The international penile advanced cancer trial (InPACT): The first phase III trial for squamous carcinoma of the penis with regional lymph node metastases.
Authors: Pettaway Curtis Alvin , Nicholson Steve , Spiess Philippe E. , Pagliaro Lance C. , Watkin Nick , Barber Jim , Carducci Michael Anthony , Trabulsi Edouard John , Crook Juanita M. , Rosen Mark Alan , Branney Peter , Oxley Jon , Billingham Lucinda , Burnett Stephanie M. , Penegar Steven , Yap Christina , Hall Emma ,   On behalf of the InPACT investigators
Published: February 2022

TPS7

Background: Penis cancer is a rare but potentially fatal disease. A limited body of evidence exists on which to base the majority of management decisions for patients with regional nodal metastases. Five-year survival for patients with a single involved inguinal lymph node treated with surgery alone is approximately 80%, whilst it ranges from 0 to 12% for patients with pelvic node involvement (N3). Additional strategies are required for the management regionally-advanced disease. InPACT (NCT02305654) aims to determine prospectively the relative benefits and sequencing of surgery, chemotherapy, and chemoradiotherapy in the management of patients with penis cancer who present with palpable or radiologically evident inguinal lymph node metastases. InPACT addresses the following questions: Is there a role for neoadjuvant therapy and, if so, which of the two options (chemotherapy or chemoradiotherapy) before surgery gives superior outcomes? Among patients whose inguinal node histology predicts a high risk of recurrence, does prophylactic pelvic lymph node dissection (PLND) plus chemoradiation to the inguinal and pelvic fields improve survival compared to chemoradiation alone? Methods: A Bayesian trial design aims to include a wide population of patients and incorporates two randomisations: InPACT-neoadjuvant and InPACT-pelvis. Participants are stratified by disease burden (extent of nodal involvement), by the presence or absence of high-risk radiological features, and by GFR. Participants with high disease burden where neoadjuvant treatment is thought to be indicated are randomised to neoadjuvant chemotherapy or neoadjuvant chemoradiotherapy. Participants with intermediate disease burden are randomised to one of 3 arms: Surgery alone or neoadjuvant chemoradiotherapy followed by surgery, or neoadjuvant chemotherapy prior to surgery. Participants in the low-burden group proceed directly to surgery. Participants with postoperative inguinal node pathology that shows high-risk features may then proceed to InPACT-pelvis where randomisation is between adjuvant chemoradiotherapy ± PLND for those not previously treated with chemoradiotherapy & between PLND & observation for those previously treated with neoadjuvant chemoradiotherapy. The study aims to recruit 200 participants. The primary outcome measure is overall survival, with secondary outcome measures of disease-specific survival, disease-free survival, and freedom from locoregional recurrence and distant metastasis. Feasibility, toxicity, the type/extent of surgical complications, and quality of life will be assessed as secondary endpoints for all the InPACT treatment arms. To October 2021, 65 participants have been recruited with centres open in the UK, US and Canada. Clinical trial information: NCT02305654.