P3, N=220, Active, not recruiting, Hoffmann-La Roche | Recruiting --> Active, not recruiting

After adjuvant chemotherapy, maintenance larotrectinib was initiated based on proven TRK inhibitor efficacy in metastatic NTRK-fusion tumors and emerging evidence for targeted therapy benefit in driver-positive early stage lung adenocarcinoma. Our findings demonstrate the value of molecular pathology in the diagnostic journey of pulmonary malignancies, guiding rare fusion detection and supporting therapeutic decisions based on rare fusions in early stage disease.

However, the clinically approved TRK inhibitors, including Larotrectinib and Entrectinib, are limited by insufficient efficacy and resistance due to kinase mutations. In the Km-12 xenograft model, DZX19 significantly suppressed tumor growth. These results indicate that DZX19 serves as a novel TRK-targeting lead compound for further investigation.

P=N/A, N=20, Completed, Grupo Espanol de Tumores Neuroendocrinos | Recruiting --> Completed

NCI-MATCH subprotocol Z1E demonstrates that larotrectinib offers clinically significant benefit with marked ORR across NTRK fusion-positive tumors with no clinically significant toxicities. These findings support the rationale for the US Food and Drug Administration's tissue-agnostic approval of larotrectinib for NTRK fusion-positive tumors. Our findings demonstrate the necessity of including NTRK1, NTRK2, and NTRK3 within comprehensive molecular assays of cancer to navigate patients to an easily administered and highly effective therapy.

The best TRK inhibitor 5c had IC50 values of 0.75 and 0.96 nM against TRKAG595R and TRKAG667C, showing better potency than drugs larotrectinib (approximately 87- and 46-fold improvement) and selitrectinib (approximately 10- and 13-fold improvement). More importantly, 5c demonstrated favorable in vivo pharmacokinetic properties and antitumor efficacy (tumor growth inhibition (TGI) of 91% at 30 mg/kg and 115% at 60 mg/kg with 4 of 6 partial regression) in a BaF3-TMP3-TRKAG667C xenograft mouse model, which is greatly superior to that of selitrectinib (TGI of 2% at 30 mg/kg). Compound 5c exhibits significant potential to overcome clinical acquired multiple resistance to TRK inhibitors.

P3, N=71, Active, not recruiting, Hoffmann-La Roche | Recruiting --> Active, not recruiting

Larotrectinib evoked broad and durable antitumor activity in a plethora of solid tumors with NTRK fusions. Safety profile was consistent with that of clinical trials, even after long-term administration. While NGS use is increasing, broader access is needed.

The impact of immunohistochemical or molecular markers on treatment selection and response was most pronounced in SDC. HER2 IHC2 + expression was observed across multiple subtypes, indicating that TDxd may represent a potential treatment option for more pts than previously anticipated. The impact of comprehensive genomic profiling on targeted treatment options is currently still modest.

Concurrent comprehensive genome profiling (FoundationOne® CDx) confirmed the LMNA-NTRK1 fusion, and treatment with the TRK inhibitor larotrectinib was started. With larotrectinib treatment, the tumor shrank in size at an early stage, and the response has been maintained for > 2 years.

At the time of this clinical case report, therapy is ongoing for 21 months without any signs of further disease progression. This study demonstrates the efficacy and safety of larotractinib as both adjuvant therapy and first-line therapy in a complex clinical case of colon cancer against the background of severe concomitant pathology, when chemotherapy is contraindicated.