Results from a mid-stage clinical trial conducted by a small biotechnology company iTeos Therapeutics have revealed that when taken in combination with GSK immunotherapy Jemperli, their drug belrestotug can successfully shrink lung tumors in patients with untreated advanced or metastatic non-small cell lung cancer.
The trial in question enrolled 124 patients suffering from a certain type of lung cancer that was then divided into 2 groups; one group was treated with 3 different doses of belrestotug in combination with Jemperli, while the other group was only treated with Jemperli. It was discovered that in the three combination therapy arms at the time of the initial assessment, tumors in participants had shrunk by 63% to 77% compared to the monotherapy, in whose case the tumors were only reported to shrink by 38%.
After a four-week or, in some cases, longer mark, patients were once again given tumor imaging scans that confirmed the initial results. In the combination groups, the overall response rate was around 60%, but it wasn’t even half of that, at only 28% in Jemperli’s case.
Despite this positive response rate, there have been concerns with the safety of these two medications together; there were a total of 3 deaths reported in the trial due to immune-related inflammation, and according to study investigators, they can be linked to the treatment. All 3 deaths were reported in the combination therapy arm, while none of the 32 participants who were administered Jemperli alone faced any fatal consequences as a result of the treatment.
There was also a notable disparity in the proportion of participants who experienced serious side effects in the combination dose group compared to the Jemperli group. About 25% to 37% of participants in the former category experienced serious side effects, while the number fell to single digits at 9% for the latter group.
ITeos Therapeutics has assured that the safety profile of their regiment is consistent with other immunotherapy combinations on the market, and that inflammatory reactions are a widely known side effect of treatments like Jemperli. In other immunotherapies in the past, the treatment also resulted in some fatalities.
In terms of efficacy, Iteos’s combined treatment is only considered partial since it did not entirely get rid of the tumor. In addition to this, it is unclear if the new proposed treatment has any effect on slowing disease progression or prolonging survival, indicators that are a more significant measure of a cancer drug’s impact.
Iteos’ drug works by targeting a protein called TIGIT, which is responsible for cracking down on the immune system’s response to cancer. By doing so, the drug allows immunotherapies such as Jemperli to heighten their anti-tumor effects. In the past, big pharmaceutical companies like Bristol Myers Squib, Roche and Merck & Co. have all tried conducting experiments to capitalize on this approach but have only been left empty-handed.
Most recently though, there have been possibilities of other successes in the TIGIT field of treatment for cancer; preliminary data from Roche’s SKYSCRAPER-01 study, which came out last year, hinted at possible benefits to the approach, and more detailed results are expected to come out this year.