RET (Ret Proto-Oncogene)

Herein, we present a rare case of MTC that caused hypercalcemia via PTHrP production. Although HHM is uncommon in thyroid cancer, the condition can cause severe hypercalcemia requiring prompt diagnosis and treatment. HHM should be considered in patients with thyroid cancer with hypercalcemia, and PTHrP measurement may aid in the diagnosis.

Oncogenic RET gene rearrangements drive a subset of lung adenocarcinomas (LUAD) and the tyrosine kinase inhibitors (TKIs) selpercatinib and pralsetinib are approved therapeutics. By contrast, upfront treatment with selpercatinib and crizotinib in orthotopic tumors yielded complete elimination of 7 of 9 TR.1 tumors and both deepened and prolonged the duration of response in TR.2 tumors. The findings provide new insight into mechanisms of acquired resistance through bypass signaling and highlight the therapeutic benefit of simultaneous upfront blockade of driver oncogenes and dominant resistance mechanisms in LUAD.

Given the current pricing, neither selpercatinib as a first-line therapy nor as a second-line therapy was deemed to be cost-effective compared with chemotherapy for advanced NSCLC patients with RET fusions. Further real-world studies of selpercatinib and development of health outcome estimate scales are needed to provide additional evidence for clinicians and health policy decision-makers.

Upon re-evaluation one year later, imaging revealed recurrent paratracheal, pulmonary, hepatic, and possible adrenal metastases, prompting re-initiation of selpercatinib at a reduced dose, which she tolerated and continues to this day with surveillance of symptoms, serial electrocardiograms, laboratory work, and imaging. This case illustrates the aggressive course of RET M918T-mutated MEN2B and underscores the importance of early genetic diagnosis, vigilant surveillance, and continuity of selective RET inhibitor therapy to optimize disease control.

Pralsetinib was added to osimertinib, resulting in a response lasting 4 months...After one month with alectinib only, osimertinib was added due to the progression, resulting in another response of more than two months. Upon progression with quadruple alterations (EGFR 19del, EGFR C797S, MET amplification, and RET fusions), cabozantinib-gefitinib combination was initiated, leading to rapid deterioration...At the same time, comprehensive genomic testing remains essential for therapeutic decision-making, with ctDNA analysis complementing tissue-based approaches. Notably, the FGFR3-TACC3 fusion may represent a novel resistance mechanism contributing to the limited efficacy of EGFR-TKI.

In addition, 9 exhibited remarkable antitumor activity at a dose of 10 mg/kg/day, indicating that it completely hindered the growth of tumors induced by BAF3-KIF3B-RET-WT xenografts. In summary, 9 can be demonstrated to act as a potential RET inhibitor, as well as a treatment for RET-related cancers.

While these practices have become more commonplace, unified guidelines have yet to be established. In this review of the literature, we evaluate the advantages and pitfalls of sequential biomarker testing during disease progression in patients with mCRC.

These molecular changes were associated with higher cell motility of TPC-1-SelpRWT1-knockdown. Collectively, these findings suggest that WT1 is a critical regulator involved in tumor plasticity, thereby supporting selpercatinib resistance.

The therapeutic strategy involved an immediate switch from rivaroxaban to therapeutic low-molecular-weight heparin (LMWH) and the initiation of dual targeted therapy with selpercatinib and tepotinib. Upon diagnosis of NBTE, a rapid oncologic work-up is warranted, as ongoing tumor progression is highly likely. This case questions the appropriateness of direct oral anticoagulants in patients with NBTE and active, progressive malignancy.

Safety was consistent with previous ARROW reports; no hypersensitivity was reported in patients receiving prior immunotherapies. Pralsetinib produced robust, durable responses with manageable safety in treatment-naïve and previously treated patients with RET fusion-positive NSCLCs, confirming previous findings with longer follow-up.

P3, N=605, Active, not recruiting, Daiichi Sankyo | Trial completion date: Jan 2026 --> Feb 2027

However, QTc prolongation occurred in both of our patients, suggesting that it may represent a clinically relevant concern in selected individuals. Appropriate dose adjustment and careful monitoring may facilitate continued treatment in selected patients.