HUTCHMED (China) Limited and AstraZeneca PLC announced that preliminary results from the SAVANNAH Phase II trial showed that TAGRISSO® (osimertinib) plus savolitinib demonstrated an objective response rate ("ORR") of 49% (95% confidence interval ["CI"], 39-59%) in patients with epidermal growth factor receptor-mutated ("EGFRm") non-small cell lung cancer ("NSCLC") with high levels of mesenchymal epithelial transition ("MET") overexpression and/or amplification, defined as IHC90+ and/or FISH10+, whose disease progressed on treatment with TAGRISSO®. The highest ORR was observed in patients with high levels of MET who were not treated with prior chemotherapy (52% [95% CI, 41-63%]). In patients whose tumors did not show high levels of MET, the ORR was 9% (95% CI, 4-18%).

These results are being shared at the International Association for the Study of Lung Cancer (IASLC) 2022 World Conference on Lung Cancer (WCLC), taking place on August 6-9, 2022 in Vienna, Austria. Savolitinib, marketed in China under the brand name ORPATHYS®, is an oral, potent and highly selective MET tyrosine kinase inhibitor ("TKI") being jointly developed and commercialized by AstraZeneca and HUTCHMED. While EGFR-targeted therapy can provide a durable survival benefit to patients with EGFRm NSCLC, most will eventually develop resistance to their treatment, with MET being the most common resistance biomarker.1 Among patients screened for enrolment in SAVANNAH, all of whom experienced disease progression on TAGRISSO®, 62% had tumors with MET overexpression and/or amplification, and more than one-third (34%) met the defined high MET level cut-off.

In this analysis, patients' MET overexpression and/or amplification levels were determined by two tests: immunohistochemistry ("IHC"), which detects if cancer cells have a particular protein or marker on their surface, and fluorescence in situ hybridization ("FISH"), which detects a specific DNA sequence from cancer cells. All patients in this analysis (n=193) had at least IHC50+ and/or FISH5+, and were treated with savolitinib 300mg once daily added to TAGRISSO® 80mg once daily following disease progression on TAGRISSO® alone. The safety profile of TAGRISSO® plus savolitinib was consistent with the known profiles of the combination and each treatment alone.

No new safety signals were identified. Less than half (45%) of patients in this analysis experienced Grade 3 or higher adverse events ("AEs"), with those most frequently reported including pulmonary embolism, dyspnea, decreased neutrophil count and pneumonia. AEs attributable to savolitinib and leading to discontinuation occurred in 13% of patients.

The global SAFFRON Phase III trial will further assess the TAGRISSO® plus savolitinib combination versus platinum-based doublet chemotherapy in patients with EGFRm, MET-overexpressed and/or amplified, locally advanced or metastatic NSCLC following TAGRISSO®. Patients are being prospectively selected using the high MET level cut-off identified in SAVANNAH.