About a clinical case

In February 2023, Max, a 26 kg English setter, a hunting dog, aged 6 years and 10 months, consulted at the Coutras clinic for loss of appetite, vomiting, and soft, black stools (with abundant mucus and presence of blood). The ultrasound revealed a thickening of the stomach wall and led to the decision for an extensive enterectomy approximately 10 cm on either side of the ileocaecal fold, performed eight days after the initial consultation by Dr Ludovic CUQ.

The immediate postoperative outcomes are good with no notable issues regarding healing and a return to normal transit within two weeks post-surgery. However, the histopathological diagnosis made on a section of the intestinal wall in the region of the ileocaecal valve confirms a mucinous intestinal carcinoma, characteristic of a "ringed" appearance, which is highly infiltrative.  

In light of the announcement of a very reserved prognosis, given the aggressive, destructive, and infiltrative behaviour along the digestive wall of the tumour (a largely ulcerated lesion topped in the ulcerative focus with fibrinous-haemorrhagic and neutrophilic material), an extension assessment is proposed to the owner, who also agrees to the implementation of autologous immunotherapy APAVAC® carried out from the tumour sample, preserved at -18°C.

What results ?

Without any associated chemotherapy, the therapeutic anti-tumour vaccination campaign begins on 4th July (4 weekly injections followed by 4 monthly injections).  

• Weight recovery is effective within 3 weeks, with a return to hunting in the second month.
• The extension assessment and its follow-up at the end of the vaccination schedule (end of December 2023) are normal.
• Abdominal ultrasounds at 14 and then 21 months confirm the absence of any signs of local recurrence.
• At two years, post-operatively, Max benefits from a very good general condition and has resumed optimal sporting activity.

Why autologous immunotherapy ?

In this specific case of a very poor prognosis for a poorly defined, highly infiltrative small intestine tumour, developed in the mucosa and extending into the muscularis mucosa, the submucosa, and the muscular layer, the average survival time is estimated to be between 6 and 12 months, potentially extended by chemotherapy. However, its effectiveness remains limited and may adversely affect the quality of life of the dog and its family environment.

On the other hand, without any risk of residual toxicity (autologous harvesting associated with biocompatible hydroxyapatite particles), the APAVAC® treatment allows for the fixation, concentration, and vectorisation of tumour antigens which, when associated with heat shock proteins, aim to activate the animal's specific immune system against its own tumour.  

Its mechanism of action relies on the direct cytotoxic effect of CD8+ T lymphocytes but also involves the activation of CD4+ helper T lymphocytes, which are essential for the continuous and prolonged stimulation of effector cells that exert cytotoxicity against tumour cells, in order to limit their spread and the occurrence of potential metastases.