Preprint Watch 2026-10-30: 6 Clinical Failures Flagged for PDCD1 | Claidex

Claidex Preprint Watch

doi:10.64898/2026.10.27.26366457

Preprint WatchStrongOctober 30th, 2026

Integrated Genomic and Immune Profiling Reveals PIK3CA-Mutant HPV16-Positive Cervical Cancer as a Clinically Aggressive and Immunologically Distinct Subtype in Patients from Eastern India

Ghosh, A.; Ghosh, A.; Sinha, A.; Mathai, S.; Bhaumik, J.; Mukhopadhyay, A.; Majumder, S.; Maitra, A.; Biswas, N. K.; Mondal, K.; Majumder, P. P.; Sengupta, S.

PD-1 upregulation and PD-1 to PD-L1 transcriptional coupling occur exclusively in PIK3CA-mutant HPV16-positive cervical tumours, defining an immunologically distinct and immunosuppressive subtype proposed as amenable to targeted and checkpoint-directed intervention.

Strong contradiction

6 prior failures

Three or more documented clinical failures match this mechanism, or a Phase 3 efficacy failure is on record.

A medRxiv preprint reports whole-exome and RNA sequencing of 49 HPV16-positive cervical tumours from eastern India, finding PIK3CA mutated in 42 percent and describing PD-1 upregulation with PD-1 to PD-L1 transcriptional coupling occurring exclusively in PIK3CA-mutant tumours, which the authors read as an immunosuppressive microenvironment amenable to checkpoint-directed therapy. The Claidex graph holds six PDCD1 failures, four of them efficacy failures, and one sits in the same disease: camrelizumab-apatinib-pdcd1-first-line-cervical-cancer-phase2-efficacy-failure. The others are pembrolizumab-pdcd1-adjuvant-locally-advanced-cscc-keynote-630-phase3-efficacy-failure, pembrolizumab-enzalutamide-pdcd1-mhspc-keynote-991-phase3-efficacy-failure, pembrolizumab-enzalutamide-pdcd1-mcrpc-keynote-641-phase3-efficacy-failure, js207-pdcd1-vegfa-post-platinum-nsclc-phase2-strategic-reprioritization and pds0101-pembrolizumab-pdcd1-hpv16-head-neck-versatile-003-phase3-strategic-reprioritization, the last of which also concerned HPV16-positive disease. Severity is strong on both the failure count and the efficacy archetype. The inference under test is that transcriptional coupling of PD-1 and PD-L1 across 29 profiled tumours marks a checkpoint-responsive subtype, drawn without treatment outcomes, and that is the same inferential step that preceded the cervical and HPV16 failures already on file.

Abstract excerpt

Background: HPV16-driven cervical cancer (CaCx) is a leading cause of cancer-related mortality among Indian women. Identifying population-specific genomic and immune determinants may improve therapeutic strategies. Methods: We performed whole-exome sequencing on 49 HPV16-positive cervical tumors and matched blood samples. Available RNA-seq data from 29 out of 49 tumors were integrated, to identify recurrent mutations, altered pathways, and immune microenvironment features. Results: We identified 6,462 somatic mutations enriched in cancer-related pathways, particularly PI3K-Akt signaling. PIK3CA was the most recurrently mutated gene (42%), significantly higher frequency (p < 0.04) than in HPV16-positive TCGA-CESC tumors (26.21%). Unlike TCGA-CESC, where PIK3CA mutations were associated with early-stage disease, Indian PIK3CA-mutant tumors were enriched in advanced-stage disease. These tumors exhibited lower viral loads, higher tumor mutation burden, and more aggressive molecular phenotypes than PIK3CA-wild tumors. CIBERSORT-based immune profiling showed comparable immune-cell infiltration, including CD8+ T cells, between PIK3CA-mutant tumors and normal tissues, whereas PIK3CA-wild tumors showed significantly enhanced infiltration, compared to normal tissues. Both tumor subtypes portrayed mature tertiary lymphoid structures at higher levels than normal tissues. Compared to normal tissues, CD274 (PD-L1) expression was elevated significantly in both subtypes, while PDCD1 (PD-1) upregulation and PD-1/PD-L1 transcriptional coupling at significant levels, occurred exclusively in PIK3CA-mutant tumors. The CCL3-CCR1 axis was selectively activated in PIK3CA-mutant tumors and correlated with cytotoxic, interferon-response, myeloid, and immune checkpoint markers, indicating an immunosuppressive microenvironment. Conclusion: PIK3CA mutations define a molecularly aggressive, immunologically distinct subtype of HPV16-positive CaCx in Indian patients, underscoring their potential for targeted therapeutic interventions.

Matching Claidex post-mortems

6 of 6 indexed

This is an automated contradiction flag, not an editorial judgment on the preprint's quality. Flags identify where the preclinical literature and the clinical failure record diverge.