two new immunoconjugates found to make herceptin work better

[Lani]

They are smaller than herceptin (haven't yet discovered if small enough to cross the blood-brain barrier) and consist of a combination of a fragment of a single chain of an antibody against a different epitope(target) on her2 as well as either an RNase(enzyme breaking down RNA) or part of an immunoglobulin and are additive(if not synergistic) with herceptin

Br J Cancer. 2007 Oct 9; [Epub ahead of print]
Combinatorial experimental protocols for Erbicin-derived immunoagents and Herceptin.

De Lorenzo C, Troise F, Cafaro V, D'Alessio G.
1Dipartimento di Biologia Strutturale e Funzionale, UniversitÃ* di Napoli Federico II, via Cinthia, Napoli 80126, Italy.
Erbicin is a human anti-ErbB2 single-chain antibody fragment with high affinity and selectivity for ErbB2-positive cancer cells. Two anti-ErbB2 immunoconjugates, called Erb-hRNase and Erb-hcAb, have been prepared and found to be selectively cytotoxic on ErbB2-positive cancer cells in vitro and vivo. In Erb-hRNase, Erbicin is linked to a human RNase and in Erb-hcAb it is linked to the key structural and functional regions of a human IgG. Herceptin is an anti-ErbB2 humanised antibody successfully used in the immunotherapy of breast cancer. We report here that the Erbicin-derived immunoagents target on breast cancer cells an ErbB2 epitope different than that of Herceptin. This finding led us to verify the effects of Herceptin on breast cancer cells when it was used in combination with the Erbicin-derived immunoagents. The results indicated that in combination experiments the antitumour action of Herceptin and that of the novel agents were significantly increased in an additive fashion. An inspection of the mechanism of action of Erb-hRNase or Erb-hcAb combined with Herceptin provided evidence that the antibody combinations engendered an increased downregulation of the ErbB2 receptor, and led to an enhanced apoptotic cell death.British Journal of Cancer advance online publication, 9 October 2007; doi:10.1038/sj.bjc.6604022 www.bjcancer.com.
PMID: 17923870 [PubMed - as supplied by publisher]

Let's hope this gets out of the lab into the pharmacy soon!