What the trial was testing
The MOUNTAINEER enrolled 117 patients with colorectal cancer. The study was sponsored by Seagen and tracked outcomes across the full group of patients who matched the trial's eligibility profile.
It was initial testing (phase 2). Trials at this stage are designed to produce evidence regulators and physicians can act on — not just observations to follow up later.
What the results showed
38% tumor response rate in chemo-refractory HER2+ colon cancer.
The Lancet Oncology · 2023 · NCT03043313
These findings — that in chemotherapy-refractory HER2-positive metastatic colorectal cancer — were published in the The Lancet Oncology and represent the headline result of the study.
Researchers tracked outcomes across 117 patients enrolled in the trial. The result was consistent enough across the group that the team felt confident reporting it.
What this means for patients
For patients with colorectal cancer, this result changes the calculus on what to ask their care team about. Whether it changes day-to-day care depends on factors like disease subtype, prior treatments, and where the patient is in their care journey.
What you can do now
Tucatinib (Tukysa) plus trastuzumab is FDA-approved and available now for chemotherapy-refractory HER2-positive metastatic colorectal cancer — the first targeted regimen specifically approved for this group. Ask an oncologist about HER2 testing on your tumor.
Eligibility for the treatments mentioned above depends on specific test results and clinical history. Bring this summary, the trial name, and your most recent labs or pathology report to your next visit.
Open colorectal cancer trials
Menstrual Cup for Early Endometrial Cancer Detection in Lynch Syndrome
Study Goal: This pilot study wants to find out if using a menstrual cup can be a good, non-invasive way to collect samples from the lining of the uterus (called the endometrium) to help screen for endometrial cancer. This is especially important for women who have a higher chance of getting this cancer, such as those with a genetic condition called Lynch syndrome. Main Questions the Study Will Answer: 1. Can a menstrual cup collect enough uterine lining (endometrial tissue) for doctors to examine under a microscope? 2. Are the samples from the menstrual cup as useful for diagnosis as samples taken using the usual method (called an endometrial biopsy or EMB)? 3. Is using a menstrual cup at home easy, effective, and comfortable for participants? 4. Can scientists grow small lab models of the uterus (called organoids) from the menstrual cup samples and from biopsy samples? What Will Happen in the Study: * Participants will use a menstrual cup at home to collect menstrual blood. * They will also have a standard endometrial biopsy done by a healthcare provider. * After both collections, participants will fill out a short survey about how comfortable and easy it was to use the menstrual cup. What the Study Will Measure: * Feasibility: How well participants are able to use the menstrual cup and send in the sample. * Sample Quality: Whether the menstrual cup collects enough good-quality tissue for testing, and how it compares to biopsy samples. * Participant Experience: How women feel about using the menstrual cup, based on the survey. * Lab Testing: Whether researchers can successfully grow endometrial organoids from both types of samples. Why This Study Matters: If this method works, it could offer a gentler, more convenient way for women to get checked for endometrial cancer-especially those who need regular screening. It could also make it easier to collect samples for research and improve early detection of cancer.
A Phase II Randomized Trial of Serplulimab With Second-Line Chemo/Targeted Therapy for Early Relapse Colorectal Cancer After Adjuvant Chemotherapy
Approximately 20-50% of patients with colorectal cancer (CRC) develop distant metastasis after curative surgery, and those with early relapse within one year of completing adjuvant chemotherapy (XELOX or FOLFOX) have a particularly poor prognosis and limited treatment options. Standard second-line therapy with FOLFIRI plus targeted therapy (bevacizumab or cetuximab) often yields suboptimal outcomes in this population. Moreover, over 95% of these patients have pMMR/MSS tumors, which are inherently resistant to immune checkpoint inhibitor monotherapy. This phase II, prospective, randomized trial aims to evaluate the efficacy and safety of adding serplulimab, a PD-1 inhibitor, to second-line chemotherapy plus targeted therapy in patients with early-relapse CRC after adjuvant chemotherapy. Eligible patients with pMMR/MSS or MSI-L tumors will be randomly assigned (1:1) to either the experimental arm (serplulimab plus FOLFIRI and targeted therapy) or the control arm (FOLFIRI plus targeted therapy alone). Randomization is stratified by primary tumor location (left vs. right colon), initial disease status (liver-only vs. extrahepatic metastasis), and RAS status (wild-type vs. mutant). A total of 40 patients (20 per arm) will be enrolled using a Pick-the-Winner design. The primary endpoint is progression-free survival (PFS). Secondary endpoints include objective response rate (ORR), overall survival (OS), R0 resection rate, and safety (NCI-CTCAE v5.0). Exploratory biomarker analyses in tumor tissue and blood (e.g., PD-L1 expression, tumor mutational burden, lymphocyte subsets, cytokines, TCR sequencing, circulating tumor DNA, and gut microbiome) will be performed to identify potential predictors of response and resistance. This is the first prospective randomized study specifically targeting early-relapse CRC after adjuvant chemotherapy. The findings will provide high-level evidence on whether adding PD-1 blockade to standard chemo-targeted therapy can improve outcomes in this high-risk, understudied population and may inform future phase III trials.