SAGE Oncotest Reveal™ Identifies Marked Ovarian Cancer Drug-Response Heterogeneity and Potential Alternatives to Platinum-Taxane Therapy

Figure 1. Patient-derived ovarian cancer tissue can be evaluated as viable 3D microtumors for ex vivo treatment-response assessment. This visual connects the clinical specimen, preserved tumor architecture, and heterogeneous dose-response patterns to carboplatin, paclitaxel, and carboplatin/paclitaxel.

Clinical question/rationale

Ovarian cancer is commonly treated with platinum-taxane chemotherapy, yet clinical outcomes vary widely even among patients managed under similar treatment paradigms [1,2]. The central clinical question addressed in this study was whether patient-derived ovarian cancer tissues show measurable ex vivo differences in sensitivity to NCCN-recommended therapies, including carboplatin/paclitaxel and commonly used alternatives [1,2].

This question is clinically relevant because treatment sensitivity is often inferred from clinical history, histology, biomarkers, prior treatment interval, and molecular testing rather than measured directly in viable tumor tissue. Genomic profiling has transformed precision oncology, but genomics alone matches only a subset of patients to actionable therapies and may not capture the functional consequences of tumor heterogeneity, microenvironmental context, or drug-combination response [3-5].

Methods

Maestri and colleagues evaluated 17 ovarian cancer specimens using SAGE Oncotest Reveal™, SageMedic’s ex vivo cytotoxicity and functional profiling assay [1]. Fresh patient-derived tissue was processed into viable 3D microtumors and exposed to NCCN-recommended ovarian cancer agents and combinations, including carboplatin, paclitaxel, carboplatin/paclitaxel, gemcitabine, doxorubicin, and olaparib [1,2]. Drug effect was quantified using standardized dose-response assessment and EC50-based measures of sensitivity [1].

Figure 2. Patient-derived ovarian cancer tissue retains clinically relevant architecture and cellular context for functional assessment. Publication Figure 1a shows representative ovarian cancer histology, supporting the tissue-origin message. Publication Figure 1c shows patient-derived 3D microtumors containing EpCAM-positive tumor cells and a smaller CD45-positive leukocyte population, supporting the biological plausibility of testing viable microtumors rather than dissociated cells alone [1].

Results

The study demonstrated substantial interpatient heterogeneity in ex vivo drug response across ovarian cancer specimens [1]. Carboplatin and paclitaxel showed 54-fold and 42-fold differences, respectively, between the 90th and 10th percentile EC50 values [1]. The carboplatin/paclitaxel combination showed much greater heterogeneity, with a 3,880-fold difference, indicating that combination response could not be reliably inferred from either single agent alone [1].

Gemcitabine showed the greatest single-agent heterogeneity, with a 1,504-fold difference in EC50 values across samples [1]. In contrast, doxorubicin and olaparib showed more consistent responses, with 20-fold and 16-fold differences, respectively, although consistent response did not necessarily imply broad efficacy [1].

Figure 3. Ovarian cancer specimens show large interpatient differences in ex vivo sensitivity to NCCN-recommended therapies. Publication Figure 2g quantifies the spread of EC50 values across agents and combinations. The figure supports the central conclusion that therapeutic response cannot be assumed from diagnosis or treatment category alone [1].

Using predefined efficacy thresholds, 64% of evaluable tumors were classified as sensitive to carboplatin/paclitaxel, 14% as intermediate, and 21% as resistant [1]. Importantly, some tumors with intermediate or resistant response to carboplatin/paclitaxel demonstrated greater sensitivity to alternative agents, including gemcitabine or doxorubicin [1].

Figure 4. Individual ovarian cancer specimens have distinct response and resistance patterns across standard and alternative therapies. Publication Figure 3a is the primary clinical figure for the webpage because it shows patient-specific drug-response profiles across the tested agents and combinations [1].

Figure 5. Tumors with reduced carboplatin/paclitaxel response may retain sensitivity to alternative agents. Publication Figure 3b provides the most actionable clinical message: some specimens classified as resistant or intermediate to carboplatin/paclitaxel showed greater sensitivity to other NCCN-listed therapies, supporting the potential role of SAGE Oncotest Reveal™ in treatment selection when standard platinum-taxane therapy appears less active ex vivo [1,2].

Clinical interpretation

The main clinical message is not simply that ovarian cancers are heterogeneous. The more actionable finding is that tumors managed under similar diagnostic and treatment paradigms may have materially different drug-response profiles when tested directly [1].

This has three practical implications. First, platinum-taxane sensitivity cannot be assumed to be uniform across ovarian cancer specimens. Second, drug-combination response may differ substantially from single-agent response, supporting the need to test clinically relevant regimens rather than extrapolating from individual agents. Third, functional profiling may identify alternative therapeutic vulnerabilities in tumors with poor measured response to standard carboplatin/paclitaxel therapy [1].

This study should not be interpreted as an outcomes-validation trial. The specimens were de-identified, and ex vivo responses were not correlated with individual patient treatment outcomes [1]. Rather, the study provides peer-reviewed SageMedic evidence that SAGE Oncotest Reveal™ can detect clinically relevant variation in drug response across real ovarian cancer tissues and generate information that may support treatment selection within existing clinical options [1,2].

Conclusion

This study showed that SAGE Oncotest Reveal™ can detect marked interpatient heterogeneity in ovarian cancer sensitivity to NCCN-recommended therapies [1,2]. Clinically, this matters because ovarian tumors that would often be treated under similar standard-of-care paradigms may differ substantially in their measured response to platinum-taxane therapy and alternative agents [1]. For biopsy selection and patient management, the findings support the value of obtaining viable tumor tissue when treatment decisions may benefit from direct functional assessment, particularly in advanced, recurrent, refractory, or suspected platinum-resistant disease.

References

1. Maestri C, Trus I, Nitiyanandan R, Kumar J, Parker RJ, De Tommasi O, et al. Heterogeneity of ex vivo tumor responses in ovarian cancer tissues. Cancer Reports. 2026;9:e70554.

2. National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Ovarian Cancer/Fallopian Tube Cancer/Primary Peritoneal Cancer. Version 2025.

3. Letai A. Functional precision cancer medicine—moving beyond pure genomics. Nat Med. 2017;23:1028-35.

4. Letai A, Bhola P, Welm AL. Functional precision oncology: testing tumors with drugs to identify vulnerabilities and novel combinations. Cancer Cell. 2022;40:26-35.

5. Flaherty KT, Gray RJ, Chen AP, et al. Molecular landscape and actionable alterations in a genomically guided cancer clinical trial: National Cancer Institute Molecular Analysis for Therapy Choice (NCI-MATCH). J Clin Oncol. 2020;38:3883-94.