A recent phase 1 clinical trial looked at the impact giving chemoradiotherapy and a PD-1 inhibitor would have from a safety perspective if they were given concurrently, rather than consecutively. The results of the trial were published in JAMA Oncology. 

Lead author, Salma K. Jabbour, MD, of the Rutgers Cancer Institute of New Jersey told MD /alert that while the goal of this trial was to look at the safety of the combination, the overall goal for her team was to help treat patients with this difficult condition before it progresses any further. 

Even with relatively good results already for stage 3 patients today, Dr Jabbour said they want to help achieve “significantly” better outcomes for future patients. 

“We would like to improve the cure rate for stage 3 lung cancer patients," Dr Jabbour said. "This really is our main goal. We know that stage 4 lung cancer patients have already achieved a great benefit from the addition of immunotherapy to their regiment of therapy and moving this into the stage 3 lung cancer space is important to hopefully achieve those same benefits in terms of improving cure rates for these patients.” 

Dr Jabbour said the prior rationale for not giving the treatments together was to ensure that patients could tolerate the two individually, with the added risk of the combination causing more numerous and potentially more dangerous side effects during chemoradiation. 

“The main side effect we were worried about in this phase 1 study was the risk of pneumonitis, which is an inflammation of the lung, which can happen with either immunotherapy or radiation or chemoradiation or radiation for that matter alone, and whether that would increase the risk of that complication," she continued.

Patients enrolled in the study were prescribed various doses of pembrolizumab, as well as different timing schedules for treatment. 

The dosing included 200 mg intravenously every three weeks, starting 2 to 6 weeks after chemoradiotherapy, 100 mg intravenously every three weeks starting at day 29 of chemoradiotherapy, the full-dose starting at day 29, reduced dose starting day 1, and full dose starting at day 1 of chemoradiotherapy. 

“All of the things we saw were relatively expected in terms of side effects. These were side effects that we would have seen with the pembrolizumab alone or with the chemotherapy and radiation alone," Dr Jabbour added. "In that sense, these were all sort of within the scope of what we would have expected with the combination of them.”

While the phase 1 trial was focused mostly on safety, Dr Jabbour said the researchers also saw positive signs when it came to treatment efficacy.

“Although the safety was very good, and we felt that the combination was well tolerated, was tolerated and safe, we did find some good results in terms of what happened to the patient’s tumors and patient outcomes. About 90% of tumors had what we call a response, meaning that the tumors shrunk in size or stayed the same, which is a very good number," she continued. "Also, we found that about 70% of patients did not have their cancer grow within a year, which is also very, very good.” 

Following the completion of their phase 1 trial, Dr Jabbour said there are already several phase 2 and 3 studies looking at the same issue, not only for non-small cell lung cancer but also small cell lung cancer. 


By Adam Hochron
Source: Md Alert Exclusive