Zach Klaassen (@zklaassen_md) ranks #4 among US gu cancer KOLs on X in 2026, by engagement from fellow physicians. 100 physicians shared, quoted or replied to their posts this year. Most-discussed trials in 2026: DASL-HiCaP (ANZUP1801), PROTEUS, TALAPRO-3. CMS Open Payments lists $290,518 in 2025 general payments.
At a Glance
- 16 posts naming a trial in 2026
- 12 trials discussed by name
- GU Cancer: US #4, Global #5 · 100 physicians engaged
- Leading physician voice: #1 of 28 physicians on DASL-HiCaP (ANZUP1801); #2 of 3 physicians on LITESPARK-024
- CMS Open Payments lists $290,518 in 2025 general payments.
This Month
What Zach Klaassen has posted in the last 30 days. Updated November 10, 2026.
#ESMO26 Management of mCRPC: Personalized treatment selection and sequencing @dmukherji @urotoday Spectrum of PARPi sensitivity in mCRPC by HRR gene alteration Evidence from PROfound, MAGNITUDE, TALAPRO-2, PROpel, and FDA pooled analysis https://t.co/utv8m4w2nT
PROTEUS Substudy: Periop Apa + ADT with RP+PLND vs RP+PLND in HR PCa @urotoday #ESMO26 Periop APA + ADT (+ RP+PLND; n= 102) vs RP+PLND alone (n=306) 🚨EFS: HR 0.38, 95% CI 0.26–0.55 🚨MFS: HR 0.49, 95% CI 0.26–0.90 🚨TT 1st Sub Rx: HR 0.29, 95% CI 0.20–0.43 🚨All Gr Hot Flush: 64% vs 0.7%
⚡️LBA4⚡️ DASL-HiCaP (ANZUP1801) Ph 3 RCT #ESMO26 Daro + ADT and definitive/salvage locoregional RT for very HR PCa @urotoday 🚨n=1,106; mFU 3.8 yrs; 85% definitive RT 🚨Primary EP MFS by CI: ⏫ for Daro vs PBO - 4-year MFS-CI 95% vs 88% - HR 0.42 (95% CI 0.27 to 0.66)
#ESMO26 DASL-HiCaP Presidential Discussant -- @Silke_Gillessen Differences in BL risk and pt selection may explain variation in treatment effects for STAMPEDE M0, ENZARAD, DASL-HiCaP Among N1 pts only, ARPI MFS benefit: ◾️STAMPEDE M0: HR 0.49, 95%CI 0.38-0.64 ◾️ENZARAD: HR 0.43, 95%CI 0.20-0.92 ◾️DASL-HiCaP: HR 0.39, 95%CI 0.19-0.81
Safety/efficacy of JNJ-6143, a first-in-class RIPTAC in heavily pre-Rxed pts with mCRPC @BGarmezy @urotoday #ESMO26 🚨Ph 1 n=105; RP2D: 50 mg 🚨At 50 mg: - <60% any-grade TRAEs - 77% PSA50; 48% PSA90 - High PSA RR irrespective of HR molecular features - 69% ORR https://t.co/tgHPuyKq9A
Long-term OS with AA/P in the PEACE-1 trial for de novo mCSPC @urotoday #ESMO26 mFU: 7.7 yrs 🚨SOC (+/-RT) + Abi vs SOC (+/-RT): abs OS ⏫ 1.5 yrs (HR 0.75, 95.1% 0.65-0.87) 🚨ADT + Doce + Abi vs Abi + ADT: abs OS ⏫ 1.8 yrs (HR 0.68, 95.1% CI 0.56-0.82) 🚨Favorable effect of triplet Rx on OS, independent of vol disease (interaction test p=0.56)
Who Amplifies Zach Klaassen
Physicians who reposted Zach Klaassen’s trial posts most often in 2026.
2026 Rankings
| List | US rank | Global rank | Physicians engaged | Physician engagements | |
|---|---|---|---|---|---|
| GU Cancer | #4 | #5 | 100 | 175 | Full ranking |
Trials Zach Klaassen Discussed in 2026
| Trial | Posts | Rank among physicians posting | Latest |
|---|---|---|---|
| DASL-HiCaP (ANZUP1801) | 3 | #1 of 28 | Oct 24, 2026 |
| PROTEUS | 2 | #5 of 56 | Oct 24, 2026 |
| TALAPRO-3 | 2 | #12 of 39 | Oct 23, 2026 |
| TALAPRO-2 | 1 | — | Oct 26, 2026 |
| JNJ-6143 | 1 | #3 of 16 | Oct 24, 2026 |
| PEACE-1 | 1 | #4 of 18 | Oct 24, 2026 |
| CAPItello-281 | 1 | #6 of 21 | Oct 23, 2026 |
| PSMAddition | 1 | #7 of 13 | Sep 5, 2026 |
| LITESPARK-011 | 1 | #10 of 37 | Feb 28, 2026 |
| LITESPARK-022 | 1 | #16 of 40 | Feb 28, 2026 |
| LITESPARK-024 | 1 | #2 of 3 | Feb 28, 2026 |
| KEYNOTE-B15 / EV-304 | 1 | #17 of 44 | Feb 27, 2026 |
Zach Klaassen on DASL-HiCaP (ANZUP1801)
⚡️LBA4⚡️ DASL-HiCaP (ANZUP1801) Ph 3 RCT #ESMO26 Daro + ADT and definitive/salvage locoregional RT for very HR PCa @urotoday 🚨n=1,106; mFU 3.8 yrs; 85% definitive RT 🚨Primary EP MFS by CI: ⏫ for Daro vs PBO - 4-year MFS-CI 95% vs 88% - HR 0.42 (95% CI 0.27 to 0.66)
#ESMO26 DASL-HiCaP Presidential Discussant -- @Silke_Gillessen Differences in BL risk and pt selection may explain variation in treatment effects for STAMPEDE M0, ENZARAD, DASL-HiCaP Among N1 pts only, ARPI MFS benefit: ◾️STAMPEDE M0: HR 0.49, 95%CI 0.38-0.64 ◾️ENZARAD: HR 0.43, 95%CI 0.20-0.92 ◾️DASL-HiCaP: HR 0.39, 95%CI 0.19-0.81
#ESMO26 Presidential Session presentation for DASL-HiCAP (ANZUP1801) @niazi_Dr7 @urotoday ⚡️MFS-CI Primary Endpoint: HR 0.42, 95%CI 0.27-0.66 ⚡️All secondary endpoints favoring addition of Daro ⚡️Limited additional toxicity by adding Daro https://t.co/PV190vLJzA https://t.co/lzN7ZApzii
Zach Klaassen on PROTEUS
PROTEUS Substudy: Periop Apa + ADT with RP+PLND vs RP+PLND in HR PCa @urotoday #ESMO26 Periop APA + ADT (+ RP+PLND; n= 102) vs RP+PLND alone (n=306) 🚨EFS: HR 0.38, 95% CI 0.26–0.55 🚨MFS: HR 0.49, 95% CI 0.26–0.90 🚨TT 1st Sub Rx: HR 0.29, 95% CI 0.20–0.43 🚨All Gr Hot Flush: 64% vs 0.7%
#APCCC26 Debate: Pts with HR localized PCa: +/- ARPI + RT + long-term ADT @ChrisSweens1 - 🌊 of data is coming PROTEUS at #ASCO26 @urotoday https://t.co/nV37MwfiRC
Zach Klaassen on TALAPRO-3
PROs in mCSPC and HRR gene alts receiving Tala + Enza vs PBO + Enza: TALAPRO-3 @AzadOncology @urotoday #ESMO26 📌No diff in change: GHS/QoL, physical functioning, fatigue 📌⏫ change from BL for appetite loss for Tala + Enza 📌No diff in TT definitive deterioration in GHS/QoL, urinary symptoms, pain
PSA EPs with exploratory gene by gene subgroups in HRR gene–altered mCSPC from TALAPRO-3 #ESMO26 @urotoday TALA + ENZA vs PBO + ENZA: 📌⏬ risk of PSA progression in ITT: HR 0.51, 95% CI 0.37–0.7 📌Improvement across all HRR alts, specifically BRCA2m and CDK12m 📌Among pts not achieving PSA <0.2 μg/L or <0.02 μg/L at 6 or 12 months: ⏫ outcomes
Zach Klaassen on TALAPRO-2
#ESMO26 Management of mCRPC: Personalized treatment selection and sequencing @dmukherji @urotoday Spectrum of PARPi sensitivity in mCRPC by HRR gene alteration Evidence from PROfound, MAGNITUDE, TALAPRO-2, PROpel, and FDA pooled analysis https://t.co/utv8m4w2nT
Zach Klaassen on JNJ-6143
Safety/efficacy of JNJ-6143, a first-in-class RIPTAC in heavily pre-Rxed pts with mCRPC @BGarmezy @urotoday #ESMO26 🚨Ph 1 n=105; RP2D: 50 mg 🚨At 50 mg: - <60% any-grade TRAEs - 77% PSA50; 48% PSA90 - High PSA RR irrespective of HR molecular features - 69% ORR https://t.co/tgHPuyKq9A
Zach Klaassen on PEACE-1
Long-term OS with AA/P in the PEACE-1 trial for de novo mCSPC @urotoday #ESMO26 mFU: 7.7 yrs 🚨SOC (+/-RT) + Abi vs SOC (+/-RT): abs OS ⏫ 1.5 yrs (HR 0.75, 95.1% 0.65-0.87) 🚨ADT + Doce + Abi vs Abi + ADT: abs OS ⏫ 1.8 yrs (HR 0.68, 95.1% CI 0.56-0.82) 🚨Favorable effect of triplet Rx on OS, independent of vol disease (interaction test p=0.56)
Zach Klaassen on CAPItello-281
Capi + Abi vs PBO + Abi in PTEN-deficient mHSPC: Updated OS from CAPItello-281 @urotoday #ESMO26 Capi + Abi vs PBO + Abi: 📌mOS: 57.4 mos vs 46.5 mos; HR 0.82, 95%CI 0.68–0.99; p=0.044 📌m-rPFS: 35.5 mos vs 26.0 mos; HR 0.83, 95%CI 0.70–0.99; p=0.033 📌mSSE-FS: 43.8 mos vs 35.9 mos; HR 0.83, 95%CI 0.69–0.99; p=0.044
Zach Klaassen on PSMAddition
PSMA imaging and Theranostics in China 🇨🇳 today #ProsTIC26 Incredible overview of development in the last 2 yrs by @yao_zhu_sh 📌 Improved reg approval 📌Participation in PSMAddition 📌Big pipeline of new isotopes/targets 📌Domestic innovation and ongoing trials @urotoday https://t.co/cjuy8z651L
Zach Klaassen’s Most-Engaged Posts in 2026
Their own 2026 posts that fellow physicians reposted most, quoted word for word.
#ESMO26 Personalized Systemic Therapy for mHSPC @AOmlin @urotoday Two Practice Decision Frameworks: 🔔High volume mHSPC in fit pts 🔔Low volume mHSPC in fit pts https://t.co/kPJJpmonEJ
#ESMO26 Upcoming Bladder Preservation Trials -- Laura Mertens Key phase II and III studies for our patients @urotoday https://t.co/HcjAPz7bb6
#ESMO26 Can we personalize and de-escalate treatment strategies in MIBC? @urotoday Two 🔑 checklists from @giannatempopatr 1) Personalizing peri-operative treatment today 2) De-escalation strategies in MIBC today https://t.co/bMpHLc5OVB
#ESMO26 Optimal induction treatment in non-metastatic bladder cancer @niklas_kluemper @urotoday Depth of response tracks with benefit: Absolute pCR gain vs EFS HR https://t.co/L7T3XcdOuD
Mechanisms of ARPI resistance in advanced PCa and examples of how to overcome them -- Ursula Vogl A laundry list of options and ongoing work being done #ESMO26 @urotoday https://t.co/yz4YHivRw3
Industry Payments
CMS Open Payments · 2025 general payments
$290,518 across 257 payments