared to Adaptimmune’s 10-14 days. This will facilitate the diversion of sales from the rival company.”