Pembrolizumab in Early TNBC
Immunotherapy has revolutionised cancer care since its advent. Triple negative breast cancers (TNBCs) are really aggressive cancers which tend to relapse early on post treatment than its counterparts. Pembrolizumab, an anti Programmed death 1 (PD-1) monoclonal antibody has shown to be promising in treating these difficult TNBCs in the Keynote 522 study by Dr. Peter Schmid et al. from the Bart’s Cancer Institute, London. Patients with TNBC with Tumor size > 2cm or any Lymph node positive disease were treated with neoadjuvant chemotherapy along with Pembrolizumab 200mg once every three weekly x 8 doses followed by Surgery (Modified Radical Mastectomy or Breast Conservation Surgery) followed by adjuvant Radiotherapy along with 9 more doses of three weekly Pembrolizumab. Pathological complete response (pCR) has been a surrogate marker for improved overall survival. The initial publication in February 2020 had shown an improved pCR with the addition of Pembrolizumab to the tune of approximately 14%. Now in the recently concluded ESMO meeting there was an update on the 5 year overall survival results, which demonstrated an approximate 5% improvement in 5 year OS from 81.7% to 86.6% with the addition of Pembrolizumab. This is a great update, as here the patients were treated irrespective of their PDL1 positive status (though the trial had >80% patients having PDL1 positive breast cancers defined as a CPS of >/= 1%). The 5 year OS in PDL1 -ve TNBC patients was also improved with the addition of Pembrolizumab. Most importantly, there was no significantly increase in side effects with the addition of Pembrolizumab to chemotherapy. This makes a new way of treating TNBC patients. How can we think something more in this??? Antiangiogenic treatment addition with Immunotherapy and chemotherapy in Non small cell lung cancers have resulted in better results, even in the PDL1 -ve cancers. Can we replicate the same in this TNBC population as well???? The UK study had > 80% patients as PDL1 +ve TNBCs.. does our patient population in the Indian subcontinent harbour a similar PDL1 +tivity??? But one thing is definitely happening: that we are gradually with small steps moving forward to cure cancers …. Wish you all a very happy and healthy Pink October ahead - The month for awareness of Breast Cancers … do regular screening to detect them early
