Gilotrif-Erbitux Combo Shows Antitumor Activity in NSCLC Subset

Patients with EGFRexon 20 insertion-positive non-small cell lung cancer experienced antitumor activity after receiving Gilotrif plus Erbitux, according to a recent study.

Patients with epidermal growth factor (EGFR) exon 20 insertion-positive non-small cell lung cancer (NSCLC) experienced antitumor activity after receiving a combination of Gilotrif (afatinib) and Erbitux (cetuximab), according to a recent study.

Gilotrif is a type of drug that blocks specific proteins that are produced by the EGFR gene, which helps stop the cancer cells from multiplying. The drug may also help prevent the growth of new blood vessels that are necessary for tumors to grow, as the National Cancer Institute defined.

Erbitux is a monoclonal antibody drug that can be used alone or in combination with another, in which it binds to the EGFR protein that can be found on some cancer cells and may prevent the growth of the cancer cells, the National Cancer Institute states.

In a study published in the journal Cancer, there were 37 total eligible patients, and all patients had stage 4 NSCLC with EGFR exon 20 insertion mutations, which were identified through next-generation sequencing, known as a method to analyze the building blocks of DNA and RNA fragments at the same time, according to the National Cancer Institute.

Of the 37 patients, 78% identified as female and 35% reported never smoking, the study stated. There were 18 patients who previously received chemotherapy, chemo-immunotherapy and/or Tagrisso (osimertinib; a type of EGFR tyrosine kinase inhibitor).

Their primary endpoint (the main result at the end of a study to see if treatment worked) was the disease control rate.

According to the study’s results, the primary endpoint was met, as disease control was demonstrated in 20 of 37 patients (54%) after receiving the Gilotrif-Erbitux combination for 18 weeks. The authors of the study determined that the best responses were in 16 patients with partial responses and 16 patients with stable responses.

The study’s secondary endpoints included objective response rate (ORR; the percentage of patients that show a partial or complete response to treatment), duration of response (DOR; the length of time when a tumor responds to treatment without spreading or worsening).

The study authors also determined that the ORR was 43%, with 16 patients having a partial response. Twelve patients showed a confirmed response after imaging, which established a confirmed ORR rate of 32%. The median DOR was reported to be 4.7 months, according to the authors.

“In this phase 2 trial, combination treatment with (Gilotrif) and (Erbitux) was effective for patients with EGFR (exon 20 insertion)-mutated NSCLC, which resulted in a DCR of 54% after 18 weeks and a confirmed ORR of 32%,” the study authors wrote.

Other secondary endpoints within the study were progression-free survival (PFS; the length of time during and after treatment when a patient lives with cancer but does not worsen), overall survial (OS; the length of time from diagnosis or the start of treatment when a patient is still alive) and safety, regarding treatment-related side effects.

The results from the study reflected that the median PFS and median OS were 5.5 months and 16.8 months, respectively. By the end of the study, 28 patients experienced a decrease in tumor size.

In terms of safety, the study authors noted that the most common treatment-related side effects were diarrhea in 70% of patients, rash in 65%, dry skin in 59%, paronychia (infection around fingernails and toenails) in 54% and erythema (skin redness) in 43%.

Serious treatment-related side effects included diarrhea in 14% of patients, rash in 14% and dry skin in 14%. There were 25 patients (68%) who required a dose reduction, which included five patients (14%) who had two dose reductions. Six patients (16%) stopped treatment because of treatment-related side effects.

“One patient died as a result of respiratory failure after the first infusion of study medication, probably related to disease progression and possibly treatment-related,” the study authors wrote. “Two other patients died during study treatment as a result of non-treatment related events, coronavirus disease 2019 infection and cardiac arrest.”

For more news on cancer updates, research and education, don’t forget to subscribe to CURE®’s newsletters here.