Abstract 73P
Background
To evaluate the therapeutic efficacy and safety of neoadjuvant PD-1 inhibitor camrelizumab combined with TPF induction chemotherapy versus camrelizumab alone in patients with locally advanced resectable oral squamous cell carcinoma (OSCC). This study also aims to build predictive models for treatment decision based on a multivariable logistic regression analysis of multi-dimensional data.
Methods
A phase II study (NCT04649476) was conducted. Untreated stage III or IVA (UICC 8th edition) OSCC patients received neoadjuvant therapy with three 2-week cycles of camrelizumab (200 mg, d1, q2w) (arm A, n=34) or three 2-week cycles of camrelizumab (200 mg, d1, q2w) combined with two 3-week cycles of TPF induction chemotherapy [docetaxel (T) 75 mg/m2, cisplatin (P) 75 mg/m2 and 750 mg/m2 5-fluorouracil (F)] (arm B, n=34), followed by surgery and adjuvant radiotherapy. The primary end point was pathological response rate.
Results
Of the 68 patients enrolled into this trial, 60 completed the full treatment protocol. The pathological response rate in arm B was 83.4%, which was much higher than arm A (16.7%). The pathological complete response (pCR) rate was 30.0% in arm B, while no patient with pCR was observed in arm A. The median follow-up duration was 9.7 months, and the 1-year event-free survival (EFS) of arm A and arm B were 66.7% and 96.7%, respectively. Grade 3-5 neoadjuvant therapy-related adverse events were occurred in 7 patients from arm B and one patient from arm A. A decision tree, mainly based on lymph node metastasis, tumor site, and infiltrated immunocytes in biopsy tissue, was developed to screen patients with high responsivity and low adverse effects. Table: 73P
Pathological response rate
| Pathological response | Arm A Camrelizumab (n = 30) | Arm B Camrelizumab + TPF (n = 30) | ||
| No. | % | No. | % | |
| pCR (0% viable tumor) | 0 | 0 | 9 | 30.0 |
| pMPR (≤10% viable tumor) | 5 | 16.7 | 16 | 53.4 |
| pPR (11-50% viable tumor) | 4 | 13.3 | 3 | 10.0 |
| pNR (51%-100% viable tumor) | 21 | 70.0 | 2 | 6.6 |
| Pathological response rate (pCR+pMPR) [95% CI interval] | 5 (16.7) [3.3 – 30.0] | 25 (83.4) [70.0 – 96.7] |
Conclusions
Neoadjuvant camrelizumab plus TPF induction chemotherapy for locally advanced resectable OSCC showed high pathological response rate, with acceptable adverse effects. Newly developed predictive models may benefit precise treatment decision for OSCC patients in clinical practice.
Clinical trial identification
NCT04649476.
Legal entity responsible for the study
Gang Chen.
Funding
Jiangsu Hengrui Pharmaceuticals Co., Ltd.
Disclosure
All authors have declared no conflicts of interest.