I have a few guesses about what it is that you're researching, e.g. tumor microenvironment, antigens, immune checkpoints, etc, and it'd be great if phase I/II/III studied oncolytic viruses, cancer vaccines, or any other type of cancer immunotherapy drugs are utilizing your biomarker/target. Regardless, if I were you I'd try to do the following: 1- gain experience in early phase clinical trials related to your area of research; 2- publish in the area of 1; 3- gain business experience in the area of 1.
Since others here might not know, there are a lot of cancer immunotherapy startups/companies, and those that are invested in by venture capital (VC) firms usually have a strong candidate drug already in clinical trials. Very few drugs are successful let alone reach phase III (their host companies are sometimes/often acquired at that point e.g. Imlygic). For instance, oncolytic viruses have gone through ~105 phase I/II/III clinical trials
http://www.ncbi.nlm.nih.gov/pubmed/26323545. To work in business development (BD) for one of their hosts, you would have to know about manufacturing, regulatory issues, clinical trial design, and finance among many other areas; google any company and look at their open positions and experience requirements. Check out Forbes to see which startups are invested in and why; that's really all that VC is about.
IMO, a clinical pharmacology fellowship
http://www.abcp.net/ would be a good idea. Its the closest thing the US has to medical training in pharmaceutical development if you don't want to do a residency with a fellowship (medical subspecialty, not clinical pharmacology) and masters in clinical research. If you're curious why I recommended 1-3 above, in the UK they have a medical specialty in pharmaceutical medicine (
https://www.fpm.org.uk/trainingexams/pmst/trainingland) that prepares people to do what you want to do through clinical trial/employment-based training in regulation, statistics, clinical pharmacology, marketing, and management.