Hello from Stuart Roberts in Sydney,

Hello from Stuart Roberts in Sydney,

Recently I visited the Prima office in Germany, meeting in person many of the people that are working on clinical development of our lead IMP321 product. I can even more proudly say after this visit that your company is in very good hands. The Prima clinical team is currently working on the initiation of two clinical studies of IMP321. One study will be a randomised, double-blind placebo-controlled Phase IIb study of IMP321 in first-line metastatic breast cancer. This trial will compare IMP321+placlitaxel vs paclitaxel alone and will take place in the EU. The other study will be a pilot Phase I study in an immuno-oncology combination (ie an anti-PD-1 monoclonal antibody plus ascending doses of IMP321) in a cancer indication and will mainly take place in Australia. Having met the folks responsible for these studies, I feel very confident that we are well on track.

The clinical and regulatory team at Prima not only bring years of experience in drug development, in companies both large and small, but they are quite passionate about the IMP321 program. Importantly, the team are determined to get IMP321’s clinical development done according to best practise. When you look at emerging biotech and medical device companies from the outside, as I did for many years as an equities analyst, you tend to think that preparing and running clinical studies is relatively simple, whereas the hard part of building value lies in new product discovery, or intellectual property, or capital raising. Listening to my colleagues at Prima, I’ve been impressed with what a complicated business clinical trials are, and therefore how important it is to get the right people to work on it. The paperwork is voluminous, the level of detail needed to be mastered is immense, and the need for good interactions with investigators, regulators and clinical research organisations located in multiple jurisdictions is imperative. People who can do this kind of thing well are worth their weight in gold, and I think we have a few of them working for us. I can also attest that our guys work extremely hard – indeed, past midnight, if necessary, as I saw while I was in Germany.

Our Phase IIb AIPAC trial in metastatic breast cancer is something all shareholders should be excited about, because the Phase IIa trial which preceded it generated some pretty exciting data. In that study our investigators took patients on the conventional chemotherapy drug paclitaxel and administered ascending subcutaneous doses of IMP321 to those patients on days 2 and 16 of the standard 28-day cycle of paclitaxel. After six months, the response rate of the patients measured according to the RECIST criteria was 50%. In plain English, half our patients had seen their tumours shrink by 30% or more. Our investigators argued that this 50% response rate compared favourably with a 25% rate registered for paclitaxel in another, much larger, study called ECOG2100, which had the same dosing regimen for paclitaxel. What impressed me when I read the relevant paper wasn’t so much the doubling of response rate as the fact that that the patients in our trial were much older than those in ECOG2100 (averaging 64 years old vs 55 for ECOG2100) and had a much greater percentage of patients with disease in three or more sites (73% vs 46%). This historical comparison had a p value of 0.007, meaning that it was highly unlikely to have happened by chance. Basically, we doubled the response rated for patients even after the patient recruitment process had stacked the deck against our product. If you want to look at the details of that clinical success, check out J Transl Med. 2010; 8: 71, which you can find in full-text form at Pubmed.

AIPAC will more or less replicate what we did with Phase IIa, but in a properly randomised and controlled manner (the IIa was open label) and with Progression-Free Survival as the Primary Endpoint. After a smaller safety run-in phase that will extend into 2016 (in the process yielding valuable safety, pharmacokinetic and pharmacodynamic data), AIPAC will recruit around 200 patients with HER-2 negative metastatic breast cancer, randomising them 1:1 to either standard-of-care paclitaxel plus placebo or paclitaxel plus IMP321. Allowing time for patient recruitment and follow-up, we estimate that AIPAC will take around three years to run. Those three years could be crucial ones for Prima given that this study is being run under Scientific Advice from the European Medicines Agency.

Previously when I had been telling people about AIPAC, I had been excited mainly by the Phase IIa data and the Scientific Advice. Now I am also telling people that we also have a great team to execute on the study. AIPAC is something we spent a lot of time talking about last week in New York, where we attended the annual Rodman and Renshaw Global Investment Conference. Marc Voigt presented at the conference on behalf of Prima and we also had a lot of one-on-ones with investors and financial professionals. Rodman has traditionally been a great way for companies like ours to kick off their investor marketing campaigns after the Northern summer lull, since something like 2,000 people go to this conference. For us at Prima, Rodman was a great experience. We had a great story to tell and, looking back on the various meetings that we had, I felt that the story was well received. More on this in my next shareholder message. Meantime, have a great weekend.

Stuart.