Determination of responsiveness to an immune checkpoint inhibitor

Abstract

The present invention relates to a method for determining the responsiveness of a patient to an immune checkpoint inhibitor (ICI), a method for determining a medical indication for immune checkpoint inhibitor therapy (ICI therapy) for a patient, and a method for making a therapy decision in a patient regarding treatment with an ICI.

Description

Determination of responsiveness to an immune checkpoint inhibitor TECHNICAL AREA

[0001] The present invention relates to a method for determining a patient's responsiveness to an immune checkpoint inhibitor (ICI), a method for determining a medical indication for immune checkpoint inhibitor therapy (ICI therapy) in a patient, and a method for making a treatment decision in a patient regarding treatment with an ICI. BACKGROUND

[0002] Breast cancer is the most common cancer among women and the leading cause of cancer-related death in the United States. Triple-negative breast cancer (TNBC), which accounts for 15-20% of all breast cancer cases, occurs predominantly in younger women and is characterized by aggressive behavior and a poor prognosis.

[0003] The immune checkpoint inhibitor (ICI) pembrolizumab was recently approved in combination with neoadjuvant chemotherapy for the treatment of early-stage triple-negative breast cancer (eTNBC). However, the use of immune checkpoint inhibitors is associated with severe, potentially irreversible side effects. Furthermore, a significant proportion of patients do not respond to the therapy, while still experiencing the same side effects. In addition, ICI therapy is expensive. For these reasons, therapeutic stratification is crucial.

[0004] Markers of tumor immunogenicity, such as tumor-infiltrating lymphocytes and the expression of programmed cell death 1 ligand T (PD-L1), have been shown to predict response to neoadjuvant chemotherapy, but are independent of the use of immune checkpoint inhibitors (ICIs). Pembrolizumab is currently used to treat eTNBC regardless of these markers. In contrast, the efficacy of chemotherapy depends on known clinicopathological parameters such as age, tumor classification, and proliferative activity, which is quantified by the Ki-67 marker.

[0005] However, routine parameters that can reliably predict the response to ICIs are currently lacking. BRIEF SUMMARY OF THE INVENTION

[0006] Against this background, an object of the present invention is to provide a predictive marker for a patient's responsiveness to an immune checkpoint inhibitor (ICI). In particular, it aims to provide a simple method for reliably deciding for or against ICI therapy.

[0007] The problem underlying the invention is solved by a method for determining a patient's responsiveness to an immune checkpoint inhibitor (ICI), comprising the following steps: a) Providing an initial biological sample from the patient, b) Examining the first biological sample for infection with human cytomegalovirus (hCMV), c) Determining responsiveness to an ICI in the presence of an infection with hCMV (hCMV) + ) is present.

[0008] According to the invention, 'responsiveness' is generally understood to mean the patient's ability to respond to therapy. In the context of the administration of immune checkpoint inhibitors (ICIs), it specifically refers to a patient's therapeutic response in the treatment of tumors. Responsiveness is determined using parameters known to those skilled in the art and includes complete response (CR) and partial response (PR). CR, or pCR (pathological complete response), means the complete disappearance of the tumor. PR, or pPR, refers to a significant reduction in tumor size; e.g., >30% according to RECIST criteria (Response Evaluation Criteria In Solid Tumors), which, according to the invention, can be used to assess responsiveness.

[0009] Immune checkpoint inhibitors (ICIs) are a class of drugs that aim to reverse the natural inhibitory function of the immune system, which tumors exploit to evade the immune response. They work by blocking immune checkpoint molecules such as PD-1, PD-L1, or CTLA-4. These molecules regulate the activity of T cells and can be triggered by tumor cells to suppress an immune response. By blocking these checkpoints, ICIs can restore T-cell activity and enable the immune system to effectively fight tumor cells. Examples of suitable ICIs according to the invention include PD-1 inhibitors, such as pembrolizumab (Keytruda) and nivolumab (Opdivo), PD-L1 inhibitors, such as atezolizumab (Tecentriq) and durvalumab (Imfinzi), CTLA-4 inhibitors, such as ipilimumab (Yervoy) and tremelimumab, LAG-3 inhibitors, such as relatlimab, and TIGIT inhibitors.

[0010] Human cytomegalovirus (hCMV) (also known as human betaherpesvirus 5 (HHV-5) or cytomegalovirus (CMV)) is an enveloped, double-stranded DNA virus (dsDNA) belonging to the family Orthoherpesviridae (formerly Herpesviridae), genus Cytomegalovirus, and is found worldwide. Transmission occurs through saliva, urine, semen, and blood transfusions. hCMV infection usually goes unnoticed in healthy individuals but can be life-threatening for people with weakened immune systems, organ transplant recipients, or newborns. hCMV is present in all geographic regions and socioeconomic groups, infecting between 60% and 70% of adults in the developed world and almost 100% in the developing world. Seroprevalence is age-dependent: 58.9% of people aged 6 and older are infected with CMV, while 90.8% of people aged 80 and older have tested positive for HCMV.

[0011] According to the invention, the 'first biological sample' comprises any cell and / or tissue type in which an hCMV infection can be detected. Since the virus replicates and persists in various cells and tissues, a wide variety of cell types and tissues are suitable, such as blood, in particular cell-free plasma and serum, leukocytes, but also saliva, urine, liver, intestinal, and lung tissue, cerebrospinal fluid, amniotic fluid, bronchoalveolar lavage (BAL), stool samples, breast milk, etc.

[0012] The first biological sample is 'provided', meaning that taking the sample from the patient is not part of the inventive method. The sample can, for example, be taken from a sample database or from a 'fresh' collection and provided for carrying out the subsequent inventive method. The method can therefore be carried out 'in vitro' or 'ex vivo'.

[0013] The examination of the first biological sample for infection with hCMV can be carried out using a number of methods known to those skilled in the art, such as molecular biological methods, including polymerase chain reaction (PCR), serological methods, including enzyme-linked immunosorbent assay (ELISA) and Western blot, virological methods, including shell vial assay, conventional cell cultures, antigen detection (e.g. pp65), histopathology and immunohistochemistry, genotyping, detection of viral transcripts, etc.

[0014] According to the invention, a status hCMV means + that an infection with hCMV is present and / or detectable.

[0015] In an alternative embodiment of the inventive method, the patient's hCMV status can be provided instead of or in addition to steps (a) and (b) (e.g. hCMV). +or hCMV'), for example, in the form of a data record from a patient or database in which the patient's hCMV status is recorded. In such cases, providing and / or examining a biological sample from the patient may not be necessary.

[0016] The inventors have surprisingly discovered that a patient's hCMV status, preferably that of a human patient, can be used alone as a predictive marker for the patient's responsiveness to ICI therapy. This addresses a pressing need and creates a way to predict the success of immunotherapy. For the first time, this enables targeted, success-oriented use of ICIs. Furthermore, the invention helps to avoid side effects and high costs when treatment is ineffective. This not only protects the patient but also relieves the burden on the healthcare system.

[0017] In a further development of the inventive method, in step c) alternatively or additionally a non-responsibility to ICI is determined if no infection with hCMV (hCMV-) is present.

[0018] This measure extends the inventive method by not only increasing the responsiveness to an ICI in hCMV + The assessment is not only based on the specific characteristics of the patient, but also, or alternatively, on the lack of response in patients with hCMV' status. In clinical practice, this measure helps to exclude patients with hCMV' status from potentially ineffective ICI therapy, thus reducing unnecessary treatment costs and side effects. This allows for more targeted ICI therapy, conserving resources and avoiding potentially ineffective treatments.

[0019] According to the invention, 'non-responsiveness' generally means the patient's inability to respond to therapy, in particular ICI therapy. This includes, among other things, stable disease (SD) and progressive disease (PD).

[0020] According to the invention, a status hCMV means that there is no infection with hCMV and / or an infection is not detectable.

[0021] Following a further development of the inventive method, the patient is a breast cancer patient.

[0022] This measure focuses the procedure on breast cancer patients, thereby targeting its application to a clinically relevant and clearly defined target group. This allows for a more precise evaluation of the efficacy of immune checkpoint inhibitors (ICIs) in this patient group.

[0023] According to the invention, all subgroups of 'breast cancer patients' are covered, including, but not limited to, patients suffering from hormone receptor-positive breast cancer, HER2-positive breast cancer or triple-negative breast cancer (TNBC).

[0024] According to a further development of the inventive method, the first biological sample is a blood sample, preferably a blood serum sample.

[0025] This measure facilitates the practical implementation of the procedure and ensures the use of an established and readily available sample type that is particularly suitable for detecting hCMV infection. Blood samples are among the most common and frequently used sample types in clinical diagnostics, simplifying the procedure and increasing its acceptance. Blood serum contains no cells and is ideally suited for serological testing, facilitating the detection of biomarkers such as hCMV antibodies or hCMV DNA. The need for invasive or more complex sample collection (e.g., biopsies) is reduced, lowering the overall cost of diagnostics.

[0026] A 'blood sample' is a biological sample taken from a patient's blood. It can include whole blood, plasma, or serum. 'Blood serum' is particularly preferred; it is the liquid, cell-free component of blood that remains after coagulation and the removal of blood cells and fibrin. It contains dissolved proteins, electrolytes, antibodies, hormones, and other biomolecules that can be used for diagnostic purposes.

[0027] In one embodiment of the invention, the method includes the following further step: a') Providing a second biological sample from the patient; b') Examining the second biological sample to determine the Ki-67 status.

[0028] This measure expands the procedure by analyzing Ki-67 status, a well-known proliferation marker that provides information about the cell division rate and thus the aggressiveness of a tumor. Determining Ki-67 status is a valuable addition to the hCMV status analysis and allows for more differentiated patient stratification. This improves the predictive power of the procedure for responding to ICI therapy. This is particularly helpful in more aggressive cancers such as triple-negative breast cancer (TNBC), where the proliferation rate is a crucial prognostic factor. The additional information about Ki-67 status enables personalized treatment decisions, for example, by considering tumor growth and proliferation rate.

[0029] The 'second biological sample' provided by the patient may differ from the first sample in type and source. Preferably, it is a sample from the tumor tissue that allows for the determination of the Ki-67 status.

[0030] The 'Ki-67 status' is a marker for cell proliferation that measures the amount of Ki-67 protein in cells. Ki-67 is a nuclear protein expressed throughout the cell cycle, except during the resting phase G0. It serves as an indicator of tumor growth activity. A high Ki-67 value, e.g., >60%, indicates a high proliferation rate and is often associated with more aggressive tumors. Linking Ki-67 status to response to immune checkpoint inhibitors (ICIs) enhances individualized treatment planning.

[0031] In an alternative embodiment of the method according to the invention, in addition to the steps (a 1 ) and (b 1The patient's Ki-67 status can be provided, for example, in the form of a data record from a patient or database that contains this information. In such cases, the provision and / or analysis of a second biological sample from the patient may also be unnecessary.

[0032] In one variant of the inventive method, in step c) a response to an ICI is determined if, in addition, the patient's Ki-67 status is approximately >60%.

[0033] This defines a specific threshold for Ki-67 status (>60%), which correlates with responsiveness to an immune checkpoint inhibitor (ICI). The Ki-67 status complements the hCMV status, thereby refining the prediction of response to ICI therapies. Setting a Ki-67 value of >60% ensures that hCMV is preferentially targeted. +Patients with high cell proliferation are included in ICI therapy because, according to the inventors, they respond better to treatment. The combination of two predictive markers (hCMV and Ki-67) can increase the success rate of ICI therapy by identifying the patients with the best chances of success.

[0034] A Ki-67 status of >60% means that at least 60% of the cells in a tumor sample are positive for Ki-67, indicating high proliferative activity. Such a value is characteristic of aggressive tumors.

[0035] Following a further development of the invention, in step c) a non-responsibility to an ICI is determined if, in addition, the patient's Ki-67 status is approximately 0-60%.

[0036] This measure expands the analysis of Ki-67 status by defining a range of 0-60% as an indicator of non-response to immune checkpoint inhibitors (ICIs). This adds a negative predictive component to the diagnostic process. The defined 60% threshold establishes a clear distinction. This allows patients whose tumors exhibit a Ki-67 status of 0-60% to be excluded from potentially ineffective treatment, thus avoiding unnecessary burdens. Focusing on patients with higher responsiveness enables a more efficient allocation of available resources. Patients with low responsiveness are protected from potential side effects of immune checkpoint inhibitors that could occur without therapeutic benefit.

[0037] A Ki-67 status of 0-60% means that up to 60% of the cells in a tumor sample are positive for Ki-67. These values ​​indicate lower cell proliferation, which may correlate with lower tumor aggressiveness.

[0038] In a further embodiment of the method according to the invention, the second biological sample is a tumor sample.

[0039] This measure clearly defines the origin of the sample and ensures its relevance for the Ki-67 status analysis. Tumor samples are the preferred source for Ki-67 analysis because this marker directly reflects the proliferative activity of tumor cells. A tumor sample is a tissue sample taken directly from the patient's tumor, such as a breast tumor. It can be obtained, for example, through biopsy or during a surgical procedure and contains tumor cells as well as surrounding tissue.

[0040] In a further embodiment of the method according to the invention, the ICI is pembrolizumab.

[0041] This strengthens the feasibility of the procedure in medical practice. Pembrolizumab (Keytruda) is a humanized monoclonal antibody. It is a well-established drug with documented efficacy and safety, particularly in tumors with high PD-1 / PD-L1 expression. Pembrolizumab is approved for a wide range of oncological indications, including triple-negative breast cancer (TNBC), especially in combination with chemotherapy, and is therefore easily integrated into existing clinical protocols. Pembrolizumab binds to the PD-1 receptor and blocks the interaction between PD-1 and its ligands PD-L1 and PD-L2. This receptor silences T-cell activity. By blocking this PD-1 receptor, pembrolizumab prevents the PD-1 receptor from silencing these immune cells, thus enhancing the immune system's ability to kill tumor cells. Pembrolizumab can reactivate the body's own anti-tumor immune response.

[0042] Following further training, the inventive method determines the patient's responsiveness to an ICI in combination with a chemotherapeutic agent (chemo-immunotherapy).

[0043] This measure expands the analysis to include the simultaneous assessment of response to immune checkpoint inhibitors (ICIs) and chemotherapy. Both treatment approaches are frequently used due to their synergistic effects. The combined assessment makes it possible to identify patients who might benefit more from chemoimmunotherapy and to exclude other patients from ineffective or burdensome therapies. This measure takes into account patients who may not respond to ICIs alone but could still receive effective treatment through the combination with chemotherapy.

[0044] According to the invention, 'chemoimmunotherapy' is understood to be a treatment strategy that combines chemotherapy and immunotherapy (e.g. ICIs) to achieve a synergistic effect against tumors.

[0045] According to a further development of the inventive method, chemoimmunotherapy comprises the administration of chemotherapeutic agents selected from the group consisting of: anthracyclines, taxanes and platinum-based agents.

[0046] This approach allows for the targeted integration of specific classes of chemotherapeutic agents by determining responsiveness. These agents are among the most effective and frequently used in breast cancer treatment. They are well-studied and often combined with immunotherapies because they can induce immunogenic cell killing, thereby enhancing the efficacy of immune checkpoint inhibitors (I-Cls). Selecting different classes of chemotherapeutic agents allows for tailoring the treatment to the tumor subtype (e.g., triple-negative breast cancer, TNBC) and the individual patient's situation.

[0047] 'Anthracyclines' are chemotherapeutic agents such as doxorubicin or epirubicin that cause DNA damage in tumor cells and inhibit their proliferation. 'Taxanes' include drugs such as paclitaxel or docetaxel, which disrupt microtubule dynamics and thereby prevent cell division. 'Platinum-based drugs' include substances such as cisplatin or carboplatin, which create DNA crosslinks and thus inhibit tumor cell division.

[0048] In a further embodiment, the inventive method is used to determine the responsiveness to an ICI and, if necessary, to chemoimmunotherapy, which is to be carried out before the primary treatment (neoadjuvant therapy).

[0049] This measure allows the success probabilities of ICI and, if applicable, chemoimmunotherapy, planned prior to surgical tumor removal, to be determined using the method according to the invention. Neoadjuvant therapy is of considerable importance in the treatment of breast cancer. Successful neoadjuvant therapy can shrink the tumor to such an extent that breast-conserving surgery becomes possible. The clinical relevance of the method according to the invention is thus further strengthened.

[0050] In a further embodiment of the method according to the invention, the breast cancer is a triple-negative breast cancer (TNBC), preferably one in an early stage ("early-stage TNBC"; eTNBC).

[0051] This measure directs the inventive method to a breast cancer subtype that is particularly aggressive and difficult to treat. TNBC is characterized by the absence of hormone receptors (estrogen and progesterone receptors) and HER2 expression, which complicates treatment because targeted therapies such as hormone therapy or HER2 antibodies cannot be used. TNBC is one of the few breast cancer subtypes in which ICIs have shown good results, particularly in early stages or in metastatic tumors. Applying the method in early TNBC stages (eTNBC) can help improve patient prognosis by maximizing the efficacy of ICIs and, if applicable, chemoimmunotherapy in a curative setting. Successful early treatment can reduce the likelihood of relapse or metastasis, which often occur in TNBC.Therefore, reliable prediction of the response to ICI or chemoimmunotherapy is of particular clinical relevance.

[0052] In a further embodiment of the method according to the invention, the breast cancer is TNBC in stage II and / or stage III.

[0053] Stage II or III triple-negative breast cancer (TNBC) is often classified as locally advanced breast cancer. Patients in these stages have a higher risk of recurrence and metastasis, which increases the importance of accurate diagnostics and targeted therapy. In stages II and III, choosing the right therapy is crucial, as it can minimize the risk of systemic disease. Predictive diagnostics based on hCMV and, if applicable, Ki-67 markers enables personalized treatment planning, which has the potential to improve cure rates and prevent recurrence. Patients who are unlikely to respond to immunosuppressive immunotherapy (ICIs) or chemoimmunotherapy can be identified and spared unnecessary side effects. This strengthens the clinical relevance of the procedure for these critical disease stages.

[0054] Stage II TNBC is characterized by a tumor approximately 2-5 cm in size (T2) or a smaller tumor with up to three affected lymph nodes (N1). There are no distant metastases (MO). Stage III TNBC is characterized by local tumor progression with a size of approximately >5 cm (T3) or extensive regional lymph node involvement (N2 / N3), but still without distant metastases (MO).

[0055] Another aspect of the invention relates to the use of the hCMV status hCMV + and / or hCMV' of a patient, preferably a breast cancer patient, to determine a patient's responsiveness to an immune checkpoint inhibitor (ICI).

[0056] The features, properties, advantages, embodiments and further developments of the method according to the invention apply accordingly to the use according to the invention.

[0057] Another object of the present invention relates to a method for determining a medical indication for immune checkpoint inhibitor therapy (ICI therapy) in a patient, preferably a breast cancer patient, comprising the following steps: a) Providing an initial biological sample from the patient, b) Examining the first biological sample for infection with human cytomegalovirus (hCMV), c) Determining a medical indication for ICI therapy in the case of hCMV infection (hCMV) + ) is present, whereby, optionally, alternatively or additionally, a medical contraindication for ICI therapy is determined if there is no infection with hCMV (hCMV - ) is present.

[0058] This measure focuses the invention on determining a medical indication.

[0059] The features, properties, advantages, embodiments and further developments of the aforementioned inventive method apply accordingly to this inventive method.

[0060] Another aspect of the present invention relates to a method for determining a patient's responsiveness to an immune checkpoint inhibitor (ICI), comprising the following steps: a) Determining hCMV status hCMV + or hCMV' of the patient, preferably a breast cancer patient, b) Determining responsiveness to an ICI in hCMV + -status, whereby, optionally, alternatively or additionally, non-responsibility to ICI is determined if an hCMV' status is present.

[0061] In contrast to the previously mentioned method according to the invention, in which a biological sample is explicitly provided and analyzed, this method enables the determination of hCMV status in an alternative way. The status can be determined using existing information, such as patient databases by accessing previous diagnostic results, electronic health records (EHRs) by using historical laboratory or diagnostic data, or reports from other healthcare facilities and their transmission of previously analyzed results. Here, it is not strictly necessary to take and analyze a new sample from the patient. Rather, the focus is on determining the status using available information. This saves time, as a repeat sample collection is unnecessary, and promotes cost efficiency, since no additional laboratory tests are required if the necessary data is already available.This procedure is particularly relevant for patients with extensive prior findings, such as oncology patients with multiple diagnoses and tests, as well as for secondary analyses in retrospective studies or when reprocessing existing data. Furthermore, patients for whom repeat sampling is not possible, e.g., due to their health condition, can still be integrated into the diagnostic and therapeutic process using existing data.

[0062] The features, properties, advantages, embodiments and further developments of the aforementioned inventive method apply accordingly to this inventive method.

[0063] Another object of the present invention relates to a method for deciding on therapy in a patient, preferably a breast cancer patient, regarding treatment with an ICI, comprising the following steps: a) Determining hCMV status hCMV +or the patient's hCMV b) Administration of an ICI to the patient in hCMV + -status, whereby, optionally, alternatively, no ICI is administered if an hCMV' status is present.

[0064] This measure extends the invention to therapeutic application and patient management. The method specifies the direct use of diagnostic results for therapy selection. The combination of diagnostics and treatment makes it possible to treat only patients who are highly likely to respond to ICI therapy. Patients with hCMV' status are excluded from potentially ineffective therapy, thereby reducing side effects and costs. The approach maximizes the effectiveness of the therapy by focusing on suitable patients and optimizes resource utilization. The transition from diagnosis to therapy facilitates the integration of the method into clinical routine and makes it immediately applicable for treating physicians.

[0065] The features, properties, advantages, embodiments and further developments of the aforementioned inventive method apply accordingly to this inventive method.

[0066] Further advantages and features will become apparent from the following description and the accompanying figures. It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations without departing from the scope of the present invention. EXAMPLES 1. Methods

[0067] Patients from the biobank who received neoadjuvant chemoimmunotherapy or chemotherapy for stage II / IH triple-negative breast cancer (TNBC) at the Department of Gynecology in Tübingen between 2016 and 2024 were eligible for inclusion in the study. Patients with systemic immunosuppression due to an autoimmune disease were excluded from the analysis. All patients gave their informed consent for the use of their material for research purposes, and the project was approved by the Ethics Committee of the University of Tübingen. Ki-67 was assessed by certified pathologists during routine examination of patient tissue. The initial quantification was divided into two groups: 0–60% and >60% positivity. Pathological complete remission (pCR) was defined as pathological stage ypTO / Tis ypNO.

[0068] The sera were collected and stored at -20°C. hCMV status was determined using the cobas Elecsys CMV IgG assay (catalog number 09118543190, Roche).

[0069] Relationships between categorical variables were determined using X 2 The Yates test without continuity correction was used to compare the results. Relationships between categorical and continuous variables were compared using a Wilcoxon signed-rank test. Multivariate comparisons of categorical variables were performed using a logistic regression model. All statistical analyses were performed in R version 4.4.1. 2. Results

[0070] A total of 170 patients were included in this retrospective analysis. Sixty-nine (40.6%) received chemoimmunotherapy (CITx) and 101 (59.4%) received chemotherapy (CTx) (characteristics in Table 3). One (0.6%) patient showed borderline hCMV reactivity and was excluded from subsequent analyses. Thirty-six (52.9% of CITx) and 54 (53.5% of CTx) patients had hCMV + 73.5% of CITx patients compared to 51.5% of CTx patients achieved a pCR (p = 0.003).

[0071] The pCR rate was high in hCMV +The incidence of pCR in patients with hCMV was significantly higher in the CITx group compared to hCMV patients (p = 0.013), but not in the CTx group (p = 0.472, Table 1). Ki-67, a predictor of chemotherapy efficacy, was associated with pCR in both groups (Table 1, CITx: p = 0.001, CTx: p = 0.004), while the age of patients achieving pCR was lower only in the CTx group (Table 1, CITx: p = 0.550, CTx: p = 0.001). hCMV status and Ki-67 showed no association with each other (Table 3 and Table 6, CITx: p = 0.080 and CTx: p = 0.399). The median age of the hCMV+ patients was higher in both groups (CITx: p = 0.021, Table 4; CTx: p = 0.072, Table 6).

[0072] In the CITx group, both hCMV status and Ki-67, but not age, were independently associated with pCR in a multivariate logistic regression model (Table 5), whereas in the CTx group, only the known predictors Ki-67 and age showed an association (Table 7). HCMV positivity versus negativity increased the probability of achieving pCR with an odds ratio of 4.76 (95% Cl 1.3–21.2, p = 0.027), while a Ki-67 of 60% versus 0–60% led to an increase in probability by an odds ratio of 5.64 (95% Cl 1.6–22.2, p = 0.008). hCMV patients with a Ki-67° 60% -Tumor achieved pCR in 5 / 16 (31.2%) individuals, while patients with hCMV + and Ki-67 >60 % -Tumors in 22 / 25 (88%, Table 2) persons achieved a pCR. > < Table 1: Pathological complete remission after neoadjuvant treatment according to hCMV serostatus, Ki-67 and age in the CITx and CTx groups. > Table 2: pCR rates based on hCMV status and Ki-67 in the CITx group. > Table 3: Comparison of patient characteristics between CITx and CTx groups. > Table 4: Comparison of hCMV serostatus, Ki-67 and age in the CITx group. > Table 5: Logistic regression model to assess the association of pCR with hCMV status, Ki-67 and age in the CITx group. > Table 6: Comparison of hCMV serostatus, Ki-67 and age in the CTx group. > Table 7: Logistic regression model to assess the association of pCR with hCMV status, Ki-67 and age in the CTx group. 3. Conclusion

[0073] In breast cancer, particularly eTNBC, response to neoadjuvant ICI cannot be predicted using routine markers. Here, the authors demonstrate that a positive hCMV serostatus is associated with pCR. This association was observed in the CITx group but not in the CTx group, suggesting that it is attributable to ICIs. The association was independent of Ki-67 and age, known predictors of chemotherapy efficacy. Ki-67 and hCMV status can be used together for patient stratification, as 31.2% of hCMV - Ki-67 0-60 % -patients and 88% of hCMV + Ki-67 260 o / o -Patients achieved a pCR.

Claims

Patent claims 1. A procedure for determining a patient's responsiveness to an immune checkpoint inhibitor (ICI), comprising the following steps: a) Providing an initial biological sample from the patient, b) Examining the first biological sample for infection with human cytomegalovirus (hCMV), c) Determining responsiveness to an ICI in the presence of an infection with hCMV (hCMV) + ) is present.

2. Method according to claim 1, characterized in that in step c) alternatively or additionally a non-responsibility to ICI is determined if no infection with hCMV (hCMV) is found. - ) is present.

3. Method according to claim 1 or 2, characterized in that the patient is a breast cancer patient.

4. Method according to one of the preceding claims, characterized in that the first biological sample is a blood sample, preferably a blood serum sample.

5. A method according to any of the preceding claims, further comprising the following step: a') Providing a second biological sample from the patient; b') Examining the second biological sample to determine the Ki-67 status.

6. Method according to claim 5, characterized in that in step c) a response to an ICI is determined if, in addition, the patient's Ki-67 status is approximately >60%.

7. Method according to claim 5 or 6, characterized in that in step c) a non-responsibility to an ICI is determined if, in addition, the Ki-67 status of the patient is approximately 0-60%.

8. Method according to one of claims 5 to 7, characterized in that the second biological sample is a tumor sample.

9. Method according to one of the preceding claims, characterized in that the ICI comprises pembrolizumab.

10. Method according to one of the preceding claims, characterized in that the patient's responsiveness to an ICI and additionally to a chemotherapeutic agent is determined (chemoimmunotherapy).

11. Method according to claim 10, characterized in that the chemoimmunotherapy comprises the administration of chemotherapeutic agents selected from the group consisting of: anthracyclines, taxanes and platinum-based agents.

12. Method according to one of the preceding claims, characterized in that the responsiveness to an ICI and, if applicable, chemoimmunotherapy is determined prior to primary treatment (neoadjuvant therapy).

13. A method according to any one of claims 3 to 12, characterized in that the breast cancer is triple-negative breast cancer (TNBC), preferably in an early stage (early-stage TNBC; eTNBC).

14. A method according to claim 13, characterized in that the breast cancer is stage II and / or stage III TNBC.

15. Use of the hCMV status hCMV + and / or hCMV' of a patient, preferably a breast cancer patient, to determine a patient's responsiveness to an immune checkpoint inhibitor (ICI).

16. A procedure for determining a medical indication for immune checkpoint inhibitor (ICI) therapy in a patient, preferably a breast cancer patient, comprising the following steps: a) Providing an initial biological sample from the patient, b) Examining the first biological sample for infection with human cytomegalovirus (hCMV), c) Determining a medical indication for ICI therapy in the case of hCMV infection (hCMV) + ) is present.

17. Method according to claim 1, characterized in that in step c) alternatively or additionally a medical contraindication for ICI therapy is determined if there is no infection with hCMV (hCMV - ) is present.

18. A procedure for determining a patient's responsiveness to an immune checkpoint inhibitor (ICI), comprising the following steps: a) Determining hCMV status hCMV + or hCMV' of the patient, preferably a breast cancer patient, b) Determining responsiveness to an ICI in hCMV + -Status.

19. Method according to claim 18, characterized in that in step b) alternatively or additionally a non-responsibility to ICI is determined if an hCMV' status is present.

20. Procedure for deciding on treatment with an ICI in a patient, preferably a breast cancer patient, comprising the following steps: a) Determining hCMV status hCMV + or the patient's hCMV b) Administration of an ICI to the patient in hCMV + -Status.

21. Method according to claim 20, characterized in that in step b) alternatively no administration of an ICI takes place if an hCMV' status is present.

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