FGFR3 S249C

We developed an effective AI system for detecting phenotypes associated with FGFR3 abnormalities that may be targetable by FGFR inhibitors. This system may allow cost and time savings in comparison to existing assays to screen bladder carcinomas for additional diagnostic testing.

Implementing a urine-based assay expands the molecular testing methods to identify additional patients that may respond to erdafitinib. Results justify further study. Clinical trial information: NCT05316155.

Background: In view of the efficacy of FGFR targeting in early and advanced bladder cancer, as has been shown for erdafitinib in the THOR and NORSE trial, molecular testing of FGFR mutations and fusions will soon become clinical routine worldwide... PCR-based FGFR assessment by Therascreen and UroTyper is highly concordant and enables fast, local FGFR assessment within few hours. FGFR3 mutations are associated with increased TROP2 & NECTIN4 expression indicating potential synergistic options which warrants further exploration as part of molecularly stratified clinical trials.

Background: Interest in FGFR-targeted (FGFRi) therapies for UC or pan-tumor use is growing (ongoing clinical studies include erdafitinib (NCT05316155; NCT04172675; NCT03390504; NCT04083976), LOXO-435 (NCT05614739), and pemigatinib (NCT03914794) following accelerated approval of erdafitinib in locally advanced/metastatic (m) post-chemotherapy UC patients with FGFR2/3 (i.e., DNA mutations and fusions) alterations (ALT). FGFR-PRS (+) captured most ALT (+) tumors and an additional 2X more with similar FGFR pathway activation. FGFR-PRS (+) tumors were associated with gene enrichments for ontologies linked to FGFR3 signaling. The correlation of FGFR-PRS score with in vitro FGFRi activity provided initial utility of the signature, which is undergoing clinical evaluation in the ALAMANCE retrospective study of UC patients treated with FGFRi or other standard-of-care therapies.

The results showed a similar trend to previous studies, where FGFR GA was reported in approximately 20% of metastatic UC patients. No difference was found in the PFS and the estimated survival rate by FGFR2/3 GA-positive or -negative patients. Our data showed that treatment pressure did not alter the FGFR status commonly.

Pemigatinib was generally well tolerated and demonstrated clinical activity in previously treated, unresectable or metastatic UC with FGFR3 mutations or fusions/rearrangements.

We report here for the first time an extraordinarily rare case of synchronous renal tumors of a PRNRP and UC in the ipsilateral kidney of an RTR. We identified simultaneous KRAS, FGFR3, and KDM6A mutations in two different renal masses in the ipsilateral kidney. Pathologic assessment with comparative molecular analysis of mutational profiles facilitates tumor studies after RT and may be of great value in clinical management strategies.

Finally, we found that FGF specifically upregulated a glycosylated form of PD-L1 in our study, and exogenous FGF led to concomitant upregulation of glycosyltransferases that may stabilize PD-L1 on the surface of HNSCC cells. Taken together, our study supports a potential role for FGF/FGFR pathway signaling as a mechanism driving immune escape and rationalizes further exploration of novel combination therapies to improve clinical responses to PD-1/PD-L1 axis inhibition in HNSCC.

BKPyV tumor positivity in the NMIBC subset with FGFR3- or PIK3CA-mutated tumors was also associated with a higher risk of progression to MIBC (p=0.019). In conclusion, our results support smoking and BKPyV infection as risk factors contributing to bladder tumorigenesis in the general patient population through distinct molecular mechanisms.

P2; Trial completion date: Aug 2023 --> Aug 2025 | Trial primary completion date: Aug 2023 --> Aug 2025

Additionally, quisinostat can also sensitize BC cells to erdafitinib by downregulating HDGF. This study discovers a new avenue for treatment of FGFR3-driven BC and uncovers new mechanistic insights. These preclinical studies pave the way for a direct translation of this combination to early phase clinical trials.

He received first-line treatment with gemcitabine and cisplatin for 6 cycles, achieving a partial response (PR). Next, he received immunotherapy maintenance with avelumab for 4 months until disease progression. A next-generation sequencing test of paraffin-embedded tumor tissue identified a fibroblast growth factor receptor 3 (FGFR3) S249C missense mutation.

P1, N=169, Recruiting, Abbisko Therapeutics Co, Ltd | Not yet recruiting --> Recruiting | Initiation date: Dec 2022 --> Jun 2023

This ongoing study suggests cfDNA is a valuable minimally invasive adjunct to tissue-based assays for the detection of FGFR alterations to identify patients for FGFR inhibitor therapy and to monitor for mechanisms of resistance.

A positive somatic mutational status of the FGFR3 gene was statistically significantly more common in the group of papillary low-grade non-muscle-invasive BC, demonstrating basal p16 IHC staining. In the study sample, there was no statistically significant relationship between the FGFR3 status of BC and gender and age differences, TILs, MMR status, PD-L1 status (SP142 and 22C3), and p16 status. The results of the study indicate the need to determine the FGFR3 status in patients with BC for further prescription of personalized therapy.

The diagnostic tool exhibited a highly specific and robust performance. It may be used as a replaceable approach for the detection of UBC.

P3; N=218 --> 39 | Trial completion date: Jan 2025 --> Jan 2023 | Active, not recruiting --> Terminated | Trial primary completion date: Jan 2024 --> Jan 2023; The sponsor has decided to close the study due to the discontinuation of infigratinib development. The discontinuation of the study was not due to safety reasons.

Derazantinib showed signals of clinical activity in some patients with mUC and FGFR1-3 GA but the observed ORR and PFS did not meet contemporary benchmarks that would support further clinical development of derazantinib as monotherapy in this indication. Derazantinib showed a well-manageable safety profile with low rates of hand-foot syndrome, stomatitis, nail toxicity and retinal side effects. Clinical trial information: NCT04045613.

This validation study supports the feasibility of applying NGS testing to leftover fixed urine cytology specimens. In addition, the potential utility of urine NGS testing as an adjunct to urine cytology in the early detection of HGUC for cases in which cytology is negative and/or atypical/suspicious should be investigated further.

P1, N=169, Not yet recruiting, Abbisko Therapeutics Co, Ltd

Thus, incorporation of urine molecular testing in THIN PREP material could enhance the diagnostic value of cytological assessment in clarification of atypical and suspicious cytological findings. This strategy, if prospectively validated, could potentially enable a more effective and timely management of these patients.

Mutant FGFR3 initiates luminal papillary BCa formation and favors BCa male sex bias, potentially through FGFR3-dependent ESR1 downregulation. Patients with premalignant lesions or early-stage BCa could thus potentially benefit from FGFR3 targeting. FGFR3 expression level in epithelia could account for FGFR3-driven carcinoma tissue specificity.

Variant histology was appreciated in 76% of FGFR mutated cases, with the micropapillary pattern being the most prevalent (n=12 | 32%). The FGFR pathway is classically associated with low-grade papillary tumors, which, through additional mutations, can cause invasive, high-grade disease. It is speculated that the initial papillary architecture present in FGFR mutated lesions may be preserved, manifesting as the micropapillary pattern appreciated in some invasive lesions.

P3; Recruiting --> Active, not recruiting

Urine cytology is useful for detecting HGUC, whereas AUC does not provide specific information and may include low-grade tumours. We found that FGFR3 activating mutation p.S249C in exon 7 is present mostly in low-grade carcinomas and excep-tionally in high-grade carcinomas. This preliminary study shows that a cytomorphology-molecular co-test in the same urine sample could contribute to define the atypical and suspicious categories of cytology by depicting low-grade tumours.

Gemcitabine-platinum combinations were the backbone of choice in 93.7% of pts receiving combined chemotherapy. Pembrolizumab and atezolizumab were the chosen first-line agents for 10.3% and 4% of the treated pts, respectively... The prevalence of FGFR alterations in advanced UC in Latin America is similar to those described in other regions. Our data suggest limited access to FGFR inhibitors for the treatment of advanced UC in Latin America.

FGFR3 mutations could be analyzed in 84% of our cohort and occurred in 9.5% of patients with high-grade muscle invasive bladder cancer in this Brazilian population. FGFR3 gene mutations are targets for therapeutic drugs in muscle-invasive bladder cancer. For this reason, know the frequency of these mutations can have a significant impact on public health policies and costs provisioning.

Among 174 pts with available FGFRalt data pre and post BCG, FGFRalt status was maintained post BCG for most (54 [31%] pts had FGFRalt pre vs 51 [29%] post BCG). Conclusions : Overall, 30.3% of pts with HR NMIBC had FGFR+ tumors and pts with HR NMIBC had similar outcomes post BCG regardless of FGFR status.

P2; Not yet recruiting --> Recruiting

There was a high level of analytical concordance in detection of FGFR alterations indicated for erdafitinib between the Qiagen companion diagnostic assay and 2 commercially available NGS platforms. >

Despite a better response to first line treatment, overall FGFR GA showed to be an independent risk factor in mUC. Thus, this determination should be included in new prognostic models. Univariable and multivariable analysis for overall survival in the first line treatment setting for mUC.

Conclusion EGFR, KRAS, ATM, SMARCA4 gene accompanied may have less correlation with FGFR3 mutation in NSCLC patients. The findings of this study could facilitate both clinical trial design and therapeutic strategies.

Targetable mutations were mainly detected in BLCA, and S249C, Y373C, G370C, and R248C were hotspot mutations that could be targeted by an FDA approved erdafitinib...FGFG3 abnormal expression and alterations exhibited clinical correlations with patient prognosis in several tumors. This work exhibited the full alteration spectrum of FGFR3 and indicated several new clues for their application as potential therapeutic targets and prognostic indicators.

P2; N=25; Not yet recruiting; Sponsor:Memorial Sloan Kettering Cancer Center

Cisplatin and docetaxel also induced dose dependent responses, and upon combination with the inhibitors, both positive and neutral effects were found. The data suggest that FDA approved drugs alpelisib and erdafitinib efficiently inhibit TSCC/BOTSCC cell line growth, especially when combined irrespective of presence of corresponding mutations and should be further explored, for use upon recurrent disease.

Background: Enfortumab Vedotin (EV), an antibody-drug conjugate that targets nectin-4, is approved for metastatic urothelial carcinoma (mUC) progressing post-platinum and PD1/L1 inhibitor therapy. In this multi-center retrospective cohort, FGFR2/3 activating genomic alterations did not appear to compromise response to EV in mUC. Larger studies are required to confirm our findings and optimal sequencing of EV and erdafitinib in mUC pts with FGFR2/3 genomic alterations requires further assessment.

Food and Drug Administration (FDA) has approved Balversa (erdafitinib) for metastatic bladder cancer treatment, and more FGFR inhibitors are currently being evaluated clinically in many other cancer types, including lung cancer...Hopefully, more patients with other FGFR mutations may benefit from FGFR inhibitors as well, which needs further clinical investigation. Meanwhile, the exclusive relationship between druggable FGFR mutations and other actionable variations in lung cancers defines a unique molecular subtype, extending the number of patients who can benefit from targeted therapy.

Finally, malignant Brenner tumors had overall distinct genomic signatures compared to FGFR-mutated ovarian serous, endometrioid, and clear cell carcinoma subtypes. This study provides insights into the molecular pathogenesis of malignant Brenner tumors, contrasts the extent of FGFR1/2/3 alterations in ovarian serous, clear cell and endometrioid carcinomas and emphasizes the potential value of novel and FDA-approved, anti-FGFR inhibitors, such as erdafitinib and pemigatinib, in refractory, FGFR3-mutated malignant Brenner tumors.