New Approach May Offer Stronger Treatment Effects in Metastatic Breast Cancer

Metastatic breast cancer treatment with the combination of PCS6422 and capecitabine (NGC-Cap) may increase the cancer-killing power of treatment without adding significant safety concerns, according to preliminary results from an ongoing phase 2 clinical study that were shared in a news release from Processa Pharmaceuticals.

In the news release, the company, who is developing this investigational approach, shared an update from the first 16 of 19 patients enrolled in the trial. Patients receiving NGC-Cap experienced significantly higher exposure to the specific metabolites within capecitabine known to destroy cancer cells compared with those who received capecitabine alone. Processa reported that this increased drug activity did not lead to more severe side effects compared with capecitabine alone.

This early outcome suggests that NGC-Cap may strengthen how well capecitabine works, according to the news release, which went on to emphasize that company believes this could lead to better cancer control for patients who have advanced or metastatic breast cancer.

“These emerging data continue to validate the central premise of our Next Generation Cancer strategy,” said Dr. David Young, president of Research and Development at Processa. “NGC-Cap appears to meaningfully increase exposure to the capecitabine metabolites responsible for killing cancer cells, while reducing exposure to the catabolite metabolites associated with dose-limiting toxicity such as hand-foot-syndrome (HFS), a profile that is difficult to achieve with conventional Mono-Cap dosing.”

A formal interim analysis is planned for early 2026 once data from the first 20 patients are available, according to the release.

Understanding the Study Design and Safety Findings

A total of 19 patients enrolled in the ongoing trial. They were randomly assigned to receive either investigational NGC-Cap, consisting of PCS6422 at 150 milligrams (mg) twice daily combined with capecitabine, or standard capecitabine monotherapy (referred to as Mono-Cap) at 1,000 milligrams per kilogram (mg/m²) twice daily. The safety review considered information from the first 16 patients.

Patients taking NGC-Cap had more side effects related to the increased cancer-killing activity. They also reported a greater number of these effects per patient compared with those who received capecitabine alone. Importantly, side effect severity remained comparable between both treatment groups. This similarity suggests that stronger cancer-killing metabolite exposure did not increase overall toxicity intensity.

Capecitabine breaks down into catabolite metabolites, including one known as FBAL. FBAL exposure is associated with specific treatment-related side effects, including hand-foot-syndrome. Patients in the NGC-Cap group experienced up to ten times less FBAL exposure than patients who received standard Mono-Cap therapy.

Corresponding with this reduced exposure, the number of patients who reported hand-foot-syndrome symptoms remained similar between the two study groups. However, patients who received NGC-Cap reported only grade 1 (mild) symptoms. Patients treated with standard capecitabine experienced grade 2 level symptoms (moderate).

Regulatory Next Steps for NGC-Cap

Processa expects to complete enrollment for the formal 20-patient interim analysis by the end of the first quarter of 2026. Once completed, the company plans to report safety and efficacy data from that analysis. These findings will help determine potential next steps for research and whether the therapy may move forward to larger clinical studies.

NGC-Cap is designed to raise levels of active cancer-killing metabolites and reduce formation of toxic metabolites. The goal is to improve how well capecitabine works for patients with advanced or metastatic breast cancer and to possibly increase tolerability.

Additional data in 2026 will provide a clearer understanding of what this approach could mean for patients.

“As we approach our planned interim analysis, we believe NGC-Cap continues to demonstrate a differentiated pharmacologic profile that could meaningfully improve the therapeutic index of capecitabine-based therapy,” said George Ng, CEO of Processa Pharmaceuticals. “We view this program as a key value driver for the company and an important opportunity for patients with advanced or metastatic breast cancer.”

References

1. “Processa Pharmaceuticals Provides Clinical Update on Phase 2 Study in Metastatic Breast Cancer,” by Processa Pharmaceuticals, Inc. News release; Dec. 17, 2025.

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