{"product_id":"adding-pembrolizumab-keytruda-to-chemotherapy-improves-survival-in-early-triple-negative-breast-cancer","title":"Adding Pembrolizumab (Keytruda) to Chemotherapy Improves Survival in Early Triple-Negative Breast Cancer","description":"\u003cp\u003eThe KEYNOTE-522 clinical trial showed that adding the immunotherapy drug pembrolizumab (Keytruda) to standard chemotherapy before and after surgery significantly improves outcomes for patients with early-stage triple-negative breast cancer, one of the most aggressive forms of breast cancer. After a median follow-up of about 39 months, 84.5% of patients who received pembrolizumab plus chemotherapy were alive without cancer recurrence or progression, compared with 76.8% of those who received chemotherapy alone — a 37% reduction in the risk of cancer events or death. These findings establish pembrolizumab as an important new treatment option that can help prevent recurrence in this challenging disease.\u003c\/p\u003e\n\n\u003ch1\u003eAdding Pembrolizumab (Keytruda) to Chemotherapy Improves Survival in Early Triple-Negative Breast Cancer\u003c\/h1\u003e\n\n\u003ch2\u003eTable of Contents\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"#ddn-key-points\"\u003eKey Points\u003c\/a\u003e\u003c\/li\u003e\n\n  \u003cli\u003e\u003ca href=\"#background\"\u003eUnderstanding Triple-Negative Breast Cancer\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#study\"\u003eAbout the KEYNOTE-522 Trial\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#participants\"\u003eWho Participated in the Study\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#treatment\"\u003eThe Treatment Plan\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#endpoints\"\u003eHow the Study Measured Success\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#findings\"\u003eKey Findings: Event-Free Survival\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#events\"\u003eBreaking Down the First Events\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#survival\"\u003eOverall Survival and Other Results\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#safety\"\u003eSafety and Side Effects\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#limitations\"\u003eStudy Strengths and Limitations\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#implications\"\u003eWhat This Means for Patients\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#ddn-faq\"\u003eFrequently Asked Questions\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"#source\"\u003eSource Information\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c!-- ddn:keypoints:start --\u003e\n\u003ch2 id=\"ddn-key-points\"\u003eKey Points\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eIn the KEYNOTE-522 trial of 1,174 patients, adding pembrolizumab to chemotherapy reduced the risk of cancer events or death by 37% in early triple-negative breast cancer.\u003c\/li\u003e\n\u003cli\u003eEvent-free survival at 3 years was 84.5% with pembrolizumab plus chemotherapy versus 76.8% with chemotherapy alone.\u003c\/li\u003e\n\u003cli\u003eThe pembrolizumab group had a lower rate of distant recurrence (7.7%) compared with chemotherapy alone (13.1%).\u003c\/li\u003e\n\u003cli\u003eThe benefit was consistent across all patient subgroups, regardless of PD-L1 expression or lymph-node involvement.\u003c\/li\u003e\n\u003cli\u003eSerious treatment-related side effects occurred in 34.1% of pembrolizumab patients versus 20.1% with chemotherapy alone; treatment-related deaths were rare.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- ddn:keypoints:end --\u003e\n\n\n\u003ch2 id=\"background\"\u003eUnderstanding Triple-Negative Breast Cancer\u003c\/h2\u003e\n\n\u003cp\u003eTriple-negative breast cancer (TNBC) is a subtype of breast cancer that lacks three common receptors that fuel most breast cancers: estrogen receptors, progesterone receptors, and the HER2 protein. Because these tumors do not respond to hormone therapy or HER2-targeted drugs, treatment traditionally relies on chemotherapy.\u003c\/p\u003e\n\n\u003cp\u003eTNBC is known to be more aggressive than other breast cancer types. Even when patients receive the standard curative-intent chemotherapy regimen containing anthracyclines (such as doxorubicin or epirubicin) and taxanes (such as paclitaxel), the risk of recurrence and death remains substantial.\u003c\/p\u003e\n\n\u003cp\u003eThe numbers are sobering: among patients with stage II or III triple-negative breast cancer, approximately 71% are alive and free of cancer events at 5 years, and overall survival at 5 years is approximately 77%. For patients with early-stage disease, neoadjuvant chemotherapy — chemotherapy given \u003cem\u003ebefore\u003c\/em\u003e surgery — is the current standard of care.\u003c\/p\u003e\n\n\u003cp\u003eThe short-term goal of neoadjuvant therapy is to achieve a \u003cstrong\u003epathological complete response\u003c\/strong\u003e, meaning that no invasive cancer remains in the breast tissue and lymph nodes at the time of surgery. Patients who achieve this response tend to have better long-term outcomes. The long-term goal of combining neoadjuvant and adjuvant (post-surgery) therapy is to prevent the cancer from coming back as metastatic disease.\u003c\/p\u003e\n\n\u003cp\u003eIn recent years, researchers have explored whether immune checkpoint inhibitors — drugs that help the body's immune system recognize and attack cancer cells — could improve outcomes in TNBC. These drugs target proteins called \u003cstrong\u003eprogrammed death 1 (PD-1)\u003c\/strong\u003e or \u003cstrong\u003eprogrammed death ligand 1 (PD-L1)\u003c\/strong\u003e, which cancer cells use to hide from the immune system.\u003c\/p\u003e\n\n\u003cp\u003eThe KEYNOTE-522 trial was designed to answer a critical question: could adding the PD-1 inhibitor pembrolizumab to standard chemotherapy improve outcomes for patients with early-stage TNBC?\u003c\/p\u003e\n\n\u003ch2 id=\"study\"\u003eAbout the KEYNOTE-522 Trial\u003c\/h2\u003e\n\n\u003cp\u003eKEYNOTE-522 is a phase 3, randomized, double-blind, placebo-controlled clinical trial — considered the gold standard of medical research. In a double-blind trial, neither the patients nor their doctors know who is receiving the active drug versus the placebo, which helps eliminate bias.\u003c\/p\u003e\n\n\u003cp\u003eThe trial was conducted at 181 sites (plus 2 satellite sites) across 21 countries, making it one of the most extensive studies ever conducted in this patient population. Patients were enrolled from March 2017 through September 2018.\u003c\/p\u003e\n\n\u003cp\u003eEach patient was randomly assigned in a \u003cstrong\u003e2:1 ratio\u003c\/strong\u003e — meaning for every patient who received placebo, two received pembrolizumab. In total, 1,174 patients were enrolled: \u003cstrong\u003e784 in the pembrolizumab–chemotherapy group and 390 in the placebo–chemotherapy group\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eBefore randomization, patients were stratified (grouped) according to three factors:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eNodal status (whether cancer had spread to lymph nodes: positive or negative)\u003c\/li\u003e\n  \u003cli\u003eTumor size (T1, meaning tumor diameter greater than 1.0 to 2.0 cm; T2, greater than 2.0 to 5.0 cm; T3, greater than 5.0 cm; or T4, locally advanced disease)\u003c\/li\u003e\n  \u003cli\u003eFrequency of carboplatin administration (once weekly or once every 3 weeks)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe trial was sponsored by Merck Sharp and Dohme, a subsidiary of Merck, and was overseen by an independent data and safety monitoring committee that periodically reviewed safety and efficacy results. All patients provided written informed consent, and the trial protocol was approved by ethics committees at each participating institution.\u003c\/p\u003e\n\n\u003cp\u003eThis report describes the results of the \u003cstrong\u003efourth planned interim analysis, with a data cutoff of March 23, 2021\u003c\/strong\u003e. The median follow-up at this point was \u003cstrong\u003e39.1 months\u003c\/strong\u003e (range, 30.0 to 48.0 months).\u003c\/p\u003e\n\n\u003ch2 id=\"participants\"\u003eWho Participated in the Study\u003c\/h2\u003e\n\n\u003cp\u003eThe study enrolled adult patients with \u003cstrong\u003enewly diagnosed, previously untreated, nonmetastatic stage II or III triple-negative breast cancer\u003c\/strong\u003e. Triple-negative status was centrally confirmed using standard guidelines from the American Society of Clinical Oncology and the College of American Pathologists.\u003c\/p\u003e\n\n\u003cp\u003eEligible patients had specific tumor characteristics, including T1c N1–2 or T2–4 N0–2 disease (based on the 7th edition of the American Joint Committee on Cancer staging criteria). They also needed to have a good performance status — specifically an Eastern Cooperative Oncology Group (ECOG) performance-status score of 0 or 1, which means they were fully active or restricted only in physically strenuous activity but able to carry out work of a light or sedentary nature.\u003c\/p\u003e\n\n\u003cp\u003ePatients were eligible for the trial \u003cstrong\u003eregardless of their PD-L1 expression status\u003c\/strong\u003e, meaning the drug was studied in all patients with early TNBC, not just those whose tumors tested positive for PD-L1.\u003c\/p\u003e\n\n\u003cp\u003eImportantly, at baseline, the characteristics of patients were well balanced between the two treatment groups, meaning the groups were comparable in terms of age, disease stage, and other important factors.\u003c\/p\u003e\n\n\u003cp\u003eA total of 783 patients in the pembrolizumab–chemotherapy group and 389 in the placebo–chemotherapy group received at least one dose of trial treatment or underwent surgery (the \"as-treated\" population). No patients were still receiving treatment at the time of this analysis.\u003c\/p\u003e\n\n\u003ch2 id=\"treatment\"\u003eThe Treatment Plan\u003c\/h2\u003e\n\n\u003cp\u003eThe treatment plan in KEYNOTE-522 was carefully structured and involved two phases: a neoadjuvant (pre-surgery) phase and an adjuvant (post-surgery) phase.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eNeoadjuvant phase:\u003c\/strong\u003e\u003c\/p\u003e\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFirst neoadjuvant treatment (cycles 1–4):\u003c\/strong\u003e Patients received four cycles of either pembrolizumab (200 mg) or placebo, given as an intravenous infusion once every 3 weeks. At the same time, all patients received paclitaxel (80 mg per square meter of body-surface area) once weekly plus carboplatin — either at a dose calibrated to an area under the concentration–time curve (AUC) of 5 mg per milliliter per minute given once every 3 weeks, or 1.5 mg per milliliter per minute given once weekly for the first 12 weeks.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSecond neoadjuvant treatment (cycles 5–8):\u003c\/strong\u003e Patients then received four more cycles of pembrolizumab or placebo, again once every 3 weeks, alongside either doxorubicin (60 mg per square meter) or epirubicin (90 mg per square meter), plus cyclophosphamide (600 mg per square meter), all given once every 3 weeks for 12 weeks.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003eGlucocorticoids could be used to prevent allergic reactions before chemotherapy and to manage immune-related side effects.\u003c\/p\u003e\n\n\u003cp\u003eAfter completing the neoadjuvant phase, patients underwent \u003cstrong\u003edefinitive surgery\u003c\/strong\u003e — either breast-conserving surgery or mastectomy, with sentinel lymph-node evaluation or axillary dissection — at 3 to 6 weeks after their last neoadjuvant treatment cycle.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAdjuvant phase:\u003c\/strong\u003e After surgery, patients received radiation therapy as clinically indicated, plus either pembrolizumab (the pembrolizumab–chemotherapy group) or placebo (the placebo–chemotherapy group) once every 3 weeks for up to nine additional cycles. Adjuvant pembrolizumab or placebo could begin either at the same time as radiation therapy or 2 weeks after completing radiation. Notably, adjuvant treatment with capecitabine (another chemotherapy drug) was not allowed in this trial.\u003c\/p\u003e\n\n\u003cp\u003ePatients stopped treatment if their disease progressed in a way that prevented surgery, if the cancer recurred, or if they experienced unacceptable side effects.\u003c\/p\u003e\n\n\u003ch2 id=\"endpoints\"\u003eHow the Study Measured Success\u003c\/h2\u003e\n\n\u003cp\u003eThe trial had two \u003cstrong\u003eprimary endpoints\u003c\/strong\u003e (the main outcomes used to determine whether the treatment worked):\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePathological complete response (pCR):\u003c\/strong\u003e Defined as no residual invasive cancer in the breast and no cancer in the sampled lymph nodes at the time of definitive surgery (pathological stage ypT0–Tis ypN0). These results were reported previously from an earlier analysis of this trial and showed that significantly more patients achieved pCR with pembrolizumab.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEvent-free survival (EFS):\u003c\/strong\u003e Defined as the time from randomization until any of the following events, whichever came first: disease progression that prevented definitive surgery, local recurrence (cancer returning in the same area), distant recurrence (cancer spreading to other parts of the body), the development of a second primary cancer, or death from any cause.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eSecondary endpoints\u003c\/strong\u003e included:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eOverall survival (how long patients lived regardless of whether the cancer returned)\u003c\/li\u003e\n  \u003cli\u003eEvent-free survival among patients with PD-L1–positive tumors\u003c\/li\u003e\n  \u003cli\u003ePathological complete response according to a stricter definition (no residual invasive or in-situ cancer, ypT0 ypN0)\u003c\/li\u003e\n  \u003cli\u003ePathological complete response defined as no invasive cancer in the breast regardless of ductal carcinoma in situ or lymph-node involvement (ypT0–Tis)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eAn \u003cstrong\u003eexploratory endpoint\u003c\/strong\u003e was distant progression–free or distant recurrence–free survival, defined as the time from randomization to distant cancer spread, distant recurrence, or death from any cause.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eHow patients were monitored:\u003c\/strong\u003e After completing neoadjuvant therapy, patients were followed for disease status and survival every 3 months for the first 2 years after randomization, then every 6 months for years 3 through 5, and annually thereafter.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003ePD-L1 testing:\u003c\/strong\u003e Tumor samples were tested at a central laboratory using the PD-L1 IHC 22C3 pharmDx assay. PD-L1 expression was measured using the \u003cstrong\u003ecombined positive score (CPS)\u003c\/strong\u003e, which is the number of PD-L1–positive cells (tumor cells, lymphocytes, and macrophages) divided by the total number of tumor cells, multiplied by 100. A CPS of 1 or higher was considered PD-L1–positive.\u003c\/p\u003e\n\n\u003ch2 id=\"findings\"\u003eKey Findings: Event-Free Survival\u003c\/h2\u003e\n\n\u003cp\u003eThe results of this fourth planned interim analysis were striking. A total of \u003cstrong\u003e123 patients (15.7%) in the pembrolizumab–chemotherapy group experienced an event or died, compared with 93 patients (23.8%) in the placebo–chemotherapy group\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eThe hazard ratio for an event or death was \u003cstrong\u003e0.63 (95% confidence interval [CI], 0.48 to 0.82; P\u0026lt;0.001)\u003c\/strong\u003e. In plain language, this means patients who received pembrolizumab had a \u003cstrong\u003e37% lower risk\u003c\/strong\u003e of experiencing a cancer event or dying during the follow-up period compared with patients who received chemotherapy alone.\u003c\/p\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eestimated event-free survival at 36 months\u003c\/strong\u003e (3 years) was:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e84.5%\u003c\/strong\u003e (95% CI, 81.7 to 86.9) in the pembrolizumab–chemotherapy group\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e76.8%\u003c\/strong\u003e (95% CI, 72.2 to 80.7) in the placebo–chemotherapy group\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThis means that at 3 years, about 84 out of every 100 patients who received pembrolizumab were alive and free of cancer events, compared with about 77 out of every 100 who received chemotherapy alone — a difference of 7.7 percentage points in favor of pembrolizumab.\u003c\/p\u003e\n\n\u003cp\u003eThe median event-free survival was \u003cstrong\u003enot reached in either group\u003c\/strong\u003e, which means that at the time of this analysis, more than half of the patients in both groups were still event-free, so researchers could not yet calculate an \"average\" survival time — a good sign.\u003c\/p\u003e\n\n\u003cp\u003eThe statistical threshold for significance at this interim analysis was P\u0026lt;0.01034 (a two-sided alpha level), and the result easily crossed that threshold, confirming that the improvement in event-free survival was statistically significant and not due to chance.\u003c\/p\u003e\n\n\u003ch2 id=\"events\"\u003eBreaking Down the First Events\u003c\/h2\u003e\n\n\u003cp\u003eResearchers also examined the specific types of events that occurred first in each group. Understanding these details helps doctors know exactly what benefit pembrolizumab provides.\u003c\/p\u003e\n\n\u003cp\u003eHere is the breakdown of first events in the trial:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDisease progression that prevented definitive surgery:\u003c\/strong\u003e 14 patients (1.8%) in the pembrolizumab group vs. 15 patients (3.8%) in the placebo group\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLocal recurrence\u003c\/strong\u003e (cancer returning in the breast or chest wall area): 28 patients (3.6%) vs. 17 patients (4.4%)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDistant recurrence\u003c\/strong\u003e (cancer spreading to other organs): 60 patients (7.7%) vs. 51 patients (13.1%) — this was the most common type of event in both groups\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSecond primary cancer\u003c\/strong\u003e (an entirely new cancer): 6 patients (0.8%) vs. 4 patients (1.0%). Sites of second primary cancers included the blood, bone marrow, chest wall, colon, endometrium, ovaries, stomach, and tongue\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDeath\u003c\/strong\u003e: 15 patients (1.9%) vs. 6 patients (1.5%)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eNotably, 13 patients in the pembrolizumab group and 9 in the placebo group who had a local recurrence subsequently developed a distant recurrence.\u003c\/p\u003e\n\n\u003cp\u003eThe most important observation here is that the largest gap between groups was in \u003cstrong\u003edistant recurrence\u003c\/strong\u003e — the type of recurrence that is most dangerous because it means the cancer has spread to other parts of the body. The pembrolizumab group had nearly half the rate of distant recurrence (7.7% vs. 13.1%).\u003c\/p\u003e\n\n\u003cp\u003eThe event-free survival benefit was \u003cstrong\u003econsistent across all prespecified patient subgroups\u003c\/strong\u003e, including subgroups defined by PD-L1 expression and lymph-node involvement. This means the benefit was seen regardless of whether a patient's tumor tested positive or negative for PD-L1, and regardless of whether the cancer had spread to lymph nodes.\u003c\/p\u003e\n\n\u003ch2 id=\"survival\"\u003eOverall Survival and Other Results\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eOverall survival\u003c\/strong\u003e — the ultimate measure of whether a treatment helps patients live longer — showed a promising trend, though the data were still immature at the time of this analysis.\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eA total of \u003cstrong\u003e80 patients (10.2%) in the pembrolizumab group died\u003c\/strong\u003e, compared with \u003cstrong\u003e55 patients (14.1%) in the placebo group\u003c\/strong\u003e\n\u003c\/li\u003e\n  \u003cli\u003eThe hazard ratio for death was \u003cstrong\u003e0.72 (95% CI, 0.51 to 1.02)\u003c\/strong\u003e — suggesting a 28% reduction in the risk of death, though this did not quite reach statistical significance because the confidence interval includes 1.0\u003c\/li\u003e\n  \u003cli\u003eEstimated overall survival at 36 months was \u003cstrong\u003e89.7%\u003c\/strong\u003e (95% CI, 87.3 to 91.7) in the pembrolizumab group vs. \u003cstrong\u003e86.9%\u003c\/strong\u003e (95% CI, 83.0 to 89.9) in the placebo group\u003c\/li\u003e\n  \u003cli\u003eThe median overall survival was \u003cstrong\u003enot reached in either group\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eIn other words, at 3 years, approximately 90% of patients who received pembrolizumab were still alive, compared with approximately 87% of those who received chemotherapy alone. The researchers note that follow-up for overall survival is ongoing, and these numbers may change as more events occur.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDistant progression–free or distant recurrence–free survival\u003c\/strong\u003e — the measure of how long patients lived without the cancer spreading to distant organs — showed a hazard ratio of \u003cstrong\u003e0.61 (95% CI, 0.46 to 0.82)\u003c\/strong\u003e in favor of the pembrolizumab group. This translates to a 39% reduction in the risk of distant spread or death.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eExploratory analysis by pathological complete response:\u003c\/strong\u003e The researchers also looked at whether achieving a pathological complete response (pCR) affected event-free survival, recognizing that this was a non-randomized, exploratory analysis:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eAmong patients who achieved pCR, 27 of 494 (5.5%) in the pembrolizumab group and 16 of 217 (7.4%) in the placebo group had an event or died (hazard ratio, 0.73; 95% CI, 0.39 to 1.36)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThis suggests that even among patients who achieved a complete response to neoadjuvant therapy, those who received pembrolizumab also tended to have slightly better event-free survival, although this difference was not statistically significant in this exploratory analysis.\u003c\/p\u003e\n\n\u003ch2 id=\"safety\"\u003eSafety and Side Effects\u003c\/h2\u003e\n\n\u003cp\u003eSafety findings were consistent with what researchers already knew about pembrolizumab and chemotherapy from earlier phases of this trial and other studies. Adverse events occurred predominantly during the neoadjuvant phase of treatment.\u003c\/p\u003e\n\n\u003cp\u003eThe most common treatment-related adverse events of any grade (ranging from mild to severe) were \u003cstrong\u003enausea, hair loss (alopecia), and anemia\u003c\/strong\u003e — side effects commonly associated with the chemotherapy backbone used in this trial.\u003c\/p\u003e\n\n\u003cp\u003eKey safety data from this analysis:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDiscontinuation of the trial regimen\u003c\/strong\u003e due to treatment-related adverse events occurred in \u003cstrong\u003e27.7% of patients in the pembrolizumab group\u003c\/strong\u003e vs. \u003cstrong\u003e14.1% in the placebo group\u003c\/strong\u003e. This higher rate of discontinuation in the pembrolizumab group reflects the added side effects of the immunotherapy drug\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSerious treatment-related adverse events\u003c\/strong\u003e occurred in \u003cstrong\u003e34.1% of patients in the pembrolizumab group\u003c\/strong\u003e vs. \u003cstrong\u003e20.1% in the placebo group\u003c\/strong\u003e\n\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTreatment-related deaths\u003c\/strong\u003e occurred in \u003cstrong\u003e4 patients (0.5%) in the pembrolizumab group\u003c\/strong\u003e and \u003cstrong\u003e1 patient (0.3%) in the placebo group\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eAdverse events were monitored throughout treatment and for 30 days after discontinuation, with serious adverse events tracked for 90 days after discontinuation. They were graded using the National Cancer Institute's Common Terminology Criteria for Adverse Events, version 4.0. Immune-mediated adverse events — side effects caused by the immune system becoming overactive — were identified using a predefined list of medical terms.\u003c\/p\u003e\n\n\u003cp\u003eIt is worth noting that while pembrolizumab increased the risk of certain immune-related side effects, the overall balance strongly favored the pembrolizumab group because of the substantial reduction in cancer recurrence — the event that matters most to patients.\u003c\/p\u003e\n\n\u003ch2 id=\"limitations\"\u003eStudy Strengths and Limitations\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eStrengths of this trial:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eLarge, randomized, double-blind, placebo-controlled design (the most rigorous type of clinical evidence)\u003c\/li\u003e\n  \u003cli\u003eConducted across 21 countries at 181 sites, making results highly generalizable\u003c\/li\u003e\n  \u003cli\u003eIncluded patients regardless of PD-L1 status, reflecting the real-world population of patients with TNBC\u003c\/li\u003e\n  \u003cli\u003eLong follow-up (median 39.1 months) for a trial of this type\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eLimitations of this trial:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOverall survival data were immature\u003c\/strong\u003e at the time of this analysis. While there was a favorable trend (hazard ratio 0.72), it did not reach statistical significance, and longer follow-up is needed to confirm a survival benefit.\u003c\/li\u003e\n  \u003cli\u003eThe 95% confidence intervals for between-group differences were \u003cstrong\u003enot adjusted for multiple comparisons\u003c\/strong\u003e, so they should not be used to infer definitive treatment effects for secondary endpoints.\u003c\/li\u003e\n  \u003cli\u003eThe analysis of event-free survival according to pathological complete response was \u003cstrong\u003eexploratory and non-randomized\u003c\/strong\u003e, meaning the two groups (those with pCR and those without) may not be directly comparable.\u003c\/li\u003e\n  \u003cli\u003eThe trial was sponsored by the pharmaceutical company that makes pembrolizumab, though it was overseen by an independent monitoring committee.\u003c\/li\u003e\n  \u003cli\u003eAdjuvant capecitabine was not allowed in this trial, so how pembrolizumab compares or combines with capecitabine in the adjuvant setting is not addressed by this study.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"implications\"\u003eWhat This Means for Patients\u003c\/h2\u003e\n\n\u003cp\u003eThese results provide strong evidence that \u003cstrong\u003eadding pembrolizumab to standard chemotherapy for early-stage triple-negative breast cancer significantly reduces the risk of cancer recurrence and death\u003c\/strong\u003e. For patients and their doctors, this study helps guide treatment decisions in several important ways:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePembrolizumab plus chemotherapy before surgery is now a proven approach.\u003c\/strong\u003e The combination not only increases the chance of achieving a complete pathological response (as shown in the earlier analysis) but also improves long-term event-free survival.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe benefit extends to all patients with early TNBC, regardless of PD-L1 status.\u003c\/strong\u003e Because patients were eligible regardless of PD-L1 expression and the benefit was consistent across subgroups, this treatment approach applies broadly to the TNBC population.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePreventing distant recurrence is the key victory.\u003c\/strong\u003e The largest difference between the two groups was in distant recurrence (7.7% vs. 13.1%), meaning pembrolizumab helps prevent the cancer from spreading to other organs — the most feared complication of breast cancer.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePatients should discuss side effects with their care team.\u003c\/strong\u003e The risk of serious treatment-related side effects is higher with pembrolizumab (34.1% vs. 20.1%), and more patients in the pembrolizumab group stopped treatment due to side effects (27.7% vs. 14.1%). However, deaths related to treatment were rare in both groups.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLonger-term data are still needed.\u003c\/strong\u003e While the 3-year results are very encouraging, the final analysis of overall survival is still ongoing. Patients and doctors should continue to follow the results of this trial as more data become available.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eFor patients newly diagnosed with early-stage triple-negative breast cancer, this study offers genuine hope. The combination of immunotherapy with modern chemotherapy — before and after surgery — represents a meaningful advance in the treatment of a cancer subtype that has historically been among the most difficult to treat.\u003c\/p\u003e\n\n\u003c!-- ddn:faq:start --\u003e\n\u003ch2 id=\"ddn-faq\"\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eWhat is triple-negative breast cancer?\u003c\/h3\u003e\n\u003cp\u003eTriple-negative breast cancer (TNBC) is a breast cancer subtype that lacks estrogen receptors, progesterone receptors, and HER2 protein. It does not respond to hormone therapy or HER2-targeted drugs, so treatment traditionally relies on chemotherapy. TNBC is known to be more aggressive than other breast cancer types, with a substantial risk of recurrence and death.\u003c\/p\u003e\n\u003ch3\u003eHow did adding pembrolizumab affect event-free survival in the KEYNOTE-522 trial?\u003c\/h3\u003e\n\u003cp\u003eIn the KEYNOTE-522 trial, after a median follow-up of 39.1 months, patients with early-stage triple-negative breast cancer who received pembrolizumab plus chemotherapy had a 37% lower risk of cancer events or death compared with chemotherapy alone. Event-free survival at 3 years was 84.5% with pembrolizumab versus 76.8% with chemotherapy alone.\u003c\/p\u003e\n\u003ch3\u003eWho was eligible for the KEYNOTE-522 trial?\u003c\/h3\u003e\n\u003cp\u003eThe trial enrolled adults with newly diagnosed, previously untreated, nonmetastatic stage II or III triple-negative breast cancer. Patients were eligible regardless of their PD-L1 expression status. They needed a good performance status (ECOG score 0 or 1) and specific tumor characteristics such as T1c N1–2 or T2–4 N0–2 disease.\u003c\/p\u003e\n\u003ch3\u003eWhat does the treatment plan involve?\u003c\/h3\u003e\n\u003cp\u003eThe KEYNOTE-522 treatment plan had a neoadjuvant phase followed by an adjuvant phase. Initially, patients received pembrolizumab or placebo with paclitaxel and carboplatin for four cycles, then with doxorubicin or epirubicin plus cyclophosphamide for four more cycles. After surgery, they received radiation if indicated and pembrolizumab or placebo for up to nine additional cycles.\u003c\/p\u003e\n\u003ch3\u003eWhat were the main side effects of pembrolizumab plus chemotherapy?\u003c\/h3\u003e\n\u003cp\u003eThe most common treatment-related side effects were nausea, hair loss, and anemia. Serious treatment-related side effects occurred in 34.1% of the pembrolizumab group versus 20.1% with chemotherapy alone. More patients in the pembrolizumab group stopped treatment due to side effects, but treatment-related deaths were rare in both groups.\u003c\/p\u003e\n\u003ch3\u003eDoes pembrolizumab work regardless of PD-L1 status?\u003c\/h3\u003e\n\u003cp\u003eYes. In the KEYNOTE-522 trial, patients were eligible regardless of PD-L1 expression, and the event-free survival benefit was consistent across all prespecified subgroups, including those defined by PD-L1 expression and lymph-node involvement. So the benefit was seen whether or not the tumor tested positive for PD-L1.\u003c\/p\u003e\n\u003ch3\u003eWhat are the limitations of the KEYNOTE-522 trial?\u003c\/h3\u003e\n\u003cp\u003eOverall survival data were immature, with a favorable trend that did not reach statistical significance. Confidence intervals for secondary endpoints were not adjusted for multiple comparisons. Analysis of event-free survival by pathological complete response was exploratory and non-randomized. The trial was sponsored by the drug's manufacturer, and adjuvant capecitabine was not allowed.\u003c\/p\u003e\n\u003c!-- ddn:faq:end --\u003e\n\n\u003ch2 id=\"source\"\u003eSource Information\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eOriginal Article:\u003c\/strong\u003e \"Event-free Survival with Pembrolizumab in Early Triple-Negative Breast Cancer\"\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAuthors:\u003c\/strong\u003e P. Schmid, J. Cortes, R. Dent, L. Pusztai, H. McArthur, S. Kümmel, J. Bergh, C. Denkert, Y.H. Park, R. Hui, N. Harbeck, M. Takahashi, M. Untch, P.A. Fasching, F. Cardoso, J. Andersen, D. Patt, M. Danso, M. Ferreira, M.-A. Mouret-Reynier, S.-A. Im, J.-H. Ahn, M. Gion, S. Baron-Hay, J.-F. Boileau, Y. Ding, K. Tryfonidis, G. Aktan, V. Karantza, and J. O'Shaughnessy, for the KEYNOTE-522 Investigators\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003ePublication:\u003c\/strong\u003e \u003cem\u003eThe New England Journal of Medicine\u003c\/em\u003e, 2022; Volume 386, pages 556–567\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDOI:\u003c\/strong\u003e 10.1056\/NEJMoa2112651\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c\/strong\u003e Merck Sharp and Dohme, a subsidiary of Merck\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eClinicalTrials.gov number:\u003c\/strong\u003e NCT03036488\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eThis patient-friendly article is based on peer-reviewed research published in The New England Journal of Medicine. It is intended for educational purposes and does not constitute medical advice. Patients should discuss their individual treatment options with their healthcare provider.\u003c\/em\u003e\u003c\/p\u003e","brand":"DiagnosticDetectives.Com","offers":[{"title":"Default Title","offer_id":47400024834204,"sku":null,"price":0.0,"currency_code":"EUR","in_stock":true}],"url":"https:\/\/diagnosticdetectives.de\/products\/adding-pembrolizumab-keytruda-to-chemotherapy-improves-survival-in-early-triple-negative-breast-cancer","provider":"DiagnosticDetectives.Com","version":"1.0","type":"link"}